Oxidative stress damage plays a vital role in cerebral ischemia/reperfusion (I/R) pathogenesis. The nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathway can be activated by pharmacological and dietary means to attenuate cellular oxidative stress. Resveratrol, a plant-derived polyphenolic compound, has antioxidant property. Recent studies have demonstrated that resveratrol has protective effects against cerebral I/R injury. However, little is known about its mechanism. Hence, this study identified the neuroprotective effect of resveratrol pretreatment and elucidate the Nrf2/ARE signaling mechanism after focal cerebral I/R injury in rats. Adult male Sprague-Dawley rats were randomly assigned to sham-operated group, ischemia/reperfusion physiological saline-treated group, and ischemia/reperfusion resveratrol-pretreatmented (15 and 30 mg/kg) groups. Rats were pretreatmented with resveratrol or physiological saline of corresponding volume administered intraperitoneally for 7 days before surgery and 30 min before middle cerebral artery occlusion. At 24 h after reperfusion, neurological score, infarct volume, and brain water content were assessed. Oxidative stress was evaluated by malondialdehyde (MDA) levels and superoxide dismutase (SOD) activity. Pathological changes of brain tissue were observed by HE staining. RT-PCR and Western blot analysed the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1). TUNEL staining detected apoptotic cells. The protein expression of Caspase-3 were studied by immunohistochemistry. Resveratrol pretreatment significantly ameliorated neurological scores, reduced infarct volume and brain water content, decreased MDA levels, restored the SOD activity, upregulated the protein and mRNA expression of Nrf2 and HO-1, downregulated the protein expression of caspase-3. TUNEL-positive cells significantly decreased compared with the physiological saline-treated group. HE staining also showed that resveratrol significantly improved neuronal injury. These results showed that resveratrol pretreatment had neuroprotective effects on cerebral I/R injury. This neuroprotective effect is likely exerted by upregulated expression of transcription factor Nrf2 and HO-1 to ameliorate oxidative damage, decreased the protein expression of caspase-3. Our finding is important for understanding the neuroprotective mechanism of resveratrol and promoting its clinical therapeutic utility.

Resveratrol has neuroprotective effects for ischemic cerebral stroke. However, its neuroprotective mechanism for stroke is less well understood. Beneficial actions of the activated Sonic hedgehog (Shh) signaling pathway in stroke, such as improving neurological function, promoting neurogenesis, anti-oxidative, anti-apoptotic, and pro-angiogenic effects, have been noted, but relatively little is known about the role of Shh signaling in resveratrol-reduced cerebral ischemic injury after stroke. The present study tests whether the Shh pathway mediates resveratrol to decrease cerebral ischemic injury and improve neurological function after stroke. We observed that resveratrol pretreatment significantly improved neurological function, decreased infarct volume, enhanced vitality, and reduced apoptosis of neurons in vivo and vitro after stroke. Meanwhile, expression levels of Shh, Ptc-1, Smo, and Gli-1 mRNAs were significantly upregulated and Gli-1 was relocated to the nucleus. Intriguingly, in vivo and in vitro inhibition of the Shh signaling pathway with cyclopamine, a Smo inhibitor, completely reversed the above effects of resveratrol. These results suggest that decreased cerebral ischemic injury and improved neurological function by resveratrol may be mediated by the Shh signaling pathway.

There is considerable interest in the use of drugs and other methods for protecting implanted neural stem cells (NSCs) from the adverse environment of injured tissue for successful cell therapy. Resveratrol can modify cardiac stem cells to enhance their survival and differentiation, however, its effect and the mechanism underlying its neuroprotective effect on NSCs following stroke remain to be fully elucidated. Nuclear factor erythroid 2-related factor 2 (Nrf-2) signaling is important in antioxidative stress, and the role of Nrf-2 signaling in the enhanced neuroprotection of NSCs by resveratrol following stroke also remains to be elucidated. In the present study, NSCs were pretreated with resveratrol prior to oxygen-glucose deprivation/reoxygenation (OGD/R) in vitro. The survival, apoptosis and proliferation of the NSCs were assessed using an MTT assay, Hoechst 33258 staining of nuclei and flow cytometry, respectively. In addition, the activity of superoxide dismutase (SOD), level of malondiadehyde (MDA) and content of glutathione (GSH) were determined. The protein expressions levels of Nrf-2, NAD(P)H:quinone oxidoreductase 1 (NQO-1), and heme oxygenase 1 (HO-1) were detected using western blot analysis. It was found that resveratrol markedly enhanced NSC survival and proliferation, decreased apoptosis and the levels of MDA, and increased the activity of SOD and content of GSH in a concentration-dependent manner following OGD/R injury in vitro. In addition, the protein expression levels of Nrf2, HO-1 and NQO1 were significantly upregulated. These findings suggested that resveratrol attenuated injury and promoted proliferation of the NSCs, at least in part, by upregulating the expression of Nrf2, HO-1 and NQO1 following OGD/R injury in vitro.

Background/Aims: Neurite outgrowth and synaptogenesis are critical steps for functional recovery after stroke. Resveratrol promotes neurite outgrowth and synaptogenesis, but the underlying mechanism is not well understood, although the Sonic hedgehog (Shh) signaling pathway may be involved. Given that resveratrol activates sirtuin (Sirt)1, the present study examined whether this is mediated by Shh signaling. Methods: Primary cortical neuron cultures were pretreated with drugs before oxygen-glucose deprivation/reoxygenation (OGD/R). Cell viability and apoptosis were evaluated with Cell Counting Kit 8 and by terminal deoxynucleotidyl transferase dUTP nick end labeling, respectively. Neurite outgrowth and synaptogenesis were assessed by immunocytochemistry and western blotting, which was also used to examine the expression of Sirt1 and Shh signaling proteins. Results: Resveratrol and the Smoothened (Smo) agonist purmophamine, which activates Shh signaling, increased the expression of growth-associated protein(GAP)-43, synaptophysin, Shh, Patched (Ptc)-1, Smo, glioma-associated oncogene homolog (Gli)-1, and Sirt1 were upregulated under these conditions. These effects were reversed by treatment with the Smo inhibitor cyclopamine, whereas the Sirt1 inhibitor sirtinol reduced the levels of Shh, Ptc-1, Smo, and Gli-1. Conclusions: Resveratrol reduces neuronal injury following OGD/R injury and enhances neurite outgrowth and synaptogenesis by activating Shh signaling, which in turn induces Sirt1.

Background/Aims: There is interest in drugs and rehabilitation methods to enhance neurogenesis and improve neurological function after brain injury or degeneration. Resveratrol may enhance hippocampal neurogenesis and improve hippocampal atrophy in chronic fatigue mice and prenatally stressed rats. However, its effect and mechanism of neurogenesis after stroke is less well understood. Sonic hedgehog (Shh) signaling is crucial for neurogenesis in the embryonic and adult brain, but relatively little is known about the role of Shh signaling in resveratrol-enhanced neurogenesis after stroke. Methods: Neural stem cells (NSCs) before oxygen-glucose deprivation/reoxygenation (OGD/R) in vitro were pretreated with resveratrol with or without cyclopamine. Survival and proliferation of NSCs was assessed by the CCK8 assay and BrdU immunocytochemical staining. The expressions and activity of signaling proteins and mRNAs were detected by immunocytochemistry, Western blotting, and RT-PCR analysis. Results: Resveratrol significantly increased NSCs survival and proliferation in a concentration-dependent manner after OGD/R injury in vitro. At the same time, the expression of Patched-1, Smoothened (Smo), and Gli-1 proteins and mRNAs was upregulated, and Gli-1 entered the nucleus, which was inhibited by cyclopamine, a Smo inhibitor. Conclusion: Shh signaling mediates resveratrol to increase NSCs proliferation after OGD/R injury in vitro.

Recent studies have indicated that resveratrol has protective effects against cerebral ischemia/reperfusion injury. However, the best therapeutic time for resveratrol treatment after acute ischemic stroke remains unknown. We aim to investigate whether resveratrol, administrated at different times after neuronal oxygen and glucose deprivation/reoxygenation (OGD/R) reduced neuronal injury in vitro. There were six experimental groups: normal, model, resveratrol pretreatment, resveratrol post-treatment, resveratrol OGD-treatment, and resveratrol whole-processing group. We found that resveratrol in a concentration-dependent manner decreased the activity of lactate dehydrogenase (LDH) and increased the activity of superoxide dismutase (SOD). Moreover, resveratrol, administrated at different times, increased neuronal viability, reduced neuronal apoptosis, upregulated the protein expressions of Nuclear factor erythroid 2-related factor 2 (Nrf-2), NAD(P)H: quinone oxidoreductase 1 (NQO-1), heme oxygenase 1 (HO-1), and Bcl-2, downregulated the protein expression of Caspase-3, and promoted Nrf-2 to transfer into the nuclei from the cytoplasm. The most effective treatment group was the whole-processing treatment group. These results suggest that resveratrol treatment at different times increased neuronal viability and inhibited neuronal apoptosis in vitro, at least in part, via enhancing the activation of the Nrf-2 signaling pathway.

Purpose: The present study was designed to determine the relationships between sarcopenia and diabetic peripheral neuropathy (DPN) in patients with type 2 diabetes mellitus (T2DM) and diabetic foot disease (DFD) respectively. Patients and Methods: A total of 1104 patients with T2DM and 257 patients with DFD were included in the study, which was designed as a cross-sectional study. Body composition was assessed using dual-energy X-ray-absorptiometry (DXA). The diagnosis of sarcopenia was based on the Baumgartner criteria. DPN was assessed by Neuropathy symptom score (NSS) and Neuropathy disability score (NDS), and the severity of neuropathy was divided into non-neuropathy symptom (NS), Mild NS, Moderate NS and Severe NS according to NSS. Logistic regression analyses were carried out to determine the relations of sarcopenia and DPN in patients with T2DM and NSS in patients with DFD, respectively. Results: The prevalence of DPN was 80.0% in T2DM patients with sarcopenia and 70.3% in non-sarcopenia patients (P=0.007). Logistic regression analyses showed DPN was one of the independent risk factors for sarcopenia in T2DM patients (OR 1.564 [95% CI: 1.004, 2.435], P=0.048). The prevalence of DPN had no statistical significance in DFD patients with or without sarcopenia. However, the NSS of DFD patients with sarcopenia was higher than that of non-sarcopenia patients. In the multivariate logistic regression analysis, NSS was determined to be associated with sarcopenia in DFD patients (OR 1.387[95% CI: 1.074, 1.789], P=0.012). The appendicular lean mass (ALM) of DFD patients without NS was higher than patients with mild, moderate and severe NS (20.71±2.73 vs 16.57±3.62 vs 17.99±3.54 vs 17.23±3.29 Kg, P=0.028). Conclusion: DPN is an independent risk factor for sarcopenia in patients with T2DM and NSS is also independently correlated with sarcopenia in patients with DFD, with the latter being more obvious with the aggravation of neurological symptoms in DFD patients.

Mesenchymal stem cells (MSCs) can differentiate into neuronal-like cell types under specific conditions. The classical antioxidant inducers such as β-mercaptoethanol (BME), butylated hydroxyanisol (BHA), and dimethylsulfoxide (DMSO) are limited in clinical because of toxicity. Resveratrol, a safer, natural antioxidant, can stimulate osteoblastic differentiation of MSCs. However, its effect of inducing MSCs to differentiate into neuronal-like cells is less well studied, and its differentiated mechanisms are not well understood. Sonic hedgehog (Shh) signaling, mediated by the primary cilia, is crucial for embryonic development and tissue differentiation, but relatively little is known about the role of Shh signaling and primary cilia in neuronal-like differentiation of MSCs. Here we show that primary cilia, harboring patched 1 (Ptc1), are present in growth-arrested MSCs and that smoothened (Smo) and Gli1 are present in cytoplasm of MSCs, which are important components of the Shh signaling pathway. After resveratrol induction, MSCs acquire neuronal-like cell morphologies and phenotypes, Smo translocates to the primary cilia, Gli1 enters the nucleus, and expressions of Smo and Gli1 proteins increase, which can be inhibited by cyclopamine, a Smo antagonist. Meanwhile, Smo agonist (SAG) attains similar effects compared with the resveratrol group. These data indicate that resveratrol can induce MSCs to differentiate into neuronal-like cells and activate Shh signaling pathway in the primary cilia. Moreover, the primary cilia and Shh signaling are essential for resveratrol inducing neuronal-like differentiation of MSCs. Our finding is important for understanding the neuronal-like differentiation mechanism of MSCs for resveratrol and promoting its clinical therapeutic utility.