Pengwei Zhuang

Direct Stimulation of Adult Neural Stem/Progenitor Cells In Vitro and Neurogenesis In Vivo by Salvianolic Acid B

Background Small molecules have been shown to modulate the neurogenesis processes. In search for new therapeutic drugs, the herbs used in traditional medicines for neurogenesis are promising candidates. Methodology and Principal Findings We selected a total of 45 natural compounds from Traditional Chinese herbal medicines which are extensively used in China to treat stroke clinically, and tested their proliferation-inducing activities on neural stem/progenitor cells (NSPCs). The screening results showed that salvianolic acid B (Sal B) displayed marked effects on the induction of proliferation of NSPCs. We further demonstrated that Sal B promoted NSPCs proliferation in dose- and time-dependent manners. To explore the molecular mechanism, PI3K/Akt, MEK/ERK and Notch signaling pathways were investigated. Cell proliferation assay demonstrated that Ly294002 (PI3K/Akt inhibitor), but neither U0126 (ERK inhibitor) nor DAPT (Notch inhibitor) inhibited the Sal B-induced proliferation of cells. Western Blotting results showed that stimulation of NSPCs with Sal B enhanced the phosphorylation of Akt, and Ly294002 abolished this effect, confirming the role of Akt in Sal B mediated proliferation of NSPCs. Rats exposed to transient cerebral ischemia were treated for 4 weeks with Sal B from the 7th day after stroke. BrdU incorporation assay results showed that exposure Sal B could maintain the proliferation of NSPCs after cerebral ischemia. Morris water maze test showed that delayed post-ischemic treatment with Sal B improved cognitive impairment after stroke in rats. Significance Sal B could maintain the NSPCs self-renew and promote proliferation, which was mediated by PI3K/Akt signal pathway. And delayed post-ischemic treatment with Sal B improved cognitive impairment after stroke in rats. These findings suggested that Sal B may act as a potential drug in treatment of brain injury or neurodegenerative diseases.

Baicalin regulates neuronal fate decision in neural stem/progenitor cells and stimulates hippocampal neurogenesis in adult rats.

Recent studies revealed that baicalin, a flavonoid compound derived from the root of Scutellaria baicalensis Georgi, could promote neuron differentiation of NSPCs after commencing the differentiation process in vitro. However, this may not be the most efficacious strategy to determinate cell fate. Here, we have investigated whether baicalin can influence early events of neuron generation and stimulate adult neurogenesis.

Salvianolic Acids for Injection (SAFI) Suppresses Inflammatory Responses in Activated Microglia to Attenuate Brain Damage in Focal Cerebral Ischemia.

BACKGROUND Inflammatory reactions induced by microglia in the brain play crucial roles in ischemia/reperfusion (I/R) cerebral injuries. Microglia activation has been shown to be closely related to TLR4/NF-κB signal pathways. Salvianolic acids for injection (SAFI) have been used in clinical practice to treat ischemic stroke with reported neuroprotective effects; however, the underlying mechanisms are still uncertain. OBJECTIVE AND METHODS First, we studied the effect of SAFI on inflammatory responses in LPS-stimulated BV-2 microglia. Then, to discover whether the beneficial in vitro effects of SAFI lead to in vivo therapeutic effects, an MCAO (Middle cerebral artery occlusion) rat model was further employed to elucidate the probable mechanism of SAFI in treating ischemic stroke. Rats in the SAFI group were given SAFI (23 or 46mg/kg) before I/R injury. RESULTS The results showed that SAFI treatment significantly decreased neuroinflammation and the infarction volume compared with the vehicle group. Activation of microglia cells was reduced, and TLR4/NF-κB signals, which were markedly inhibited by SAFI treatment in ischemic hemisphere, were accompanied by reduced expression and release of cytokines IL-1β and IL-6. CONCLUSION This study provides evidence that SAFI effectively protects the brain after cerebral ischemia, which may be caused by attenuating inflammation in microglia.

Reversal of Muscle Atrophy by Zhimu-Huangbai Herb-Pair via Akt/mTOR/FoxO3 Signal Pathway in Streptozotocin-Induced Diabetic Mice

Skeletal muscle atrophy is one of the serious complications of diabetes. Zhimu-Huangbai herb-pair (ZB) is widely used in Chinese traditional medicine formulas for treating Xiaoke (known as diabetes) and its complications. However, the effect of ZB on reversal of muscle atrophy and the underlying mechanisms remain unknown. In this research, we investigated the effect and possible mechanisms of ZB on skeletal muscle atrophy in diabetic mice. Animal model of diabetic muscle atrophy was developed by high fat diet (HFD) feeding plus streptozotocin (STZ) injection. After oral adminstration of ZB for 6 weeks, the effects of ZB on reversal of muscle atrophy and the underlying mechanisms were evaluated by biochemical, histological and western blot methods. The skeletal muscle weight, strength, and cross-sectional area of diabetic mice were significantly increased by ZB treatment. Biochemical results showed that ZB treatment reduced the serum glucose level, and elevated the serum insulin-like growth factor 1 (IGF-1) and insulin levels significantly compared with untreated diabetic group. The western blot results showed that ZB activated the mTOR signal pathway, shown as increased phosphorylations (p-) of Akt, mTOR, Raptor, S6K1 and reduced Foxo3 expression compared with the model group. ZB could reverse muscle atrophy in diabetic mice. This may be through activation of mTOR signaling pathway that promotes protein synthesis, and inactivation foxo3 protein that inhibits protein degradation. These findings suggested that ZB may be considered as a potential candidate drug in treatment of diabetic muscle atrophy.

Application of GC/MS-based metabonomic profiling in studying the therapeutic effects of Huangbai–Zhimu herb-pair (HZ) extract on streptozotocin-induced type 2 diabetes in mice

A protocol for metabolic profiling of mice urine was developed based on gas chromatograph-mass spectrometer (GC-MS) to explore metabolic state directly. The intra-day, inter-day, repeatability, and stability RSD for most endogenous compounds were less than 3%. Type 2 diabetic mellitus (T2DM) mice model was induced by high calorie diet combined with streptozocin. Urine from the control, T2DM and Huangbai-Zhimu herb-pair (HZ) treatment mice were enrolled in the subsequent study to show the usefulness of the method. OPLS-DA scores plots demonstrate that the cluster of T2DM mice is separated from that of control mice, while HZ-T2DM mice are located close to control mice, indicating that metabolic profiles of these HZ-T2DM mice are placed toward those of control group. The results illustrate that HZ treatment could lower the level of d-glucose, hexadecanoic acid, octadecanoic acid, propanoic acid, 3-hydroxybutyric acid, and 2,3-dihydroxybutanoic acid in urine of DM mice, meanwhile the results show that HZ treatment could ameliorate T2DM symptoms by intervening the fatty acid metabolism, starch and sucrose metabolism, and glyoxylate and dicarboxylate metabolism. This preliminary application indicated that the method is suitable and reliable for urine metabolic profiling. This study might explain the metabolic effects of T2DM and the mechanisms of action of HZ against T2DM.

cAMP-PKA-CaMKII signaling pathway is involved in aggravated cardiotoxicity during Fuzi and Beimu Combination Treatment of Experimental Pulmonary Hypertension

Aconiti Lateralis Radix Praeparata (Fuzi) and Fritillariae Thunbergii bulbus (Beimu) have been widely used clinically to treat cardiopulmonary related diseases in China. However, according to the classic rules of traditional Chinese medicine, Fuzi and Beimu should be prohibited to use as a combination for their incompatibility. Therefore, it is critical to elucidate the paradox on the use of Fuzi and Beimu combination therapy. Monocrotaline-induced pulmonary hypertension rats were treated with either Fuzi, Beimu, or their combination at different stages of PH. We demonstrated that at the early stage of PH, Fuzi and Beimu combination significantly improved lung function and reduced pulmonary histopathology. However, as the disease progressed, when Fuzi and Beimu combination were used at the late stage of PH, right ventricular chamber dilation was histologically apparent and myocardial apoptosis was significantly increased compared with each drug alone. Western-blotting results indicated that the main chemical ingredient of Beimu could down-regulate the protein phosphorylation levels of Akt and PDE4D, whereas the combination of Fuzi and Beimu could up-regulate PKA and CaMKII signaling pathways. Therefore, we concluded that Fuzi and Beimu combination potentially aggravated the heart injury due to the inhibition of PDK1/Akt/PDE4D axis and subsequent synergistic activation of βAR-Gs-PKA/CaMKII signaling pathway.

Looking for agonists of β2 adrenergic receptor from Fuzi and Chuanwu by virtual screening and dual-luciferase reporter assay

Abstract More and more studies demonstrated that β2 adrenergic receptor (β2-AR) plays a crucial role for the treatment of heart failure. Chuanwu and Fuzi have been used over thousands of years in China for the treatment of heart failure. Considering the effects of these herbs are very similar to β2-AR agonists, we presume whether β2-AR agonists can be found from Fuzi and Chuanwu. Fuzi and Chuanwu decoction were used to receive the luciferase reporter activity assay to verify the hypothesis, and the result is positive and encouraging. For it is very difficult to get all of the monomer compounds of Fuzi and Chuanwu, virtual screening was used to find potential β2-AR agonists and a cell-based β2-AR agonist functional evaluation model, combined with a luciferase reporter assay system, was used to confirm the final result. In this research, 45 compounds were identified as β2-AR agonists, and four compounds were verified and the rest need further experiment.

Reversal of muscle atrophy by Zhimu and Huangbai herb pair via activation of IGF-1/Akt and autophagy signal in cancer cachexia.

PurposeMuscle atrophy is the prominent clinical feature of cancer-induced cachexia. Zhimu and Huangbai herb pair (ZBHP) has been used since ancient China times and have been phytochemically investigated for constituents that might cause anti-cancer, diabetes, and their complication. In this study, the effects and mechanisms of ZBHP on reversal of muscle atrophy were explored.MethodsC57BL/6 mice implanted with colon-26 adenocarcinoma were chosen to develop cancer cachexia for evaluating the effects of ZBHP on reversal of muscle atrophy. The body weight, survival time, inflammatory cytokines, and pathological changes of muscle were monitored. In addition, IGF-1/Akt and autophagy pathway members were analyzed to interpret the mechanism of drug response.ResultsThe function and morphology of skeletal muscle in cachexia model were significantly disturbed, and the survival time was shortened. Consistently, inflammatory cytokines and muscle atrophy-related atrogin-1, MuRF1, and FOXO3 were significantly increased, and IGF-1/Akt and autophagy signal pathways were depressed. Treatment with ZBHP significantly alleviated tumor-free body weight reduction and cachexia-induced changes in cytokines and prolonged survival. ZBHP treatment not only inhibited the muscle atrophy-related genes but also activated the IGF-1/Akt and autophagy signal pathways to facilitate the protein synthesis.ConclusionsThe results revealed that ZBHP treatment could inhibit the muscle atrophy induced by cancer cachexia and prolong the survival time, and ZBHP may be of value as a pharmacological alternative in treatment of cancer cachexia.

Suxiaojiuxin pill enhances atherosclerotic plaque stability by modulating the MMPs/TIMPs balance in ApoE-deficient mice.

Abstract: Suxiaojiuxin pill (SX) is a famous Chinese formulated product, which has been used to treat coronary heart disease and angina pectoris in China. This study was carried out to investigate the effect and possible mechanism of SX on the stability of atherosclerotic plaque in ApoE-deficient mice. ApoE−/− mice of 6–8 weeks old were fed with high-fat diet for developing artherosclerosis. After oral administration of SX for 8 weeks, histopathology of aortic plaque was performed by Sudan III and hematoxylin–eosin staining, and muscle protein was detected by Western blotting (WB). The mRNA and proteins associated with aortic plaque stability were detected by reverse transcription-polymerase chain reaction and WB, respectively. SX treatment could not only reduce serum triglyceride level and plaque area but also increase fibrous cap thickness and collagen content compared with the model group. WB results showed that SX could increase &agr;-smooth muscle actin, tissue inhibitor of metalloproteinase 1 (TIMP-1), and TIMP-2 protein expression, whereas decrease matrix metalloproteinase 2 (MMP-2) and MMP-9 protein expression. Moreover, SX could upregulate the expression of &agr;-smooth muscle actin mRNA and downregulate the expression of vascular endothelial growth factor mRNA. These results showed that SX could enhance atherosclerotic plaque stability in ApoE-deficient mice. The mechanism may be associated with modulating the MMPs/TIMPs balance.

Urine Metabonomics Reveals Early Biomarkers in Diabetic Cognitive Dysfunction

Recently, increasing attention has been paid to diabetic encephalopathy, which is a frequent diabetic complication and affects nearly 30% of diabetics. Because cognitive dysfunction from diabetic encephalopathy might develop into irreversible dementia, early diagnosis and detection of this disease is of great significance for its prevention and treatment. This study is to investigate the early specific metabolites biomarkers in urine prior to the onset of diabetic cognitive dysfunction (DCD) by using metabolomics technology. An ultra-high performance liquid-chromatography-quadrupole time-of-flight-mass spectrometry (UPLC-Q/TOF-MS) platform was used to analyze the urine samples from diabetic mice that were associated with mild cognitive impairment (MCI) and nonassociated with MCI in the stage of diabetes (prior to the onset of DCD). We then screened and validated the early biomarkers using OPLS-DA model and support vector machine (SVM) method. Following multivariate statistical and integration analysis, we found that seven metabolites could be accepted as early biomarkers of DCD, and the SVM results showed that the prediction accuracy is as high as 91.66%. The identities of four biomarkers were determined by mass spectrometry. The identified biomarkers were largely involved in nicotinate and nicotinamide metabolism, glutathione metabolism, tryptophan metabolism, and sphingolipid metabolism. The present study first revealed reliable biomarkers for early diagnosis of DCD. It provides new insight and strategy for the early diagnosis and treatment of DCD.