SIRT1-dependent myoprotective effects of resveratrol on muscle injury induced by compression

Indoxyl sulfate induced frailty in patients with end-stage renal disease by disrupting the PGC-1α-FNDC5 axis

OBJECTIVE

Sarcopenia or frailty is common among patients with chronic kidney disease (CKD). The protein-bound uremic toxin indoxyl sulfate (IS) is associated with frailty. IS induces apoptosis and disruption of mitochondrial activity in skeletal muscle. However, the association of IS with anabolic myokines such as irisin in patients with CKD or end-stage renal disease (ESRD) is unclear. This study aims to elucidate whether IS induces frailty by dysregulating irisin in patients with CKD.

MATERIALS AND METHODS

The handgrip strength of 53 patients, including 28 patients with ESRD, was examined. Serum concentrations of IS and irisin were analyzed. CKD was established in BALB/c mice through 5/6 nephrectomy. Pathologic analysis of skeletal muscle was assessed through haematoxylin and eosin and Masson's trichrome staining. Expression of peroxisome proliferator-activated receptor-gamma coactivator PGC-1α and irisin were analyzed using real-time polymerase chain reaction and Western blotting.

RESULTS

Handgrip strength was lower among patients with ESRD than among those without ESRD. In total, 64.3% and 24% of the patients in the ESRD and control groups had low handgrip strength, respectively (p < 0.05). Serum concentrations of IS were significantly higher in the ESRD group than in the control group (222.81 ± 90.67 μM and 23.19 ± 33.28 μM, respectively, p < 0.05). Concentrations of irisin were lower in the ESRD group than in the control group (64.62 ± 32.64 pg/mL vs. 99.77 ± 93.29 pg/mL, respectively, p < 0.05). ROC curves for low handgrip strength by irisin and IS were 0.298 (95% confidence interval (CI): 0.139-0.457, p < 0.05) and 0.733 (95% CI: 0.575-0.890, p < 0.05), respectively. The percentage of collagen was significantly higher in mice with 5/6 nephrectomy than in the control group. After resveratrol (RSV) treatment, the percentage of collagen significantly decreased. RSV modulates TGF-β signaling. In vitro analysis revealed that IS treatment suppressed expression of PGC-1α and FNDC5 in a dose-dependent manner, whereas RSV treatment attenuated IS-induced phenomena in C2C12 cells.

CONCLUSION

IS was positively correlated with frailty in patients with ESRD through the modulation of the PGC-1α-FNDC5 axis. RSV may be a potential drug for reversing IS-induced suppression of the PGC-1α-FNDC5 axis in skeletal muscle.

Advance in topical biomaterials and mechanisms for the intervention of pressure injury

Pressure injuries (PIs) are localized tissue damage resulting from prolonged compression or shear forces on the skin or underlying tissue, or both. Different stages of PIs share common features include intense oxidative stress, abnormal inflammatory response, cell death, and subdued tissue remodeling. Despite various clinical interventions, stage 1 or stage 2 PIs are hard to monitor for the changes of skin or identify from other disease, whereas stage 3 or stage 4 PIs are challenging to heal, painful, expensive to manage, and have a negative impact on quality of life. Here, we review the underlying pathogenesis and the current advances of biochemicals in PIs. We first discuss the crucial events involved in the pathogenesis of PIs and key biochemical pathways lead to wound delay. Then, we examine the recent progress of biomaterials-assisted wound prevention and healing and their prospects.

Role of microRNAs in Pressure Ulcer Immune Response, Pathogenesis, and Treatment

Pressure ulcers are preventable, yet highly prevalent, chronic wounds that have significant patient morbidity and high healthcare costs. Like other chronic wounds, they are characterized by impaired wound healing due to dysregulated immune processes. This review will highlight key biochemical pathways in the pathogenesis of pressure injury and how this signaling leads to impaired wound healing. This review is the first to comprehensively describe the current literature on microRNA (miRNA, miR) regulation of pressure ulcer pathophysiology.

SIRT1-dependent mechanisms and effects of resveratrol for amelioration of muscle wasting in NASH mice

Background

In non-alcoholic steatohepatitis (NASH), muscle wasting was an aggravating factor for the progression of hepatic steatosis. This study explores the potential benefits of chronic treatment with resveratrol, a strong activator of SIRT1 on the muscle wasting of NASH mice.

Methods

In vivo and in vitro study, we evaluate the SIRT1-dependent mechanisms and effects of resveratrol administration for 6 weeks with high-fat-methionine and choline deficient diet-induced NASH mice and palmitate-pretreated C2C12 myoblast cells.

Results

Resveratrol treatment improved grip strength and muscle mass of limbs, increased running distance and time on exercise wheels in NASH mice. There is a negative correlation between muscular SIRT1 activity and 3-nitrotyrosine levels of NASH and NASH-resv mice. The SIRT1-dependent effect of muscle wasting was associated with the suppression of oxidative stress, upregulation of antioxidants, inhibition of protein degradation, activation of autophagy, suppression of apoptotic activity, upregulation of lipolytic genes and the reduction of fatty infiltration in limb muscles of NASH mice. In vitro, resveratrol alleviated palmitate acid-induced oxidative stress, lipid deposition, autophagy dysfunction, apoptotic signals, and subsequently reduced fusion index and myotube formation of C2C12 cells. The beneficial effects of resveratrol were abolished by EX527.

Conclusions

Our study suggests that chronic resveratrol treatment is a potential strategy for amelioration of hepatic steatosis and muscle wasting in NASH mouse model.

Synchrotron radiation imaging analysis of neural damage in mouse soleus muscle

Damage to lower limb muscles requires accurate analysis of the muscular condition via objective microscopic diagnosis. However, microscopic tissue analysis may cause deformation of the tissue structure due to injury induced by external factors during tissue sectioning. To substantiate these muscle injuries, we used synchrotron X-ray imaging technology to project extremely small objects, provide three-dimensional microstructural analysis as extracted samples. In this study, we used mice as experimental animals to create soleus muscle models with various nerve injuries. We morphologically analyzed and quantified the damaged Section and Crush muscles, respectively, via three-dimensional visualization using synchrotron radiation X-ray imaging to diagnose muscle injury. Results of this study can also be used as basic data in the medical imaging field.

Protective Effects of Resveratrol Supplementation on Contusion Induced Muscle Injury

Muscle injuries frequently occur in contact sports events. The current treatment options for soft tissue injuries remain suboptimal and often result in delayed or incomplete recovery of damaged muscles. Resveratrol (RES) is a phenolic phytochemical, well-known for its antioxidant and anti-inflammatory properties. The purpose of this study is to evaluate the potential beneficial effects of RES supplementation on inflammation and regeneration in skeletal muscle after a contusion injury, in comparison to a conventional treatment of nonsteroidal anti-inflammatory drugs (NSAID). After one week of acclimation, forty eight -week-old male ICR mice were randomly divided into the five groups (n=8 per group): 1) normal control (NC), 2) mass-drop injury without any treatment (mass-drop injury, MDI), 3) post-injury NSAID treatment (MDI+ 10mg/kg NSAID), 4) post-injury RES supplementation (MDI+ 25mg/kg/day RES) and 5) post-injury treatment with RES and NSAID (MDI + resveratrol+ NSAID). After muscle contusion injury of the left gastrocnemius muscle, RES or NSAID were orally administered post-injury once a day for 7 days. Results showed that the MDI group had significantly higher serum uric acid (UA), CREA (creatinine), LDH (lactic dehydrogenase) and creatine kinase (CK) than the normal control group. Treatment with resveratrol reduced muscle damage as evidenced by the significantly decreased serum levels of UA, CREA, LDH and CK after contusion-induced muscle injuries in mice. In addition, RES and RES + NSAID groups promoted muscle satellite cell regeneration with increase in desmin protein after injury. Our results suggest that resveratrol combined with NSAID potentially improve muscle recovery and may be a potential candidate for further development as an effective clinical treatment for muscle repair.

Therapeutic Effects of Resveratrol Liposome on Muscle Injury in Rats

BACKGROUND In this study we prepared liposome microbubbles loading resveratrol (LMLR) and evaluated its therapeutic effect on injury of gastrocnemius muscle in rats. MATERIAL AND METHODS LMLR was prepared and characterized by particle size, potential, and microscopy, and a rat model of acute blunt injury of gastrocnemius muscle was established. After treatments with resveratrol or LMLR, the therapeutic effects were evaluated by hematoxylin-eosin (HE) staining. The expression of MHCIIB and vimentin in mRNA level was measured by real-time PCR. The expression of desmin and collagen I protein was assessed by immunohistochemistry. RESULTS LMLR showed regular cycle shape in a size of ~1000 nm. LMLR was negatively charged (-30 mV). The in vitro release of LMLR was close to 80% at 10 h and 90% at 48 h. Acute gastrocnemius muscle injury was established in rats and tissue recovery was observed after LMLR treatment as evidenced by HE staining, decreased expression of MHCIIB, and increased expression of vimentin. Moreover, LMLR treatment obviously facilitated desmin expression and reduced collagen I expression. CONCLUSIONS LMLR is effective in treating acute blunt injury of gastrocnemius muscle in rats.

Effects of Derinat on ischemia-reperfusion-induced pressure ulcer mouse model

Sodium salt of deoxyribonucleic acid (DNA), Derinat, isolated from the soft roes of Russian sturgeon, has been utilized as an immunomodulator for the treatment of reactive oxygen species (ROS)-associated diseases in clinics. Here we show that treatment with Derinat has an anti-inflammatory and anti-oxidative effects on cutaneous ischemia-reperfusion (IR) injury in pressure ulcer (PU) model mice. Dorsal skin damage and dermal edema in mild PU model mice were attenuated by treatment with Derinat. Immunohistochemical and biochemical analyses showed that Derinat suppressed IR-induced oxidative damage, i.e. accumulation of 8-hydroxy-2'-deoxyguanosine (8-OHdG), and related inflammatory factors such as cyclooxygenase 2 (COX-2) and IL-6 receptor (IL-6R) in dorsal skin from PU model mice. We also verified that phospholyated/non-phosphorylated ratio of extracellular signal-regulated kinase (Erk) and p38 mitogen-activated protein kinase (MAPK) increased after IR, which were attenuated by Derinat. We then compared the effect of Derinat with that of salmon DNA and other PU therapeutic agents, prostaglandin E1 (PGE1) and basic fibroblast growth factor (bFGF), by using severe PU model mice. The effects of Derinat and salmon-DNA were compatible with those of PGE1 and bFGF. These results suggest that Derinat other fish-derived DNA formulation could be effective enough and become intriguing new therapeutic options.

The influence of isoflavone for denervation-induced muscle atrophy

PURPOSE

Decrease in activity stress induces skeletal muscle atrophy. A previous study showed that treatment with a high level (20%) of isoflavone inhibits muscle atrophy after short-term denervation (at 4 days) in mice. The present study was designed to elucidate whether the dietary isoflavone aglycone (AglyMax) at a 0.6% prevents denervation-mediated muscle atrophy, based on the modulation of atrogin-1- or apoptosis-dependent signaling.

METHODS

Mice were fed either a normal diet or 0.6% AglyMax diet. One week later, the right sciatic nerve was cut. The wet weight, mean fiber area, amount of atrogin-1 and cleaved caspase-3 proteins, and the percentages of apoptotic nuclei were examined in the gastrocnemius muscle at 14 days after denervation.

RESULTS

The 0.6% AglyMax diet significantly attenuated denervation-induced decreases in fiber atrophy but not the muscle wet weight. In addition, dietary isoflavone suppressed the denervation-induced apoptosis in spite of there being no significant changes in the amount of cleaved caspase-3 protein. In contrast, the 0.6% AglyMax diet did not significantly modulate the protein expression of atrogin-1 in the denervated muscle of mice.

CONCLUSIONS

The isoflavone aglycone (AglyMax) at a 0.6% significantly would modulate muscle atrophy after denervation in mice, probably due to the decrease in apoptosis-dependent signaling.

Protective effects of resveratrol on osteoporosis via activation of the SIRT1-NF-κB signaling pathway in rats

The aim of the present study was to determine the protective effects of resveratrol on a rat model of osteoporosis and examine the associated mechanisms of its action. Rats were randomized into the following groups: Control, osteoporosis, osteoporosis + low-dose resveratrol, osteoporosis + middle-dose resveratrol and osteoporosis + high-dose resveratrol groups. Resveratrol treatment was administered 7 days after surgery for 8 weeks. ELISA assay was used to analyze alkaline phosphatase (ALP) and osteocalcin (OC) protein levels. Western blotting was performed to assess the protein expression of sirtuin 1 (SIRT1), nuclear factor (NF)-κB and NF-κB inhibitor (IkB) α. In the present study, the results indicated that resveratrol markedly improved the bone mineral density value, femoral porosity and bone mechanical tests in osteoporosis rats. Administration of resveratrol significantly decreased the serum levels of ALP and OC in rats with osteoporosis. Finally, treatment with resveratrol significantly promoted the protein expression of SIRT1, suppressed NF-κB and activated the IkBα protein expression in rats with osteoporosis. In conclusion, treatment with resveratrol significantly improved the final body weight of the osteoporosis rats via the SIRT1-NF-κB signaling pathway. The present study suggested that resveratrol exerted a protective effect on osteoporosis through activation of the SIRT1-NF-κB signaling pathway in rats.

Resveratrol inhibits age-dependent spontaneous tumorigenesis by SIRT1-mediated post-translational modulations in the annual fish Nothobranchius guentheri

Resveratrol, SIRT1 activator, inhibits carcinogenesis predominantly performed in transgenic animal models, orthotopic cancers of nude mice or different cancer cell lines, but its effects during process of spontaneous tumors using vertebrate models remain untested. Spontaneous liver neoplasm is an age-related disease and is inhibited by resveratrol in the annual fish Nothobranchius guentheri, which indicates that the fish can act as an excellent model to study spontaneous tumorigenesis. Totally, 175 fish were fed with resveratrol and another 175 fish for controls. Treated fish were fed with resveratrol (25 μg/fish/day) from sexual maturity (4-month-old) until they were sacrificed at 6-, 9- and 12-month-old. Immunoblot, immunohistochemistry and co-immunoprecipitation were employed to investigate the underlying mechanisms that resveratrol inhibited age-dependent spontaneous tumorigenesis in the fish. Results showed that resveratrol increased protein level of SIRT1 and alleviated age-associated tumorigenesis in liver. With SIRT1 up-regulation, resveratrol reduced proliferation by deacetylating K-Ras and inactivating K-Ras/PI3K/AKT pathway; and promoted apoptosis through deacetylation and dephosphorylation of FoxOs, up-regulation of DLC1 and interaction between SIRT1 and DLC1, and dephosphorylation of DLC1 in spontaneous neoplasms. We established a novel short-lived fish model for understanding the molecular mechanisms of drugs on age-dependent spontaneous tumorigenesis.

PINK1 signaling in mitochondrial homeostasis and in aging (Review)

Mitochondrial dysfunction is involved in the pathology of Parkinson's disease, an age-associated neurodegenerative disorder. Phosphatase and tensin homolog (PTEN)-induced putative kinase protein 1 (PINK1) is responsible for the most common form of recessive Parkinson's disease. PINK1 is a mitochondrial kinase that is involved in mitrochondrial quality control and promotes cell survival. PINK1 has been shown to protect against neuronal cell death induced by oxidative stress. Accordingly, PINK1 deficiency is associated with mitochondrial dysfunction as well as increased oxidative cellular stress and subsequent neuronal cell death. In addition, several mitochondrial chaperone proteins have been shown to be substrates of the PINK1 kinase. In this review, we discuss recent studies concerning the signaling cascades and molecular mechanisms involved in the process of mitophagy, which is implicated in neurodegeneration and in related aging associated with oxidative stress. Particular attention will be given to the molecular mechanisms proposed to explain the effects of natural compounds and/or food ingredients against oxidative stress. Knowledge of the molecular mechanisms involved in this cellular protection could be critical for developing treatments to prevent and control excessive progression of neurodegenerative disorders.

SIRT1 exerts neuroprotective effects by attenuating cerebral ischemia/reperfusion-induced injury via targeting p53/microRNA-22

The aim of this study was to investigate whether the SIRT1 exerts neuroprotective effects by attenuating cerebral ischemia/reperfusion-induced injury (CIRI) via targeting p53/microRNA-22. We found that the overexpression of sirtuin 1 (SIRT1) decreased the infarct volume, suppressed p53 protein expression and activated microRNA-22 expression following CIRI. An injection of lipopolysaccharide (LPS, 1 mg/ml; Sigma, St. Louis, MO USA) into the corpus callosum was used to induce CIRI in rats. The infarct volume and neurological deficit score were used to examine the effects of SIRT1 on CIRI. Furthermore, the overexpression of SIRT1 was found to suppress caspase-3 activity, inhibit the activation of the Bax signaling pathway, reduce tumor necrosis factor-α (TNF-α) and interleukin (IL)-6) activity, decrease cyclooxygenase (COX)‑2 and inducible nitric oxide synthase (iNOS) protein expression, and increase IL-10 activity following CIRI. Following the downregulation of SIRT1, p53 protein expression was significantly increased, microRNA-22 expression was inhibited, caspase-3 activity was increased and the Bax signaling pathway was activated. In addition, the activity of TNF-α and IL-6 was was enhanced, COX-2 and iNOS protein expression was increased, and IL-10 activity was reduced following CIRI. Thus, the data from our study suggest that SIRT1 attenuates CIRI by targeting the p53/microRNA-22 axix, while suppressing apoptosis, inflammation, COX-2 and iNOS expression.

Resveratrol: How Much Wine Do You Have to Drink to Stay Healthy?

Resveratrol is a naturally occurring stilbene endowed with multiple health-promoting effects. It is produced by certain plants including several dietary sources such as grapes, apples, raspberries, blueberries, plums, peanuts, and products derived therefrom (e.g., wine). Resveratrol can be isolated and purified from these biological sources or synthesized in a few steps with an overall high yield. This compound and its glucoside, the trans-polydatin piceid, have received worldwide attention for their beneficial effects on cardiovascular, inflammatory, neurodegenerative, metabolic, and age-related diseases. These health-promoting effects are particularly attractive given the prevalence of resveratrol-based nutraceuticals and the paradoxical epidemiologic observation that wine consumption is inversely correlated to the incidence of coronary heart disease. However, the notion of resveratrol as a "magic bullet" was recently challenged by clinical trials showing that this polyphenol does not have a substantial influence on health status and mortality risk. In the present review, we discuss the proposed therapeutic attributes and the mode of molecular actions of resveratrol. We also cover recent pharmacologic efforts to improve the poor bioavailability of resveratrol and influence the transition between body systems in humans. We conclude with some thoughts about future research directions that might be meaningful for resolving controversies surrounding resveratrol.