Vascular Electrical Stimulation with Wireless, Battery-Free, and Fully Implantable Features Reduces Atherosclerotic Plaque Formation Through Sirt1-Mediated Autophagy.

Electrical stimulation (ES) is a safe and effective procedure in clinical rehabilitation with few adverse effects. However, studies on ES for atherosclerosis (AS) are scarce because ES does not provide a long-term intervention for chronic disease processes. Battery-free implants and surgically mounted them in the abdominal aorta of high-fat-fed Apolipoprotein E (ApoE-/- ) mice are used, which are electrically stimulated for four weeks using a wireless ES device to observe changes in atherosclerotic plaques. Results showed that there is almost no growth of atherosclerotic plaque at the stimulated site in AopE-/- mice after ES. RNA-sequencing (RNA-seq) analysis of Thp-1 macrophages reveal that the transcriptional activity of autophagy-related genes increase substantially after ES. Additionally, ES reduces lipid accumulation in macrophages by restoring ABCA1- and ABCG1-mediated cholesterol efflux. Mechanistically, it is demonstrated that ES reduced lipid accumulation through Sirtuin 1 (Sirt1)/Autophagy related 5 (Atg5) pathway-mediated autophagy. Furthermore, ES reverse autophagic dysfunction in macrophages of AopE-/- mouse plaques by restoring Sirt1, blunting P62 accumulation, and inhibiting the secretion of interleukin (IL)-6, resulting in the alleviation of atherosclerotic lesion formation. Here, a novel approach is shown in which ES can be used as a promising therapeutic strategy for AS treatment through Sirt1/Atg5 pathway-mediated autophagy.

SIRT1 as a Potential Therapeutic Target for Chronic Obstructive Pulmonary Disease.

Chronic obstructive pulmonary disease (COPD) is a common, preventable, and treatable disease characterized by irreversible airflow obstruction and lung function decline. It is well established that COPD represents a major cause of morbidity and mortality globally. Due to the substantial economic and social burdens associated with COPD, it is necessary to discover new targets and develop novel beneficial therapies. Although the pathogenesis of COPD is complex and remains to be robustly elucidated, numerous studies have shown that oxidative stress, inflammatory responses, cell apoptosis, autophagy, and aging are involved in the pathogenesis of COPD. Sirtuin 1 (SIRT1) is a nicotinamide adenine dinucleotide (NAD+)-dependent deacetylase belonging to the silent information regulator 2 (Sir2) family. Multiple studies have indicated that SIRT1 plays an important role in oxidative stress, apoptosis, inflammation, autophagy, and cellular senescence, which contributes to the pathogenesis and development of COPD. This review aimed to discuss the functions and mechanisms of SIRT1 in the progression of COPD and concluded that SIRT1 activation might be a potential therapeutic strategy for COPD.

Epithelial-mesenchymal transition and cancer stem cells: A route to acquired cisplatin resistance through epigenetics in HNSCC.

Chemoresistance is associated with tumor recurrence, metastases, and short survival. Cisplatin is one of the most used chemotherapies in cancer treatment, including head and neck squamous cell carcinoma (HNSCC), and many patients develop resistance. Here, we established cell lines resistant to cisplatin to better understand epigenetics and biological differences driving the progression of HNSCC after treatment. Cisplatin resistance was established in CAL-27 and SCC-9 cell lines. Gene expression of HDAC1, HDAC2, SIRT1, MTA1, KAT2B, KAT6A, KAT6B, and BRD4 indicated the cisplatin activates the epigenetic machinery. Increases in tumor aggressiveness were detected by BMI-1 and KI-67 in more resistant cell lines. Changes in cellular shape and epithelial-mesenchymal transition (EMT) activation were also observed. HDAC1 and ZEB1 presented an opposite distribution with down-regulation of HDAC1 and up-regulation of ZEB1 in the course of chemoresistance. Up-regulation of ZEB1 and BMI-1 in patients with HNSCC is also associated with a poor response to therapy. Cancer stem cells (CSC) population increased significantly with chemoresistance. Down-regulation of HDAC1, HDAC2, and SIRT1 and accumulation of Vimentin and ZEB1 were observed in the CSC population. Our results suggest that in the route to cisplatin chemoresistance, epigenetic modifications can be associated with EMT activation and CSC accumulation which originate more aggressive tumors.

L-limonene reduces aortic artery atherosclerosis by inhibiting oxidative stress/inflammatory responses in diabetic rats fed high-fat diet.

Atherosclerosis, a leading cause of mortality worldwide, is driven by multiple risk factors such as diabetes. Oxidative stress and inflammation assist interrelated roles in diabetes-accelerated atherosclerosis. Thereby, treatment of diabetic atherosclerosis from an oxidative stress/inflammatory perspective seems to be a more effective modality to prevent and delay plaque formation and progression. This study aimed to evaluate the effects of l-limonene (LMN) on oxidative stress/inflammatory responses in the aortic artery of diabetic atherosclerosis-modeled rats. Male Wistar rats (n = 30, 250-280 g, 12 weeks old) were used to establish a diabetic atherosclerosis model (8 weeks) using high-fat diet/low-dose streptozotocin. LMN (200 mg/kg/day) was administered orally, starting on day 30th before tissue sampling. Plasma lipid profiles, aortic histopathological changes, atherogenic index, aortic artery levels of oxidative stress markers (manganese superoxide dismutase, glutathione, and 8-isoprostane), inflammatory markers (tumor necrosis factor-alpha, interleukin (IL)-6, and IL-10), and expression of phosphorylated adenosine monophosphate-activated protein kinase (p-AMPK)/AMPK, Sirtuin 1 (SIRT1), and p-p65/p65 proteins were evaluated. The administration of LMN to diabetic rats improved lipid profiles, aortic histopathological morphology, and atherogenic index (P < 0.05 to P < 0.001). It also increased enzymatic antioxidant activities, decreased 8-isoprostane level, suppressed inflammatory response, upregulated p-AMPK and SIRT1 proteins, and downregulated p-p65 protein (P < 0.05 to P < 0.01). Inhibiting the AMPK through the administration of compound C significantly abolished or reversed the positive effects of LMN in diabetic rats (P < 0.05 to P < 0.01). LMN treatment had dual anti-oxidative and anti-inflammatory actions against atherosclerosis in the aortic artery of diabetic rats. Atheroprotection by LMN was mediated partly through modulation of AMPK/SIRT1/p65 nuclear factor kappa B signaling pathway. LMN appears to be a promising anti-atherosclerotic modality to improve the quality of life in diabetic patients.

Adipocytes-derived exosomal miR-122 promotes non-alcoholic fat liver disease progression via targeting Sirt1.

AIMS: Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease that affects adipose function. This study aimed to explore the function of adipocytes-derived exosomal (ADEs) miR-122 in NAFLD. METHODS: A high-fat and high-fructose diet-induced rat model and a palmitic acid (PA)-induced in vitro model were established. The RNA level of miR-122 and Sirt1 was measured using qRT-PCR. The protein levels of exosome biomarkers, and lipogenesis, inflammation and fibrosis biomarkers were determined by western blotting. Cell viability and apoptosis were assessed using cell counting kit-8 and flow cytometry, respectively. Serum alanine aminotransferase, aspartate aminotransferase, total cholesterol, triglyceride levels were measured. Liver tissue damage was assessed using haematoxylin and eosin staining. The interaction between miR-122 and Sirt1 3'UTR was assessed using a luciferase reporter gene assay. RESULTS: ADEs exhibited abundant level of miR-122 and promoted lipogenesis, impaired hepatocyte survival, enhanced liver damage and increased serum lipid levels in vivo and in vitro. Inhibition of miR-122 in ADEs alleviated NAFLD progression, lipid and glucose metabolism, liver inflammation and fibrosis both in vivo and in vitro. miR-122 binds directly to the 3'UTR of Sirt1 to suppress its expression. Moreover, Sirt1 overexpression reversed the increase in cell apoptosis, glucose and lipid metabolism, liver inflammation and fibrosis induced by ADEs in vivo and in vitro. CONCLUSIONS: The ADEs miR-122 promotes the progression of NAFLD via modulating Sirt1 signalling in vivo and in vitro. The ADEs miR-122 may be a promising diagnostic biomarker and therapeutic target for NAFLD.

Molecular mechanisms of doxorubicin-induced cardiotoxicity: novel roles of sirtuin 1-mediated signaling pathways.

Doxorubicin (DOX) is an anthracycline chemotherapy drug used in the treatment of various types of cancer. However, short-term and long-term cardiotoxicity limits the clinical application of DOX. Currently, dexrazoxane is the only approved treatment by the United States Food and Drug Administration to prevent DOX-induced cardiotoxicity. However, a recent study found that pre-treatment with dexrazoxane could not fully improve myocardial toxicity of DOX. Therefore, further targeted cardioprotective prophylaxis and treatment strategies are an urgent requirement for cancer patients receiving DOX treatment to reduce the occurrence of cardiotoxicity. Accumulating evidence manifested that Sirtuin 1 (SIRT1) could play a crucially protective role in heart diseases. Recently, numerous studies have concentrated on the role of SIRT1 in DOX-induced cardiotoxicity, which might be related to the activity and deacetylation of SIRT1 downstream targets. Therefore, the aim of this review was to summarize the recent advances related to the protective effects, mechanisms, and deficiencies in clinical application of SIRT1 in DOX-induced cardiotoxicity. Also, the pharmaceutical preparations that activate SIRT1 and affect DOX-induced cardiotoxicity have been listed in this review.

Influence of narrow-band ultraviolet B therapy on sirtuin 1 expression in lesional skin of patients with chronic plaque psoriasis: Relation to clinical improvement and interferon-γ expression.

BACKGROUND: Reduced sirtuin 1 (Sirt1) expression in psoriasis was previously reported, and its activation was associated with disease improvement. Narrow-band ultraviolet B (NB-UVB) downregulates several pro-inflammatory cytokines such as interferon-γ (IFN-γ) and influences keratinocyte differentiation in psoriasis. OBJECTIVES: The aim of this study was to study the in vivo influence NB-UVB treatment on Sirt1 expression in psoriatic skin in relation to disease improvement and IFN-γ expression. METHODS: Twenty-six patients with chronic plaque psoriasis were evaluated, and psoriasis area severity index (PASI) was calculated. Skin biopsies were taken from lesional skin of the patients before and after 3 months of treatment with NB-UVB and from 26 controls, where the distribution and immunohistochemistry (IHC) scores of Sirt1 and IFN-γ were determined. RESULTS: After 3 months of treatment, Sirt1 distribution and epidermal IHC score were significantly higher, whereas Sirt1 dermal IHC score and IFN-γ distribution, epidermal and dermal IHC scores were significantly lower than the pre-treatment values. Before and after 3 months of NB-UVB therapy, PASI showed a significant negative correlation with Sirt1 distribution and epidermal IHC score; and a significant positive correlation with interferon-γ distribution and epidermal IHC score. Moreover, Sirt1 distributions were negatively correlated with the corresponding interferon-γ distributions. Conclusions The detected upregulation of epidermal Sirt1 following NB-UVB therapy possibly represents another mechanism by which NB-UVB can act in psoriasis and also highlights the role of Sirt1 upregulation in psoriasis treatment.

6-Gingerol, a functional polyphenol of ginger, reduces pulmonary fibrosis by activating Sirtuin1.

Pulmonary fibrosis in general is the final common outcome of various interstitial lung diseases. In recent years, the incidence of pulmonary fibrosis has been rising with poor prognosis. 6-gingerol is deemed as a functional polyphenol of ginger. The aim of the present study was to investigate the effect of 6-gingerol, on pulmonary fibrosis. Mice were randomly divided into four groups: control, bleomycin, bleomycin + 6-gingerol 100 mg/kg, bleomycin + 6-gingerol 250 mg/kg, and the survival rates of the groups were recorded. Pathological and fibrotic changes in the lungs were identified by H&E and Masson staining, respectively. The levels of hydroxyproline and protein deposited in lung tissues were then, respectively, determined by colorimetry and western blotting. Subsequently, the proportion of cells and inflammatory factors in the alveolar lavage fluid were estimated. Following the identification of the possibility of Sirtuin1 (SIRT1) in the pharmacological mechanism through molecular docking and western blotting, human embryonic lung fibroblasts MRC-5 were treated with TGF-ß1 and SIRT1 inhibitor to study the role of SIRT1 in the regulatory effect of 6-gingerol. From the results, 6-gingerol was found to increase the survival rate of mice and reduce lung pathology and fibrosis in mice. And, it significantly reduced the levels of hydroxyproline and the proteins deposited in lung tissues. Moreover, the number of neutrophils, basophils, monocytes, and the levels of inflammatory factors in the alveolar lavage fluid were also reduced. SIRT1 inhibitor blocked the function of 6-gingerol to inhibit fibrosis. To sum up, 6-gingerol relieves pulmonary fibrosis via activating SIRT1. This finding expands the pharmacological effect of 6-gingerol, and it is expected to advance the development of treatments for pulmonary fibrosis.

Mitoquinone intravitreal injection ameliorates retinal ischemia-reperfusion injury in rats involving SIRT1/Notch1/NADPH axis.

Retinal ischemia-reperfusion injury (RIRI) is an important pathological process of many ocular diseases. Mitoquinone (MitoQ), a mitochondrial targeted antioxidant, is a potential compound for therapeutic development of RIRI. This study observed the effect of MitoQ on RIRI, and further explored its possible molecular mechanism. Temporary increase in intraocular pressure was used to establish rat model of RIRI to observe the effect of MitoQ treatment on retinal function, pathological injury, oxidative stress, inflammation and apoptosis. Immunohistochemistry and Western blot were used to detect expressions of cleaved caspase 3, B cell leukemia/lymphoma 2 associated X (Bax), nicotinamide adenine dinucleotide phosphate oxidase (NOX1), NOX4, cleaved-Notch 1, hairy and enhancer of split 1 (Hes1), and sirtuin 1 (SIRT 1) in retina were detected by immunohistochemistry and Western blot. MitoQ treatment significantly improved retinal function and pathological injury, inhibited the over-production of reactive oxygen species, increased the expression of superoxide dismutase 1 (SOD 1), suppressed the releases of inflammatory cytokines, and inhibited retinal cells apoptosis. MitoQ also down-regulated the expressions of cleaved caspase 3, Bax, NOX 1, NOX 4, cleaved-Notch 1, and Hes 1, increased the expression of SIRT 1 protein and its activity. These effects were significantly reversed by SIRT1 inhibitor EX527. Our data suggests that MitoQ, as a potentially effective drug for improving RIRI, may act through the SIRT1/Notch1/NADPH signal axis.

SIRT1 attenuates murine allergic rhinitis by downregulated HMGB 1/TLR4 pathway.

Conventional allergic rhinitis (AR) treatments have limitations due to the lack of safety and complete cure strategy. We evaluated the effects of silent information regulator 1 (SIRT1), a multifunctional molecule involved in a variety of inflammatory pathways, on murine AR model. Ovalbumin (OVA)-induced murine model was constructed, and recombinant SIRT1 was administered into the nostril continuously. The expression of SIRT1 was measured at mRNA and protein levels, and the allergic symptoms were evaluated. Protein levels of OVA-specific IgE, leukotriene C4 (LTC4), eosinophil cation protein (ECP), prostaglandin D2 (PGD2), as well as different inflammatory cytokine mediators in the serum and nasal lavage fluid (NLF), were assessed by ELISA. The effects of SIRT1 on human primary nasal epithelial cells challenged with tumour necrosis factor (TNF)-α were also evaluated by investigating the HMGB1/TLR4 signalling pathway. Administration of SIRT1 significantly alleviated OVA-induced AR symptoms with lower numbers of sneezing and nasal rubbing events, decreased levels of OVA-specific IgE, LTC4, ECP, PGD2, less inflammatory cells and downregulated levels of Th2 type cytokines. SIRT1 also reduced the genes of HMGB1/TLR4 signalling pathway in the murine model and cultured human nasal epithelial cells. Expression of SIRT1 is impaired in OVA-induced AR model. The administration of SIRT1 alleviates the allergic symptoms of mice, regulates the production of pro-inflammatory mediators predominantly produced by Th2 cells in AR and attenuates expressions of proteins relevant to HMGB1/TLR4 signalling pathway. All the results showed that SIRT1 is promising as a therapeutic agent of AR.

Nephroprotective effect of Ginsenoside Rg1 in lipopolysaccharide-induced sepsis in mice through the SIRT1/NF-κB signaling.

INTRODUCTION: During sepsis, the kidney is one of the most vulnerable organs. Sepsis-associated acute kidney injury (S-AKI) is hallmarked by renal inflammation, apoptosis, and oxidative injury. Ginsenoside Rg1 (Rg1) is a natural product that possesses abundant pharmacological actions and protects against many sepsis-related diseases. Nevertheless, its role and related mechanism in S-AKI remain to be determined. MATERIALS AND METHODS: S-AKI was induced using lipopolysaccharide (LPS, 10 mg/kg) via a single intraperitoneal injection. Rg1 (200 mg/kg) was intraperitoneally administered for 3 consecutive days before LPS treatment. For histopathological examination, murine kidney tissues were stained with hematoxylin and eosin. Tubular injury score was calculated to evaluate kidney injury. Serum creatinine and BUN levels were measured for assessing renal dysfunction. The levels and activities of oxidative stress markers (MDA, 4-HNE, PC, GSH, SOD, and CAT) in renal tissue were measured by corresponding kits. Renal cell apoptosis was detected by TUNEL staining. The protein levels of apoptosis-related markers (Bcl-2, Bax, and Cleaved caspase-3), proinflammatory factors, SIRT1, IκBα, p-NF-κB p65, and NF-κB p65 in kidneys were determined using western blotting. Immunofluorescence staining was employed to assess p-NF-κB p65 expression in renal tissues. RESULTS: LPS-induced injury of kidneys and renal dysfunction in mice were ameliorated by Rg1. Rg1 also impeded LPS-evoked renal cell apoptosis in kidneys. Moreover, Rg1 attenuated LPS-triggered inflammation and oxidative stress in kidneys by inhibiting proinflammatory cytokine release, enhancing antioxidant levels and activities, and reducing lipid peroxidation. However, all these protective effects of Rg1 in LPS-induced AKI mice were reversed by EX527, an inhibitor of sirtuin 1 (SIRT1). Mechanistically, Rg1 upregulated SIRT1 protein expression, increased SIRT1 activity, and inactivated NF-κB signaling in the kidney of LPS-induced AKI mice, which was also reversed by EX527. CONCLUSIONS: Rg1 ameliorates LPS-induced kidney injury and suppresses renal inflammation, apoptosis, and oxidative stress in mice via regulating the SIRT1/NF-κB signaling.

Qiliqiangxin: A multifaceted holistic treatment for heart failure or a pharmacological probe for the identification of cardioprotective mechanisms?

The active ingredients in many traditional Chinese medicines are isoprene oligomers with a diterpenoid or triterpenoid structure, which exert cardiovascular effects by signalling through nutrient surplus and nutrient deprivation pathways. Qiliqiangxin (QLQX) is a commercial formulation of 11 different plant ingredients, whose active compounds include astragaloside IV, tanshione IIA, ginsenosides (Rb1, Rg1 and Re) and periplocymarin. In the QUEST trial, QLQX reduced the combined risk of cardiovascular death or heart failure hospitalization (hazard ratio 0.78, 95% confidence interval 0.68-0.90), based on 859 events in 3119 patients over a median of 18.2 months; the benefits were seen in patients taking foundational drugs except for sodium-glucose cotransporter 2 (SGLT2) inhibitors. Numerous experimental studies of QLQX in diverse cardiac injuries have yielded highly consistent findings. In marked abrupt cardiac injury, QLQX mitigated cardiac injury by upregulating nutrient surplus signalling through the PI3K/Akt/mTOR/HIF-1α/NRF2 pathway; the benefits of QLQX were abrogated by suppression of PI3K, Akt, mTOR, HIF-1α or NRF2. In contrast, in prolonged measured cardiac stress (as in chronic heart failure), QLQX ameliorated oxidative stress, maladaptive hypertrophy, cardiomyocyte apoptosis, and proinflammatory and profibrotic pathways, while enhancing mitochondrial health and promoting glucose and fatty acid oxidation and ATP production. These effects are achieved by an action of QLQX to upregulate nutrient deprivation signalling through SIRT1/AMPK/PGC-1α and enhanced autophagic flux. In particular, QLQX appears to enhance the interaction of PGC-1α with PPARα, possibly by direct binding to RXRα; silencing of SIRT1, PGC-1α and RXRα abrogated the favourable effects of QLQX in the heart. Since PGC-1α/RXRα is also a downstream effector of Akt/mTOR signalling, the actions of QLQX on PGC-1α/RXRα may explain its favourable effects in both acute and chronic stress. Intriguingly, the individual ingredients in QLQX - astragaloside IV, ginsenosides, and tanshione IIA - share QLQX's effects on PGC-1α/RXRα/PPARα signalling. QXQL also contains periplocymarin, a cardiac glycoside that inhibits Na+ -K+ -ATPase. Taken collectively, these observations support a conceptual framework for understanding the mechanism of action for QLQX in heart failure. The high likelihood of overlap in the mechanism of action of QLQX and SGLT2 inhibitors requires additional experimental studies and clinical trials.

SIRT1 slows the progression of lupus nephritis by regulating the NLRP3 inflammasome through ROS/TRPM2/Ca2+ channel.

Systemic lupus erythematosus (SLE) is a chronic multisystem inflammatory disease associated with autoantibody formation. Lupus nephritis (LN) is one of the most severe organ manifestations of SLE. The inflammatory response is a key factor in kidney injury, and the NLRP3 inflammasome is frequently associated with the pathogenesis of LN. Sirtuin 1 (SIRT1), a nicotinamide adenine dinucleotide (NAD +)-dependent histone deacetylase, is a promising therapeutic target for preventing renal injury. However, the mechanism of SIRT1 in LN remains unclear. Here, we aimed to investigate the mechanism by which SIRT inhibits the NLRP3 inflammasome to slow the progression of LN. We detected the expression of SIRT1 and the infiltration of macrophages in MRL/lpr mice; the results showed that the expression of SIRT1 was decreased, and the symptoms of lupus nephritis were relieved after the use of resveratrol, which upregulated SIRT1. In vitro studies showed that after lipopolysaccharide (LPS) stimulation, SIRT1 expression decreased, and the NLRP3 inflammasome was activated. Upregulation of SIRT1 inhibits NLRP3 inflammasome activation and assembly by interfering with two signalling pathways. First, SIRT1 affects NF-κB expression, transcription, and inflammatory cytokine expression. Second, SIRT1 modulates calcium influx induced by transient receptor potential channel M2 (TRPM2), which could be partly due to the inhibition of reactive oxygen species (ROS) production. Our findings suggest that upregulated SIRT1 inhibits the NLRP3 inflammasome to slow the progression of lupus nephritis by regulating NF-κB and ROS/TRPM2/Ca2+ channels. This study reveals a new anti-inflammatory mechanism of SIRT1, suggesting that SIRT1 may be a potential therapeutic target for the prevention of LN.

Radial Extracorporeal Shock Wave Therapy Combined with Resveratrol Derivative Alleviates Chronic Nonbacterial Prostatitis in Rats.

Resveratrol (Res) is a non-flavonoid polyphenol compound with biological pleiotropic properties, but low bioavailability limits its application value. Here, we synthesized a new Res derivative ((E)-5-(dimethylamino)-2-(4-methoxystyryl)phenol), and attempted to determine the function of Res derivative combined with radial extracorporeal shock wave therapy (rESWT) in chronic nonbacterial prostatitis (CNP). CNP model rats were constructed by subcutaneous administration of prostatein suspension (15 mg/ml), followed by rESWT treatment alone or in associated with Res or Res derivatives. In this study, inflammatory cell infiltration and tissue fibrosis in the prostate tissues of CNP rats were significantly deteriorated, which was effectively abolished by rESWT treatment alone or in combination with Res or Res derivative. The expression of interleukin 1ß (IL-1ß), tumor necrosis factor-α (TNF-α), nerve growth factor (NGF), and nuclear factor kappa-B (NF-κB) were increased, while silent information regulator 1 (SIRT1) expression was suppressed in the prostate tissues of CNP rats, which were then rescued by rESWT treatment alone or in associated with Res or Res derivative. Importantly, compared with Res derivative treatment alone or rESWT combined with Res treatment, combination treatment with rESWT and Res derivative was more effective in alleviating inflammation and fibrosis, in reducing IL-1ß, TNF-α, NGF, and SIRT1 expression, and in facilitating SIRT1 expression. Overall, rESWT combined with Res derivative treatment improved CNP in rat by reducing inflammation and fibrosis, which attributed to regulate the expression of SIRT1 and NF-κB. Thus, this work provides a theoretical basis for rESWT combined with Res derivative in the clinical treatment of CNP.

CycloZ Improves Hyperglycemia and Lipid Metabolism by Modulating Lysine Acetylation in KK-Ay Mice.

BACKGRUOUND: CycloZ, a combination of cyclo-His-Pro and zinc, has anti-diabetic activity. However, its exact mode of action remains to be elucidated. METHODS: KK-Ay mice, a type 2 diabetes mellitus (T2DM) model, were administered CycloZ either as a preventive intervention, or as a therapy. Glycemic control was evaluated using the oral glucose tolerance test (OGTT), and glycosylated hemoglobin (HbA1c) levels. Liver and visceral adipose tissues (VATs) were used for histological evaluation, gene expression analysis, and protein expression analysis. RESULTS: CycloZ administration improved glycemic control in KK-Ay mice in both prophylactic and therapeutic studies. Lysine acetylation of peroxisome proliferator-activated receptor gamma coactivator 1-alpha, liver kinase B1, and nuclear factor-κB p65 was decreased in the liver and VATs in CycloZ-treated mice. In addition, CycloZ treatment improved mitochondrial function, lipid oxidation, and inflammation in the liver and VATs of mice. CycloZ treatment also increased the level of ß-nicotinamide adenine dinucleotide (NAD+), which affected the activity of deacetylases, such as sirtuin 1 (Sirt1). CONCLUSION: Our findings suggest that the beneficial effects of CycloZ on diabetes and obesity occur through increased NAD+ synthesis, which modulates Sirt1 deacetylase activity in the liver and VATs. Given that the mode of action of an NAD+ booster or Sirt1 deacetylase activator is different from that of traditional T2DM drugs, CycloZ would be considered a novel therapeutic option for the treatment of T2DM.

Oligochitosan-based nanovesicles for nonalcoholic fatty liver disease treatment via the FXR/miR-34a/SIRT1 regulatory loop.

Non-alcoholic fatty liver disease (NAFLD) is currently a common chronic liver disease worldwide. By now, however, there isn't any FDA-approved specific drug for NAFLD treatment. It has been noticed that farnesoid X receptor (FXR), miR-34a and Sirtuin1 (SIRT1) is related to the occurrence and development of NAFLD. A oligochitosan-derivated nanovesicle (UBC) with esterase responsive degradability was designed to co-encapsulate FXR agonist (obeticholic acid, OCA) and miR-34a antagomir (anta-miR-34a) into the hydrophobic membrane and the center aqueous lumen of nanovesicles, respectively, by dialysis method. The action of UBC/OCA/anta-miR-34a loop on the regulation of lipid deposition via nanovesicles was evaluated on high-fat HepG2 cells and HFD-induced mice. The obtained dual drug-loaded nanovesicles UBC/OCA/anta-miR-34a could enhance the cellular uptake and intracellular release of OCA and anta-miR-34a, leading to the reduced lipid deposition in high-fat HepG2 cells. In NAFLD mice models, UBC/OCA/anta-miR-34a achieved the best curative effect on the recovery of body weight and hepatic function. Meanwhile, in vitro and vivo experiments validated that UBC/OCA/anta-miR-34a effectively activated the expression level of SIRT1 by enhancing the FXR/miR-34a/SIRT1 regulatory loop. This study provides a promising strategy for constructing oligochitosan-derivated nanovesicles to co-deliver OCA and anta-miR-34a for NAFLD treatment. STATEMENT OF SIGNIFICANCE: This study proposed a strategy to construct oligochitosan-derivated nanovesicles to co-deliver obeticholic acid and miR-34a antagomir for NAFLD treatment. Based on the FXR/miR-34a/SIRT1 action loop, this nanovesicle effectively exerted a synergetic effect of OCA and anta-miR-34a to significantly regulate lipid deposition and recover liver function in NAFLD mice.

Effects of oleoylethanolamide supplementation on the expression of lipid metabolism-related genes and serum NRG4 levels in patients with non-alcoholic fatty liver disease: A randomized controlled trial.

BACKGROUND: This study investigated the effects of oleoylethanolamide (OEA) supplementation on the expression levels of SIRT1, AMPK, PGC-1α, PPAR-γ, CEBP-α and CEBP-ß genes and serum neuregulin 4 (NRG4) levels in patients with non-alcoholic fatty liver diseases (NAFLD). METHODS: Sixty obese patients with NAFLD were equally allocated into either OEA or placebo group for 12 weeks. The mRNA expression levels of genes were determined using the reverse transcription polymerase chain reaction (RT-PCR) technique. Serum NRG4 level was also assessed using an enzyme-linked immunosorbent assay (ELISA) kit. RESULTS: At the endpoint, mRNA expression levels of SIRT1(p = 0.001), PGC-1α (p = 0.011) and AMPK (p = 0.019) were significantly higher in the OEA group compared to placebo group. However, no significant differences were observed in the expression levels of PPAR-γ, CEBP-α and CEBP-ß between the two groups. Serum NRG4 levels significantly increased in the OEA group compared with the placebo group after controlling for confounders (p = 0.027). In the OEA group, significant relationships were found between percent of changes in the expression levels of the SIRT1, AMPK and PGC-1α as well as serum NRG4 level with percent of changes in some anthropometric measures. Moreover, in the intervention group, percent of changes in high-density lipoprotein cholesterol was positively correlated with percent of changes in the expression levels of the SIRT1 and AMPK. While, percent of changes in triglyceride was inversely correlated with percent of changes in the expression levels of SIRT1. CONCLUSION: OEA could beneficially affect expression levels of some lipid metabolism-related genes and serum NRG4 level. "REGISTERED UNDER IRANIAN REGISTRY OF CLINICAL TRIALS IDENTIFIER NO: IRCT20090609002017N32".

Linalool attenuates lipid accumulation and oxidative stress in metabolic dysfunction-associated steatotic liver disease via Sirt1/Akt/PPRA-α/AMPK and Nrf-2/HO-1 signaling pathways.

INTRODUCTION: Linalool is a monoterpene that occurs naturally in various aromatic plants and is identified in our previous study as a potential candidate for protection against high-fat diet (HFD)-induced metabolic dysfunction-associated steatotic liver disease (MASLD). However, little is known about its direct effects on hepatic lipid metabolism and oxidative stress. Therefore, this study aims to investigate the therapeutic effect of linalool against MASLD and the underlying mechanism. METHODS: To establish a rat model of MASLD, male Wistar rats were fed HFD for 16 weeks and orally administered linalool (100 mg/kg body weight) for 45 days starting from week 14. RESULTS: Linalool significantly reduced HFD-induced liver lipid accumulation and restored altered adipokine levels. Mechanistically, linalool downregulated the mRNA expression of sterol regulatory element binding protein 1 and its lipogenesis target genes fatty acid synthase and acetyl-CoA carboxylase, and upregulated the mRNA expression of genes involved in fatty acid oxidation (peroxisome proliferator-activated receptor (PPAR)-alpha [PPAR-α], lipoprotein lipase and protein kinase B [Akt]) as well as the upstream mediators sirtuin 1 (Sirt1) and AMP-activated protein kinase (AMPK) in the liver of MASLD rats. In addition, linalool also curbed oxidative stress by increasing antioxidant enzymes and activating nuclear erythroid-2-related factor 2 (Nrf-2) and its downstream target genes involved in antioxidant properties. CONCLUSION: Therefore, this study concludes that linalool attenuates lipid accumulation in the liver by inhibiting de novo lipogenesis, promoting fatty acid oxidation, and attenuating oxidative stress by regulating Sirt1/Akt/PPRA-α/AMPK and Nrf-2/ HO-1 signaling pathways.

Dexpanthenol protects against lipopolysaccharide-induced acute kidney injury by restoring aquaporin-2 levels via regulation of the silent information regulator 1 signaling pathway.

BACKGROUND: Acute kidney injury (AKI) is a serious pathology that causes dysfunction in concentrating urine due to kidney damage, resulting in blood pressure dysregulation and increased levels of toxic metabolites. Dexpanthenol (DEX), a pantothenic acid analog, exhibits anti-inflammatory and anti-apoptotic properties in various tissues. This study investigated the protective effects of DEX against systemic inflammation-induced AKI. METHODS: Thirty-two female rats were randomly assigned to the control, lipopolysaccharide (LPS), LPS+DEX, and DEX groups. LPS (5 mg/kg, single dose on the third day, 6 h before sacrifice) and DEX (500 mg/kg/d for 3 d) were administered intraperitoneally. After sacrifice, blood samples and kidney tissues were collected. Hematoxylin and eosin, caspase-3 (Cas-3), and tumor necrosis factor alpha (TNF-α) staining were performed on the kidney tissues. The total oxidant status (TOS) and total antioxidant status were measured using spectrophotometric methods. Aquaporin-2 (AQP-2), silent information regulator 1 (SIRT1), and interleukin-6 (IL-6) were detected using quantitative reverse transcription-polymerase chain reaction analysis. RESULTS: Histopathological analysis revealed that DEX treatment ameliorated histopathological changes. In the LPS group, an increase in the blood urea nitrogen, creatinine, urea, IL-6, Cas-3, TNF-α, and TOS levels and oxidative stress index was observed compared with the control group, whereas AQP-2 and SIRT1 levels decreased. DEX treatment reversed these effects. CONCLUSIONS: DEX was found to effectively prevent inflammation, oxidative stress, and apoptosis in the kidneys via the SIRT1 signaling pathway. These protective properties suggest DEX's potential as a therapeutic agent for the treatment of kidney pathologies.

Thioredoxin-1 Promotes Mitochondrial Biogenesis Through Regulating AMPK/Sirt1/PGC1α Pathway in Alzheimer's Disease.

Alzheimer's disease (AD) is the most common neurodegenerative disease. Increasing studies suggest that mitochondrial dysfunction is closely related to the pathogenesis of AD. Thioredoxin-1 (Trx-1), one of the major redox proteins in mammalian cells, plays neuroprotection in AD. However, whether Trx-1 could regulate the mitochondrial biogenesis in AD is largely unknown. In the present study, we found that Aß25-35 treatment not only markedly induced excessive production of reactive oxygen species and apoptosis, but also significantly decreased the number of mitochondria with biological activity and the adenosine triphosphate content in mitochondria, suggesting mitochondrial biogenesis was impaired in AD cells. These changes were reversed by Lentivirus-mediated stable overexpression of Trx-1 or exogenous administration of recombinant human Trx-1. What's more, adeno-associated virus-mediated specific overexpression of Trx-1 in the hippocampus of ß-amyloid precursor protein/presenilin 1 (APP/PS1) mice ameliorated the learning and memory and attenuated hippocampal Aß deposition. Importantly, overexpression of Trx-1 in APP/PS1 mice restored the decrease in mitochondrial biogenesis-associated proteins, including adenosine monophosphate -activated protein kinase (AMPK), silent information regulator factor 2-related enzyme 1 (Sirt1) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α). In addition, Lentivirus-mediated overexpression of Trx-1 in rat adrenal pheochromocytoma (PC12) cells also restored the decrease of AMPK, Sirt1, and PGC1α by Aß25-35 treatment. Pharmacological inhibition of AMPK activity significantly abolished the effect of Trx-1 on mitochondrial biogenesis. Taken together, our data provide evidence that Trx-1 promoted mitochondrial biogenesis via restoring AMPK/Sirt1/PGC1α pathway in AD.