SIRT1/PGC-1 pathway activation triggers autophagy/mitophagy and attenuates oxidative damage in intestinal epithelial cells

Unveiling the role of miR-186 in SIRT1 regulation in adipocytes: implications for adipogenesis and inflammation in obesity

Objectives

MicroRNAs (miRNAs) play a crucial role in the onset and progress of obesity. The inflammation of adipose tissue is deemed causative of the complications associated with obesity. This study delved into the potential mechanisms of miRNA-mediated SIRT1 regulation and inflammatory factors modulation in 3T3-L1 cells.

Methods

3T3-L1 cells were differentiated into mature and hypertrophied adipocytes and the expression of selected miRNAs was evaluated by real-time PCR. 3T3-L1 cells were transfected with the mimic and inhibitor sequences of miR-186, together with the appropriate controls. Western blot analysis assessed the expression level of SIRT1 protein, and the interaction between miR-186 and SIRT1 was scrutinized through a luciferase reporter gene assay.

Results

Across all the mature and hypertrophied cells, the evaluated miRNAs exhibited a significant increase in expression, highlighting their involvement in fat accumulation at a cellular scale. Notably, miR-186-5p displayed the highest expression in differentiated cells and the hypertrophy model. Induction of miR-186 led to attenuation of SIRT1, while its inhibition by miR-186 inhibitor resulted in upregulation of SIRT1 expression. miR-186 caused a remarkable elevation in the expression of inflammatory genes, including IL-6, IL-1β, TNF-α, and MCP-1, indicating a noticeable pattern of relationship between miR-186-induced SIRT-1 inhibition and inflammation.

Conclusions

miR-186 emerges as a pivotal factor in amplifying inflammatory cytokines and down-regulates SIRT1, an effect that might highlight the involvement of SIRT1 in the inflammatory responses of adipocytes, as well as underscoring the crucial role of miR-186 in this process. These findings present miR-186 as a promising target for addressing health challenges related to obesity.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-024-01525-0.

Genome-wide association analysis reveals insights into the genetic architecture of mesenteric torsion in pigs

Mesenteric torsion (MT) is a condition that affects several animal species and can lead to the animals' death. However, little is known about its etiology. Therefore, this study aimed to identify genomic regions and candidate genes associated with MT. Phenotypic and genotypic data from 405 pigs, including MT records and genealogy were used. In the model, contemporary group (sex, year, and week of weaning) was considered fixed effect, the linear effect of weaning weight as a covariate, while direct additive genetic effect was random. In the genome-wide association study, genomic windows explaining more than 0.3% of the genetic variance were considered significant. Fifty-two significant windows were identified, covering 299 genes located on 15 chromosomes. The HSD17B4, TNFAIP8, TENM4, CHD2, RGMA, OPRM1, PPARGC1A, CHIA, KCNJ2, KCNJ16, KCNJ15, ELN, SGO1, IL17A, IL17F, GATA4, OVOL2, GLI3, and RAP1A genes were considered candidates to MT since they are related to intestinal morphogenesis, feeding behavior, intestinal barrier, digestion, and intestinal motility. These processes could induce intestinal malformations, dysbiosis, excessive fermentation, delay intestinal transit, and obstruction. Our findings contribute to understanding the mechanisms involved in the occurrence of MT in pigs and may help to elucidate the etiology of intestinal torsion/volvulus in other mammals, including humans.

Cilostazol attenuates cisplatin-induced acute liver injury by targeting the SIRT1/AMPK/PGC-1α signaling pathway, with an impact on miRNA-34a

The dominant chemotherapeutic agent, cisplatin (CP), is widely used to manage various cancer types. Despite its effectiveness, CP use is associated with severe hepatotoxicity. Cilostazol (CSZ), a selective phosphodiesterase III inhibitor, has recently demonstrated remarkable anti-inflammatory and anti-apoptotic properties in different diseases. Additionally, it exhibits hepatoprotective effects against various forms of liver injury. Hence, this study aimed to assess the potential hepatoprotective and ameliorative effects of CSZ on CP-induced acute liver injury (ALI) and to elucidate the underlying molecular mechanisms. To achieve this, ALI was induced by a single injection of CP (20 mg/kg; i.p.) in male Wistar rats pretreated with CSZ (5 or 10 mg/kg) administered orally for one week. The findings revealed that CSZ effectively reversed CP-induced hepatic dysfunction, as evidenced by notable liver function tests and improvements in histological examination. Additionally, CSZ protected against CP-mediated liver oxidative stress by decreasing MDA levels while increasing GSH and GPx levels and enhancing SOD activity. Furthermore, CSZ exhibited a potent anti-inflammatory effect, reducing the expression of pro-inflammatory cytokines, including NF-κB, IL-1β, and TNF-α. Regarding hepatocyte apoptosis, CSZ suppressed Bax immunoexpression and caspase-3 and caspase-9 levels while enhancing Bcl-2 expression, thereby mitigating hepatic cell death. The hepatoprotective effects of CSZ could be attributed to the regulation of the miRNA-34a/AMPK/SIRT1/PGC-1α signaling pathway, leading to the activation of the Nrf2/HO-1-mediated antioxidative defense mechanism. In conclusion, CSZ could be a promising therapeutic agent for preventing CP-induced ALI, potentially improving the quality of life for cancer patients.

Urolithin as a Metabolite of Ellagitannins and Ellagic Acid from Fruits and Nuts Produced by the Gut Microbiota: Its Role on Non-Communicable Diseases

PURPOSE OF REVIEW

This narrative review investigates how urolithins produced by the gut microbiota can regulate transcription factors (such as NRF2, NF-kB, and PPAR-γ) associated with senescence, inflammation, and imbalanced redox status. It also discusses the potential benefits of urolithins for patients with chronic diseases, including cardiovascular disease, cancer, diabetes, obesity, and chronic kidney disease.

RECENT FINDINGS

Studies have shown that urolithins have many health benefits, including anti-inflammatory, antioxidant, antimicrobial, and anti-atherosclerotic effects. They are also linked to improved mitochondrial function and imbalanced redox associated with activating the Nrf2/ARE pathway. Urolithins are metabolites produced by gut microbiota from ellagic acid and ellagitannins, polyphenols primarily found in nuts and fruits, including pomegranates and berries like raspberries, cloudberries, and blackberries.

Nicotinamide Riboside Mitigates Retinal Degeneration by Suppressing Damaged DNA-Stimulated Microglial Activation and STING-Mediated Pyroptosis

Purpose

Microglial activation plays a pivotal role in the pathogenesis of retinal degeneration, contributing to neuroinflammation within the retina. Previous studies identified that nicotinamide riboside (NR) mitigated light-induced retinal degeneration (LIRD) and inhibited microglial activation. The cGAS-STING signaling pathway has been recognized as a key mediator of inflammation in response to cellular stress and tissue damage. This study further explores the regulatory impact of NR on microglial activation and STING-mediated pyroptosis in retinal degeneration.

Methods

Balb/c mice were subjected to bright light exposure to induce retinal degeneration. Bioinformatics analysis was used to identify the upregulated key genes and signaling pathways involved in the progression of retinal degeneration, based on mouse transcriptomes from the LIRD model. Molecular biology techniques and immunofluorescence staining were used to assess cGAS-STING activation and expression of pyroptosis-associated molecules. Retinal function, photoreceptor apoptosis and inflammatory response were evaluated in the presence and absence of NR supplementation.

Results

Exposure to bright light resulted in mitochondrial dysfunction and the release of dsDNA, significantly triggering the activation of cGAS-STING pathway and microglial pyroptosis. In contrast, NR treatment preserved mitochondrial biosynthesis, inhibited STING expression in reactive microglia, and dampened the pro-inflammatory response. Additionally, intraperitoneal administration of the STING inhibitor H151 reduced light-induced microglial activation and pyroptosis, while improving retinal function and promoting photoreceptor survival.

Conclusions

These findings suggest that NR confers neuroprotection by attenuating damaged DNA-triggered STING-mediated microglial activation and pyroptosis. Targeting the cGAS-STING pathway presents a promising therapeutic avenue for retinal degeneration.

BMAL1 attenuates intervertebral disc degeneration by activating the SIRT1/PGC-1α pathway: evidence from vitro studies

To explore the potential effects and the corresponding mechanisms of brain and muscle arnt-like protein-1 (BMAL1) on the progression of intervertebral disc degeneration (IVDD) in vitro studies. The expression of BMAL1, SIRT1 and PINK1 were evaluated by the method of siRNA/pcDNA in the immortalized nucleus pulposus (NP) cells. The expression of SIRT1/PGC-1α pathway was assessed. The characteristics of NP cell, containing the activity and density, the level of apoptosis, inflammatory response, reactive oxygen species (ROS), senescence, and mitophagy were evaluated. The overexpression of BMAL1 was achieved with the pcDNA3.1, the expression of SIRT1 and PGC-1α were increased, the inflammatory response, the ROS, the level of apoptosis and senescence were decreased, however, the level of mitophagy, the activity and density of NP cell were enhanced. The BMAL1 inhibites the progression of IVDD by activating the SIRT1/PGC-1α pathway in the vitro studies.

The Sirt1/FOXO signal pathway involves in regulating osteomyelitis progression via modulating mitochondrial dysfunctions and osteogenic differentiation

The Sirtuin-1 (Sirt1) gene has been reported to be closely associated with the progression of multiple diseases, but its role in regulating osteomyelitis (OM) pathogenesis has not been explored. The murine long bone-derived osteocyte-like MLO-Y4 cells and osteoblast-like MC3T3-E1 cells were exposed to Staphylococcal protein A (SpA) treatment to establish the in vitro OM models. The expression levels of Osteoblast-specific genes (OCN, OPN and RUNX2), osteoclastic genes (CTSK, MMP9 and ACP5) and the FOXO pathway-related proteins (FOXO1, p-FOXO1, FOXO3 and p-FOXO3) were detected by performing Real-Time qPCR and Western Blot analysis. Osteoblastic differentiation of the cells were evaluated by using the alizarin red S staining assay and TRAP staining assay, and membrane potential and superoxide production were measured to evaluate the mitochondrial functions of the cells. SpA treatment significantly suppressed osteogenic differentiation and induced mitochondrial dysfunction in MLO-Y4 and MC3T3-E1 cells, and promoting osteoclastogenesis in RAW264.7 cells, suggesting that the in vitro OM models were successfully established. Of note, SpA decreased the expression levels of Sirt1 in the OM cells, and SpA-induced detrimental effects on the OM cells were all reversed by overexpressing Sirt1. Mechanistically, Sirt1-overexpression increased the levels of phosphorylated FOXO-related proteins (p-FOXO1 and p-FOXO3) to activate the FOXO signal pathway and ameliorated OM progression in SpA-treated cells. Collectively, it was revealed in the present study that overexpression of Sirt1 activated the FOXO signal pathway to ameliorate SpA-induced detrimental effects in the OM cells, and Sirt1 could be potentially used as therapeutic agent for OM in clinic.

PGC-1α activation to enhance macrophage immune function in mycobacterial infections

Nontuberculous Mycobacteria (NTM) are a heterogeneous group of environmental microorganisms with distinct human pathogenesis. Their incidence and prevalence are rising worldwide, due in part to elevated antimicrobial resistance which complicates treatment and potential successful outcomes. Although information exists on the clinical significance of NTMs, little is known about host immune response to infection. NTM infections alter macrophage mitochondrial capacity and decrease ATP production, efficient immune response, and bacterial clearance. Transcription factor peroxisome proliferator activated receptor (PPAR) γ coactivator-1α (PGC-1α) is a master regulator of mitochondrial biogenesis, influencing metabolism, mitochondrial pathways, and antioxidant response. Mitochondrial transcription factor A (TFAM) is a protein essential for mitochondrial DNA (mtDNA) genome stability, integrity, and metabolism. Both PGC-1α and TFAM regulate mitochondrial biogenesis and activity, and their disruption is linked to inflammatory signaling and altered macrophage function. We show that NTM causes macrophage mitochondrial damage and disrupted bioenergetics. Mechanistically we show that this is related to attenuation of expression of PGC-1α and TFAM in infected macrophages. Importantly, rescuing expression of PGC-1α and TFAM using pharmacologic approaches restored macrophage immune function. Our results suggest that pharmacologic approaches to enhance mitochondrial function provide a novel approach to target macrophage immune function and means to combat NTM infections.

Panax quinquefolium saponins protects neuronal activity by promoting mitophagy in both in vitro and in vivo models of Alzheimer's disease

ETHNOPHARMACOLOGICAL RELEVANCE

In the realm of traditional Chinese medicine, Panax quinquefolius L. has garnered significant attention for its potential to treat various ailments associated with deficiencies, including qi, blood, and kidneys. As its primary bioactive constituent, Panax quinquefolius saponins (PQS) have the potential therapeutic role of Alzheimer's disease (AD) treatment, but with unclear mechanisms of action. Meanwhile, AD is considered as a common dementia disease with kidney insufficiency and deficiency by traditional medicine, and often accompanied by autophagy in modern medical research.

AIM OF THE STUDY

This study aimed to investigate the therapeutic effects of PQS on AD through the regulation of mitophagy.

MATERIALS AND METHODS

The chemical constituents of PQS were characterized using the UPLC-QTOF-MS technique. After that, the HT22 cell line was used to establish the D-galactose-induced cell model, and the SAMP8 mice model of AD was also employed. Cell viability was assessed using the CCK-8 assay, ROS detection, JC-1 staining, Mito-tracker Red and LC3 staining, and Mito-tracker Green and Lyso-tracker Red staining were used to assess levels of mitophagy. The Morris Water Maze (MWM) was used for the experimental evaluation of learning and memory abilities in mice. Subsequently, the mechanism was studied by pathological staining and western blotting.

RESULTS

Fifty-eight triterpenoid saponins were identified from PQS, and PQS alleviated D-galactose-induced HT22 cell death and increased intracellular levels of mitochondrial autophagy-related factors. In vivo, PQS significantly improved cognitive deficits and mitigated AD-like pathological features by activating the mitophagy mechanism. Furthermore, PQS may promote Pink1/Parkin-mediated mitophagy by activating the AMPK/mTOR/ULK1/DRP1 and SIRT1/PGC-1α pathways.

CONCLUSION

In conclusion, PQS have demonstrated the potential to mitigate mitochondrial dysfunction and enhance cognitive function in AD through the activation of mitophagy. This promising strategy holds great promise for the treatment of AD.

Tanshinone IIA, a component of Salvia miltiorrhiza Bunge, attenuated sepsis-induced liver injury via the SIRT1/Sestrin2/HO-1 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

As a traditional Chinese medicine, Salvia miltiorrhiza Bunge has been widely used to treat ischemic and inflammation-related diseases for more than 2000 years. S. miltiorrhiza Bunge has hepatoprotective effects, but the underlying mechanism is not fully understood.

OBJECTIVE

To verify the effect of tanshinone IIA (Tan IIA), the main fat-soluble component of S. miltiorrhiza Bunge, on liver damage induced by sepsis/LPS-induced inflammation and further explore the underlying mechanisms.

MATERIALS AND METHODS

Mice were administered Tan IIA 2 h before cecal ligation and puncture (CLP). Liver damage was evaluated by hematoxylin-eosin staining and changes in related serum factor levels. The expression of silent information regulator sirtuin 1 (SIRT1), Sestrin2, HO-1 and inflammatory cytokines was examined by immunohistochemistry or western blotting. LPS was used to induce the inflammatory response in vitro, and the activity of the related signaling pathway in response to Tan IIA was detected by western blotting. The SIRT1 inhibitor EX-527 and small interfering RNAs (siRNAs) were employed to determine the key roles of SIRT1 and Sestrin2 in Tan IIA's function.

RESULTS

We found that Tan IIA significantly improved the pathological changes and function of the liver, and alleviated liver damage in CLP mice. Additionally, SIRT1, Sestrin2, and HO-1 expression was significantly elevated after Tan IIA treatment compared with that in the CLP group both in vivo and in vitro, and Tan IIA treatment additionally suppressed pro-inflammatory cytokine release. However, inhibition of either SIRT1 or Sestrin2 remarkably abrogated the protective effects of Tan IIA. Most importantly, Sestrin2 appeared to function downstream of SIRT1 based on their expression changes after EX-527 or siRNA treatment.

CONCLUSION

Tan IIA inhibited sepsis/LPS-induced inflammation through the SIRT1/Sestrin2/HO-1 pathway, thereby protecting against sepsis-induced liver injury (SLI). This study suggests that Tan IIA has therapeutic potential against SLI and that the SIRT1/Sestrin2/HO-1 signaling pathway might be a viable target for SLI treatment.

Protective effect of dapagliflozin on lipopolysaccharide-induced acute lung injury via the SIRT-1/PGC-1α pathway

BACKGROUND

Acute systemic inflammation affects many organs and it occurs in a wide range of conditions such as acute lung injury (ALI). Inflammation-triggered oxidative pathways together with the caspase activation seen in ALI, result in apoptosis. Dapagliflozin (DPG) is an agent that is known to have oxidative stress-reducing and anti-inflammatory effects in many tissues.

METHODS AND RESULTS

Thirty-two Wistar albino rats were divided into four groups: control, lipopolysaccharide (LPS) (5 mg/kg), LPS + DPG (10 mg/kg) and DPG. DPG was orally administered for five consecutive days LPS was intraperitoneally applied in a single dose on the fifth day and the animals were euthanized six hours after the last drug administration. Lung tissues were harvested. In addition to hematoxylin-eosin staining, caspase-3 (Cas-3) and tumor necrosis factor alpha (TNF-α) immunostainings were conducted. While total oxidant status (TOS), total antioxidant status (TAS), and oxidative stress index (OSI) were examined biochemically, Sirtuin-1 (SIRT-1), Peroxisome proliferator-activated receptor-gamma coactivator 1-alpha (PGC-1α), B-cell lymphoma 2 (Bcl-2), and Bcl-2 associated X protein (Bax) were examined by PCR. Histopathological analysis revealed hyperemia, edema, inflammatory cell infiltration, and epithelial cell loss. In LPS group, Cas-3, TNF-α, TOS, OSI, and Bax values increased whereas SIRT-1, PGC-1α, and Bcl-2 values decreased. All these changes were restored with DPG treatment.

CONCLUSION

DPG exhibited protective effects against inflammation, oxidative stress, and subsequent apoptosis observed in systemic inflammation-induced ALI likely through SIRT-1/ PGC-1α pathway.

Melatonin protects porcine oocytes from gossypol-induced meiosis defects via regulation of SIRT1-mediated mitophagy

Cottonseed meal (CSM) is an ideal source of protein feed ingredients. However, the gossypol contained in it has toxic effects on animals, limiting its use in livestock production. The underlying mechanisms remain largely unknown. This study aimed to investigate the adverse effects of gossypol exposure and assess whether melatonin, a natural antioxidant, could alleviate oocyte damage induced by gossypol. Porcine cumulus oocyte complexes (COCs) were treated with gossypol alone or co-treated with melatonin for 44 h during in vitro maturation. The results demonstrated that gossypol exposure induced oxidative stress and mitochondrial dysfunction, leading to oocyte maturation failure. Conversely, melatonin co-treatment mitigated these detrimental effects, by promoting oocyte mitophagy, as evidenced by the upregulation of PINK1, Parkin, and LC3 expressions, along with the downregulation of P62. Further investigation revealed that gossypol treatment significantly decreased SIRT1 protein expression, while melatonin co-treatment markedly increased it. Using the SIRT1 inhibitor Ex527 confirmed that melatonin enhances mitophagy through SIRT1, improving mitochondrial function and rescuing oocyte maturation. This study revealed the potential harm of gossypol on mammalian reproductive health, provided experimental reference for the protective effect of melatonin, and provided theoretical basis for the effective prevention and treatment of reproductive damage caused by gossypol.

Antioxidant and Laxative Effects of Methanol Extracts of Green Pine Cones (Pinus densiflora) in Sprague-Dawley Rats with Loperamide-Induced Constipation

Oxidative stress is the key cause of the etiopathogenesis of several diseases associated with constipation. This study examined whether the green pine cone can improve the symptoms of constipation based on the antioxidant activities. The changes in the key parameters for the antioxidant activity and laxative effects were examined in the loperamide (Lop)-induced constipation of Sprague-Dawley (SD) rats after being treated with the methanol extracts of green pine cone (MPC, unripe fruits of Pinus densiflora). MPC contained several bioactive compounds, including diterpenoid compounds such as dehydroabietic acid, taxodone, and ferruginol. In addition, it exhibited high scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals. These effects of MPC successfully reflected the improvement in nicotinamide adenine dinucleotide phosphate oxidase (NADP) H oxidase transcription, superoxide dismutase (SOD) levels, and nuclear factor erythroid 2-related factor 2 (Nrf2) phosphorylation levels in the mid colon of Lop+MPC-treated SD rats. Furthermore, significant improvements in the stool parameters, gastrointestinal (GI) transit, intestine length, and histopathological structure of the mid colon were detected in the Lop-induced constipation rats after MPC treatment. The other parameters, including the regulators for the adherens junction (AJ) and tight junction (TJ), and GI hormone secretion for laxative effects, were improved significantly in Lop+MPC-treated SD rats. These effects were also verified in Lop+MPC-treated primary rat intestine smooth muscle cells (pRISMCs) through analyses for antioxidant defense mechanisms. Overall, the finding of this study offers novel scientific evidence that MPC could be considered as a significant laxative for chronic constipation based on its antioxidant activity.

JiangyaTongluo decoction ameliorates tubulointerstitial fibrosis via regulating the SIRT1/PGC-1α/mitophagy axis in hypertensive nephropathy

Introduction

With the increasing prevalence of hypertension, the incidence of kidney diseases is also increasing, resulting in a serious public burden. Jiangya Tongluo decoction (JYTL), a recognized prescription in traditional Chinese medicine (TCM), is commonly used to calm an overactive liver and reduce excess yang, while also promoting blood flow to alleviate obstructions in the meridians. Previous research has indicated that JYTL may help mitigate kidney damage caused by hypertension; however, the underlying mechanisms have not been thoroughly assessed.

Methods

First, an amalgamation of UPLC-QE/MS and network pharmacology techniques was employed to pinpoint potential active components, primary targets, and crucial action mechanisms of JYTL in treating hypertensive nephropathy (HN). Then, we used spontaneous hypertensive rats (SHRs) and Wistar-Kyoto rats (WKYs) to evaluate the efficacy of JYTL on HN with valsartan as a positive reference. We also conducted DCFH-DA fluorescence staining in rat renal tissues to detect the level of ROS. Western blotting and immunohistochemistry were performed to investigate further the effect of JYTL decoction on key targets and signaling pathways.

Results

Through UPLC-QE/MS and network analysis, 189 active ingredients and 5 hub targets were identified from JYTL. GSEA in the MitoCarta3.0 database and PPI network analysis revealed that JYTL predominantly engages in the Sirt1-mitophagy signaling pathway. Tanshinone iia, quercetin, and adenosine in JYTL are the main active ingredients for treating HN. In vivo validation showed that JYTL decoction could improve kidney function, ameliorate tubulointerstitial fibrosis (TIF), and improve mitochondrial function by inhibiting ROS production and regulating mitochondrial dynamics in SHRs. JYTL treatment could also increase the expression of SIRT1, PGC-1α, Nrf1, and TFAM, and activate PINK1/Parkin-mediated mitophagy.

Conclusion

JYTL decoction may exert renal function protective and anti-fibrosis effects in HN by ameliorating mitochondrial function and regulating the SIRT1/PGC-1α-mitophagy pathway.

The relationship between SIRT1 and inflammation: a systematic review and meta-analysis

Recent studies underscore the anti-inflammatory role of SIRT1; however, its levels during inflammatory states remain ambiguous. We synthesized relevant studies up to 20 March 2024 to evaluate the relationship between SIRT1 and inflammation, using data from three major databases. Employing a random-effects model, we analyzed both cross-sectional and longitudinal studies, calculating weighted mean differences (WMDs) for pooled effect sizes. Subgroup and sensitivity analyses, along with a risk of bias assessment, were also conducted. We reviewed 13 publications, encompassing 21 datasets and 2,028 participants. The meta-analysis indicated higher SIRT1 levels in inflammatory groups compared to control groups pre-adjustment (WMD, 3.18 ng/ml; 95% CI 2.30, 4.06 ng/ml; P<0.001; I²= 99.7%) and post-adjustment (WMD, 0.88 ng/ml; 95% CI 0.14, 1.62 ng/ml; P<0.001; I²= 99.5%). Notably, middle-aged patients with inflammation exhibited lower SIRT1 levels (WMD, -0.85 ng/ml; 95% CI -1.47, -0.22 ng/ml; P= 0.008; I²= 95.4%), while groups characterized by East Asian descent, plasma studies, autoimmune conditions, and musculoskeletal disorders showed higher levels. The findings suggest that inflammation generally upregulates SIRT1, potentially elucidating its role in immunobiological processes. However, the significant heterogeneity observed, partly due to the cross-sectional nature of some data, limits insights into the duration of disease progression, which remains highly variable.

Ginsenoside Rh4 Ameliorates Cisplatin-Induced Intestinal Toxicity via PGC-1[Formula: see text]-Mediated Mitochondrial Autophagy and Apoptosis Pathways

Cisplatin-evoked profound gastrointestinal symptomatology is one of the most common side effects of chemotherapy drugs, causing further gastrointestinal cell and intestinal mucosal injury. Ginsenoside Rh4 (G-Rh4), an active component extracted from red ginseng, possesses beneficial anti-oxidative and anti-apoptosis effects. This study aimed to assess the effectiveness of pharmacological intervention with G-Rh4 mitigating intestinal toxicity evoked by cisplatin in a murine model and in IEC-6 cells in vitro. Following oral administration for 10 days, G-Rh4 (10[Formula: see text]mg/kg and 20[Formula: see text]mg/kg) significantly increased the indicators of diamine oxidase (DAO) affected by cisplatin (20[Formula: see text]mg/kg) in mice, and histopathological analysis further indicated that G-Rh4 could effectively improve intestinal tissue morphology, as well as the expression of peroxisome proliferator-activated receptor-gamma coactivator 1 [Formula: see text] (PGC-1[Formula: see text] pathway and autophagy-related proteins. Moreover, in vitro experiments demonstrated that G-Rh4 exerted a concentration-dependent increase in cell viability, while also inhibiting cytotoxicity and abnormal rise of reactive oxygen species (ROS). Notably, ROS also activate PGC-1[Formula: see text] protein and mediate the occurrence of mitochondrial autophagy and apoptosis pathways. The molecular docking approach was employed to dock G-Rh4 with PGC-1[Formula: see text] and AMPK, revealing a binding energy of [Formula: see text]7.3[Formula: see text]kcal/mol and [Formula: see text]8.1[Formula: see text]kcal/mol and indicating a tight interaction between the components and the target. G-Rh4 could reduce the expression of autophagy-related protein p62/p53, reduce the accumulation of autophagy products, and promote the flow of autophagy. In conclusion, G-Rh4 exerted protective effects against cisplatin-induced intestinal toxicity, at least partially through PGC-1[Formula: see text]-mediated autophagy and apoptosis.

Atractylenolide-I Attenuates MPTP/MPP+‑Mediated Oxidative Stress in Parkinson's Disease Through SIRT1/PGC‑1α/Nrf2 Axis

Parkinson's disease (PD) is typically marked by motor dysfunction accompanied by loss of dopaminergic (DA) neurons and aggravated oxidative stress in the substantia nigra pars compacta (SNpc). Atractylenolide-I (ATR-I) is a potent antioxidant sesquiterpene with neuroprotective properties. However, whether ATR-I plays a neuroprotective role against oxidative stress in PD remains unclear. The objective of this study was to explore the mechanism of antioxidant action of ATR-I in PD models both in vivo and in vitro. Here, we show that ATR-I alleviated motor deficits in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mice. Moreover, ATR-I treatment effectively reduced DA neuron loss and increased tyrosine hydroxylase expression in the SNpc of MPTP-induced mice. Additionally, ATR-I inhibited oxidative stress (as manifested by elevated superoxide dismutase and glutathione peroxidase activities, and reduced malondialdehyde content) in MPTP-induced mice and attenuated reactive oxygen species levels in 1-methyl-4-phenylpyridinum (MPP+)-treated SH-SY5Y cells. Finally, ATR-I upregulated expressions of silent information regulator 1 (SIRT1), peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), NF-E2-related factor-2 (Nrf2), and heme oxygenase-1 in MPTP-induced mice and MPP+-treated SH-SY5Y cells, but had little effect on these factors in the presence of the SIRT1 inhibitor EX527. Taken together, these findings indicated that the important antioxidant role of ATR-I in MPTP/MPP+-mediated oxidative stress and the pathogenesis of PD through the SIRT1/PGC-1α/Nrf2 axis, highlighting its potential as a therapeutic option for PD.

Estrogen Regulates Ca2+ to Promote Mitochondrial Function Through G-Protein-Coupled Estrogen Receptors During Oocyte Maturation

Estrogen is a steroid hormone that plays a key role in regulating many physiological processes, such as follicle activation and development and oocyte maturation in mammals. Ca2+ is crucial in oogenesis, oocyte maturation, ovulation, and fertilization. However, the mechanism by which estrogen regulates Ca2+ during oocyte maturation in mice has not been reported. This study revealed that Ca2+ levels in oocytes significantly increase during the 4-12 h period in vitro. Oocytes treated with 0.1 µM estrogen and 1 µM G1, a G-protein-coupled estrogen receptor (GPER) agonist, showed significantly increased Ca2+ levels, while treatment with 1 µM G15, an antagonist of GPER, significantly decreased Ca2+ levels. Notably, estrogen regulates Ca2+ in oocytes through the GPER pathway and promotes the expression of the Ca2+-producing protein EPAC1. In addition, estrogen alleviates the inhibitory effect of the Ca2+ chelator BAPTA-AM during oocyte maturation by promoting Ca2+ production. Furthermore, estrogen can promote the expression of the mitochondrial generation-associated protein SIRT1 through the GPER pathway, alleviate mitochondrial oxidative damage caused by BAPTA-AM, and restore the mitochondrial membrane potential level. Collectively, this study demonstrates that estrogen can regulate Ca2+ through the GPER-EPAC1 pathway and promote the expression of SIRT1, which promotes oocyte mitochondrial function during oocyte maturation.

Quercetin prevents methylmercury-induced mitochondrial dysfunction in the cerebral cortex of mice

Methylmercury (MeHg) exposure can cause nerve damage and mitochondrial dysfunction. Mitochondrial dysfunction is mainly mediated by mitochondrial biogenesis and mitochondrial dynamics disorders. Quercetin (QE) plays an important role in activating silencing information regulator 2 related enzyme 1 (SIRT1), and SIRT1 activates peroxisome-proliferator-activated receptor-γ co-activator 1α (PGC-1α), which can regulate mitochondrial biogenesis and mitochondrial dynamics. The main purpose of this study was to explore the alleviating effects of QE on MeHg-induced nerve damage and mitochondrial dysfunction. The results showed that QE could reduce the excessive production of reactive oxygen species (ROS) and the loss of membrane potential induced by MeHg. Meanwhile, QE activated SIRT1 activity and SIRT1/PGC-1α signaling pathway, improved mitochondrial biogenesis and fusion and reduced mitochondrial fission. In summary, we hypothesized that QE prevents MeHg-induced mitochondrial dysfunction by activating SIRT1/PGC-1α signaling pathway.

m6A demethylase FTO transcriptionally activated by SP1 improves ischemia reperfusion-triggered acute kidney injury by activating Ambra1/ULK1-mediated autophagy

Ischemia reperfusion (I/R) was considered as one of main causes of acute kidney injury (AKI). However, the exact mechanism remains unclear. Here, this study aimed to investigate the role and mechanism of the m6A demethylase fat mass and obesity-associated (FTO) protein in I/R-induced AKI. HK-2 cells and SD rats were utilized to establish hypoxia/reoxygenation (H/R) or I/R induced AKI models. The changes of RNAs and proteins were quantified using RT-qPCR, western blot, and immunofluorescence assays, respectively. Cell proliferation and apoptosis were assessed by CCK-8 and flow cytometry. Interactions between molecules were investigated using RIP, ChIP, Co-IP, RNA pull-down, and dual luciferase reporter assays. Global m6A quantification was evaluated by kits. TUNEL and HE staining were employed for histopathological examinations. Oxidative stress-related indicators and renal function were determined using ELISA assays. The FTO expression was downregulated in H/R-induced HK-2 cells and renal tissues from I/R-induced rats. Overexpression of FTO improved the cell viability but repressed apoptosis and oxidative stress in H/R-treated HK-2 cells, as well as enhanced renal function and alleviated kidney injury in I/R rats. Notably, the FTO overexpression significantly increased autophagy-related LC3 and ULK1 levels. When autophagy was inhibited, the protective effects of FTO in AKI were diminished. Notably, Ambra1, a crucial regulator of autophagy, was repressed in H/R-induced HK-2 cells. However, the FTO overexpression restored the Ambra1 expression by reducing m6A modification of its mRNA. SP1, acting as an upstream transcription factor, directly interacts with the FTO promoter to enhance FTO expression. Knockdown of SP1 or Ambra1 suppressed the beneficial effects of FTO upregulation on autophagy and oxidative stress injury in H/R-stimulated cells. FTO, transcriptionally activated by SP1, promoted autophagy by upregulating Ambra1/ULK1 signaling, thereby inhibiting oxidative stress and kidney injury. These findings may provide some novel insights for AKI treatment.

Rebalance of mitophagy by inhibiting LRRK2 improves colon alterations in an MPTP in vivo model

Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene are common genetic causes of Parkinson's disease (PD). Studies demonstrated that variants in LRRK2 genetically link intestinal disorders to PD. We aimed to evaluate whether the selective inhibitor of LRRK2, PF-06447475 (PF-475), attenuates the PD induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in central nervous system (CNS) and in the gastrointestinal system. CD1 mice received four intraperitoneal injections of MPTP (20 mg/kg, total dose of 80 mg/kg) at 2 h intervals (day 1). After 24 h PF-475 was administered intraperitoneally at the doses of 2.5, 5, and 10 mg/kg for seven days. LRRK2 inhibition reduced brain α-synuclein and modulated mitophagy pathway and reduced pro-inflammatory markers and α-synuclein aggregates in colonic tissues through the modulation of mitophagy proteins. LRRK2 inhibition suppressed MPTP-induced enteric dopaminergic neuronal injury and protected tight junction in the colon. Results suggested that PF-475 may attenuate gastrointestinal dysfunction associated to PD.

Regulation of the SIRT3/SOD2 Signaling Pathway by a Compound Mixture from Polygonum orientale L. for Myocardial Damage

BACKGROUND

Polygonum orientale L. (PO) has demonstrated notable efficacy in treating coronary heart disease. Previous research identified eight key active components in PO for cardiomyocyte protection, but the underlying mechanisms remained unclear; Methods: Network pharmacology and molecular docking were used to identify potential target proteins of PO's active components. Experimental models assessed the cardioprotective effects and mechanisms; Results: Network analysis and molecular docking revealed that the active components exhibited the highest binding affinity with SOD2, indicating it as a key element in the cardiac protection of PO. In vivo, PO extract improved myocardial structure and function, and increased SOD2 protein levels. In vitro, the active components of PO (Mixture) mitigated oxidative stress and apoptosis, upregulating SIRT3 and decreasing acetylated SOD2, leading to increased SOD2 and reduced ROS levels. The observed effects were reversed by a SIRT3 inhibitor, indicating the involvement of the SIRT3/SOD2 signaling pathway; Conclusions: This comprehensive approach elucidated the critical mechanisms underlying the cardioprotective properties of PO's bioactive constituents, highlighting the regulation of the SIRT3/SOD2 signaling pathway as a new mechanism for PO's anti-cardiovascular disease effects, and suggesting the Mixture's potential as a promising drug candidate.

Declined flesh quality resulting from niacin deficiency is associated with elevated glycolysis and impaired mitochondrial homeostasis in grass carp (Ctenopharyngodon idella)

Energy metabolism exerts profound impacts on flesh quality. Niacin can be transformed into nicotinamide adenine dinucleotide (NAD), which is indispensable to energy metabolism. To investigate whether niacin deficiency could affect energy metabolism and flesh quality, six diets with graded levels of 0.49, 9.30, 21.30, 33.30, 45.30 and 57.30 mg/kg niacin were fed to grass carp (Ctenopharyngodon idella) for 63 days. The results showed that niacin deficiency declined flesh quality by changing amino acid and fatty acid profiles, decreasing shear force, increasing cooking loss and accelerating pH decline. The accelerated pH decline might be associated with enhanced glycolysis as evident by increased hexokinase (HK), pyruvate kinase (PK) and lactic dehydrogenase (LDH) activities, and mitochondrial dysfunction as evident by destroyed mitochondrial morphology, impaired respiratory chain complex I and antioxidant ability. Based on PWG and cooking loss, the niacin requirements for sub-adult grass carp were 31.95 mg/kg and 29.66 mg/kg diet, respectively.

Solanum melongena L. Extract Promotes Intestinal Tight Junction Re-Assembly via SIRT-1-Dependent Mechanisms

Tight junction disruption can lead to pathogenesis of various diseases without therapeutic strategy to recover intestinal barrier integrity. The main objective of this study is to demonstrate the effect of Solanum melongena L. extract (SMLE) on intestinal tight junction recovery and its underlying mechanism. Intestinal barrier function is attenuated by Ca2+ depletion. SMLE treatment increased TER value across T84 cell monolayers. Permeability assay reveals that Ca2+ depletion promotes 4-kDa FITC-dextran permeability, but not 70-kDa FITC-dextran. SMLE suppresses the rate of 4-kDa FITC-dextran permeability, indicating that SMLE inhibits paracellular leak pathway permeability. SMLE-mediated TER increase and leak pathway suppression are abolished by neither calcium/calmodulin-dependent protein kinase kinase β (CaMKKβ) inhibitor nor AMP-activated protein kinase (AMPK) inhibitor. Furthermore, mammalian target of rapamycin (mTOR) and extracellular signal-regulated kinase (ERK) inhibitors have no effects on SMLE-mediated TER increase and leak pathway suppression. Interestingly, SMLE is unable to enhance TER value and diminish leak pathway permeability in T84 cell monolayers pre-treated with sirtuin-1 (SIRT-1) inhibitor. Immunofluorescence staining reveals that SMLE enhances re-assembly of tight junction proteins, including occludin and ZO-1 to intercellular space but this effect is abolished by SIRT-1 inhibitor. These data suggest that SMLE promotes intestinal tight junction re-assembly via SIRT-1-dependent manner.

Mitochondrial Morphology and Function Abnormality in Ovarian Granulosa Cells of Patients with Diminished Ovarian Reserve

In this study, we examined the changes in the mitochondrial structure and function in cumulus granulosa cells of patients with diminished ovarian reserve (DOR) to explore the causes and mechanisms of decreased mitochondrial quality. The mitochondrial ultrastructure was observed by transmission electron microscope, and the function was determined by detecting the ATP content, reactive oxygen species (ROS) levels, the number of mitochondria, and the mitochondrial membrane potential. The expression of ATP synthases in relation to mitochondrial function was analyzed. Additionally, protein immunoblotting was used to compare the expression levels of mitochondrial kinetic protein, the related channel protein in the two groups. Patients with DOR had abnormal granulosa cell morphology, increased mitochondrial abnormalities, decreased mitochondrial function, and disturbed mitochondrial dynamics. Additionally, the silent information regulator 1 (SIRT1)/phospho-AMP-activated protein kinase (P-AMPK)-peroxisome proliferator-activated receptor-gamma coactivator 1 alpha (PGC-1α) pathway expression was decreased, which was speculated to be associated with the decreased mitochondrial mass in the DOR group. The mitochondrial mass was decreased in granulosa cells of patients in the DOR group. The mitochondrial dysfunction observed in granulosa cells of patients in the DOR group may be associated with dysregulation of the SIRT1/P-AMPK-PGC-1α-mitochondrial transcription factor A (TFAM) pathway.

Biogenic selenium nanoparticles alleviate intestinal barrier injury in mice through TBC1D15/Fis1/Rab7 pathway

Intestinal diseases often stem from a compromised intestinal barrier. This barrier relies on a functional epithelium and proper turnover of intestinal cells, supported by mitochondrial health. Mitochondria and lysosomes play key roles in cellular balance. Our previous researches indicate that biogenic selenium nanoparticles (SeNPs) can alleviate intestinal epithelial barrier damage by enhancing mitochondria-lysosome crosstalk, though the detailed mechanism is unclear. This study aimed to investigate the role of mitochondria-lysosome crosstalk in the protective effect of SeNPs on intestinal barrier function in mice exposed to lipopolysaccharide (LPS). The results showed that LPS exposure increased intestinal permeability in mice, leding to structural and functional damage to mitochondrial and lysosomal. Oral administration of SeNPs significantly upregulated the expression levels of TBC1D15 and Fis1, downregulated the expression levels of Rab7, Caspase-3, Cathepsin B, and MCOLN2, effectively alleviated LPS-induced mitochondrial and lysosomal dysfunction and maintained the intestinal barrier integrity in mice. Furthermore, SeNPs notably inhibited mitophagy caused by adenovirus-associated virus (AAV)-mediated RNA interference the expression of TBC1D15 in the intestine of mice, maintained mitochondrial and lysosomal homeostasis, and effectively alleviated intestinal barrier damage. These results suggested that SeNPs can regulate mitochondria-lysosome crosstalk and inhibit its damage by regulating the TBC1D15/Fis1/Rab7- signaling pathway. thereby alleviating intestinal barrier damage. It lays a theoretical foundation for elucidating the mechanism of mitochondria-lysosome crosstalk in regulating intestinal barrier damage and repair, and provides new ideas and new ways to establish safe and efficient nutritional regulation strategies to prevent and treat intestinal diseases caused by inflammation.

Effect of polydimethylsiloxane surface morphology on osteogenic differentiation of mesenchymal stem cells through SIRT1 signalling pathway

Constructing surface topography with a certain roughness is a widely used, non-toxic, cost-effective and effective method for improving the microenvironment of cells, promoting the proliferation and osteogenic differentiation of mesenchymal stem cells (MSCs), and promoting the osseointegration of grafts and further improving their biocompatibility under clinical environmental conditions. SIRT1 plays an important regulatory role in the osteogenic differentiation of bone marrow-derived MSCs (BM-MSCs). However, it remains unknown whether SIRT1 plays an important regulatory role in the osteogenic differentiation of BM-MSCs with regard to surface morphology. Polydimethylsiloxane (PDMS) with different surface morphologies were prepared using different grits of sandpaper. The value for BMSCs added on different surfaces was detected by cell proliferation assays. RT-qPCR and Western blotting were performed to detect SIRT1 activation and osteogenic differentiation of MSCs. Osteogenesis of MSCs was detected by alkaline phosphatase (ALP) and alizarin red S staining. SIRT1 inhibition experiments were performed to investigate the role of SIRT1 in the osteogenic differentiation of MSCs induced by surface morphology. We found that BM-MSCs have better value and osteogenic differentiation ability on a surface with roughness of PDMS-1000M. SIRT1 showed higher gene and protein expression on a PDMS-1000M surface with a roughness of 13.741 ± 1.388 µm. The promotion of the osteogenic differentiation of MSCs on the PDMS-1000M surface was significantly decreased after inhibiting SIRT1 expression. Our study demonstrated that a surface morphology with certain roughness can activate the SIRT1 pathway of MSCs and promote the osteogenic differentiation of BMSCs via the SIRT1 pathway.

Sex comparison of oxidative stress, mitochondrial dysfunction, and apoptosis triggers induced by single-dose Abamectin in albino rats

Abamectin (AB) is widely used in agriculture and has been employed as an insecticide, nematicide, and livestock pest control agent. However, it may also pose a serious threat to mammals. The primary purpose of this research was to compare the sex variations between male and female rats during exposure and to assess the risk of toxicity of abamectin, which are still largely unknown. The twenty albino rats were divided randomly into four groups (n = 5): 1) the male control group; 2) the male treatment group treated with AB (1 mg/kg B.W.); 3) the female control group; and 4) the female treatment group treated with AB (1 mg/kg B.W.). AB administration caused a drop in body weight in females more than males with showing oxidative stress in both sexes of animals, as characterized by an increase in MDA content and a decrease in glutathione (GSH) content and superoxide dismutase (SOD) activity. Reported sex-specific effects suggested that females are more susceptible from males in brain tissues for alteration of antioxidant markers while females' liver and kidney tissues showed more level of lipid peroxidation than males. In addition, mitochondrial dysfunction was associated with a significant decrease in NADH dehydrogenase (Complex I) and a significant decrease in mitochondrial ATPase, which led to apoptosis and histopathological alterations in the targeted tissues, indicating that females are higher sensitive than males to these biological events. In brief, the results of this study led to female rats are generally more sensitive than male rats to neurobehavioral and hepatic complications associated with abamectin treatment. Further evaluation should be performed to determine the adverse outcome pathways involved and to determine the effects of sex on improving the risk assessment of abamectin in both sexes.

DsbA-L ameliorates renal aging and renal fibrosis by maintaining mitochondrial homeostasis

Renal fibrosis is the final pathological change in renal disease, and aging is closely related to renal fibrosis. Mitochondrial dysfunction has been reported to play an important role in aging, but the exact mechanism remains unclear. Disulfide-bond A oxidoreductase-like protein (DsbA-L) is mainly located in mitochondria and plays an important role in regulating mitochondrial function and endoplasmic reticulum (ER) stress. However, the role of DsbA-L in renal aging has not been reported. In this study, we showed a reduction in DsbA-L expression, the disruption of mitochondrial function and an increase in fibrosis in the kidneys of 12- and 24-month-old mice compared to young mice. Furthermore, the deterioration of mitochondrial dysfunction and fibrosis were observed in DsbA-L-/- mice with D-gal-induced accelerated aging. Transcriptome analysis revealed a decrease in Flt4 expression and inhibition of the PI3K-AKT signaling pathway in DsbA-L-/- mice compared to control mice. Accelerated renal aging could be alleviated by an AKT agonist (SC79) or a mitochondrial protector (MitoQ) in mice with D-gal-induced aging. In vitro, overexpression of DsbA-L in HK-2 cells restored the expression of Flt4, AKT pathway factors, SP1 and PGC-1α and alleviated mitochondrial damage and cell senescence. These beneficial effects were partially blocked by inhibiting Flt4. Finally, activating the AKT pathway or improving mitochondrial function with chemical reagents could alleviate cell senescence. Our results indicate that the DsbA-L/AKT/PGC-1α signaling pathway could be a therapeutic target for age-related renal fibrosis and is associated with mitochondrial dysfunction.

Sirtuins in intervertebral disc degeneration: current understanding

BACKGROUND

Intervertebral disc degeneration (IVDD) is one of the etiologic factors of degenerative spinal diseases, which can lead to a variety of pathological spinal conditions such as disc herniation, spinal stenosis, and scoliosis. IVDD is a leading cause of lower back pain, the prevalence of which increases with age. Recently, Sirtuins/SIRTs and their related activators have received attention for their activity in the treatment of IVDD. In this paper, a comprehensive systematic review of the literature on the role of SIRTs and their activators on IVDD in recent years is presented. The molecular pathways involved in the regulation of IVDD by SIRTs are summarized, and the effects of SIRTs on senescence, inflammatory responses, oxidative stress, and mitochondrial dysfunction in myeloid cells are discussed with a view to suggesting possible solutions for the current treatment of IVDD.

PURPOSE

This paper focuses on the molecular mechanisms by which SIRTs and their activators act on IVDD.

METHODS

A literature search was conducted in Pubmed and Web of Science databases over a 13-year period from 2011 to 2024 for the terms "SIRT", "Sirtuin", "IVDD", "IDD", "IVD", "NP", "Intervertebral disc degeneration", "Intervertebral disc" and "Nucleus pulposus".

RESULTS

According to the results, SIRTs and a large number of activators showed positive effects against IVDD.SIRTs modulate autophagy, myeloid apoptosis, oxidative stress and extracellular matrix degradation. In addition, they attenuate inflammatory factor-induced disc damage and maintain homeostasis during disc degeneration. Several clinical studies have reported the protective effects of some SIRTs activators (e.g., resveratrol, melatonin, honokiol, and 1,4-dihydropyridine) against IVDD.

CONCLUSION

The fact that SIRTs and their activators play a hundred different roles in IVDD helps to better understand their potential to develop further treatments for IVDD.

NOVELTY

This review summarizes current information on the mechanisms of action of SIRTs in IVDD and the challenges and limitations of translating their basic research into therapy.

Chronic exposure to polystyrene nanoplastics induces intestinal mechanical and immune barrier dysfunction in mice

Micro(nano)plastics are prevalent in the environment, and prolonged exposure to them represents a threat to human health. The goal of this study is to assess the health risk of long-term exposure to nanoplastics (NPs) at environmental concentrations on the intestinal mechanical and immune barrier in mice. In this study, mice were provided drinking water containing polystyrene NPs (PS-NPs; 0.1, 1, and 10 mg·L-1) for 32 consecutive weeks. The levels of endocytosis proteins caveolin and clathrin and of tight junctional proteins claudin-1, occludin, and ZO-1, and morphological changes, proportion of lymphocytes B in MLNs and lymphocytes T in IELs and LPLs were determined by immunohistochemistry, hematoxylin-eosin, and flow cytometry assays in the intestinal tissues of mice at 28 weeks. The activities or concentrations of ROS, SOD, MDA, and GSH-Px and inflammatory factors (IL-1β, IL-6, and TNF-α) in the intestinal tissues of mice were measured by ELISA at 12, 16, 20, 24, and 32 weeks. Compared with the control group, oral ingested PS-NPs entered the intestinal tissues of mice and upregulated expression levels of the clathrin and caveolin. The intestinal tissue structure of mice in the PS-NPs (1 and 10 mg·L-1) exposure groups showed significant abnormalities, such as villus erosion, decreased of crypts numbers and large infiltration of inflammatory cells. Exposure to 0.1 mg·L-1 PS-NPs decreased occludin protein levels, but not claudin-1 and ZO-1 levels. The levels of these three tight junction proteins decreased significantly in the 1 and 10 mg·L-1 PS-NPs exposed groups. Exposure to PS-NPs led to a significant time- and dose-dependent increase in ROS and MDA levels, and concurrently decreased GSH-Px and SOD contents. Exposure to PS-NPs increased the proportion of B cells in MLNs, and decreased the proportion of CD8+ T cells in IELs and LPLs. The levels of pro-inflammatory cytokines IL-6, TNF-α and IL-1β were markedly elevated after PS-NPs exposure. Long-term PS-NPs exposure impaired intestinal mechanical and immune barrier, and indicate a potentially significant threat to human health.

Mitochondrial dynamics as a novel treatment strategy for triple-negative breast cancer

INTRODUCTION

Triple-negative breast cancer (TNBC), recognized as the most heterogeneous type of breast cancer (BC), exhibits a worse prognosis than other subtypes. Mitochondria dynamics play a vital role as mediators in tumorigenesis by adjusting to the cell microenvironments. However, the relationship between mitochondrial dynamics and metabophenotype exhibits discrepancies and divergence across various research and BC models. Therefore, this study aims to explore the role of mitochondrial dynamics in TNBC drug resistance and tumorigenesis.

METHODS

The Wst-8 test was conducted to assess doxorubicin sensitivity in HCC38, MDA-MB-231 (TNBC), and MCF-7 (luminal). Confocal microscopy and FACS were used to quantify the mitochondrial membrane potential (ΔφM), mitophagy, and reactive oxygen species (ROS) production. Agilent Seahorse XF Analyzer was utilized to measure metabolic characteristics. Dynamin-related protein-1 (DRP1), Parkin, and p62 immunohistochemistry staining were performed using samples from 107 primary patients with BC before and after neoadjuvant chemotherapy (NAC).

RESULTS

MDA-MB-231, a TNBC cell line with reduced sensitivity to doxorubicin, reduced ΔφM, and enhanced mitophagy to maintain ROS production through oxidative phosphorylation (OXPHOS)-based metabolism. HCC38, a doxorubicin-sensitive cell line, exhibited no alterations in ΔφM or mitophagy. However, it demonstrated an increase in ROS production and glycolysis. Clinicopathological studies revealed that pretreatment (before NAC) expression of DRP1 was significant in TNBC, as was pretreatment expression of Parkin in the hormone receptor-negative group. Furthermore, low p62 levels seem to be a risk factor for recurrence-free survival.

CONCLUSION

Our findings indicated that the interplay between mitophagy, linked to a worse clinical prognosis, and OXPHOS metabolism promoted chemotherapy resistance in TNBC. Mitochondrial fission is prevalent in TNBC. These findings suggest that targeting the unique mitochondrial metabolism and dynamics in TNBC may offer a novel therapeutic strategy for patients with TNBC.

Ligilactobacillus Salivarius improve body growth and anti-oxidation capacity of broiler chickens via regulation of the microbiota-gut-brain axis

Certain strains of probiotic bacteria can secret functional substances namely digestive enzymes and functional peptides to regulate physiological conditions such as digestion and anti-oxidation, which are often incorporated in industrial broiler chick production. However, few studies have detailed the action mechanisms and effects of these bacteria on regulating growth and anti-oxidation levels in broiler chickens. Ligilactobacillus salivarius is a strain of probiotic bacteria used as dietary supplement. In the present study, Ligilactobacillus salivarius was evaluated for its secreted digestive enzymes in vitro. To detailed evaluate the action mechanisms and effects of gastrointestinal tract (GIT) microbiota on alleviating anti-oxidation levels of broiler chickens through the gut-brain axis. Ligilactobacillus salivarius was cultured and supplemented in the food of broilers to evaluate the probiotic effect on growth and anti-oxidation by modulation of gut microbial composition and its functional metabolites using metagenomic and metabolomic assays. Biochemical results showed that Ligilactobacillus salivarius secreted digestive enzymes: protease, lipase, and amylase. Broiler chickens with Ligilactobacillus salivarius supplemented for 42 days, showed increased body weights, a reduced oxidative status, decreased malondialdehyde levels, and improved activities rates of total superoxide dismutase, glutathione peroxidase IIand IV improved. The microbial composition of caecum was more abundant than those broiler without probiotics supplementation, owing 400 of total number (489) of bacterial operational taxonomic units (OTU). The genera of Lactobacillus, Megamonas, Ruminoccoccaceae, Ruminococcus, Alistipes and Helicobacter shared the dominant proportion of Candidatus _Arthromitus compared with the control chickens. These functional bacteria genera assisted in the transportation and digestion of amino acids, carbohydrates, and ions, synthesis of cellular membranes, and anti-oxidation. Uncultured_organism_g_ Anaerosporobacter, Lactobacillus salivarius, uncultured_bacterium_g_ Ruminococcaceae_UCG-014, uncultured_bacterium_g_ Peptococcus were strongly and positively correlated with body growth performance and anti-oxidation. A metabonomic assay suggested that the secreted of gamma-aminobutyric acid and monobactam was metabolized according to the Kyoto Encyclopedia of Genes and Genomes analysis. In conclusion, Ligilactobacillus salivarius optimized microbial composition of the caecum and secreted functional peptides through gut-brain axis to improve the body growth and antioxidation of broiler chicken.

Abnormalities in the SIRT1-SIRT3 axis promote myocardial ischemia-reperfusion injury through ferroptosis caused by silencing the PINK1/Parkin signaling pathway

BACKGROUND

Myocardial ischemia-reperfusion injury (MIRI) is one of the main reasons for poor prognosis in patients with ischemic cardiomyopathy (ICM). To date, the mechanism remains unknown. As members of the silent information regulator 2 (SIR2) family, both SIRT1 and SIRT3 have been shown to play critical roles in protecting cardiomyocytes against MIRI, but their specific protective mechanism, their interact between the two and their relationship with ferroptosis are still unclear. Hence, in this study, we investigated the interact and specific mechanism of SIRT1 and SIRT3 in protecting cardiomyocytes against MIRI, as well as their association with ferroptosis.

METHODS

Bioinformatics analysis methods were used to explore the expression of SIRT1 and SIRT3 during MIRI, and then a cell hypoxia/reoxygenation injury model was constructed to verify the results. Then, Pearson correlation analysis was further used to explore the relationship between SIRT1 and SIRT3, whose roles in the regulation of ferroptosis were also analysed by gene knock down, Western Blotting and flow cytometry. Several biomarkers, such as Fe2+ concentration, lipid peroxidation marker MDA and mitochondrial membrane potential (MMP), were used to evaluate changes in ferroptosis.

RESULTS

The expression of SIRT1 and SIRT3 was abnormal during MIRI, and SIRT1 was significantly negatively correlated with SIRT3 in the SIRT1-SIRT3 axis. Further analysis revealed that the SIRT1-SIRT3 axis was closely correlated with ferroptosis, and its silencing effectively increase the incidence of ferroptosis. Furthermore, SIRT1-SIRT3 axis silencing was accompanied by changes in PINK1, Parkin, P62/SQSTM1 and LC3 expression. PINK1 silencing significantly increased the incidence of ferroptosis, while resveratrol (Res) and/or honokiol (HKL) effectively reversed the outcome.

CONCLUSION

Abnormalities in the SIRT1-SIRT3 axis promote MIRI through ferroptosis caused by silencing the PINK1/Parkin signaling pathway.

CircHIPK3 relieves vascular calcification via mediating SIRT1/PGC-1α/MFN2 pathway by interacting with FUS

BACKGROUND

Circular RNAs (circRNAs) have been reported to regulate the biological processes of human diseases. CircHIPK3 has been implicated in vascular calcification, but the downstream regulatory mechanisms remain unclear. Our study aimed to understand the regulatory function of circHIPK3 in vascular calcification.

METHODS

CircHIPK3 expression in atherosclerosis (AS) serum samples and vascular smooth muscle cells (VSMCs) calcification model was assessed by quantitative real-time polymerase chain reaction (qRT-PCR). The binding relationships between fused in sarcoma (FUS) and circHIPK3 or sirtuin 1 (SIRT1) were verified by RNA immunoprecipitation (RIP) assay and RNA pull-down assays. Alkaline phosphatase (ALP) activity and alizarin red staining assays were performed to evaluate the biological effect of β-glycerophosphate (β-GP) and circHIPK3 on calcium deposition. qRT-PCR and western blot assays were used to examine the effect of β-GP, circHIPK3, SIRT1, mitofusin 2 (MFN2), and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) on VSMCs calcification and the expression of calcification-related proteins.

RESULTS

In AS serum samples and VSMCs calcification model, the expression of circHIPK3 was significantly reduced. CircHIPK3 overexpression inhibited ALP activity and calcium deposition in β-GP-induced VSMCs. Moreover, circHIPK3 could recruit FUS to further stabilize SIRT1 mRNA. CircHIPK3 promoted MFN2 expression to alleviate VSMCs calcification via activating SIRT1/PGC-1α signaling.

CONCLUSION

The positive regulation of circHIPK3/FUS/SIRT1/PGC-1α/MFN2 signaling pathway contributed to the alleviate VSMCs calcification, revealing a novel regulatory axis for vascular calcification.

A genomic perspective of the aging human and mouse lung with a focus on immune response and cellular senescence

BACKGROUND

The aging lung is a complex process and influenced by various stressors, especially airborne pathogens and xenobiotics. Additionally, a lifetime exposure to antigens results in structural and functional changes of the lung; yet an understanding of the cell type specific responses remains elusive. To gain insight into age-related changes in lung function and inflammaging, we evaluated 89 mouse and 414 individual human lung genomic data sets with a focus on genes mechanistically linked to extracellular matrix (ECM), cellular senescence, immune response and pulmonary surfactant, and we interrogated single cell RNAseq data to fingerprint cell type specific changes.

RESULTS

We identified 117 and 68 mouse and human genes linked to ECM remodeling which accounted for 46% and 27%, respectively of all ECM coding genes. Furthermore, we identified 73 and 31 mouse and human genes linked to cellular senescence, and the majority code for the senescence associated secretory phenotype. These cytokines, chemokines and growth factors are primarily secreted by macrophages and fibroblasts. Single-cell RNAseq data confirmed age-related induced expression of marker genes of macrophages, neutrophil, eosinophil, dendritic, NK-, CD4+, CD8+-T and B cells in the lung of aged mice. This included the highly significant regulation of 20 genes coding for the CD3-T-cell receptor complex. Conversely, for the human lung we primarily observed macrophage and CD4+ and CD8+ marker genes as changed with age. Additionally, we noted an age-related induced expression of marker genes for mouse basal, ciliated, club and goblet cells, while for the human lung, fibroblasts and myofibroblasts marker genes increased with age. Therefore, we infer a change in cellular activity of these cell types with age. Furthermore, we identified predominantly repressed expression of surfactant coding genes, especially the surfactant transporter Abca3, thus highlighting remodeling of surfactant lipids with implications for the production of inflammatory lipids and immune response.

CONCLUSION

We report the genomic landscape of the aging lung and provide a rationale for its growing stiffness and age-related inflammation. By comparing the mouse and human pulmonary genome, we identified important differences between the two species and highlight the complex interplay of inflammaging, senescence and the link to ECM remodeling in healthy but aged individuals.

SIRT1 alleviates insulin resistance and respiratory distress in late preterm rats by activating QKI5-mediated PPARγ/PI3K/AKT pathway

Neonatal respiratory distress syndrome (NRDS) is a common complication of gestational diabetes mellitus (GDM) and late preterm births. Research suggests that SIRT1 was involved in LPS-induced acute respiratory distress syndrome, but its mechanism remains to be further explored. Here, pregnant rats were intraperitoneally injected with 45 mg/Kg streptozotocin at day 0 of gestation to induce GDM and injected with LPS at day 17 of gestation to induce late preterm birth. Pioglitazone (a PPARγ agonist) was administered from day 17 to parturition in GDM group, and it was administered for 3 days before LPS injection in late preterm birth group. SRT1720 (a SIRT1 activator) was administered by oral gavage from day 0 to day 17 in both groups. Our data showed that activation of SIRT1 or PPARγ alleviated the abnormal blood glucose metabolism and lung tissue injury, downregulated expression of surfactant proteins (SP-B and SP-C), and decreased activation of the PI3K/AKT pathway induced by GDM and late preterm birth in neonatal rats. Moreover, an insulin resistance model was established by treating primary AT-II cells with insulin. Activation of SIRT1 reversed insulin-induced reduction in cell proliferation, glucose consumption, SP-B and SP-C expression, and the activity of the PI3K/AKT pathway and increase in cellular inflammation and apoptosis. Mechanistically, SIRT1 upregulated PPARγ expression via deacetylation of QKI5, an RNA binding protein that can stabilize its target mRNA molecules, and then activated the PI3K/AKT pathway. In conclusion, SIRT1 promotes the expression of PPARγ via upregulation of QKI5 and activates the PI3K/AKT pathway, thus mitigating NRDS caused by GDM and late preterm birth.

Gut microbiota metabolites, redox status, and the related regulatory effects of probiotics

Oxidative stress is a state of imbalance between oxidation and antioxidation. It is caused by excess levels of free radicals and leads to the damage of DNA, proteins, and lipids. The crucial role of gut microbiota in regulating oxidative stress has been widely demonstrated. Studies have suggested that the redox regulatory effects of gut microbiota are related to gut microbiota metabolites, including fatty acids, lipopolysaccharides, tryptophan metabolites, trimethylamine-N-oxide and polyphenolic metabolites. In recent years, the potential benefits of probiotics have been gaining increasing scientific interest owing to their ability to modulate gut microbiota and oxidative stress. In this review, we summarise the adverse health effects of oxidative stress and discuss the role of the gut microbiota and its metabolites in redox regulation. Based on the influence of gut microbiota metabolites, the roles of probiotics in preventing oxidative stress are highlighted.

SPC-180002, a SIRT1/3 dual inhibitor, impairs mitochondrial function and redox homeostasis and represents an antitumor activity

Since sirtuins (SIRTs) are closely associated with reactive oxygen species (ROS) and antioxidant system, the development of their selective inhibitors is drawing attention for understanding of cellular redox homeostasis. Here, we describe the pharmacological properties of SPC-180002, which incorporates a methyl methacrylate group as a key pharmacophore, along with its comprehensive molecular mechanism as a novel dual inhibitor of SIRT1/3. The dual inhibition of SIRT1/3 by SPC-180002 disturbs redox homeostasis via ROS generation, which leads to an increase in both p21 protein stability and mitochondrial dysfunction. Increased p21 interacts with and inhibits CDK, thereby interfering with cell cycle progression. SPC-180002 leads to mitochondrial dysfunction by inhibiting mitophagy, which is accompanied by a reduction in oxygen consumption rate. Consequently, SPC-180002 strongly suppresses the proliferation of cancer cells and exerts anticancer effect in vivo. Taken together, the novel SIRT1/3 dual inhibitor, SPC-180002, impairs mitochondrial function and redox homeostasis, thereby strongly inhibiting cell cycle progression and cancer cell growth.

The long non-coding RNA maternally expressed 3-micorRNA-15a-5p axis is modulated by melatonin and prevents nucleus pulposus cell inflammation and apoptosis

Nucleus pulposus (NP) cell apoptosis is regarded as a critical risk factor for intervertebral disc degeneration (IVDD). Melatonin exerts a protective role on NP cells. The study concentrates on the role and mechanism of lncRNA MEG3 in melatonin-mediated effects on NP cells. An in vitro IVDD model was constructed using IL-1β on human NP cells. qRT-PCR investigated MEG3, miR-15a-5p and PGC-1α mRNA levels in tissues and NP cells. IL-1β-treated NP cells subsequent to transfection, followed by melatonin treatment. NP cell proliferation, viability, apoptosis and inflammatory reactions were assayed. Western blot checked the profiles of PGC-1α, SIRT1 and NF-κB p65. Student's t-test or one-way analysis of variance (ANOVA) followed by Tukey's test was used for statistical tests. As indicated by the data, melatonin weakened NP cell inflammation and apoptosis and enhanced MEG3 expression. MEG3 expression was attenuated in IVDD tissues. MEG3 knockdown impaired the function of melatonin, which was, however, strengthened by miR-15a-5p knockdown. MEG3 targeted miR-15a-5p, which targeted PGC-1α and repressed the PGC-1α/SIRT1 pathway. Collectively, this study has disclosed that the MEG3-miR-15a-5p-PGC-1α/SIRT1 pathway modulated by melatonin can hamper NP cell apoptosis and inflammation elicited by IL-1β.

Arabinogalactan Alleviates Lipopolysaccharide-Induced Intestinal Epithelial Barrier Damage through Adenosine Monophosphate-Activated Protein Kinase/Silent Information Regulator 1/Nuclear Factor Kappa-B Signaling Pathways in Caco-2 Cells

Intestinal epithelial barrier (IEB) damage is an important aspect in inflammatory bowel disease (IBD). The objective of this study was to explore the protective effects and mechanisms of arabinogalactan (AG) on lipopolysaccharide (LPS)-stimulated IEB dysfunction. The results show that AG (1, 2, and 5 mg/mL) mitigated 100 μg/mL LPS-stimulated IEB dysfunction through increasing transepithelial electrical resistance (TEER), reducing fluorescein isothiocyanate (FITC)-dextran (4 kDa) flux, and up-regulating the protein and mRNA expression of tight junction (TJ) proteins (Claudin-1, Zonula occludens-1 (ZO-1) and Occludin). In addition, AG ameliorated LPS-stimulated IEB dysfunction by reducing interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and IL-1β levels, decreasing the reactive oxygen species (ROS) level, increasing superoxide dismutase (SOD) activity, increasing the glutathione (GSH) level, and decreasing the levels of malondialdehyde (MDA) and intracellular calcium ([Ca2+]i). Furthermore, 2 mg/mL AG up-regulated the expression of silent information regulator 1 (SIRT1), the phosphorylated adenosine monophosphate-activated protein kinase (AMPK), and peroxisome proliferator-activated receptor gamma coactivator (PGC)-1α and inhibited the phosphorylation of nuclear factor kappa-B (NF-κB) and the inhibitor of NF-κBα (IκBα). Therefore, AG could maintain IEB integrity by activating AMPK/SIRT1 and inhibiting the NF-κB signaling pathway. In conclusion, AG can regulate the AMPK/SIRT1/NF-κB signaling pathway to reduce inflammation and oxidative stress, thus alleviating LPS-stimulated IEB damage.

Apelin alleviates sepsis-induced acute lung injury in part by modulating the SIRT1/NLRP3 pathway to inhibit endothelial cell pyroptosis

BACKGROUND

Sepsis, an intricate systemic inflammatory syndrome, gives rise to various life-threatening complications, with acute lung injury (ALI) being prominently encountered. ALI, clinically characterized by pulmonary infiltration, hypoxemia, and edema, stands as a prevailing consequence of sepsis. This work sought to elucidate the mechanism of Apelin in mitigating sepsis-induced ALI (siALI).

METHODS

A mouse sepsis model was constructed by cecal ligation and puncture surgery, followed utilizing histopathological analysis using HE staining. mRNA levels of inflammatory cytokines (IL-1β, IL-6, and TNF-α) were assessed utilizing qRT-PCR, while ELISA was employed to measure the levels of vWF, VEGF, IL-1β, and IL-18. Western blot was conducted to examine protein levels of NLRP3, Caspase-1 p20, GSDMD-N, and SIRT1. To evaluate the extent of endothelial cell (EC) pyroptosis, immunofluorescence co-staining of CD31, NLRP3, and Caspase-1 p20 was fulfilled. Furthermore, TUNEL staining was utilized to ascertain the degree of plasma membrane damage and cell death.

RESULTS

Apelin demonstrated its potential in ameliorating siALI in mice by diminishing mRNA expression levels of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α) as well as expression levels of vWF and VEGF. Apelin inhibited protein expression of NLRP3, Caspase-1 p20, and GSDMD-N, indicating that EC pyroptosis was suppressed. Finally, Apelin could upregulate the protein expression of SIRT1. This upregulation led to the inhibition of protein expression of NLRP3, Caspase-1 p20, and GSDMD-N, consequently suppressing EC pyroptosis. As a result, a reduction in the expression of inflammatory cytokines IL-1β and IL-18 ultimately alleviated siALI.

CONCLUSION

Apelin was confirmed to alleviate siALI partially by modulating SIRT1/NLRP3 pathway to inhibit EC pyroptosis, which dawned on the molecular mechanism of siALI and had important clinical significance for treating ALI effectively.

Rebalancing of mitochondrial homeostasis through an NAD+-SIRT1 pathway preserves intestinal barrier function in severe malnutrition

BACKGROUND

The intestine of children with severe malnutrition (SM) shows structural and functional changes that are linked to increased infection and mortality. SM dysregulates the tryptophan-kynurenine pathway, which may impact processes such as SIRT1- and mTORC1-mediated autophagy and mitochondrial homeostasis. Using a mouse and organoid model of SM, we studied the repercussions of these dysregulations on malnutrition enteropathy and the protective capacity of maintaining autophagy activity and mitochondrial health.

METHODS

SM was induced through feeding male weanling C57BL/6 mice a low protein diet (LPD) for 14-days. Mice were either treated with the NAD+-precursor, nicotinamide; an mTORC1-inhibitor, rapamycin; a SIRT1-activator, resveratrol; or SIRT1-inhibitor, EX-527. Malnutrition enteropathy was induced in enteric organoids through amino-acid deprivation. Features of and pathways to malnutrition enteropathy were examined, including paracellular permeability, nutrient absorption, and autophagic, mitochondrial, and reactive-oxygen-species (ROS) abnormalities.

FINDINGS

LPD-feeding and ensuing low-tryptophan availability led to villus atrophy, nutrient malabsorption, and intestinal barrier dysfunction. In LPD-fed mice, nicotinamide-supplementation was linked to SIRT1-mediated activation of mitophagy, which reduced damaged mitochondria, and improved intestinal barrier function. Inhibition of mTORC1 reduced intestinal barrier dysfunction and nutrient malabsorption. Findings were validated and extended using an organoid model, demonstrating that resolution of mitochondrial ROS resolved barrier dysfunction.

INTERPRETATION

Malnutrition enteropathy arises from a dysregulation of the SIRT1 and mTORC1 pathways, leading to disrupted autophagy, mitochondrial homeostasis, and ROS. Whether nicotinamide-supplementation in children with SM could ameliorate malnutrition enteropathy should be explored in clinical trials.

FUNDING

This work was supported by the Bill and Melinda Gates Foundation, the Sickkids Research Institute, the Canadian Institutes of Health Research, and the University Medical Center Groningen.

Oncogenic KRAS mutation confers chemoresistance by upregulating SIRT1 in non-small cell lung cancer

Kirsten rat sarcoma viral oncogene homologue (KRAS) is a frequent oncogenic driver of solid tumors, including non-small cell lung cancer (NSCLC). The treatment and outcomes of KRAS-mutant cancers have not been dramatically revolutionized by direct KRAS-targeted therapies because of the lack of deep binding pockets for specific small molecule inhibitors. Here, we demonstrated that the mRNA and protein levels of the class III histone deacetylase SIRT1 were upregulated by the KRASMut-Raf-MEK-c-Myc axis in KRASMut lung cancer cells and in lung tumors of a mouse model with spontaneous KrasG12D expression. KRASMut-induced SIRT1 bound to KRASMut and stably deacetylated KRASMut at lysine 104, which increased KRASMut activity. SIRT1 knockdown (K/D) or the SIRT1H363Y mutation increased KRASMut acetylation, which decreased KRASMut activity and sensitized tumors to the anticancer effects of cisplatin and erlotinib. Furthermore, in KrasG12D/+;Sirt1co/co mice, treatment with cisplatin and erlotinib robustly reduced the tumor burden and increased survival rates compared with those in spontaneous LSL-KrasG12D/+;Sirt1+/+ mice and mice in each single-drug treatment group. Then, we identified p300 as a KRASMut acetyltransferase that reinforced KRASMut lysine 104 acetylation and robustly decreased KRASMut activity. KRASMut lysine 104 acetylation by p300 and deacetylation by SIRT1 were confirmed by LC‒MS/MS. Consistent with this finding, the SIRT1 inhibitor EX527 suppressed KRASMut activity, which synergistically abolished cell proliferation and colony formation, as well as the tumor burden in KRASMut mice, when combined with cisplatin or erlotinib. Our data reveal a novel pathway critical for the regulation of KRASMut lung cancer progression and provide important evidence for the potential application of SIRT1 inhibitors and p300 activators for the combination treatment of KRASMut lung cancer patients.

AIFM2 promotes hepatocellular carcinoma metastasis by enhancing mitochondrial biogenesis through activation of SIRT1/PGC-1α signaling

AIFM2 is a crucial NADH oxidase involved in the regulation of cytosolic NAD+. However, the role of AIFM2 in the progression of human cancers remains largely unexplored. Here, we elucidated the clinical implications, biological functions, and molecular mechanisms of AIFM2 in hepatocellular carcinoma (HCC). We found that AIFM2 is significantly upregulated in HCC, which is most probably caused by DNA hypomethylation and downregulation of miR-150-5p. High expression of AIFM2 is markedly associated with poor survival in patients with HCC. Knockdown of AIFM2 significantly impaired, while forced expression of AIFM2 enhanced the metastasis of HCC both in vitro and in vivo. Mechanistically, increased mitochondrial biogenesis and oxidative phosphorylation by activation of SIRT1/PGC-1α signaling contributed to the promotion of metastasis by AIFM2 in HCC. In conclusion, AIFM2 upregulation plays a crucial role in the promotion of HCC metastasis by activating SIRT1/PGC-1α signaling, which strongly suggests that AIFM2 could be targeted for the treatment of HCC.

Syringin Prevents 6-Hydroxydopamine Neurotoxicity by Mediating the MiR-34a/SIRT1/Beclin-1 Pathway and Activating Autophagy in SH-SY5Y Cells and the Caenorhabditis elegans Model

Defective autophagy is one of the cellular hallmarks of Parkinson's disease (PD). Therefore, a therapeutic strategy could be a modest enhancement of autophagic activity in dopamine (DA) neurons to deal with the clearance of damaged mitochondria and abnormal protein aggregates. Syringin (SRG) is a phenolic glycoside derived from the root of Acanthopanax senticosus. It has antioxidant, anti-apoptotic, and anti-inflammatory properties. However, whether it has a preventive effect on PD remains unclear. The present study found that SRG reversed the increase in intracellular ROS-caused apoptosis in SH-SY5Y cells induced by neurotoxin 6-OHDA exposure. Likewise, in C. elegans, degeneration of DA neurons, DA-related food-sensitive behaviors, longevity, and accumulation of α-synuclein were also improved. Studies of neuroprotective mechanisms have shown that SRG can reverse the suppressed expression of SIRT1, Beclin-1, and other autophagy markers in 6-OHDA-exposed cells. Thus, these enhanced the formation of autophagic vacuoles and autophagy activity. This protective effect can be blocked by pretreatment with wortmannin (an autophagosome formation blocker) and bafilomycin A1 (an autophagosome-lysosome fusion blocker). In addition, 6-OHDA increases the acetylation of Beclin-1, leading to its inactivation. SRG can induce the expression of SIRT1 and promote the deacetylation of Beclin-1. Finally, we found that SRG reduced the 6-OHDA-induced expression of miR-34a targeting SIRT1. The overexpression of miR-34a mimic abolishes the neuroprotective ability of SRG. In conclusion, SRG induces autophagy via partially regulating the miR-34a/SIRT1/Beclin-1 axis to prevent 6-OHDA-induced apoptosis and α-synuclein accumulation. SRG has the opportunity to be established as a candidate agent for the prevention and cure of PD.

Age-related advanced glycation end-product accumulation impairs mitochondrial regulation after vitrification†

Vitrification is an important assisted reproductive technology, although it induces mitochondrial dysfunction in embryos. Herein, we aimed to investigate whether age-associated accumulation of advanced glycation end-products (AGEs) in oocytes impairs the recovery of embryos from cryopreservation-induced mitochondrial dysfunction/damage. Mouse eight-cell stage embryos developed in vitro were vitrified and warmed and incubated up to the blastocyst stage. AGE levels in oocytes were higher in both aged mice and AGE accumulation mouse models (MGO-mice) than those in young and control mice. In addition, the level of SIRT1 upregulation was lower for embryos of aged and MGO-mice than that for embryos of young and control mice. The highest mitochondrial DNA (mtDNA) content was detected in blastocysts derived from vitrified embryos of aged and MGO-mice. The spent culture medium of blastocysts derived from both aged and MGO-mice contained higher mtDNA content than that of the blastocysts derived from young and control mice. EX527 increased mtDNA content in the spent culture medium of vitrified embryos derived from young mice. In addition, p62 aggregate levels were higher in vitrified embryos of control mice than those in vitrified embryos of MGO-mice. The SIRT1 activator, resveratrol, increased p62 aggregation levels in vitrified embryos derived from young and aged mice, whereas vitrification did not affect p62 aggregation levels in embryos from aged mice. Therefore, age-associated AGE accumulation induces decreased responsive SIRT1 upregulation following vitrified-warmed treatment and impairs mitochondrial quality control activity in vitrified embryos.

PGC-1α Agonist Rescues Doxorubicin-Induced Cardiomyopathy by Mitigating the Oxidative Stress and Necroptosis

Cardiomyopathy (particularly dilated cardiomyopathy (DCM)) significantly contributes to development and progression of heart failure (HF), and inflammatory factors further deteriorate the symptoms. Morphological and functional defects of the heart in doxorubicin (DOX)-induced cardiomyopathy (cardiotoxicity) are similar to those of DCM. We used anagonist of PGC-1α (PPAR (peroxisome proliferator-activated receptor-gamma)-γ coactivator-1α) that is considered as the 'master regulator' of mitochondrial biogenesis with an aim to rescue the DOX-induced deleterious effects on the heart. Forty male C57BL/6J mice (8 weeks old) were divided in four groups, Control, DOX, ZLN005, and ZLN005 + DOX (n = 10 each group). The DOX-induced (10 mg/kg, single dose) cardiomyopathy mimics a DCM-like phenotype with marked morphologic alteration in cardiac tissue and functional derangements. Significant increased staining was observed for Masson Trichrome/Picrosirius red and α-Smooth Muscle Actinin (α-SMA) that indicated enhanced fibrosis in the DOX group compared to the control that was attenuated by (peroxisome proliferator-activated receptor-gamma (PPAR-γ) coactivator) (PGC)-1α (alpha) agonist (four doses of 2.5 mg/kg/dose; cumulative dose = 10 mg/kg). Similarly, elevated expression of necroptosis markers along with enhanced oxidative stress in the DOX group were alleviated by PGC-1α agonist. These data collectively suggested the potent therapeutic efficacy of PGC-1α agonist in mitigating the deleterious effects of DOX-induced cardiomyopathy, and it may be targeted in developing the future therapeutics for the management of DCM/HF.

Melatonin promotes gut anti-oxidative status in perinatal rat by remodeling the gut microbiome

Gut health is important for nutrition absorption, reproduction, and lactation in perinatal and early weaned mammals. Although melatonin functions in maintaining circadian rhythms and preventing obesity, neurodegenerative diseases, and viral infections, its impact on the gut microbiome and its function in mediating gut health through gut microbiota remain largely unexplored. In the present study, the microbiome of rats was monitoring after fecal microbiota transplantation (FMT) and foster care (FC). The results showed that FMT and FC increased intestinal villus height/crypt depth in perinatal rats. Mechanistically, the melatonin-mediated remodeling of gut microbiota inhibited oxidative stress, which led to attenuation of autophagy and inflammation. In addition, FMT and FC encouraged the growth of more beneficial intestinal bacteria, such as Allobaculum, Bifidobacterium, and Faecalibaculum, which produce more short-chain fatty acids to strengthen intestinal anti-oxidation. These findings suggest that melatonin-treated gut microbiota increase the production of SCFAs, which improve gut health by reducing oxidative stress, autophagy and inflammation. The transfer of melatonin-treated gut microbiota may be a new and effective method by which to ameliorate gut health in perinatal and weaned mammals.

Dihydromyricetin supplementation improves ethanol-induced lipid accumulation and inflammation

Introduction

Excessive alcohol consumption leads to a myriad of detrimental health effects, including alcohol-associated liver disease (ALD). Unfortunately, no available treatments exist to combat the progression of ALD beyond corticosteroid administration and/or liver transplants. Dihydromyricetin (DHM) is a bioactive polyphenol and flavonoid that has traditionally been used in Chinese herbal medicine for its robust antioxidant and anti-inflammatory properties. It is derived from many plants, including Hovenia dulcis and is found as the active ingredient in a variety of popular hangover remedies. Investigations utilizing DHM have demonstrated its ability to alleviate ethanol-induced disruptions in mitochondrial and lipid metabolism, while demonstrating hepatoprotective activity.

Methods

Female c57BL/6J mice (n = 12/group) were treated using the Lieber DeCarli forced-drinking and ethanol (EtOH) containing liquid diet, for 5 weeks. Mice were randomly divided into three groups: (1) No-EtOH, (2) EtOH [5% (v/v)], and (3) EtOH [5% (v/v)] + DHM (6 mg/mL). Mice were exposed to ethanol for 2 weeks to ensure the development of ALD pathology prior to receiving dihydromyricetin supplementation. Statistical analysis included one-way ANOVA along with Bonferroni multiple comparison tests, where p ≤ 0.05 was considered statistically significant.

Results

Dihydromyricetin administration significantly improved aminotransferase levels (AST/ALT) and reduced levels of circulating lipids including LDL/VLDL, total cholesterol (free cholesterol), and triglycerides. DHM demonstrated enhanced lipid clearance by way of increased lipophagy activity, shown as the increased interaction and colocalization of p62/SQSTM-1, LC3B, and PLIN-1 proteins. DHM-fed mice had increased hepatocyte-to-hepatocyte lipid droplet (LD) heterogeneity, suggesting increased neutralization and sequestration of free lipids into LDs. DHM administration significantly reduced prominent pro-inflammatory cytokines commonly associated with ALD pathology such as TNF-α, IL-6, and IL-17.

Discussion

Dihydromyricetin is commercially available as a dietary supplement. The results of this proof-of-concept study demonstrate its potential utility and functionality as a cost-effective and safe candidate to combat inflammation and the progression of ALD pathology.