A SIRT3/AMPK/autophagy network orchestrates the protective effects of trans-resveratrol in stressed peritoneal macrophages and RAW 264.7 macrophages

Comparison of the predictive value of TyG index and METS-IR for OSA combined with NAFLD: a retrospective observational study based on a physical examination population

BACKGROUND

Obstructive sleep apnoea (OSA), Non-alcoholic fatty liver disease (NAFLD) and insulin resistance (IR) are interlinked. The aim of our study was to investigate the predictive value of metabolic score for insulin resistance (METS-IR) and triglyceride-glucose(TyG) index in relation to OSA combined with NAFLD in physical examination population.

METHODS

This is a retrospective observational study. 329 physical examiners who attended the healthcare centre of the First Affiliated Hospital of Wenzhou Medical University for polysomnography and abdominal ultrasonography (or CT abdominal scanning) from September 2021 to July 2024. Subjects were categorized into two groups according to the presence or absence of combined NAFLD. Logistic regression analysis and restricted cubic spline model (RCS) were used to evaluate the relationship between TyG index and METS-IR and NAFLD. The predictive value of TyG index and METS-IR for NAFLD was determined by receiver operating characteristic curves (ROC curves).

RESULTS

A total of 329 subjects were analyzed. The prevalence of NAFLD increased with increasing TyG index (P for trend < 0.001), and METS-IR showed an increasing-decreasing-increasing trend with NAFLD risk (P for trend < 0.001). RCS analysis showed a dose-response relationship between NAFLD risk and METS-IR (p = 0.012) and a linear relationship with the TyG index (p = 0.078), with a significant increase in the risk of NAFLD when the METS-IR exceeded a threshold of 47.47 (OR = 1). Compared with TyG index (AUC = 0.775, 95% CI: 0.711-0.828), METS-IR (AUC = 0.778, 95% CI: 0.716-0.836) had a higher predictive value for NAFLD in the OSA physical examination population.

CONCLUSIONS

In the OSA population, TyG index and METS-IR had predictive value for the development of NAFLD, with METS-IR being superior to TyG index.

The effect of oxidative stress on the adenosine A2A receptor activity and signalling

The adenosine A2A receptor (A2AR) is a G-protein coupled receptor that has important anti-inflammatory effects in response to some agonists and consequently is considered a therapeutic target. Its activity is affected by local membrane lipid environment and presence of certain phospholipid classes, so studies should be conducted using extraction methods such as styrene maleic acid co-polymers (SMA) that retain the local lipids. Currently, little is known about the effect of oxidative stress, which may arise from inflammation, on the A2AR. Therefore, it was over-expressed in Pichia pastoris, SMA was used to extract the A2AR from cell membranes and its response to ligands was tested in the presence or absence of the radical initiator AAPH or reactive aldehyde acrolein. SMA-extracted A2AR was able to undergo conformational changes, measured by tryptophan fluorescence, in response to its ligands but oxidative treatments had no effect on the structural changes. Similarly, the treatments did not affect temperature-dependent protein unfolding. In contrast, in HEK293 cells expressing the A2AR, oxidative treatments increased cAMP levels in response to the agonist NECA but had no effect on direct activation of adenylate cyclase. Thus, oxidative stress may be a homeostatic mechanism that abrogates inflammation via the A2AR signalling pathway.

Roles of SIRT3 in cardiovascular and neurodegenerative diseases

Sirtuin-3 (SIRT3) in mitochondria has nicotinamide adenine dinucleotide (NAD+)-dependent protein deacetylase activity. As such, SIRT3 is crucial in cardiovascular and neurodegenerative diseases. Advanced proteomics and transcriptomics studies have revealed that SIRT3 expression becomes altered when the heart or brain is affected by external stimuli or disease, such as diabetic cardiomyopathy, atherosclerosis, myocardial infarction, Alzheimer's disease, Huntington's disease, and Parkinson's disease. More specifically, SIRT3 participates in the development of these disorders through its deacetylase activity and in combination with downstream signaling pathways. The paper reviews SIRT3's expression changes, roles, and mechanisms associated with the development of cardiovascular and neurodegenerative diseases. Additionally, strategies targeting SIRT3 to treat or regulate cardiovascular and neurodegenerative disease development are discussed.

A Hepatic Oxidative Metabolite of Palmatine Ameliorates DSS-Induced Ulcerative Colitis by Regulating Macrophage Polarization Through AMPK/NF-κB Pathway

Palmatine (PAL) and berberine are both classified as protoberberine alkaloids, derived from several traditional Chinese herbs such as Coptis chinensis Franch. and Phellodendron chinense Schneid. These compounds are extensively used in treating dysentery and colitis. PAL is one of the crucial quality markers for these plants in the Chinese Pharmacopoeia. A key metabolite of PAL, 8-Oxypalmatine (OPAL), shows favorable anti-inflammatory activity and better safety compared to PAL, though its mechanisms in ulcerative colitis (UC) are not fully understood. This study used a dextran sodium sulfate-induced colitis mouse model to explore OPAL's effects. The results indicated that OPAL provided superior therapeutic effects to those of PAL, alleviating colitis symptoms and reducing colon inflammation by modulating pro-inflammatory (tumor necrosis factor-α, interleukin-1β, and interleukin-6) and anti-inflammatory (transforming growth factor-β and interleukin-10) cytokines. Additionally, OPAL helped rebuild the mucus barrier and upregulated tight junction proteins, thereby restoring intestinal integrity. Notably, OPAL inhibited the M1 macrophages infiltration while promoting M2 macrophage distribution in the colon. Its role in fostering M2 polarization and modulating the inflammatory cytokine profile was further confirmed in vitro. Importantly, the anti-inflammatory effects were primarily linked to AMP-activated protein kinase activation, which subsequently inhibited the nuclear factor-kappa B pathway. These findings highlight OPAL as a crucial active metabolite responsible for the therapeutic effects of PAL against UC, emphasizing its potential as a novel treatment for this condition.

High glucose promotes macrophage switching to the M1 phenotype via the downregulation of STAT-3 mediated autophagy

AIM

Imbalanced M1/M2 macrophage phenotype activation is a key point in diabetic kidney disease (DKD). Macrophages mainly exhibit the M1 phenotype, which contributes to inflammation and fibrosis in DKD. Studies have indicated that autophagy plays an important role in M1/M2 activation. However, the mechanism by which autophagy regulates the macrophage M1/M2 phenotype in DKD is unknown. Thus, the aim of the present study was to explore whether high glucose-induced macrophages switch to the M1 phenotype via the downregulation of STAT-3-mediated autophagy.

METHODS

DKD model rats were established in vivo via the intraperitoneal injection of streptozocin (STZ). The rats were sacrificed at 18 weeks for histological and molecular analysis. RAW264.7 cells were cultured in vitro with 30 mM glucose in the presence or absence of a STAT-3 activator (colivelin) and an autophagy activator (rapamycin). Moreover, M1 and M2 macrophage activation models were established as a control group. Immunofluorescence and Western blot analyses were used to detect the expression of autophagy-related proteins (LC3 and Beclin-1), M1 markers (iNOS and CD11c) and M2 markers (MR and CD206).

RESULTS

In DKD, macrophages exhibit an M1 phenotype. Under high-glucose conditions, RAW264.7 macrophages switched to the M1 phenotype. Autophagy was downregulated in high glucose-induced M1 macrophages. Both the STAT-3 activator and the autophagy activator promoted the transition of glucose-induced M1 macrophages to M2 macrophages. Moreover, STAT-3 activation increased the expression of autophagy markers (LC3 and Beclin-1). However, the autophagy activator had no effect on STAT-3 phosphorylation.

CONCLUSION

High glucose promotes macrophage switching to the M1 phenotype via the downregulation of STAT-3-mediated autophagy.

Simple Preparation and Bone Regeneration Effects of Poly(vinyl alcohol)-Resveratrol Self-Cross-Linked Hydrogels

Hydrogels have broad application prospects in bone repair. Pure poly(vinyl alcohol) (PVA) hydrogels have limited applications because of their low hardness and poor mechanical properties. This study found that resveratrol (Res) and PVA self-assembled and cross-linked through the formation of strong hydrogen bonds after freeze-thawing, forming an easily available PVA-Res supramolecular hydrogel through a green process. PVA-Res hydrogels with different Res wt %:10 wt % PVA ratios were prepared through freeze-thawing and designated as 0.4, 1.2, and 2.0 wt % PVA-Res hydrogels. Rheological studies demonstrated that the viscoelastic modulus of the PVA-Res hydrogels was significantly improved compared to pure PVA hydrogels. The viscoelastic modulus G' of 1.2% PVA-Res hydrogel was 2299 Pa, which was 8.5-fold that of the pure PVA hydrogel. We conducted a study on cell proliferation and osteogenic differentiation using MC3T3-E1 (preosteoblasts from newborn mouse calvaria). The results showed that the 0.4% PVA-Res hydrogel promotes alkaline phosphatase activity and mineral deposition. Real-time quantitative PCR (RT-qPCR) analysis demonstrated that the 0.4% PVA-Res hydrogel upregulated the expression of osteogenic differentiation-related genes (BMP-9, OCN, and ALP). Furthermore, RT-qPCR and flow cytometry demonstrated that the 0.4% PVA-Res hydrogel could effectively promote the M2 transformation and polarization of mouse mononuclear macrophage leukemia cells (Raw 264.7). The expression of related genes, such as Arg-1 and CD206, significantly increased, whereas that of M1 polarization-related genes, such as iNOS and TNF-α, significantly decreased. In summary, PVA-Res supramolecular hydrogels are potential materials for use in bone repair.

Viral myocarditis: From molecular mechanisms to therapeutic prospects

Myocarditis is characterized as local or diffuse inflammatory lesions in the myocardium, primarily caused by viruses and other infections. It is a common cause of sudden cardiac death and dilated cardiomyopathy. In recent years, the global prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the widespread vaccination have coincided with a notable increase in the number of reported cases of myocarditis. In light of the potential threat that myocarditis poses to global public health, numerous studies have sought to elucidate the pathogenesis of this condition. However, despite these efforts, effective treatment strategies remain elusive. To collate the current research advances in myocarditis, and thereby provide possible directions for further research, this review summarizes the mechanisms involved in viral invasion of the organism and primarily focuses on how viruses trigger excessive inflammatory responses and in result in different types of cell death. Furthermore, this article outlines existing therapeutic approaches and potential therapeutic targets for the acute phase of myocarditis. In particular, immunomodulatory treatments are emphasized and suggested as the most extensively studied and clinically promising therapeutic options.

Exosome prospects in the diagnosis and treatment of non-alcoholic fatty liver disease

The growing prevalence of NAFLD and its global health burden have provoked considerable research on possible diagnostic and therapeutic options for NAFLD. Although various pathophysiological mechanisms and genetic factors have been identified to be associated with NAFLD, its treatment remains challenging. In recent years, exosomes have attracted widespread attention for their role in metabolic dysfunctions and their efficacy as pathological biomarkers. Exosomes have also shown tremendous potential in treating a variety of disorders. With increasing evidence supporting the significant role of exosomes in NAFLD pathogenesis, their theragnostic potential has become a point of interest in NAFLD. Expectedly, exosome-based treatment strategies have shown promise in the prevention and amelioration of NAFLD in preclinical studies. However, there are still serious challenges in preparing, standardizing, and applying exosome-based therapies as a routine clinical option that should be overcome. Due to the great potential of this novel theragnostic agent in NAFLD, further investigations on their safety, clinical efficacy, and application standardization are highly recommended.

Molecular crosstalk and putative mechanisms underlying mitochondrial quality control: The hidden link with methylmercury-induced cognitive impairment

Methylmercury (MeHg) is a neurotoxin associated with foetal neurodevelopmental and adult cognitive deficits. Neurons are highly dependent on the tricarboxylic acid cycle and oxidative phosphorylation to produce ATP and meet their high energy demands. Therefore, mitochondrial quality control (MQC) is critical for neuronal homeostasis. While existing studies have generated a wealth of data on the toxicity of MeHg, the complex cascades and molecular pathways governing the mitochondrial network remain to be elucidated. Here, 0.6, 1.2 and 2.4 mg/kg body weight of MeHg were administered intragastrically to pregnant Sprague Dawley rats to model maternal MeHg exposure. The results of the in vivo study revealed that MeHg-treated rats tended to perform more directionless repetitive strategies in the Morris Water Maze and fewer target-orientation strategies than control offspring. Moreover, pathological injury and synaptic toxicity were observed in the hippocampus. Transmission electron microscopy (TEM) demonstrated that the autophagosomes encapsulated damaged mitochondria, while showing a typical mitochondrial fission phenotype, which was supported by the activation of PINK1-dependent key regulators of mitophagy. Moreover, there was upregulation of DRP1 and FIS1. Additionally, MeHg compensation promoted mitochondrial biogenesis, as evidenced by the activation of the mitochondrial PGC1-α-NRF1-TFAM signalling pathway. Notably, SIRT3/AMPK was activated by MeHg, and the expression and activity of p-AMPK, p-LKB1 and SIRT3 were consistently coordinated. Collectively, these findings provide new insights into the potential molecular mechanisms regulating MeHg-induced cognitive deficits through SIRT3/AMPK MQC network coordination.

Exosomes regulate SIRT3-related autophagy by delivering miR-421 to regulate macrophage polarization and participate in OSA-related NAFLD

PURPOSE

To analyze the role of and mechanism underlying obstructive sleep apnea (OSA)-derived exosomes in inducing non-alcoholic fatty liver (NAFLD).

METHODS

The role of OSA-derived exosomes was analyzed in inducing hepatocyte fat accumulation in mice models both in vivo and in vitro.

RESULTS

OSA-derived exosomes caused fat accumulation and macrophage activation in the liver tissue. These exosomes promoted fat accumulation; steatosis was more noticeable in the presence of macrophages. Macrophages could internalize OSA-derived exosomes, which promoted macrophage polarization to the M1 type. Moreover, it inhibited sirtuin-3 (SIRT3)/AMP-activated protein kinase (AMPK) and autophagy and promoted the activation of nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3 (NLRP3) inflammasomes. The use of 3-methyladenine (3-MA) to inhibit autophagy blocked NLRP3 inflammasome activation and inhibited the M1 polarization of macrophages. miR-421 targeting inhibited SIRT3 protein expression in the macrophages. miR-421 was significantly increased in OSA-derived exosomes. Additionally, miR-421 levels were increased in OSA + NAFLD mice- and patient-derived exosomes. In the liver tissues of OSA and OSA + NAFLD mice, miR-421 displayed similar co-localization with the macrophages. Intermittent hypoxia-induced hepatocytes deliver miR-421 to the macrophages via exosomes to inhibit SIRT3, thereby participating in macrophage M1 polarization. After OSA and NAFLD modeling in miR-421-/- mice, liver steatosis and M1 polarization were significantly reduced. Additionally, in the case of miR-421 knockout, the inhibitory effects of OSA-derived exosomes on SIRT3 and autophagy were significantly alleviated. Furthermore, their effects on liver steatosis and macrophage M1 polarization were significantly reduced.

CONCLUSIONS

OSA promotes the delivery of miR-421 from the hepatocytes to macrophages. Additionally, it promotes M1 polarization by regulating the SIRT3/AMPK-autophagy pathway, thereby causing NAFLD.

SIRT3: A potential therapeutic target for liver fibrosis

Sirtuin3 (SIRT3) is a nicotinamide adenine dinucleotide (NAD+)-dependent protein deacetylase located in the mitochondria, which mainly regulates the acetylation of mitochondrial proteins. In addition, SIRT3 is involved in critical biological processes, including oxidative stress, inflammation, DNA damage, and apoptosis, all of which are closely related to the progression of liver disease. Liver fibrosis characterized by the deposition of extracellular matrix is a result of long termed or repeated liver damage, frequently accompanied by damaged hepatocytes, the recruitment of inflammatory cells, and the activation of hepatic stellate cells. Based on the functions and pharmacology of SIRT3, we will review its roles in liver fibrosis from three aspects: First, the main functions and pharmacological effects of SIRT3 were investigated based on its structure. Second, the roles of SIRT3 in major cells in the liver were summarized to reveal its mechanism in developing liver fibrosis. Last, drugs that regulate SIRT3 to prevent and treat liver fibrosis were discussed. In conclusion, exploring the pharmacological effects of SIRT3, especially in the liver, may be a potential strategy for treating liver fibrosis.

Polyphenols: immunonutrients tipping the balance of immunometabolism in chronic diseases

Mounting evidence progressively appreciates the vital interplay between immunity and metabolism in a wide array of immunometabolic chronic disorders, both autoimmune and non-autoimmune mediated. The immune system regulates the functioning of cellular metabolism within organs like the brain, pancreas and/or adipose tissue by sensing and adapting to fluctuations in the microenvironment's nutrients, thereby reshaping metabolic pathways that greatly impact a pro- or anti-inflammatory immunophenotype. While it is agreed that the immune system relies on an adequate nutritional status to function properly, we are only just starting to understand how the supply of single or combined nutrients, all of them termed immunonutrients, can steer immune cells towards a less inflamed, tolerogenic immunophenotype. Polyphenols, a class of secondary metabolites abundant in Mediterranean foods, are pharmacologically active natural products with outstanding immunomodulatory actions. Upon binding to a range of receptors highly expressed in immune cells (e.g. AhR, RAR, RLR), they act in immunometabolic pathways through a mitochondria-centered multi-modal approach. First, polyphenols activate nutrient sensing via stress-response pathways, essential for immune responses. Second, they regulate mammalian target of rapamycin (mTOR)/AMP-activated protein kinase (AMPK) balance in immune cells and are well-tolerated caloric restriction mimetics. Third, polyphenols interfere with the assembly of NLR family pyrin domain containing 3 (NLRP3) in endoplasmic reticulum-mitochondria contact sites, inhibiting its activation while improving mitochondrial biogenesis and autophagosome-lysosome fusion. Finally, polyphenols impact chromatin remodeling and coordinates both epigenetic and metabolic reprogramming. This work moves beyond the well-documented antioxidant properties of polyphenols, offering new insights into the multifaceted nature of these compounds. It proposes a mechanistical appraisal on the regulatory pathways through which polyphenols modulate the immune response, thereby alleviating chronic low-grade inflammation. Furthermore, it draws parallels between pharmacological interventions and polyphenol-based immunonutrition in their modes of immunomodulation across a wide spectrum of socioeconomically impactful immunometabolic diseases such as Multiple Sclerosis, Diabetes (type 1 and 2) or even Alzheimer's disease. Lastly, it discusses the existing challenges that thwart the translation of polyphenols-based immunonutritional interventions into long-term clinical studies. Overcoming these limitations will undoubtedly pave the way for improving precision nutrition protocols and provide personalized guidance on tailored polyphenol-based immunonutrition plans.

Sirtuins in macrophage immune metabolism: A novel target for cardiovascular disorders

Sirtuins (SIRT1-SIRT7), as a family of NAD+-dependent protein modifying enzymes, have various catalytic functions, such as deacetylases, dealkalylases, and deribonucleases. The Sirtuins family is directly or indirectly involved in pathophysiological processes such as glucolipid metabolism, oxidative stress, DNA repair and inflammatory response through various pathways and assumes an important role in several cardiovascular diseases such as atherosclerosis, myocardial infarction, hypertension and heart failure. A growing number of studies supports that metabolic and bioenergetic reprogramming directs the sequential process of inflammation. Failure of homeostatic restoration leads to many inflammatory diseases, and that macrophages are the central cells involving the inflammatory response and are the main source of inflammatory cytokines. Regulation of cellular metabolism has emerged as a fundamental process controlling macrophage function, but its exact signaling mechanisms remain to be revealed. Understanding the precise molecular basis of metabolic control of macrophage inflammatory processes may provide new approaches for targeting immune metabolism and inflammation. Here, we provide an update of studies in cardiovascular disease on the function and role of sirtuins in macrophage inflammation and metabolism, as well as drug candidates that may interfere with sirtuins, pointing to future prospects in this field.

The Role of AMPK Signaling in Ulcerative Colitis

Ulcerative colitis (UC) is a chronic non-specific inflammatory bowel disease characterized by inflammation and ulcer formation of the intestinal mucosa. Due to its high recurrence rate, prolonged course, limited curative options, and significant impact on patients' quality of life, along with a notable potential for malignant transformation, UC is designated as a refractory global health challenge by the World Health Organization (WHO). The elucidation of the pathogenesis and therapeutic strategies for UC requires further in-depth investigation. AMP-activated protein kinase (AMPK) serves as a central regulator of cellular energy metabolic homeostasis. Emerging evidence indicates that interventions involving traditional Chinese medicine (TCM) components, as well as other pharmacological measures, exert beneficial effects on the intestinal mucosal inflammation and epithelial barrier dysfunction in UC by modulating AMPK signaling, thereby influencing biological processes such as cellular autophagy, apoptosis, inflammatory responses, macrophage polarization, and NLRP3 inflammasome-mediated pyroptosis. The role of AMPK in UC is of significant importance. This manuscript provides a comprehensive overview of the mechanisms through which AMPK is involved in UC, as well as a compilation of pharmacological agents capable of activating the AMPK signaling pathway within the context of UC. The primary objective is to facilitate a deeper comprehension of the pivotal role of AMPK in UC among researchers and clinical practitioners, thereby advancing the identification of novel therapeutic targets for interventions in UC.

Sirtuin-3-Mediated Cellular Metabolism Links Cardiovascular Remodeling with Hypertension

Hypertension can cause structural and functional abnormalities in the cardiovascular system, which can be attributed to both hemodynamic and nonhemodynamic factors. These alterations are linked with metabolic changes and are induced by pathological stressors. Sirtuins are enzymes that act as stress sensors and regulate metabolic adaptation by deacetylating proteins. Among them, mitochondrial SIRT3 performs a crucial role in maintaining metabolic homeostasis. Evidence from experimental and clinical studies has shown that hypertension-induced decreases in SIRT3 activity can lead to cellular metabolism reprogramming and, subsequently, increased susceptibility to endothelial dysfunction, myocardial hypertrophy, myocardial fibrosis, and heart failure. This review presents recent research advances in SIRT3-mediated metabolic adaptation in hypertensive cardiovascular remodeling.

Sirtuin 3 regulation: a target to alleviate β-hydroxybutyric acid-induced mitochondrial dysfunction in bovine granulosa cells

BACKGROUND

During the transition period, the insufficient dry matter intake and a sharply increased in energy consumption to produce large quantities of milk, high yielding cows would enter a negative energy balance (NEB) that causes an increase in ketone bodies (KBs) and decrease in reproduction efficiency. The excess concentrations of circulating KBs, represented by β-hydroxybutyric acid (BHBA), could lead to oxidative damage, which potentially cause injury to follicular granulosa cells (fGCs) and delayed follicular development. Sirtuin 3 (Sirt3) regulates mitochondria reactive oxygen species (mitoROS) homeostasis in a beneficial manner; however, the molecular mechanisms underlying its involvement in the BHBA-induced injury of fGCs is poorly understood. The aim of this study was to explore the protection effects and underlying mechanisms of Sirt3 against BHBA overload-induced damage of fGCs.

RESULTS

Our findings demonstrated that 2.4 mmol/L of BHBA stress increased the levels of mitoROS in bovine fGCs. Further investigations identified the subsequent mitochondrial dysfunction, including an increased abnormal rate of mitochondrial architecture, mitochondrial permeability transition pore (MPTP) opening, reductions in mitochondrial membrane potential (MMP) and Ca²⁺ release; these dysfunctions then triggered the caspase cascade reaction of apoptosis in fGCs. Notably, the overexpression of Sirt3 prior to treatment enhanced mitochondrial autophagy by increasing the expression levels of Beclin-1, thus preventing BHBA-induced mitochondrial oxidative stress and mitochondrial dysfunction in fGCs. Furthermore, our data suggested that the AMPK-mTOR-Beclin-1 pathway may be involved in the protective mechanism of Sirt3 against cellular injury triggered by BHBA stimulation.

CONCLUSIONS

These findings indicate that Sirt3 protects fGCs from BHBA-triggered injury by enhancing autophagy, attenuating oxidative stress and mitochondrial damage. This study provides new strategies to mitigate the fGCs injury caused by excessive BHBA stress in dairy cows with ketosis.

The role of Sirt3-induced autophagy in renal structural damage caused by periodontitis in rats

OBJECTIVE

This research aimed to explore the effect of periodontitis on renal tissues injury in rats and the role of Sirtuin3 (Sirt3) and its regulation of autophagy in this progression.

MATERIAL AND METHODS

Thirty Wistar rats were assigned into three groups: control, periodontitis (P), and periodontitis with gavage administration of Sirt3 activator resveratrol (P + RSV). To induce periodontitis, the wire ligature was placed around the cervical region of the rat maxillary first molar. After 8 weeks, micro-computed tomography (Micro-CT) and hematoxylin and eosin (HE) were used to evaluate the alveolar bone resorption and periodontal inflammation. Serum and urine biochemical indicators were measured to assess renal function. The pathological changes of the kidney were observed via HE and periodic acid Schiff (PAS) staining. Autophagosome was viewed by transmission electron microscopy (TEM). Real-time PCR and western blot were used to test expressions of Sirt3 and autophagy indicators in renal and periodontal tissues, including mammalian target of rapamycin (mTOR), phosphor-mTOR (p-mTOR), BECN1 (Beclin-1), and microtubule-associated protein 1 light chain 3 (LC3).

RESULTS

Alveolar bone destruction, resorption, and periodontal inflammation were observed in the P group (compared with the control group), and the above indexes were significantly improved after RSV intervention; the obvious changes in renal tissue structure in the P group were partially recovered after RSV intervention, while renal functional status was not affected (among the three groups); in addition, the levels of Sirt3 and autophagy in kidney and periodontal tissues of P group were inhibited, manifested as a decrease in the number of autophagosomes (renal tissue) and expressions of autophagy marker Beclin-1 and LC3 conversion rate and an increase in the expression of p-mTOR. After Sirt3 activation (RSV), the above indicators were significantly improved.

CONCLUSION

Periodontitis causes renal structural damage in rats, which may be connected to the effect of Sirt3-induced autophagy.

Role of SIRT3 in neurological diseases and rehabilitation training

Sirtuin3 (SIRT3) is a deacetylase that plays an important role in normal physiological activities by regulating a variety of substrates. Considerable evidence has shown that the content and activity of SIRT3 are altered in neurological diseases. Furthermore, SIRT3 affects the occurrence and development of neurological diseases. In most cases, SIRT3 can inhibit clinical manifestations of neurological diseases by promoting autophagy, energy production, and stabilization of mitochondrial dynamics, and by inhibiting neuroinflammation, apoptosis, and oxidative stress (OS). However, SIRT3 may sometimes have the opposite effect. SIRT3 can promote the transfer of microglia. Microglia in some cases promote ischemic brain injury, and in some cases inhibit ischemic brain injury. Moreover, SIRT3 can promote the accumulation of ceramide, which can worsen the damage caused by cerebral ischemia-reperfusion (I/R). This review comprehensively summarizes the different roles and related mechanisms of SIRT3 in neurological diseases. Moreover, to provide more ideas for the prognosis of neurological diseases, we summarize several SIRT3-mediated rehabilitation training methods.

Incorporating Mitochondrial Gene Expression Changes Within a Testable Mathematical Model for Alzheimer’s Disease: Stress Response Modulation Predicts Potential Therapeutic Targets

Background: Alzheimer’s disease is a specific form of dementia characterized by the aggregation of amyloid-β plaques and tau tangles. New research has found that the formation of these aggregates occurs after dysregulation of cellular respiration and the production of radical oxygen species. Proteomic data shows that these changes are also related to unique gene expression patterns. Objective: This study is designed to incorporate both proteomic and gene expression data into a testable mathematical model for AD. Manipulation of this new model allows the identification of potential therapeutic targets for AD. Methods: We investigate the impact of these findings on new therapeutic targets via metabolic flux analysis of sirtuin stress response pathways while also highlighting the importance of metabolic enzyme activity in maintaining proper respiratory activity. Results: Our results indicate that protective changes in SIRT1 and AMPK expression are potential avenues for therapeutics. Conclusion: Combining our mitochondrial gene expression analyses with available protein data allowed the construction of a new mathematical model for AD that provides a useful approach to test the efficacy of potential AD therapeutic targets.

Resveratrol promotes osteogenesis and angiogenesis through mediating immunology of senescent macrophages

Orthopedic implants have been used clinically to restore the functions of the compromised bone tissues, but there is still a relatively high risk of failure for elderly people. A critical reason is pro-inflammatory immune microenvironment created by senescent macrophages with homeostasis imbalance impairs osteogenesis and angiogenesis, two major processes involved in implant osseointegration. The present work proposes to use resveratrol as an autophagy inducing agent to upregulate the autophagy level of senescent macrophages to restore homeostasis, consequently generating a favorable immune microenvironment. The results show 0.1-1 µM of resveratrol can induce autophagy of senescent macrophages, promote cell viability and proliferation, reduce intracellular reactive oxygen species (ROS) level, and polarize the cells to pro-healing M2 phenotype. The immune microenvironment created by senescent macrophages upon resveratrol stimulation can promote osteogenesis and angiogenesis, as manifested by upregulated proliferation, alkaline phosphatase activity, type I collagen secretion, and extracellular matrix mineralization of senescent osteoblasts as well as nitric oxide production, migration, and in vitro angiogenesis of senescent endothelial cells. In addition, resveratrol-loaded silk fibroin coatings can be fabricated on titanium surface through electrophoretic co-deposition and the coatings show beneficial effects on the functions of senescent macrophages. Our results suggest resveratrol can be used as surface additive of titanium implants to promote osseointegration of elderly people though regulating immunology of senescent macrophages.

Correlation between coenzyme Q10 content and the nutrient sensors in AKI induced by Hemiscorpius lepturus envenomation

Introduction: Acute kidney injury (AKI) may have a negative effect on mitochondrial hemostasis and bioenergetics as well as coenzyme Q₁₀ (CoQ₁₀) content. PGC-1α, AMPK, sirtuin 1 (Sirt1), and Sirt3, as the key metabolic regulators under nutritional stress, stimulate energy production via mitochondrial biogenesis during AKI. However, no report is available on the relationship between CoQ₁₀ level and nutrient sensors in the pathophysiology of AKI caused by Hemiscorpius lepturus scorpion envenomation. Methods: Three doses of venoms (1, 5, and 10 mg/kg) were administered by subcutaneous (SC) injection to male albino mice. The animals were sacrificed 1 day or 7 days after administration of venom and their kidneys were collected to analyze gene expression involved in AKI, nutrient sensors, and apoptosis signaling activation by real-time polymerase chain reaction (PCR) and the measurement of CoQ₁₀ level using the High-performance liquid chromatography (HPLC) method. Results: The data indicated a significant decrease in CoQ₁₀ level after the administration of venom in 5 and 10 mg/kg. In addition, 1 day after the treatment, a significant over-expression of Sirt1 (5 and 10 mg/kg) was observed compared with normal mice. Overexpression of Sirt3 occurred 1 day and 7 days after treatment only at the dose of 5.0 mg/kg of venom. Furthermore, over-expression of AMPK as an important mitochondrial energetic sensor happened 1 day and 7 days after the injection of venom (5 mg/kg) (P < 0.01). The significant increase in the gene expression of caspase-9 and 3 after the injection of venom (5 and 10 mg/kg) confirmed the role of cell death signaling. Conclusion: The venom-induced energy-sensing pathways have a key role in gene expression of PGC-1α, AMPK, Sirt3, and CoQ₁₀ content after venom-induced AKI.

The Role of Mitochondrial Dynamin in Stroke

Stroke is one of the leading causes of death and disability in the world. However, the pathophysiological process of stroke is still not fully clarified. Mitochondria play an important role in promoting nerve survival and are an important drug target for the treatment of stroke. Mitochondrial dysfunction is one of the hallmarks of stroke. Mitochondria are in a state of continuous fission and fusion, which are termed as mitochondrial dynamics. Mitochondrial dynamics are very important for maintaining various functions of mitochondria. In this review, we will introduce the structure and functions of mitochondrial fission and fusion related proteins and discuss their role in the pathophysiologic process of stroke. A better understanding of mitochondrial dynamin in stroke will pave way for the development of new therapeutic options.

Mechanisms and Therapeutic Strategies of Viral Myocarditis Targeting Autophagy

Viral myocarditis is caused by infection with viruses or bacteria, including coxsackievirus B3 (CVB3), and is characterized by acute or chronic inflammatory responses in the heart. The mortality associated with severe viral myocarditis is considerable. In some patients, viral myocarditis may develop into dilated cardiomyopathy or heart failure. Autophagy is involved in a wide range of physiological processes, including viral infection and replication. In the present review, we focus on the responses of cardiac tissues, cardiomyocytes, and cardiac fibroblasts to CVB3 infection. Subsequently, the effects of altered autophagy on the development of viral myocarditis are discussed. Finally, this review also examined and assessed the use of several popular autophagy modulating drugs, such as metformin, resveratrol, rapamycin, wortmannin, and 3-methyladenine, as alternative treatment strategies for viral myocarditis.

Macrophage polarization by potential nutraceutical compounds: A strategic approach to counteract inflammation in atherosclerosis

Chronic inflammation represents a main event in the onset and progression of atherosclerosis and is closely associated with oxidative stress in a sort of vicious circle that amplifies and sustains all stages of the disease. Key players of atherosclerosis are monocytes/macrophages. According to their pro- or anti-inflammatory phenotype and biological functions, lesional macrophages can release various mediators and enzymes, which in turn contribute to plaque progression and destabilization or, alternatively, lead to its resolution. Among the factors connected to atherosclerotic disease, lipid species carried by low density lipoproteins and pro-oxidant stimuli strongly promote inflammatory events in the vasculature, also by modulating the macrophage phenotyping. Therapies specifically aimed to balance macrophage inflammatory state are increasingly considered as powerful tools to counteract plaque formation and destabilization. In this connection, several molecules of natural origin have been recognized to be active mediators of diverse metabolic and signaling pathways regulating lipid homeostasis, redox state, and inflammation; they are, thus, considered as promising candidates to modulate macrophage responsiveness to pro-atherogenic stimuli. The current knowledge of the capability of nutraceuticals to target macrophage polarization and to counteract atherosclerotic lesion progression, based mainly on in vitro investigation, is summarized in the present review.

The disbalance of LRP1 and SIRPα by psychological stress dampens the clearance of tumor cells by macrophages

The relationship between chronic psychological stress and tumorigenesis has been well defined in epidemiological studies; however, the underlying mechanism remains underexplored. In this study, we discovered that impaired macrophage phagocytosis contributed to the psychological stress-evoked tumor susceptibility, and the stress hormone glucocorticoid (GC) was identified as a principal detrimental factor. Mechanistically, GC disturbed the balance of the “eat me” signal receptor (low-density lipoprotein receptor-related protein-1, LRP1) and the “don't eat me” signal receptor (signal regulatory protein alpha, SIRPα). Further analysis revealed that GC led to a direct, glucocorticoid receptor (GR)-dependent trans-repression of LRP1 expression, and the repressed LRP1, in turn, resulted in the elevated gene level of SIRPα by down-regulating miRNA-4695-3p. These data collectively demonstrate that stress induces the imbalance of the LRP1/SIRPα axis and entails the disturbance of tumor cell clearance by macrophages. Our findings provide the mechanistic insight into psychological stress-evoked tumor susceptibility and indicate that the balance of LRP1/SIRPα axis may serve as a potential therapeutic strategy for tumor treatment.

Exosomes Derived from ADSCs Attenuate Sepsis-Induced Lung Injury by Delivery of Circ-Fryl and Regulation of the miR-490-3p/SIRT3 Pathway

Sepsis-induced lung injury is a clinical syndrome characterized by injury of alveolar epithelium cells (AECs). Previous investigations illustrate that exosomes secreted from adipose-derived stem cells (ADSCs) have therapeutic effects in a variety of disease treatments, but roles and mechanisms regarding ADSC-derived exosomes in sepsis-induced lung injury are unclear. In this study, high-throughput sequencing was used to explore the molecular delivery of ADSC exosomes. A sepsis-induced lung injury mouse model and a lipopolysaccharide-induced AEC damage model were used for mechanistic analysis. The results showed that ADSC exosomes have high levels of the circular RNA (circ)-Fryl. Downregulation of circ-Fryl suppressed ADSC protective effects exosomes against sepsis-induced lung injury by decreasing apoptosis and inflammatory factor expression. Bioinformatics and luciferase reporting experiments showed that miR-490-3p and SIRT3 are downstream targets of circ-Fryl. miR-490-3p overexpression or SIRT3 silencing reversed ADSC exosome protective effects. Studying the mechanism showed that overexpression of circ-Fryl promoted autophagy activation by inducing SIRT3/AMPK signaling. Autophagy activation can suppress sepsis-induced lung injury by decreasing apoptosis and inflammatory factor expression. Taken together, our results suggest that exosomes derived from ADSCs attenuate sepsis-induced lung injury by delivery of circ-Fryl and regulation of the miR-490-3p/SIRT3 pathway.

Programmable dual responsive system reconstructing nerve interaction with small-diameter tissue-engineered vascular grafts and inhibiting intimal hyperplasia in diabetes

Small-diameter tissue-engineered vascular grafts (sdTEVGs) with hyperglycemia resistance have not been constructed. The intimal hyperplasia caused by hyperglycemia remains problem to hinder the patency of sdTEVGs. Here, inspired by bionic regulation of nerve on vascular, we found the released neural exosomes could inhibit the abnormal phenotype transformation of vascular smooth muscle cells (VSMCs). The transformation was a prime culprit causing the intimal hyperplasia of sdTEVGs. To address this concern, sdTEVGs were modified with an on-demand programmable dual-responsive system of ultrathin hydrogels. An external primary Reactive Oxygen Species (ROS)-responsive Netrin-1 system was initially triggered by local inflammation to induce nerve remolding of the sdTEVGs overcoming the difficulty of nerve regeneration under hyperglycemia. Then, the internal secondary ATP-responsive DENND1A (guanine nucleotide exchange factor) system was turned on by the neurotransmitter ATP from the immigrated nerve fibers to stimulate effective release of neural exosomes. The results showed nerve fibers grow into the sdTEVGs in diabetic rats 30 days after transplantation. At day 90, the abnormal VSMCs phenotype was not detected in the sdTEVGs, which maintained long-time patency without intima hyperplasia. Our study provides new insights to construct vascular grafts resisting hyperglycemia damage.

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VSMCs undergo a phenotypic transformation under high glucose, which lead to intimal hyperplasia in sdTEVGs.

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Neural exosomes could inhibit the abnormal phenotype transformation of VSMCs from contractile to synthetic.

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SdTEVGs with on-demand programmable dual responsive system inhibited intimal hyperplasia in diabetes.

Effects of different intensities of continuous training on vascular inflammation and oxidative stress in spontaneously hypertensive rats

We aimed to study the effects and underlying mechanism of different intensities of continuous training (CT) on vascular inflammation and oxidative stress in spontaneously hypertensive rats (SHR). Rats were divided into five groups (n = 12): Wistar‐Kyoto rats sedentary group (WKY‐S), sedentary group (SHR‐S), low‐intensity CT group (SHR‐L), medium‐intensity CT group (SHR‐M) and high‐intensity CT group (SHR‐H). Changes in body mass, heart rate and blood pressure were recorded. The rats were euthanized after 14 weeks, and blood and vascular tissue samples were collected. Haematoxylin and Eosin staining was used to observe the aortic morphology, and Western blot was used to detect the expression of mesenteric artery proteins. After CT, the mean arterial pressures improved in SHR‐L and SHR‐M and increased in SHR‐H compared with those in SHR‐S. Vascular inflammation and oxidative stress levels significantly subsided in SHR‐L and SHR‐M (p < 0.05), whereas in SHR‐H, only vascular inflammation significantly subsided (p < 0.05), and oxidative stress remained unchanged (p > 0.05). AMPK and SIRT1/3 expressions in SHR‐L and SHR‐M were significantly up‐regulated than those in SHR‐S (p < 0.05). These results indicated that low‐ and medium‐intensity CT can effectively reduce the inflammatory response and oxidative stress of SHR vascular tissue, and high‐intensity CT can improve vascular tissue inflammation but not oxidative stress.

LC3B/p62-mediated mitophagy protects A549 cells from resveratrol-induced apoptosis

AIMS

Complicated mechanisms in cancer cells have been restricting the medicinal value of resveratrol (Res). The mechanisms by which Res exerts its anti-tumor activity in lung cancer cells have diverged among reports in recent years, whether cells choose to undergo autophagic cell death or apoptosis remains controversial. Yet, whether Res-induced autophagic cell death transforms into apoptosis is still unknown, and by which autophagy regulates programmed cell death is still undefined.

MAIN METHODS

Here, A549 cells were treated with Res to investigate the mechanisms of autophagy and apoptosis using western blot, immunofluorescence staining for LC3B.

KEY FINDINGS

Non-canonical autophagy was induced by Res-treatment in a Beclin-1- and ATG5-independent manner, with apoptosis being activated simultaneously. Autophagy induced by Res was activated by rapamycin with decreased apoptosis, suggesting that autophagy may serve as a protective pathway in cells. Mitophagy was found to be induced by Res using fluorescence co-localization of mitochondria with lysosomes. Subsequently, it was identified that mitophagy was mediated by LC3B/p62 interaction and could be inhibited by LC3B knockout and p62 knockdown following increased apoptosis.

SIGNIFICANCE

In conclusion, the current results demonstrate that Res-induced non-canonical autophagy in A549 lung cancer cells with apoptosis activation simultaneously, while LC3B/p62-mediated mitophagy protects tumor cells against apoptosis, providing novel mechanisms about the critical role of mitophagy in regulating cell fate.

Melatonin Attenuates Sepsis-Induced Small-Intestine Injury by Upregulating SIRT3-Mediated Oxidative-Stress Inhibition, Mitochondrial Protection, and Autophagy Induction

Melatonin reportedly alleviates sepsis-induced multi-organ injury by inducing autophagy and activating class III deacetylase Sirtuin family members (SIRT1-7). However, whether melatonin attenuates small-intestine injury along with the precise underlying mechanism remain to be elucidated. To investigate this, we employed cecal ligation and puncture (CLP)- or endotoxemia-induced sepsis mouse models and confirmed that melatonin treatment significantly prolonged the survival time of mice and ameliorated multiple-organ injury (lung/liver/kidney/small intestine) following sepsis. Melatonin partially protected the intestinal barrier function and restored SIRT1 and SIRT3 activity/protein expression in the small intestine. Mechanistically, melatonin treatment enhanced NF-κB deacetylation and subsequently reduced the inflammatory response and decreased the TNF-α, IL-6, and IL-10 serum levels; these effects were abolished by SIRT1 inhibition with the selective blocker, Ex527. Correspondingly, melatonin treatment triggered SOD2 deacetylation and increased SOD2 activity and subsequently reduced oxidative stress; this amelioration of oxidative stress by melatonin was blocked by the SIRT3-selective inhibitor, 3-TYP, and was independent of SIRT1. We confirmed this mechanistic effect in a CLP-induced sepsis model of intestinal SIRT3 conditional-knockout mice, and found that melatonin preserved mitochondrial function and induced autophagy of small-intestine epithelial cells; these effects were dependent on SIRT3 activation. This study has shown, to the best of our knowledge, for the first time that melatonin alleviates sepsis-induced small-intestine injury, at least partially, by upregulating SIRT3-mediated oxidative-stress inhibition, mitochondrial-function protection, and autophagy induction.

Amyloid-β (25-35) regulates neuronal damage and memory loss via SIRT1/Nrf2 in the cortex of mice

Alzheimer's disease (AD) is the most common type of dementia. AD is pathologically characterized by synaptic dysfunction and cognitive decline due to the aggregation of a large amount of amyloid-β (Aβ) protein in the brain. However, recent studies have discovered that the Aβ is produced as an antimicrobial peptide that acts against bacteria and viruses. This has renewed interest in the effect of Aβ on AD. Thus, in this study, we investigated the different concentrations of Aβ_25-35 on neuroprotection and further explore the related mechanisms. Firstly, we detected the cognitive function using the Y-maze test, novel object recognition memory task and Morris water maze test. Then, we analyzed the ultrastructure of synapses and mitochondria, in addition to evaluating SOD levels. We also examined the effect of Aβ_25-35 on the viability and structure of the primary neurons. The western blot analysis was used to measure the protein levels. The results showed that mice treated with high concentration of Aβ_25-35 impaired the learning-memory ability and disordered the structure of neurons and mitochondria. Meanwhile, high concentration of Aβ_25-35 decreased the SIRT1/Nrf2 related antioxidant capacity and induced apoptosis. In contrast, mice treated with low concentration of Aβ_25-35 increased SOD levels and SIRT1/Nrf2 expressions, and induced autophagy. Our data suggest that low concentration of Aβ_25-35 may increase SOD levels through SIRT1/Nrf2 and induce autophagy.

Role of histone deacetylase Sirt3 in the development and regression of atherosclerosis

Atherosclerosis (AS) is the most common cause of death in cardiovascular diseases and poses severe challenges to human life and safety. Epigenetics plays a vital role in every single link of AS. Whereas, how epigenetics regulates its development and regression is still unknown. Sirt3, a recognized histone deacetylase, having been reported to be involved in other acylation processes in recent years, is broadening its role in epigenetic modifications. Sirt3 is an important factor in the normal physiology of blood vessels through deacetylation of mitochondrial proteins and participates in various metabolic activities. Besides, medical research targeting Sirt3 is in full swing as well. This review combining histone deacetylase Sirt3 with AS, aims to clarify the latest progress in the significant role of Sirt3 in the development and regression of AS and to provide a novel prospect for a new regulatory factor and potential intervention target for AS.

Neuroprotective Effect of Cudrania tricuspidata Fruit Extracts on Scopolamine-Induced Learning and Memory Impairment

Cudrania tricuspidata has diverse biological activities, such as antioxidant, anti-inflammatory, anticancer, and neuroprotective effects. This study investigated the protective effects of C. tricuspidata fruit extracts (CTFE) against scopolamine (SCO)-induced neuron impairment. The neuroprotective effects of CTFE on SCO-induced memory dysfunction were confirmed in mice using the Barnes maze test. The results showed that co-treatment of SCO and CTFE increased the stay time in the target zone compared with SCO treatment alone. Similarly, the results obtained by the fear conditioning test revealed that SCO-CTFE co-treatment induced the freezing action time under both the contextual fear condition and the cued fear condition compared with SCO treatment alone. Moreover, we showed that CTFE reduced the SCO-induced acetylcholinesterase (AChE) activity, thereby increasing the acetylcholine concentration in mice hippocampal tissues. Consistent with the improvement of memory and recognition function in vivo, our in vitro results showed that CTFE induced cAMP response element binding protein (CREB) and extracellular regulated kinase 1/2 (ERK1/2) activity in PC12 cells and reduced SCO-induced AChE activity. In addition, the microarray results of the hippocampal tissue support our data showing that CTFE affects gene expressions associated with neurogenesis and neuronal cell differentiation markers such as spp1 and klk6. Overall, CTFE exerts a neuroprotective effect via regulation of the CREB and ERK1/2 signaling pathways and could be a therapeutic candidate for neurodegenerative diseases.

Notoginseng Leaf Triterpenes Ameliorates OGD/R-Induced Neuronal Injury via SIRT1/2/3-Foxo3a-MnSOD/PGC-1α Signaling Pathways Mediated by the NAMPT-NAD Pathway

Background

Cerebral ischemic stroke (CIS) is a common cerebrovascular disease whose main risks include necrosis, apoptosis, and cerebral infarction. But few therapeutic advances and prominent drugs seem to be of value for ischemic stroke in the clinic yet. In the previous study, notoginseng leaf triterpenes (PNGL) from Panax notoginseng stem and leaf have been confirmed to have neuroprotective effects against mitochondrial damages caused by cerebral ischemia in vivo. However, the potential mechanisms of mitochondrial protection have not been fully elaborated yet.

Methods

The oxygen and glucose deprivation and reperfusion (OGD/R)-induced SH-SY5Y cells were adopted to explore the neuroprotective effects and the potential mechanisms of PNGL in vitro. Cellular cytotoxicity was measured by MTT, viable mitochondrial staining, and antioxidant marker detection in vitro.Mitochondrial functions were analyzed by ATP content measurement, MMP determination, ROS, NAD, and NADH kit in vitro. And the inhibitor FK866 was adopted to verify the regulation of PNGL on the target NAMPT and its key downstream.

Results

In OGD/R models, treatment with PNGL strikingly alleviated ischemia injury, obviously preserved redox balance and excessive oxidative stress, inhibited mitochondrial damage, markedly alleviated energy metabolism dysfunction, improved neuronal mitochondrial functions, obviously reduced neuronal loss and apoptosis in vitro, and thus notedly raised neuronal survival under ischemia and hypoxia. Meanwhile, PNGL markedly increased the expression of nicotinamide phosphoribosyltransferase (NAMPT) in the ischemic regions and OGD/R-induced SH-SY5Y cells and regulated the downstream SIRT1/2-Foxo3a and SIRT1/3-MnSOD/PGC-1α pathways. And FK866 further verified that the protective effects of PNGL might be mediated by the NAMPT in vitro.

Conclusions

The mitochondrial protective effects of PNGL are, at least partly, mediated via the NAMPT-NAD+ and its downstream SIRT1/2/3-Foxo3a-MnSOD/PGC-1α signaling pathways. PNGL, as a new drug candidate, has a pivotal role in mitochondrial homeostasis and energy metabolism therapy via NAMPT against OGD-induced SH-SY5Y cell injury.

Cisplatin induced testicular damage through mitochondria mediated apoptosis, inflammation and oxidative stress in rats: impact of resveratrol

The target of this study was to explore the role of mitochondria mediated apoptosis and inflammation in cisplatin-induced testicular damage and to evaluate the ameliorative effect of resveratrol. Adult male Wistar rats were randomly allocated to 4 groups. Group I (Control) received normal saline, Group II (Resveratrol) received resveratrol (50 mg/kg/day), Group III (Cisplatin) received cisplatin (7.5 mg/kg/week, i.p.) and Group IV (Resveratrol + Cisplatin) received resveratrol and cisplatin in the same regimen of treatment. Treatment with resveratrol in Groups II and IV started 48h before cisplatin injection and continued for further 4 successive weeks. Cisplatin-treated rats showed reduced body weight, absolute testes weight and sperm count, motility and viability. On the other hand, cisplatin treatment increased the percentage of sperm abnormalities. It also decreased serum testosterone level, mitochondrial membrane potential while, increased cytochrome C liberation from the mitochondria into the cytosol. The activities of caspase-3 & -9 were increased. The level of TNF-α, IL-6 and Bax were increased whereas Bcl-2 was decreased. Oxidative stress markers were found to increase with a concomitant reduction in the antioxidant enzymes and GSH levels. These results were confirmed by immunohistochemical and histopathological analysis. Contrary to all these results, there were improvements in cisplatin induced testicular damage through attenuation of mitochondria mediated apoptosis, inflammation, and oxidative stress owing to resveratrol pretreatment. Thus, resveratrol, as a potential therapeutic agent, may hold promise in preventing mitochondria mediated apoptosis and inflammation in cisplatin-induced testicular damage in rats.

Mechanism of progression of diabetic kidney disease mediated by podocyte mitochondrial injury

Diabetic kidney disease (DKD) is an important diabetic microvascular complication, which has become the main cause of end-stage renal disease (ESRD) all over the world. It is of great significance to find effective therapeutic targets and improve the prognosis of the disease. Traditionally, it is believed that the activation of the renin-angiotensin-aldosterone system (RAAS) is the main reason for the progression of DKD, but with the progress of research, it is known that the production of proteinuria in patients with DKD is also related to podocyte injury and loss. Many studies have shown that mitochondrial dysfunction in podocytes plays an important role in the occurrence and development of DKD, and oxidative stress is also the main pathway and common hub of diabetes to the occurrence and development of microvascular and macrovascular complications. Thus, the occurrence and progression of DKD is correlated with not only the activation of the RAAS, but also the damage of mitochondria, oxidative stress, and inflammatory mediators. Besides, diabetes-related metabolic disorders can also cause abnormalities in mitochondrial dynamics, autophagy and cellular signal transduction, which are intertwined in a complex way. Therefore, in this review, we mainly explore the mechanism and the latest research progress of podocyte mitochondria in DKD and summarize the main signal pathways involved in them. Thus, it provides feasible clinical application and future research suggestions for the prevention and treatment of DKD, which has important practical significance for the later treatment of patients with DKD.

Theacrine, a purine alkaloid from kucha, protects against Parkinson's disease through SIRT3 activation

BACKGROUND

Oxidative damage of dopaminergic neurons is the fundamental causes of Parkinson's disease (PD) that has no standard cure at present. Theacrine, a purine alkaloid from Chinese tea Kucha, has been speculated to benefit the neurodegeneration in PD, through similar actions to its chemical analogue caffeine, albeit excluding side effects. Theacrine has nowadays gained a lot of interest for its multiple benefits, while the investigations are weak and insufficient.

HYPOTHESIS/PURPOSE

It is well-known that tea has a wide range of functions, especially in the prevention and treatment of neurodegenerative diseases. Theacrine is an active monomer compound in Camellia assamica var. kucha Hung T. Chang & H.S.Wang (Kucha), which appears to be effective and safe in PD therapy. The aim of this study is to examine its actions in diverse PD models and explore the mechanisms.

STUDY DESIGN

For determination of theacrine's effects, we employed diverse oxidative damage-associated PD models, including 6-OHDA-treated rats, MPTP-treated mice/zebrafish and MPP⁺-treated SH-SY5Y cells, and using caffeine, selegiline and depranyl as positve control. For investigation and verification of the mechanisms, we utilized approaches testing mitochondrial function-related parameters and enzyme activity as well as applied gene knockdown and overexpression.

METHODS

We employed behavioral tests including spontaneous activity, pole, swimming, rotarod and gait, immunohistochemistry, HPLC, flow cytometry, immunohistochemistry, Western blot, gene knockdown by siRNA and overexpression by plasmid in this study.

RESULTS

Theacrine is demonstrated to retrieve the loss of dopaminergic neurons and the damages of behavioral performance in multiple animal models of PD (6-OHDA-treated rats and in MPTP-treated mice and zebrafish). The followed data of MPP⁺-treated SH-SY5Y cells indicate that theacrine relieves apoptosis resulted from oxidative damage and mitochondrial dysfunction. Further investigations illustrate that theacrine activates SIRT3 directly. It is of advantage to prevent apoptosis through SIRT3-mediated SOD2 deacetylation that reduces ROS accumulation and restores mitochondrial function. This concept is elaborated by 3TYP that inhibits SIRT3 enzyme activity and knockdown/overexpression of SIRT3 gene, demonstrating a crucial role of SIRT3 in theacrine-benefited dopaminergic neurons.

CONCLUSION

Theacrine prevents apoptosis of dopaminergic neurons through directly activating SIRT3 which deacetylating SOD2 and restoring mitochondrial functions.

New insights into the effects of caffeine on adult hippocampal neurogenesis in stressed mice: Inhibition of CORT-induced microglia activation

Chronic stress-evoked depression has been implied to associate with the decline of adult hippocampal neurogenesis. Caffeine has been known to combat stress-evoked depression. Herein, we aim to investigate whether the protective effect of caffeine on depression is related with improving adult hippocampus neurogenesis and explore the mechanisms. Mouse chronic water immersion restraint stress (CWIRS) model, corticosterone (CORT)-established cell stress model, a coculture system containing CORT-treated BV-2 cells and hippocampal neural stem cells (NSCs) were utilized. Results showed that CWIRS caused obvious depressive-like disorders, abnormal 5-HT signaling, and elevated-plasma CORT levels. Notably, microglia activation-evoked brain inflammation and inhibited neurogenesis were also observed in the hippocampus of stressed mice. In comparison, intragastric administration of caffeine (10 and 20 mg/kg, 28 days) significantly reverted CWIRS-induced depressive behaviors, neurogenesis recession and microglia activation in the hippocampus. Further evidences from both in vivo and in vitro mechanistic experiments demonstrated that caffeine treatment significantly suppressed microglia activation via the A2AR/MEK/ERK/NF-κB signaling pathway. The results suggested that CORT-induced microglia activation contributes to stress-mediated neurogenesis recession. The antidepression effect of caffeine was associated with unlocking microglia activation-induced neurogenesis inhibition.

Dysfunction of ATG7-dependent autophagy dysregulates the antioxidant response and contributes to oxidative stress-induced biological impairments in human epidermal melanocytes

Autophagy is a process involving the self-digestion of components that participates in anti-oxidative stress responses and protects cells against oxidative damage. However, the role of autophagy in the anti-oxidative stress responses of melanocytes remains unclear. To investigate the role of autophagy in human epidermal melanocytes, we knocked down and overexpressed ATG7, the critical gene of autophagy, in normal human epidermal melanocytes. We demonstrated that ATG7-dependent autophagy could affect melanin content of melanocytes by regulating melanogenesis. Moreover, suppression of ATG7-dependent autophagy inhibits proliferation and promotes oxidative stress-induced apoptosis of melanocytes, whereas enhancement of ATG7-dependent autophagy protects melanocytes from oxidative stress-induced apoptosis. Meanwhile, deficiency of ATG7-dependent autophagy results in premature senescence of melanocytes under oxidative stress. Notably, we verified that ATG7-dependent autophagy could alter oxidative stress homeostasis by regulating reactive oxygen species (ROS) production, nuclear factor erythroid 2-related factor 2 (Nrf2) antioxidant pathway, and the activity of several antioxidant enzymes in melanocytes. In conclusion, our study suggested that ATG7-dependent autophagy is indispensable for redox homeostasis and the biological functions of melanocytes, such as melanogenesis, proliferation, apoptosis, and senescence, especially under oxidative stress.

Exogenous NADPH ameliorates myocardial ischemia-reperfusion injury in rats through activating AMPK/mTOR pathway

Our previous study shows that nicotinamide adenine dinucleotide phosphate (NADPH) plays an important role in protecting against cerebral ischemia injury. In this study we investigated whether NADPH exerted cardioprotection against myocardial ischemia/reperfusion (I/R) injury. To induce myocardial I/R injury, rats were subjected to ligation of the left anterior descending branch of coronary artery for 30 min followed by reperfusion for 2 h. At the onset of reperfusion, NADPH (4, 8, 16 mg· kg⁻¹· d⁻¹, iv) was administered to the rats. We found that NADPH concentrations in plasma and heart were significantly increased at 4 h after intravenous administration. Exogenous NADPH (8−16 mg/kg) significantly decreased myocardial infarct size and reduced serum levels of lactate dehydrogenase (LDH) and cardiac troponin I (cTn-I). Exogenous NADPH significantly decreased the apoptotic rate of cardiomyocytes, and reduced the cleavage of PARP and caspase-3. In addition, exogenous NADPH reduced mitochondrial vacuolation and increased mitochondrial membrane protein COXIV and TOM20, decreased BNIP3L and increased Bcl-2 to protect mitochondrial function. We conducted in vitro experiments in neonatal rat cardiomyocytes (NRCM) subjected to oxygen–glucose deprivation/restoration (OGD/R). Pretreatment with NADPH (60, 500 nM) significantly rescued the cell viability and inhibited OGD/R-induced apoptosis. Pretreatment with NADPH significantly increased the phosphorylation of AMPK and downregulated the phosphorylation of mTOR in OGD/R-treated NRCM. Compound C, an AMPK inhibitor, abolished NADPH-induced AMPK phosphorylation and cardioprotection in OGD/R-treated NRCM. In conclusion, exogenous NADPH exerts cardioprotection against myocardial I/R injury through the activation of AMPK/mTOR pathway and inhibiting mitochondrial damage and cardiomyocyte apoptosis. NADPH may be a potential candidate for the prevention and treatment of myocardial ischemic diseases.

SIRT3 Acts as a Positive Autophagy Regulator to Promote Lipid Mobilization in Adipocytes via Activating AMPK

Obesity is increasing at an alarming rate worldwide, which is characterized by the excessive accumulation of triglycerides in adipocytes. Emerging evidence has demonstrated that macroautophagy and chaperone-mediated autophagy (CMA) regulate lipid mobilization and play a key role in energy balance. Sirtuin 3 (SIRT3) is an NAD⁺-dependent deacetylase, which is important in regulating macroautophagy and lipid metabolism. It is still unknown whether SIRT3 modulates macroautophagy and CMA in adipocytes. The current study found that macroautophagy was dynamically regulated during 3T3-L1 adipocyte differentiation, which coincided with SIRT3 expression. In mature adipocytes, overexpression of SIRT3 activated macroautophagy, mainly on lipid droplets (LDs), through activating the AMP-activated protein kinase (AMPK)-unc-51-like kinase 1 (ULK1) pathway, which in turn resulting in smaller LD size and reduced lipid accumulation. Moreover, SIRT3 overexpression induced the formation of perilipin-1 (PLN1)-heat shock cognate 71 kDa protein (HSC70)-lysosome-associated membrane protein 2 (LAMP2) complex, to activate CMA and cause the instability of LDs in adipocytes. In summary, we found SIRT3 is a positive regulator of macroautophagy and CMA in adipocytes, which might be a promising therapeutic target for treatment of obesity and its related metabolic dysfunction.

SIRT3 protects against early brain injury following subarachnoid hemorrhage via promoting mitochondrial fusion in an AMPK dependent manner

Background

Subarachnoid hemorrhage (SAH), an acute cerebrovascular accident, features with its high death and disability rate. Sirtuin3 (SIRT3) is a NAD+ dependent deacetylase which mainly located in mitochondria. Reduced SIRT3 function was indicated to involve in many disorders of central nervous system. Herein, we aimed to explore the neuroprotective effects of SIRT3 on SAH and to furtherly explore the underlying mechanisms.

Methods

Adult C57BL/6 J male mice (8–10 weeks) were used to establish SAH models. The pharmacological agonist of SIRT3, Honokiol (HKL), was injected in an intraperitoneal manner (10 mg/kg) immediately after the operation. Brain edema and neurobehavioral score were assessed. Nissl staining and FJC staining were used to evaluate the extent of neuronal damage. The changes of mitochondria morphology were observed with transmission electron microscopy. Western blot was used for analyzing the protein level of SIRT3 and the downstream signaling molecules.

Result

SIRT3 was downregulated after SAH, and additional treatment of SIRT3 agonist HKL alleviated brain edema and neurobehavioral deficits after SAH. Additionally, electron microscopy showed that HKL significantly alleviated the morphological damage of mitochondria induced by SAH. Further studies showed that HKL could increase the level of mitochondrial fusion protein Mfn1 and Mfn2, thus maintaining (mitochondrial morphology), protecting mitochondrial function and promoting neural survival. While, additional Compound C (CC) treatment, a selective AMPK inhibitor, abolished these protective effects.

Conclusions

Activation of SIRT3 protects against SAH injury through improving mitochondrial fusion in an AMPK dependent manner.

"Shanghuo" increases disease susceptibility: Modern significance of an old TCM theory

ETHNOPHARMACOLOGICAL RELEVANCE

"Shanghuo", a concept based on Traditional Chinese Medicine (TCM) theory, describes a status of Yin-Yang imbalance when Yang overwhelms Yin. The imbalance of Yin-Yang resembles the breaking of homeostasis and manifests by the impaired physiological functions, which leads to the onset, recurrence, and progression of diseases. Since ancient times, Chinese Materia Medica (CMM), such as herbal tea, has been applied as a treatment for "Shanghuo".

AIM OF THE STUDY

This review is aimed to describe the origin of "Shanghuo" from the Yin-Yang theory in TCM, as well as explore the relevance and correlations between "Shanghuo" and diseases susceptibility from the perspective of modern medicine. We also propose several strategies from CMM to improve the status of "Shanghuo" for the purpose of treating diseases.

METHODS

Systematic research of articles with keywords including Shanghuo, Yin-Yang, emotional stress and disease susceptibility was done by using the literature databases (Web of Science, Google Scholar, PubMed, CNKI). Related books, PhD and master's dissertations were also researched. Full scientific plant names were validated by "The Plant List" (www.theplantlist.org).

RESULTS

To date, a large number of publications have reported research on sub-health status, but studies about the theory or intervention of "Shanghuo" are rarely found. The articles we reviewed indicate that accumulated emotional stress is critical for the cause of "Shanghuo". As a status similar to sub-health, "Shanghuo" is also manifested by impaired physiological functions and decreased nonspecific resistance, which increase susceptibility to various diseases. What's more, some studies highlight the importance of TCM treatment towards "Shanghuo" in maintaining normal physiological functions, such as immunity, lipid metabolism and ROS clearance.

CONCLUSIONS

Researches on "Shanghuo" and its mechanism are every rare currently and are in need of investigation in the future. Studies on disease susceptibility recently are mostly about susceptible genes that relate to a few parts of people, however, for most of the people, accumulated emotional stress or other stressors is accountable for the susceptibility of diseases. Given that emotional stress plays an important factor in the causation of "Shanghuo", we reviewed the articles about this relevance and discussed the connection of "Shanghuo" with disease susceptibility in a novel perspective. In addition, we have reviewed the disease susceptibility model of restraint stress from its biochemical manifestation to application in CMM assessment. Although it would be a breakthrough in evaluating CMM efficacy of attenuating disease-susceptibility, understanding the comprehensive theory and establishing more models of "Shanghuo" would be required in further investigation.

Sirt3-dependent deacetylation of COX-1 counteracts oxidative stress-induced cell apoptosis

The mitochondrial complexes are prone to sirtuin (Sirt)3-mediated deacetylation modification, which may determine cellular response to stimuli, such as oxidative stress. In this study, we show that the cytochrome c oxidase (COX)-1, a core catalytic subunit of mitochondrial complex IV, was acetylated and deactivated both in 2,2'-azobis(2-amidinopropane) dihydrochloride-treated NIH/3T3 cells and hydrogen peroxide-treated primary neuronal cells, correlating with apoptotic cell death induction by oxidative stress. Inhibition of Sirt3 by small interfering RNA or the inhibitor nicotinamide induced accumulation of acetylation of COX-1, reduced mitochondrial membrane potential, and increased cell apoptosis. In contrast, overexpression of Sirt3 enhanced deacetylation of COX-1 and inhibited oxidative stress-induced apoptotic cell death. Significantly, rats treated with ischemia/reperfusion injury, a typical oxidative stress-related disease, presented an inhibition of Sirt3-induced hyperacetylation of COX-1 in the brain tissues. Furthermore, K13, K264, K319, and K481 were identified as the acetylation sits of COX-1 in response to oxidative stress. In conclusion, COX-1 was discovered as a new deacetylation target of Sirt3, indicating that the Sirt3/COX-1 axis is a promising therapy target of stress-related diseases.-Tu, L.-F., Cao, L.-F., Zhang, Y.-H., Guo, Y.-L., Zhou, Y.-F., Lu, W.-Q., Zhang, T.-Z., Zhang, T., Zhang, G.-X., Kurihara, H., Li, Y.-F., He, R.-R. Sirt3-dependent deacetylation of COX-1 counteracts oxidative stress-induced cell apoptosis.

Resveratrol decreases CD45+ CD206- subtype macrophages in LPS-induced murine acute lung injury by SOCS3 signalling pathway

Acute lung injury/acute respiratory distress syndrome (ALI/ARDS) are life-threatening condition in critically ill patients. Resveratrol (Res), a natural polyphenol, has therapeutic effect in animal model with ALI; however, whether Res attenuates ALI through modulation of macrophage phenotypes in the animal model remains unknown. We in this study treated LPS-induced murine ALI with 30 mg/kg Res and observed significantly reduced severity of ALI in the Res-treated mice 48 hours after Res treatment. Neutrophil infiltrates were significantly reduced, accompanied with lower infiltration of CD45⁺ Siglec F^- phenotype macrophages, but higher population of CD45⁺ Siglec F⁺ and CD45⁺ CD206⁺ alternatively activated macrophages (M2 cells) in the Res-treated mice with ALI. In addition, the expression of IL-1beta and CXCL15 cytokines was suppressed in the treated mice. However, Res treatment in mice with myeloid cell-restricted SOCS3 deficiency did not significantly attenuate ALI severity and failed to increase population of both CD45⁺ Siglec F⁺ and CD45⁺ CD206⁺ M2 subtype macrophages in the murine ALI. Further studies in wild-type macrophages revealed that Res treatment effectively reduced the expression of IL-6 and CXCL15, and increased the expression of arginase-1, SIRT1 and SOCS3. However, macrophages' lack of SOCS3 expression were resistant to the Res-induced suppression of IL-6 and CXCL15 in vitro. Thus, we conclude that Res suppressed CD45⁺ Siglec F^- and CD45⁺ CD206^- M1 subtype macrophages through SOCS3 signalling in the LPS-induced murine ALI.

Sirtuin Family Members Selectively Regulate Autophagy in Osteosarcoma and Mesothelioma Cells in Response to Cellular Stress

The class III NAD⁺ dependent deacetylases-sirtuins (SIRTs) link transcriptional regulation to DNA damage response and reactive oxygen species generation thereby modulating a wide range of cellular signaling pathways. Here, the contribution of SIRT1, SIRT3, and SIRT5 in the regulation of cellular fate through autophagy was investigated under diverse types of stress. The effects of sirtuins' silencing on cell survival and autophagy was followed in human osteosarcoma and mesothelioma cells exposed to DNA damage and oxidative stress. Our results suggest that the mitochondrial sirtuins SIRT3 and 5 are pro-proliferative under certain cellular stress conditions and this effect correlates with their role as positive regulators of autophagy. SIRT1 has more complex role which is cell type specific and can affect autophagy in both positive and negative ways. The mitochondrial sirtuins (SIRT3 and SIRT5) affect both early and late stages of autophagy, whereas SIRT1 acts mostly at later stages of the autophagic process. Investigation of potential crosstalk between SIRT1, SIRT3, and SIRT5 revealed several feedback loops and a significant role of SIRT5 in regulating SIRT3 and SIRT1. Results presented here support the notion that sirtuin family members play important as well as differential roles in the regulation of autophagy in osteosarcoma vs. mesothelioma cells exposed to DNA damage and oxidative stress, and this can be exploited in increasing the response of cancer cells to chemotherapy.

FOXO3a from the Nucleus to the Mitochondria: A Round Trip in Cellular Stress Response

Cellular stress response is a universal mechanism that ensures the survival or negative selection of cells in challenging conditions. The transcription factor Forkhead box protein O3 (FOXO3a) is a core regulator of cellular homeostasis, stress response, and longevity since it can modulate a variety of stress responses upon nutrient shortage, oxidative stress, hypoxia, heat shock, and DNA damage. FOXO3a activity is regulated by post-translational modifications that drive its shuttling between different cellular compartments, thereby determining its inactivation (cytoplasm) or activation (nucleus and mitochondria). Depending on the stress stimulus and subcellular context, activated FOXO3a can induce specific sets of nuclear genes, including cell cycle inhibitors, pro-apoptotic genes, reactive oxygen species (ROS) scavengers, autophagy effectors, gluconeogenic enzymes, and others. On the other hand, upon glucose restriction, 5′-AMP-activated protein kinase (AMPK) and mitogen activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) -dependent FOXO3a mitochondrial translocation allows the transcription of oxidative phosphorylation (OXPHOS) genes, restoring cellular ATP levels, while in cancer cells, mitochondrial FOXO3a mediates survival upon genotoxic stress induced by chemotherapy. Interestingly, these target genes and their related pathways are diverse and sometimes antagonistic, suggesting that FOXO3a is an adaptable player in the dynamic homeostasis of normal and stressed cells. In this review, we describe the multiple roles of FOXO3a in cellular stress response, with a focus on both its nuclear and mitochondrial functions.

Mechanisms and disease implications of sirtuin-mediated autophagic regulation

Accumulating evidence has indicated that sirtuins are key components of diverse physiological processes, including metabolism and aging. Sirtuins confer protection from a wide array of metabolic and age-related diseases, such as cancer, cardiovascular and neurodegenerative diseases. Recent studies have also suggested that sirtuins regulate autophagy, a protective cellular process for homeostatic maintenance in response to environmental stresses. Here, we describe various biological and pathophysiological processes regulated by sirtuin-mediated autophagy, focusing on cancer, heart, and liver diseases, as well as stem cell biology. This review also emphasizes key molecular mechanisms by which sirtuins regulate autophagy. Finally, we discuss novel insights into how new therapeutics targeting sirtuin and autophagy may potentially lead to effective strategies to combat aging and aging-related diseases.

Synthesis, Characterization and Antioxidant Properties of a New Lipophilic Derivative of Edaravone

As part of a program aimed to obtain antioxidants able to interact with cell membrane, edaravone (EdV, 3-methyl-1-phenyl-2-pyrazolin-5-one), a well-known free radical scavenger, has been modified by alkylation at its allylic position (4) with a C-18 hydrocarbon chain, and the increased lipophilicity has been determined towards the interaction with liposomes. The obtained derivative has been studied by means of density functional theory (DFT) methods in order to characterize its lowest energy conformers and predict its antioxidant properties with respect to the parent compound EdV. The in vitro antioxidant activity of C18-edaravone was studied by means of the α,α-diphenyl-β-picrylhydrazyl (DPPH) assay and in lipid peroxidation experiments performed on artificial lipid membranes using water-soluble as well as lipid-soluble radical initiators. Moreover, since oxidative stress is involved in numerous retinal degenerative diseases, the ability of C18-edaravone to contrast 2,2-azobis (2-amidinopropane hydrochloride) (AAPH)-induced cell death was assessed in adult retinal pigmented epithelium (ARPE-19) cells. Overall, the results demonstrated that the newly synthesized molecule has a high affinity for lipid membrane, increasing the efficacy of the unmodified edaravone under stress conditions.

miR-23b-3p regulates apoptosis and autophagy via suppressing SIRT1 in lens epithelial cells

Age-related cataract is one of the prior causes of blindness and the incidence rates of cataract are even rising. Oxidative stress plays an important role in the pathogenesis of cataracts. Under oxidative stress, lens epithelial cell (LEC cell) apoptosis is activated, which might lead to the opacity of the lens and accelerate the progression of cataract development. Meanwhile, autophagy is also active to face oxidative stress. miRNAs have been reported to involve cataract. However, the underlying mechanism is not clear. The present study aimed to investigate the regulatory effect of miR23b-3p on apoptosis and autophagy in LEC cells under oxidative stress. The expression levels of miR-23b-3p were examined in age-related cataract tissues and LEC cells treated with hydrogen peroxide, showing that miR23b-3p expression levels were upregulated. Knockdown of miR23b-3p expression in LEC cells brought about apoptosis significantly decreased while autophagy significantly increased during hydrogen peroxide. We predicted microRNA miRNA-23b-3p might participate in regulating silent information regulator 1 (SIRT1) by bioinformatics database of TargetScan. Luciferase reporter assays confirmed that miRNA-23b-p could suppress SIRT1 expression by binding its 3'UTR. In addition, overexpression or knockdown of miR-23b-3p could decrease or increase SIRT1 expression, which indicated that Mir-23b-3p could suppress SIRT1 expression. In addition, enhanced SIRT1 could attenuate the regulation of cell apoptosis and autophagy induced by overexpression of miR-23b-3p. Taken together, our findings revealed that miR-23b-3p regulated apoptosis and autophagy via suppressing SIRT1 in LEC cell under oxidative stress, which could provide new ideas for clinical treatment of cataract.