New insights into salvianolic acid A action: Regulation of the TXNIP/NLRP3 and TXNIP/ChREBP pathways ameliorates HFD-induced NAFLD in rats

Reduced methylation of PP2Ac promotes ethanol-induced lipid accumulation through FOXO1 phosphorylation in vitro and in vivo

Although disturbance of the methionine cycle and sequent decrease in hepatic methylation capacity are known to be important factors in the development of alcoholic liver injury, the underlying mechanisms are not fully understood. Here, we investigated the importance of the methylation of protein phosphatase 2A (PP2A) in alcoholic liver disease (ALD). We found that the severity of ethanol-induced liver injury and the extent of demethylation of PP2A catalytic C subunit (PP2Ac) were reduced after treatment with betaine, a methyl donor involved in the methionine-homocysteine cycle. These results suggest that PP2Ac methylation is decreased due to a broad decrease in hepatic methylation capacity after exposure to ethanol. Moreover, we found that the reduction in PP2Ac methylation led to increased degradation of the regulatory Bα subunit, thus promoting the phosphorylation and nuclear exclusion of Forkhead box O1 (FOXO1) and reducing FOXO1 transcriptional activity. Ultimately, the reduced activity of FOXO1 led to increased expression of TXNIP, which caused hepatic lipid accumulation. Our findings suggest that the reduction of PP2A methylation, a result of decrease hepatic methylation capacity, played an important role in ethanol-induced lipid accumulation via down-regulation of PP2A/Bα and FOXO1 phosphorylation.

Salvianolic Acid A Exhibits Anti-Inflammatory and Antiarthritic Effects via Inhibiting NF-κB and p38/MAPK Pathways

INTRODUCTION

Osteoarthritis (OA), a chronic joint disease, combines with massive inflammation and plays a vital role in cartilage degeneration. The main strategy in clinic is controlling inflammation, thereby treating osteoarthritis. Salvianolic acid A (SAA) is a type of phenolic acid, derived from a traditional chinese herbal medicine Danshen that is extensively used clinically.

METHODS AND RESULTS

We observed the anti-inflammatory and antiarthritic effects of SAA in IL-1β-stimulated cells. We found that SAA evidently decreased the expression of mainly inflammatory factors, exerted the remarkable effects of anti-inflammation and anti-arthritis. Furthermore, SAA inhibited the expression of Matrix metalloproteinases (MMP1, MMP13), and ADAMTS-5 and raised the synthesis of collagen II and aggrecan. Additionally, the results indicated that SAA gave rise to the effects by down-regulation of NF-κB and p38/MAPK pathways.

DISCUSSION

Our study demonstrates that SAA may be a promising anti-inflammatory for the treatment of OA in clinic.

Short Exposure to Ethanol Diminishes Caspase-1 and ASC Activation in Human HepG2 Cells In Vitro

This paper discusses how the assembly of pro-caspase-1 and apoptosis-associated speck-like protein containing a caspase-recruitment domain (ASC) in macromolecular protein complexes, inflammasomes, activates caspase-1. The present study investigates the molecular mechanisms of inflammasome activation in HepG2 cells and examines how short exposures to ethanol (EtOH) affect inflammasome activation. HepG2 cells were treated with lipopolysaccharide (LPS), ATP or nigericin (NIG) in a two-step model. After LPS priming, ATP or NIG were added. As inhibitors, sodium orthovanadate (general inhibitor of tyrosine phosphatases), AC-YVAD-CMK (caspase-1 inhibitor) or AZ10606120 (purinergic receptor P2X7R inhibitor) were applied after LPS priming. To monitor the inflammasome activation, the caspase-1 activity, ASC speck formation, reactive oxygen species (ROS) production and cell death were analyzed. To elucidate the mechanistical approach of EtOH to the inflammasome assembly, the cells were treated with EtOH either under simultaneous LPS administration or concurrently with ATP or NIG application. The co-stimulation with LPS and ATP induced a significant ASC speck formation, caspase-1 activation, cell death and ROS generation. The inhibition of the ATP-dependent purinoreceptor P2X7 decreased the caspase-1 activation, whereas sodium orthovanadate significantly induced caspase-1. Additional treatment with EtOH reversed the LPS and ATP-induced caspase-1 activation, ASC speck formation and ROS production. The ASC speck formation and caspase-1 induction require a two-step signaling with LPS and ATP in HepG2 cells. Inflammasome activation may depend on P2X7. The molecular pathway of an acute effect of EtOH on inflammasomes may involve a reduction in ROS generation, which in turn may increase the activity of tyrosine phosphatases.

Salvianolic Acid A Ameliorates Early-Stage Atherosclerosis Development by Inhibiting NLRP3 Inflammasome Activation in Zucker Diabetic Fatty Rats

Salvianolic acid A (SAA), an important bioactive polyphenolic acid found in Salvia miltiorrhiza Bunge, may be used for treating metabolic disorders due to its anti-inflammatory activity. Since chronic inflammation plays an important role in type 2 diabetes mellitus (T2DM) complicated with atherosclerosis (AS), SAA may have beneficial effects on AS. Here, we evaluated the effects of SAA on metabolic disorders in male Zucker diabetic fatty (ZDF) rats induced by a high-fat diet and Vitamin D3 injections. Compared with the model group, the SAA high dosage (1 mg/kg) group exhibited decreased hemoglobin A1C levels but unchanged blood glucose levels. The disrupted lipid profiles were ameliorated by SAA, with significantly decreased levels of blood cholesterol, LDL-C and triglyceride. The protective effects of SAA against early AS were further confirmed by histopathological examination of aortic tissues. In addition, we observed that SAA decreased serum hs-CRP levels and suppressed the activation of NLRP3 inflammasome and NF-κB signaling in aortic tissues of ZDF rats. Collectively, our results demonstrate the potential of SAA to alleviate AS and T2DM in ZDF rats as a result of its anti-inflammatory effects.

Cilostazol ameliorates high free fatty acid (FFA)-induced activation of NLRP3 inflammasome in human vascular endothelial cells

Cardiovascular disease is recognized as a leading cause of death worldwide, but the risk of death is 2-3 times higher for individuals with diabetes. NLRP3 inflammasome activation is a leading pathway of vascular damage, and new treatment methods are needed to reduce NLRP3 inflammasome expression, along with a detailed understanding of how those treatments work. In a series of assays on human vascular endothelial cells that were exposed to high concentrations of free fatty acids (FFA) to induce a diabetes-like environment, we found a significant impact of cilostazol, a vasodilator widely used to treat blood flow problems and well-tolerated medication. To our knowledge, this study is the first to demonstrate the effects of cilostazol in primary human aortic endothelial cells. We found that cilostazol significantly reduced NLRP3 inflammasome activation, as well as the activity of other related and harmful factors, including oxidative stress, expression of NADPH oxidase 4 (NOX-4), thioredoxin-interacting protein (TxNIP), high mobility group box 1 (HMGB-1), interleukin 1β (IL-1β) and IL-18. Cilostazol also protected the functionality of sirtuin 1 (SIRT1), which serves to restrict NLRP3 inflammasome activity, when exposure to FFAs would have otherwise impaired its function. Thus, it appears that cilostazol's mechanism of action in reducing NLRP3 inflammasome activation is an indirect one; it protects SIRT1, which then allows SIRT1 to perform its regulatory job. Cilostazol has potential as an already-available, well-tolerated preventive medication that may alleviate some of the adverse vascular effects of living with diabetes. The findings of the present study lay the groundwork for further research on the potential of cilostazol as a safe and effective treatment against diabetic endothelial dysfunction and vacular disease.

Chemical and pharmacological research on the polyphenol acids isolated from Danshen: A review of salvianolic acids

Danshen, the dried root of Salvia miltiorrhiza Bge, is a common medicinal herb in Traditional Chinese Medicine, which has been used for the treatment of a number of diseases for thousands of years. More than 2000 years ago, the Chinese early pharmacy monograph "Shennong Materia Medica" recorded that Danshen could be used for the treatment of gastrointestinal diseases, cardiovascular diseases, certain gynecological diseases, etc. Since then, Danshen has been widely used clinically in many different prescriptions for many different diseases, especially for the treatment of cardiovascular diseases. Nowadays, many pharmacological studies about the water-soluble components from Danshen have been reported, especially salvianolic acids. It turned out that salvianolic acids showed strong anti-lipid peroxidation and anti-thrombic activities, and among them, SalAA and SalAB were the most potent. This review focused on the achievements in research of salvianolic acids regarding their bioactivities and pharmacological effects. These studies not only shed light on the water-soluble active components of Danshen and their mechanisms at the molecular level, but also provided theoretical information for the development of new medicines from Danshen for the treatment of cardiovascular and cerebrovascular diseases, inflammatory diseases, metabolic diseases, etc.

Chinese Medicinal Herbs Targeting the Gut-Liver Axis and Adipose Tissue-Liver Axis for Non-Alcoholic Fatty Liver Disease Treatments: The Ancient Wisdom and Modern Science

Non-alcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases worldwide. The pathogenesis of NAFLD is complex. Frontline western medicines only ameliorate the symptoms of NAFLD. On the contrary, the uniqueness of Chinese medicine in its interpretation of NAFLD and the holistic therapeutic approach lead to a promising therapeutic efficacy. Recent studies reveal that the gut-liver axis and adipose tissue-liver axis play important roles in the development of NAFLD. Interestingly, with advanced technology, many herbal formulae are found to target the gut-liver axis and adipose tissue-liver axis and resolve the inflammation in NAFLD. This is the first review summarizes the current findings on the Chinese herbal formulae that target the two axes in NAFLD treatment. This review not only demonstrates how the ancient wisdom of Chinese medicine is being interpreted by modern pharmacological studies, but also provides valuable information for the further development of the herbal-based treatment for NAFLD.

Transcriptome sequencing of Salvia miltiorrhiza after infection by its endophytic fungi and identification of genes related to tanshinone biosynthesis

Context: Salvia miltiorrhiza Bunge (Labiatae) is a traditional Chinese herb. Endophytic fungi, which are biotic elicitors, can induce accumulation of secondary metabolites in their host plants.Objective: To analyze the interaction mechanism between S. miltiorrhiza and endophytic fungi.Materials and methods: Endophytic fungi U104 producing tanshinone IIA were isolated from the healthy disease-free tissue of root of S. miltiorrhiza by conventional methods. The endophytic fungus U104 of S. miltiorrhiza was co-cultured with the sterile seedlings of S. miltiorrhiza for 20 d (temp:day/night = 26 °C/18 °C, photoperiod:12/12 h, illuminance:2000 Lx). Transcriptome sequencing of S. miltiorrhiza seedlings after 20 d of co-cultivation was performed using the Illumina platform.Results: A total of 3713 differentially expressed genes (DEGs) were obtained. These different expression genes, such as STPII, LTP2, MYB transcription factors, CNGC, CDPK, Rboh, CaM, MAP2K1/MEK1, WRKY33, SGT1/SGT and Hsp90/htpG, showed that host S. miltiorrhiza had biological defence response in the initial stage of interaction. Under the induction of endophytic fungi, 14 key enzyme genes were up-regulated in the tanshinone biosynthesis pathway: DXS, DXS2, DXR, HMGR3, AACT, MK, PMK, GGPPS2, GPPS, KSL, IDI, IPII, FDPS and CPS.Discussion and conclusions: A total of 14 key genes were obtained from the tanshinone component synthesis and metabolic pathways, providing a reasonable explanation for the accumulation of tanshinone components, an accumulation induced by endophytic fungi, in the host plants. The large amounts of data generated in this study provide a strong and powerful platform for future functional and molecular studies of interactions between host plants and their endophytic fungi.

Mechanisms of beneficial effects of exercise training on non-alcoholic fatty liver disease (NAFLD): Roles of oxidative stress and inflammation

Non-alcoholic fatty liver disease (NAFLD) is a common chronic liver disorder which is associated with accumulation of fats in the liver. It causes a wide variety of pathological effects such as non-alcoholic steatohepatitis (NASH) and cirrhosis, insulin resistance, obesity, hypertension, dyslipidaemia, diabetes and cardiovascular disease. The molecular mechanisms that cause the initiation and progression of NAFLD are not fully understood. Oxidative stress (OS) induced by reactive oxygen species (ROS) and inflammation are likely a significant mechanism which can lead to hepatic cell death and tissue injury. Mitochondrial abnormalities, down-regulation of several antioxidant enzymes, glutathione (GSH) depletion and decreased activity of GSH-dependent antioxidants, accumulation of leukocytes and hepatic inflammation are the major sources of ROS overproduction in NAFLD. Excessive production of ROS suppresses the capacity of other antioxidant defence systems in NAFLD and causes further oxidative damage. Regular exercise can be considered as an effective strategy for treatment of NAFLD. It improves NAFLD by reducing intrahepatic fat content, increasing β-oxidation of fatty acids, inducing hepato-protective autophagy, overexpressing peroxisome proliferator-activated receptor- γ (PPAR-γ), as well as attenuating hepatocyte apoptosis and increasing insulin sensitivity. Exercise training also suppresses ROS overproduction and OS in NAFLD via up-regulation of several antioxidant enzymes and anti-inflammatory mediators. Therefore, an understanding of these molecules and signalling pathways gives us valuable information about NAFLD progression and a method for developing a suitable clinical treatment. This review aimed to evaluate sources of ROS and OS in NAFLD and the molecular mechanisms involved in the beneficial effects of exercises on NAFLD.

Dietary curcumin enhances insulin clearance in diet-induced obese mice via regulation of hepatic PI3K-AKT axis and IDE, and preservation of islet integrity

Background

Although type 2 diabetes mellitus (T2DM) is primarily characterized by sustained high levels of circulating glucose, other factors, such as obesity, chronic inflammation, fatty liver, and islet dysfunction significantly contribute to the development of this disease. To date, curcumin (CUR), a natural polyphenol and primary component of turmeric, shows putative therapeutic properties such as reducing the incidence of obesity-related diseases in mice. However, the mechanism by which CUR regulates insulin levels remains unclear.

Methods

This study investigates how dietary CUR improves insulin clearance and maintains a proper range of circulating insulin level in the diet-induced obesity (DIO) mouse model. Male C57BL/6 J mice were fed a control, a high fat/high sugar (HFS) or a HFS diet containing 0.4% (w/w) curcumin (HFS + CUR) (N = 16 per group) for 16 weeks.

Results

Mice given HFS + CUR had reduced body weight and fat accumulation in the liver and had lower blood insulin levels under fasting conditions compared to mice on HFS alone, resulting from significantly improved insulin clearance via upregulation of hepatic insulin-degrading enzyme (IDE). We also observed restoration of phosphoinositide 3-kinase (PI3K), especially class Ia catalytic subunits, p110α and p110β, and class Ib regulatory subunit, p101, and phosphorylated protein kinase B (AKT) expression levels in liver on HFS + CUR diet. Additionally, HFS + CUR fed mice had significantly smaller islets of Langerhans and increased glucagon contents compared to HFS fed mice, indicating less secretion of insulin in pancreas. The expression of thioredoxin interacting protein (TXNIP), a pro-oxidant and pro-apoptotic protein, was significantly elevated in mouse and human islets cultured under HFS mimicking conditions, which was mitigated by CUR treatment.

Conclusions

CUR supplementation in obese subjects may alleviate the burden imposed by HFS diets. Our data indicate administration of dietary CUR reinstates PI3K, AKT and IDE levels in obese mice. Additionally, CUR treatment preserves islet integrity by downregulation of TXNIP transcription levels. Therefore, dietary CUR may have the potential to serve as a novel therapeutic agent to address the underlying links of obesity and T2DM.

Danshen: a phytochemical and pharmacological overview

Danshen, the dried root or rhizome of Salvia miltiorrhiza Bge., is a traditional and folk medicine in Asian countries, especially in China and Japan. In this review, we summarized the recent researches of Danshen in traditional uses and preparations, chemical constituents, pharmacological activities and side effects. A total of 201 compounds from Danshen have been reported, including lipophilic diterpenoids, water-soluble phenolic acids, and other constituents, which have showed various pharmacological activities, such as anti-inflammation, anti-oxidation, anti-tumor, anti-atherogenesis, and anti-diabetes. This article intends to provide novel insight information for further development of Danshen, which could be of great value to its improvement of utilization.

Effects of combined therapy with resveratrol, continuous and interval exercises on apoptosis, oxidative stress, and inflammatory biomarkers in the liver of old rats with non-alcoholic fatty liver disease

CONTEXT

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder.

OBJECTIVE

Effects of combined therapy with resveratrol, interval and continuous exercises on oxidative stress, inflammation, and apoptosis in the liver of rats with NAFLD.

METHODS

NAFLD rats were organised in patient, saline, resveratrol (RSV), continuous exercise, interval exercise, continuous exercise + RSV, and interval exercise + RSV groups.

RESULTS

Resveratrol supplementation alone or in combination with interval and continuous training significantly decreased malondialdehyde and TNF-α level (p < .05), while the levels of catalase; superoxide dismutase and IL-10 were significantly increased (p < .05). Although RSV alone significantly decreased the percentage of apoptotic cells (17.12%), its combination with interval (10.74%), and continuous (14.85%) exercise training demonstrated higher anti-apoptotic activity (p < .05).

CONCLUSIONS

Although resveratrol alone has an antioxidant, anti-apoptotic and anti-inflammatory properties, combined therapy with interval, and continuous training can be more effective to mitigate these abnormalities in NAFLD patients.

Salvia miltiorrhiza in diabetes: A review of its pharmacology, phytochemistry, and safety

BACKGROUND

Salvia miltiorrhiza (SM), one of the frequently used herbs in traditional Chinese medicine (TCM), has now attracted rising interests for a possible alternative in the management of diabetes. This review is aimed to providing a comprehensive perspective of SM in phytochemical constituents, pharmacological activities against diabetes and its complications, and safety.

METHODS

A comprehensive search of published literatures was conducted to locate original publications pertaining to SM and diabetes till the end of 2017 using PubMed, China National Knowledge Infrastructure, National Science and Technology Library, China Science and Technology Journal Database, and Web of Science database. The main inquiry was used for the presence of the following keywords in various combinations in the titles and abstracts: Salvia miltiorrhiza, diabetes, obesity, phytochemistry, pharmacology, and safety. About 200 research papers and reviews were consulted.

RESULTS

SM exhibited anti-diabetic activities by treating macro- and micro-vascular diseases in preclinical experiments and clinical trials through an improvement of redox homeostasis and inhibition of apoptosis and inflammation via the regulation of Wnt/β-catenin, TSP-1/TGF-β1/STAT3, JNK/PI3K/Akt, kinin B2 receptor-Akt-GSK-3β, AMPKβ/PGC-1α/Sirt3, Akt/AMPK, TXNIP/NLRP3, TGF-β1/NF-κB, mineralocorticoid receptor/Na⁺/K⁺-ATPase, AGEs/RAGE, Nrf2/Keap1, CaMKKβ/AMPK, AMPK/ACC, IRS-1/PI3K signaling pathways, and modulation of K⁺-Ca²⁺ channels, as well as influence of VEGF, NOS, AGEs, PPAR expression and hIAPP aggregation. The antidiabetic effects of this herb may be related to its TCM characters of improving blood circulation and reliving blood stasis. The main ingredients of SM included salvianolic acids and diterpenoid tanshinones, which have been well studied in the diabetic animals. Acute and subacute toxicity studies supported the notion that SM is well tolerated.

CONCLUSION

SM may offer a new strategy for prevention and treatment of diabetes and its complications that stimulates extensive research into identifying potential anti-diabetic compounds and fractions as well as exploring the underlying mechanisms of this herb. Further scientific evidences are still required from well-designed preclinical experiments and clinical trials on its anti-diabetic effects and safety.

Inhibition of Poly(I:C)-Induced Inflammation by Salvianolic Acid A in Skin Keratinocytes

Background

Skin keratinocytes participate actively in inducing immune responses when external pathogens are introduced, thereby contributing to elimination of pathogens. However, in condition where the excessive inflammation is occurred, chronic skin disease such as psoriasis can be provoked.

Objective

We tried to screen the putative therapeutics for inflammatory skin disease, and found that salvianolic acid A (SAA) has an inhibitory effect on keratinocyte inflammatory reaction. The aim of this study is to demonstrate the effects of SAA in poly(I:C)-induced inflammatory reaction in skin keratinocytes.

Methods

We pre-treated keratinocytes with SAA then stimulated with poly(I:C). Inflammatory reaction of keratinocytes was verified using real-time polymerase chain reaction, enzyme-linked immunosorbent assay and Western blot.

Results

When skin keratinocytes were pre-treated with SAA, it significantly inhibited poly (I:C)-induced expression of inflammatory cytokines including interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor-α, and CCL20. SAA inhibited poly(I:C)-induced activation of nuclear factor-κB signaling. And SAA also inhibited inflammasome activation, evidenced by decrease of IL-1β secretion. Finally, SAA markedly inhibited poly(I:C)-induced NLRP3 expression.

Conclusion

These results demonstrate that SAA has an inhibitory effect on poly(I:C)-induced inflammatory reaction of keratinocytes, suggesting that SAA can be developed for the treatment of inflammatory skin diseases such as psoriasis.

The interplay between microbiota-dependent metabolite trimethylamine N-oxide, Transforming growth factor β/SMAD signaling and inflammasome activation in chronic kidney disease patients: A new mechanistic perspective

BACKGROUND

Chronic kidney disease (CKD) signifies a frequently life-threatening condition influencing kidney structure and function. Despite its irrefutable importance, its exact pathogenesis is not completely clarified. However, CKD is known to be associated with accumulated uremic toxins/metabolites, interstitial fibrosis, and systemic inflammation. So we aimed to investigate the role of microbiota-dependent metabolite trimethylamine N-oxide (TMAO), transforming growth factor β (TGFβ)/SMAD signaling, and inflammasome activation in CKD pathogenesis through its different stages.

SUBJECTS AND METHODS

Eighty patients with CKD of stages 2 to 4 in addition 15 healthy control subjects were enrolled. SMAD3 and nucleotide-binding oligomerization domain-, leucine-rich repeat- and pyrin domain-containing 3 (NLRP3) messenger RNA (mRNA) expressions from whole blood were assessed by quantitative real-time polymerase chain reaction (RT-PCR). Serum TGF-β1 and interleukin-1β (IL-1β) levels were estimated by the enzyme-linked immunosorbent assay. Plasma and urinary TMAO levels were measured. Oxidative stress markers were also assessed.

RESULTS

SMAD3 and NLRP3 mRNA expressions were significantly upregulated in patients with CKD. Likewise, serum TGF-β1 and IL-1β levels were significantly elevated in patients with CKD, with increase in plasma and urinary TMAO levels and altered redox status throughout different CKD stages.

CONCLUSION

The study documented that TMAO could be used as a reliable biomarker to evaluate CKD progression; being linked to TGF-β/SMAD signaling, NLRP3 inflammasome activation as well as being a noninvasive applicable technique.

High cholesterol inhibits tendon-related gene expressions in tendon-derived stem cells through reactive oxygen species-activated nuclear factor-κB signaling

Clinical studies have indicated that increased serum cholesterol levels raised the risk of tendinopathy in hypercholesterolemia, but the effect of cholesterol on tendon-derived stem cells (TDSCs) and its underlying mechanism have not been studied. The purpose of this study is to investigate the association between cholesterol and tendinopathy in vitro and in vivo, and its underlying molecular mechanism as well. In TDSCs, the effect of cholesterol was assessed by quantitative polymerase chain reaction, western blot analysis, and immunofluorescence staining. Intracellular levels of reactive oxygen species (ROS) was detected, using flow cytometry. The link between nuclear factor (NF)-κB signaling and the effect of cholesterol was evaluated using a representative IκB kinase (IKK) inhibitor, BAY 11-7082. In addition, Achilles tendons from apolipoprotein E mice fed with a high-fat diet were histologically assessed using hematoxylin and eosin staining and immunohistochemistry. We found that high cholesterol apparently lowered the expression of tendon cell markers (collagen 1, scleraxis, tenomodulin), and elevated ROS levels via the NF-κB pathway both in vitro and in vivo. The ROS scavenger N-acetylcysteine (NAC) and BAY 11-7082 reversed the inhibiting effect of cholesterol on the tendon-related gene expressions of TDSCs. Moreover, NAC blocked cholesterol-induced phosphorylation of IκBα and p65. Significant histological alternation in vivo was shown in Achilles tendon in the hypercholesterolemic group. These results indicated that high cholesterol may inhibit the tendon-related gene expressions in TDSCs via ROS-activated NF-кB signaling, implying pathogenesis of tendinopathy in hypercholesterolemia and suggesting a new mechanism underlying hypercholesterolemia-induced tendinopathy.

Verapamil Attenuated Prediabetic Neuropathy in High-Fat Diet-Fed Mice through Inhibiting TXNIP-Mediated Apoptosis and Inflammation

Diabetic neuropathy (DN) is a common and severe complication of diabetes mellitus. There is still a lack of an effective treatment to DN because of its complex pathogenesis. Thioredoxin-interacting protein (TXNIP), an endogenous inhibitor of thioredoxin, has been shown to be associated with diabetic retinopathy and nephropathy. Herein, we aim to investigate the role of TXNIP in prediabetic neuropathy and therapeutic potential of verapamil which has been shown to inhibit TXNIP expression. The effects of mediating TXNIP on prediabetic neuropathy and its exact mechanism were performed using high-fat diet- (HFD-) induced diabetic mice and palmitate-treated neurons. Our results showed that TXNIP upregulation is associated with prediabetic neuropathy in HFD-fed mice. TXNIP knockdown improved DN in HFD-induced prediabetic mice. Mechanistically, increased TXNIP in dorsal root ganglion is transferred into the cytoplasm and shuttled to the mitochondria. In cytoplasm, TXNIP binding to TRX1 results in the increased oxidative stress and inflammation. In mitochondria, TXNIP binding to TRX2 induced mitochondria dysfunction and apoptosis. TXNIP isolated from TRX2 then shuttles to the cytoplasm and binds to NLRP3, resulting in further increased TXNIP-NLRP3 complex, which induced the release of IL-1β and the development of inflammation. Thus, apoptosis and inflammation of dorsal root ganglion neuron eventually cause neural dysfunction. In addition, we also showed that verapamil, a known inhibitor of calcium channels, improved prediabetic neuropathy in the HFD-fed mice by inhibiting the upregulation of TXNIP. Our finding suggests that TXNIP might be a potential target for the treatment of neuropathy in prediabetic patients with dyslipidemia.

Stressing out the mitochondria: Mechanistic insights into NLRP3 inflammasome activation

Inflammasomes are multimeric protein complexes that induce the cleavage and release of bioactive IL-1β and cause a lytic form of cell death, termed pyroptosis. Due to its diverse triggers, ranging from infectious pathogens and host danger molecules to environmental irritants, the NOD-like receptor protein 3 (NLRP3) inflammasome remains the most widely studied inflammasome to date. Despite intense scrutiny, a universal mechanism for its activation remains elusive, although, recent research has focused on mitochondrial dysfunction or potassium (K⁺ ) efflux as key events. In this review, we give a general overview of NLRP3 inflammasome activation and explore the recently emerging noncanonical and alternative pathways to NLRP3 activation. We highlight the role of the NLRP3 inflammasome in the pathogenesis of metabolic disease that is associated with mitochondrial and oxidative stress. Finally, we interrogate the mechanisms proposed to trigger NLRP3 inflammasome assembly and activation. A greater understanding of how NLRP3 inflammasome activation is triggered may reveal new therapeutic targets for the treatment of inflammatory disease.

Carbohydrate response element binding protein (ChREBP) modulates the inflammatory response of mesangial cells in response to glucose

Diabetic nephropathy (DN) is one of the most devastating complications of diabetes mellitus. Carbohydrate response element binding protein (ChREBP) is a basic helix–loop–helix leucine zipper transcription factor that primarily mediates glucose homeostasis in the body. The present study investigated the role of ChREBP in the pathogenesis of DN. The expression of ChREBP was detected in patients with type 2 diabetes mellitus (T2DM), diabetic mice, and mesangial cells. ELISA was used to measure cytokine production in mesangial cells. Flow cytometry analysis was performed to detect the apoptosis of mesangial cells in the presence of high glucose. The expression levels of ChREBP and several cytokines (TNF-α, IL-1β, and IL-6) were up-regulated in T2DM patients. The mRNA and protein levels of ChREBP were also significantly elevated in the kidneys of diabetic mice. Moreover, glucose treatment promoted mRNA levels of TNF-α, IL-1β, and IL-6 in mesangial cells. Glucose stimulation induced significant apoptosis of SV40 MES 13 cells. In addition, transfection with ChREBP siRNA significantly inhibited ChREBP expression. Consequently, the inflammatory responses and apoptosis were inhibited in SV40 MES 13 cells. These results demonstrated that ChREBP could mediate the inflammatory response and apoptosis of mesangial cells, suggesting that ChREBP may be involved in the pathogenesis of DN.

Salvianolic Acid A Attenuates Endoplasmic Reticulum Stress and Protects Against Cholestasis-Induced Liver Fibrosis via the SIRT1/HSF1 Pathway

Background: Endoplasmic reticulum stress (ER stress) plays a critical role in the pathogenesis of liver fibrosis; thus, it can be a potential therapeutic target of fibrosis. However, the mechanism of ER stress regulation in fibrosis, particularly through sirtuin 1 (SIRT1), remains unclear. The objective of this study was to investigate the effect of SIRT1-mediated inhibition of ER stress in bile duct ligation (BDL)-induced liver fibrosis, and to explore the effect of salvianolic acid A (SalA) on BDL-induced liver fibrosis through SIRT1/heat shock factor 1 (HSF1) signaling. Materials and Methods: We explored the effects of SalA on liver fibrosis and ER stress in BDL-induced liver fibrosis in rats and the human hepatic stellate cell line LX2 cells. The LX2 cells were treated with 20 ng of platelet-derived growth factor-BB homodimer (PDGF-BB) for 24 h, and then incubated in the absence or presence of SalA (25 μM) for 24 h. Results: In vivo, SalA treatment alleviated BDL-induced liver injury and ER stress. Importantly, SalA treatment increased HSF1 expression and activity using a SIRT1-dependent mechanism. In LX2 cells, PDGF-BB induced ER stress and fibrosis were blocked by HSF1 overexpression. Furthermore, SIRT1 siRNA abrogated the SalA-mediated promotion of HSF1 deacetylation and expression, suggesting that SalA-mediated protection occurs by SIRT1 targeting HSF1 for deacetylation. Conclusion: This is the first study to identify the SIRT1/HSF1 pathway as a key therapeutic target for controlling BDL-induced liver fibrosis and to show that SalA confers protection against BDL- and PDGF-BB-induced hepatic fibrosis and ER stress through SIRT1-mediated HSF1 deacetylation.

A comprehensive look at the role of hyperlipidemia in promoting colorectal cancer liver metastasis

Colorectal cancer (CRC) is one of the most malignant cancers, and it tends to migrate to the liver and has a high mortality rate. Several mechanisms behind the metastasis of CRC have been identified, including hyperlipidemia. For example, hyperlipidemia can lead to enhanced stemness and neutrophil infiltration, which increases CRC metastasis. There are three primary aspects to the relationship between hyperlipidemia and CRC metastasis: hyperlipidemia (1) promotes the initial metastatic properties of CRC, (2) stimulates CRC cells to leave the vasculature, and (3) facilitates the development of CRC metastasis. In this study, we provide a comprehensive overview of the role that hyperlipidemia played in CRC metastasis to help reduce the mortality associated with CRC metastasis from the standpoint of metabolic. We also review cancer metastasis.

Investigation on the Use of Traditional Chinese Medicine for Polycystic Ovary Syndrome in a Nationwide Prescription Database in Taiwan

Polycystic ovary syndrome (PCOS) is a common condition, affecting 5⁻10% of women of reproductive age worldwide. It has serious reproductive implications and causes mood disorders and metabolic disorders, such as type-2 diabetes. Because PCOS reflects multiple abnormalities, there is no single drug that can treat all its symptoms. Existing pharmaceutical agents, such as oral contraceptives (OCs), are suggested as a first-line therapy for menstrual irregularities; however, OCs are not appropriate for women pursuing pregnancy. Additionally, insulin-sensitizing agents, which appear to decrease insulin levels and hyperandrogenemia in women with PCOS, have been associated with a high incidence of gastrointestinal adverse effects. It is a common practice in Chinese society to receive traditional Chinese medicine (TCM) for treatment of gynecological problems and infertility. Current research demonstrates that several herbs and herbal formulas show beneficial effects in PCOS treatment. In this study, we conducted the first large-scale survey through the Taiwan National Health Insurance Program database to analyze TCM utilization patterns among women with PCOS in Taiwan during 1997⁻2010. The survey results revealed that 89.22% women with newly diagnosed PCOS had received TCM therapy. Jia-Wei-Xiao-Yao-San and Xiang-Fu (Rhizoma Cyperi) were the most commonly used formula and single herb, respectively, in the database. In addition, we found that the top five commonly prescribed single herbs and herbal formulas have shown promise in treating symptoms associated with PCOS.

Verapamil Ameliorates Hepatic Metaflammation by Inhibiting Thioredoxin-Interacting Protein/NLRP3 Pathways

Activation of thioredoxin-interacting protein (TXNIP)/nod-like receptor protein 3 (NLRP3) inflammasome plays a critical role in pathogenesis of non-alcoholic fatty liver disease. This study investigated the protective effects of verapamil on hepatic metaflammation in a rodent model of high-fat (HF) diet-induced obesity (DIO). DIO was induced in a subset of mice provided with HF diet (45% kcal fat). After 10 weeks of HF diet, verapamil was administered by intraperitoneal injection. The experimental groups included the following: (1) normal diet group, (2) normal diet + treatment with verapamil (VER) group, (3) HF control group, (4) HF+VER (25 mg/kg/day) group. After 1 week of each treatment, blood and liver tissues were collected, and glucose control, serum triglyceride (TG) level, inflammation, and TXNIP/NLRP3 inflammasome were analyzed. Verapamil administration caused no alteration in food intake. HF diet impaired glucose control and increased body weight and serum TG levels. Hepatic inflammation was aggravated in HF-fed mice, as demonstrated by increased levels of pro-inflammatory markers interleukin-1β (IL-1β) and IL-18 in the liver. On the other hand, verapamil administration significantly improved glucose control, body weight, and serum TG levels. Verapamil treatment also reduced pro-inflammatory marker levels. These improvements were accompanied by alterations in activation of TXNIP/NLRP3 inflammasome. The observed results demonstrate that verapamil ameliorates hepatic metaflammation by inhibiting TXNIP/NLRP3 pathways.

Promotion of autophagosome–lysosome fusion via salvianolic acid A-mediated SIRT1 up-regulation ameliorates alcoholic liver disease

Autophagosome and lysosome fusion was restored by salvianolic acid A-mediated SIRT1 up-regulation and protected against chronic ethanol-induced liver injury.

Protective effect of Hua Tan Qu Shi decoction against liver injury in rats with nonalcoholic fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD), is currently a worldwide health problem. None of the existing treatment medications had got a satisfactory effect. Hua Tan Qu Shi (HTQS) decoction is a Chinese herbal formula, which has been used clinically to treat NAFLD for years. However, the underlying mechanisms are still unclear.

METHODS

High-fat diet (HFD) induced non-alcoholic fatty liver disease rats treated with or without HTQS decoction by gavage for 10 weeks and examined by serology, 24-h albuminuria, histology, immunohistochemistry, and molecular analyses.

Carnosic acid protects non-alcoholic fatty liver-induced dopaminergic neuron injury in rats

Non-alcoholic fatty liver disease (NAFLD) has been reported to induce cognitive impairments of hippocampus and may influence central nervous system. In the present study, we investigated whether carnosic acid (CA) ameliorates dopaminergic neuron injury in a rat model of NAFLD. In order to induce NAFLD, rats were fed with high-fat diet (HFD) for 10 weeks. We found that continued CA administration reduced lipid accumulation marked by decreases in alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglyceride (TG), total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels, and an increase in high-density lipoprotein cholesterol (HDL-C) level in the serum. H&E staining revealed that feeding CA reduced lipid droplets accumulation, and alleviated oxidative stress by increasing in superoxide dismutase (SOD) level and decreasing in malondialdehyde (MDA) level in the liver. In addition, by measuring several parameters of gait analysis, we demonstrated that CA treatment ameliorated behavioral impairments, as evidenced by decreased duration and maximum variation, accompanied by increased average speed and cadence. Furthermore, CA treated-animals displayed an increase in the contents of dopamine (DA) and its metabolites 3,4-dihydroxyphenylacelic acid (DOPAC) and elevated the expressions of tyrosine hydroxylase (TH)-positive neurons in the substantia nigra (SN) as well as the TH protein in the striatum. Together, these findings suggest that CA may be an effective agent in protecting rats from NAFLD-induced dopaminergic neuron injury.

Melatonin alleviates cadmium-induced liver injury by inhibiting the TXNIP-NLRP3 inflammasome

Cadmium (Cd) is a persistent environmental and occupational contaminant that accumulates in the liver and induces oxidative stress and inflammation. Melatonin possesses potent hepatoprotective properties against the development and progression of acute and chronic liver injury. Nevertheless, the molecular mechanism underlying the protective effects of melatonin against Cd-induced hepatotoxicity remains obscure. In this study, we aimed to investigate the effects of melatonin on Cd-induced liver inflammation and hepatocyte death. Male C57BL/6 mice were intraperitoneally injected with melatonin (10 mg/kg) once a day for 3 days before exposure to CdCl₂ (2.0 mg/kg). We found that Cd induced hepatocellular damage and inflammatory infiltration as well as increased serum ALT/AST enzymes. In addition, we showed that Cd triggered an inflammatory cell death, which is mediated by the NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome. Moreover, melatonin treatment significantly alleviated Cd-induced liver injury by decreasing serum ALT/AST levels, suppressing pro-inflammatory cytokine production, inhibiting NLRP3 inflammasome activation, ameliorating oxidative stress, and attenuating hepatocyte death. Most importantly, melatonin markedly abrogated Cd-induced TXNIP overexpression and decreased the interaction between TXNIP and NLRP3 in vivo and in vitro. However, treatment with siRNA targeting TXNIP blocked the protective effects of melatonin in Cd-treated primary hepatocytes. Collectively, our results suggest that melatonin confers protection against Cd-induced liver inflammation and hepatocyte death via inhibition of the TXNIP-NLRP3 inflammasome pathway.

Ruscogenin Attenuates Cerebral Ischemia-Induced Blood-Brain Barrier Dysfunction by Suppressing TXNIP/NLRP3 Inflammasome Activation and the MAPK Pathway

Ruscogenin, an important steroid sapogenin derived from Ophiopogon japonicus, has been shown to inhibit cerebral ischemic injury. However, its potential molecular action on blood-brain barrier (BBB) dysfunction after stroke remains unclear. This study aimed to investigate the effects of ruscogenin on BBB dysfunction and the underlying mechanisms in middle cerebral artery occlusion/reperfusion (MCAO/R)-injured mice and oxygen–glucose deprivation/reoxygenation (OGD/R)-injured mouse brain microvascular endothelial cells (bEnd.3). The results demonstrated that administration of ruscogenin (10 mg/kg) decreased the brain infarction and edema, improved neurological deficits, increased cerebral brain flow (CBF), ameliorated histopathological damage, reduced evans blue (EB) leakage and upregulated the expression of tight junctions (TJs) in MCAO/R-injured mice. Meanwhile, ruscogenin (0.1–10 µM) treatment increased cell viability and trans-endothelial electrical resistance (TEER) value, decreased sodium fluorescein leakage, and modulated the TJs expression in OGD/R-induced bEnd.3 cells. Moreover, ruscogenin also inhibited the expression of interleukin-1β (IL-1β) and caspase-1, and markedly suppressed the expression of Nucleotide-binding domain (NOD)-like receptor family, pyrin domain containing 3 (NLRP3) and thiredoxin-interactive protein (TXNIP) in vivo and in vitro. Furthermore, ruscogenin decreased reactive oxygen species (ROS) generation and inhibited the mitogen-activated protein kinase (MAPK) pathway in OGD/R-induced bEnd.3 cells. Our findings provide some new insights into its potential application for the prevention and treatment of ischemic stroke.