Jinmaitong alleviates diabetic neuropathic pain by inhibiting JAK2/STAT3 signaling in microglia of diabetic rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Jinmaitong (JMT) is a prescription of Traditional Chinese Medicine that is composed of 12 crude drugs. It has been used in the treatment of diabetic neuropathic pain (DNP) for more than 30 years. AIM OF STUDY: Microglia are thought to play an important role in neuropathic pain. This study aimed to evaluate the protective effect of JMT against DNP and to investigate the underlying mechanisms in which the microglia and JAK2/STAT3 signaling pathway were mainly involved. MATERIALS AND METHODS: The chemical composition of JMT was analyzed using liquid chromatography tandem mass spectrometry. The diabetes model was constructed using 11 to 12-week-old male Zucker diabetic fatty (ZDF) rat (fa/fa). The model rats were divided into 5 groups and were given JMT at three dosages (11.6, 23.2, and 46.4 g/kg, respectively, calculated as the crude drug materials), JAK inhibitor AG490 (positive drug, 10 µg/day), and placebo (deionized water), respectively, for eight weeks (n = 6). Meanwhile, Zucker lean controls (fa/+) were given a placebo (n = 6). Body weight was tested weekly and blood glucose was monitored every 2 weeks. The mechanical allodynia and heat hyperalgesia were assessed using mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) tests. After treatment, the microglia activation marker Iba-1, CD11B, CD68, neuroinflammatory mediators, and mediators of the JAK2/STAT3 signaling pathway were compared between different groups. The mRNA and protein levels of target genes were assessed by quantitative real-time PCR and Western Blot, respectively. RESULTS: We found that JMT significantly inhibited the overactivation of microglia in spinal cords, and suppressed neuroinflammation of DNP model rats, thereby ameliorating neurological dysfunction and injuries. Furthermore, these effects of JMT could be attributed to the inhibition of the JAK2/STAT3 signaling pathway. CONCLUSIONS: Our findings suggested that JMT effectively ameliorated DNP by modulating microglia activation via inhibition of the JAK2/STAT3 signaling pathway. The present study provided a basis for further research on the therapeutic strategies of DNP.

Corrigendum to "Targeted metabolomics reveals the aberrant energy status in diabetic peripheral neuropathy and the neuroprotective mechanism of traditional Chinese medicine JinMaiTong" [J. Pharm. Anal. 14 (2024) 225-243].

[This corrects the article DOI: 10.1016/j.jpha.2023.09.007.].

Targeted metabolomics reveals the aberrant energy status in diabetic peripheral neuropathy and the neuroprotective mechanism of traditional Chinese medicine JinMaiTong.

Diabetic peripheral neuropathy (DPN) is a common and devastating complication of diabetes, for which effective therapies are currently lacking. Disturbed energy status plays a crucial role in DPN pathogenesis. However, the integrated profile of energy metabolism, especially the central carbohydrate metabolism, remains unclear in DPN. Here, we developed a metabolomics approach by targeting 56 metabolites using high-performance ion chromatography-tandem mass spectrometry (HPIC-MS/MS) to illustrate the integrative characteristics of central carbohydrate metabolism in patients with DPN and streptozotocin-induced DPN rats. Furthermore, JinMaiTong (JMT), a traditional Chinese medicine (TCM) formula, was found to be effective for DPN, improving the peripheral neurological function and alleviating the neuropathology of DPN rats even after demyelination and axonal degeneration. JMT ameliorated DPN by regulating the aberrant energy balance and mitochondrial functions, including excessive glycolysis restoration, tricarboxylic acid cycle improvement, and increased adenosine triphosphate (ATP) generation. Bioenergetic profile was aberrant in cultured rat Schwann cells under high-glucose conditions, which was remarkably corrected by JMT treatment. In-vivo and in-vitro studies revealed that these effects of JMT were mainly attributed to the activation of adenosine monophosphate (AMP)-activated protein kinase (AMPK) and downstream peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α). Our results expand the therapeutic framework for DPN and suggest the integrative modulation of energy metabolism using TCMs, such as JMT, as an effective strategy for its treatment.

The complete chloroplast genome sequence of Aspidopterys concava (Wall.) A. Juss. (Malpighiaceae).

Aspidopterys concava is related to a group of important medicinal plants in Malpighiaceae in southeast Asia. Here, we report the first chloroplast genome fully sequenced and annotated for Aspidopterys concava. The genome size was 160,441 bp and contained a large single-copy (LSC) region of 71,434 bp, a small single-copy (SSC) region of 53,544 bp, and a pair of inverted repeats (IRs) regions of 8943 bp. Total GC content was 37.9%. It contained 125 genes in total, comprising 82 protein-coding genes, 37 transfer RNA genes, and six ribosomal RNA genes. Phylogenetic analysis showed that A. concava was the most closely related to A. obcordata from the same genus.

[Metabolomics in Diabetic Neuropathy].

Diabetic neuropathy is a common diabetic complication.The application of metabolomics in the research on diabetic neuropathy is beneficial for us to understand the pathophysiological processes and overall metabolic disturbance of the nervous system under the condition of hyperglycemia,decipher the pathogenesis of diabetic neuropathy,and mine the potential biomarkers for clinical diagnosis and treatment.Long-term hyperglycemia may lead to disorders in multiple pathways,such as tricarboxylic acid circle,amino acid metabolism,and lipid metabolism.These metabolic changes are closely associated with the injuries of the peripheral and central nervous system.In the paper,we reviewed the metabolomics-based studies about diabetic neuropathy in the last five years.

Efficacy and Safety of Mulberry Twig Alkaloids Tablet for Treatment of Type 2 Diabetes: A Randomized, Double-Blind, Placebo-Controlled Multicenter Clinical Study.

OBJECTIVE: To assess the efficacy and safety of mulberry twig alkaloids (Sangzhi alkaloids, SZ-A) for treatment of type 2 diabetes in a randomized, double-blind, placebo-controlled multicenter clinical trial. METHODS: A total of 200 patients were randomized to receive SZ-A (n=100) or placebo (n=100) for 16 weeks. The data analysis system for electronic data capture clinical trial central randomization system was used for randomization and dispensing of drugs. The primary outcome was the change in glycosylated hemoglobin (HbA1c) level. The secondary outcome included the proportions of cases with HbA1c <7.0% and HbA1c <6.5%, fasting blood glucose (FBG), postprandial blood glucose (PBG), area under curve for the PBG (AUC0-2h), body weight, and body mass index (BMI). Adverse events (AEs), severe adverse events (SAEs), treatment-related adverse events (TAEs), gastrointestinal disorders (GDs), blood pressure, routine blood tests, and liver and kidney function were monitored. RESULTS: Compared with baseline, the change of HbA1c at week 16 was -0.80% (95% CI: -0.98% to -0.62%) and -0.09% (95% CI: -0.27% to 0.09%) in SZ-A group and placebo group, respectively. The proportion of patients with HbA1c <7% and <6.5% was higher in the SZ-A group than in the placebo group (46.8% vs. 21.6% and 29.9% vs. 10.8%). The observed values and changes in FBG, 1 h-PBG, 2 h-PBG, and AUC0-2h differed significantly between groups (P<0.001), but differences were not significant in body weight and BMI (P>0.05). The incidence rates of AEs, TAEs, and GDs differed significantly between groups (P=0.010, P=0.005, and P=0.006, respectively), whereas the incidence rates of SAEs showed no significant differences between groups (P=1.000). CONCLUSION: SZ-A are effective and safe for treatment of type 2 diabetes. The protocol was registered in http://www.chictr.org.cn/showproj.aspx?proj=60117 (ChiCTR2000038550).

Quercetin reduces inflammation in a rat model of diabetic peripheral neuropathy by regulating the TLR4/MyD88/NF-κB signalling pathway.

Neuroinflammation contributes significantly to the pathogenesis of diabetic peripheral neuropathy (DPN). Quercetin reportedly exerts neuroprotective effects in DPN. Here, we aimed to evaluate the potential anti-inflammatory effects of quercetin in a DPN rat model. Eight weeks after streptozotocin administration, diabetic rats were treated with quercetin (30 and 60 mg/kg/day orally) for 6 weeks. We assessed the mechanical withdrawal threshold (MWT), nerve conduction velocity (NCV) and morphological changes in sciatic nerves. Additionally, we measured the levels of tumour necrosis factor-alpha (TNF-α), interleukin (IL)-1ß, and IL-6 by ELISA and the expression of TLR4, MyD88, and NF-κB in sciatic nerves by western blotting and immunohistochemical assays. Our results revealed that blood glucose levels and body weight were unaltered following quercetin treatment. However, quercetin improved MWT (p < 0.05), NCV (p < 0.05), and pathological changes in the sciatic nerves of DPN rats. Quercetin significantly alleviated the increased expression of TNF-α (p < 0.05) and IL-1ß (p < 0.001). Furthermore, high-dose quercetin administration significantly downregulated the expression of TLR4 (p < 0.001), MyD88 (p < 0.001), and NF-κB (p < 0.001) in sciatic nerves of DPN rats. Our findings revealed that quercetin could reduce the levels of inflammatory factors in DPN rats, possibly mediated via the downregulation of the TLR4/MyD88/NF-κB signalling pathway. Collectively, these results suggest that although quercetin did not decreased blood glucose levels or reversed the reduced body weight, it showed anti-inflammatory and neuroprotective effects, which was beneficial for the treatment of DPN.

Jinmaitong Alleviates Diabetic Neuropathic Pain Through Modulation of NLRP3 Inflammasome and Gasdermin D in Dorsal Root Ganglia of Diabetic Rats.

Jinmaitong (JMT) is a compound prescription of traditional Chinese medicine that has been used to treat diabetic neuropathic pain (DNP) for many years. Here, we investigated the effects of JMT on the activation of NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome and pyroptosis in Dorsal root ganglia (DRG) of diabetic rats. Streptozotocin (STZ)-induced diabetic rats were gavaged with JMT (0.88 g/kg/d) or alpha-lipoic acid (ALA, positive control, 0.48 mmol/kg/d) for 12 weeks. Distilled water was administered as a vehicle control to both diabetic and non-affected control rats. Blood glucose levels and body weights were measured. Behavioral changes were tested with mechanical withdrawal threshold (MWT) and tail-flick latency (TFL) tests. Morphological injury associated with DRG was observed with hematoxylin and eosin (H&E) and Nissl's staining. mRNA and protein levels of NLRP3 inflammasome components (NLRP3, ASC, caspase-1), downstream IL-1ß and gasdermin D (GSDMD) were evaluated by immunohistochemistry, quantitative real time-PCR and western blot. The results showed that JMT had no effect on blood glucose levels and body weights, but significantly improved MWT and TFL behavior in diabetic rats, and attenuated morphological damage in the DRG tissues. Importantly, JMT decreased the mRNA and protein levels of components of NLRP3 inflammasome, including NLRP3, ASC and caspase-1. JMT also down-regulated the expression of IL-1ß and GSDMD in the DRG of DNP rats. In addition, ALA treatment did not perform better than JMT. In conclusion, JMT effectively relieved DNP by decreasing NLRP3 inflammasome activation and pyroptosis, providing new evidence supporting JMT as an alternative treatment for DNP.

Efficacy and Safety of Mulberry Twig Alkaloids Tablet for the Treatment of Type 2 Diabetes: A Multicenter, Randomized, Double-Blind, Double-Dummy, and Parallel Controlled Clinical Trial.

OBJECTIVE: This study aimed to evaluate the efficacy and safety of mulberry twig alkaloids (Sangzhi alkaloids [SZ-A]) in the treatment of type 2 diabetes (T2D). RESEARCH DESIGN AND METHODS: This was a multicenter, randomized, double-blind, double-dummy, and parallel controlled noninferiority clinical trial that was conducted for 24 weeks. A total of 600 patients were randomly allocated to the SZ-A group (n = 360) or acarbose group (n = 240). The primary efficacy end point was the change of glycosylated hemoglobin (HbA1c) compared with baseline. In addition, adverse events (AEs), severe AEs (SAEs), treatment-related AEs (TAEs), and gastrointestinal disorders (GDs) were monitored. RESULTS: After treatment for 24 weeks, the change in HbA1c was -0.93% (95% CI -1.03 to -0.83) (-10.2 mmol/mol [-11.3 to -9.1]) and -0.87% (-0.99 to -0.76) (-9.5 mmol/mol [-10.8 to -8.3]) in the SZ-A and acarbose groups, respectively, and the least squares mean difference was -0.05% (95% CI -0.18 to 0.07) (-0.5 mmol/mol [-2.0 to 0.8]) between the two groups, with no significant difference on the basis of covariance analysis (P > 0.05). The incidence of TAEs and GDs was significantly lower in the SZ-A group than the acarbose group (P < 0.01), but no differences for AEs or SAEs between the two groups were observed (P > 0.05). CONCLUSIONS: SZ-A exhibited equivalent hypoglycemic effects to acarbose in patients with T2D. Nevertheless, the incidence of TAEs and GDs was lower following SZ-A treatment than acarbose treatment, suggesting good safety.

Quercetin Attenuates Diabetic Peripheral Neuropathy by Correcting Mitochondrial Abnormality via Activation of AMPK/PGC-1α Pathway in vivo and in vitro.

The AMPK/PGC-1α pathway-mediated mitochondrial dysfunction has been supposed to play a crucial role in pathogenesis of diabetic peripheral neuropathy (DPN). The present study investigated the neuroprotective potential of quercetin, a natural AMPK activator. Streptozotocin (STZ)-induced diabetic rats that developed DPN phenotype were orally administrated with quercetin (30 and 60 mg/kg per day) for 6 weeks. The morphologic changes in the sciatic nerves (SN), the pathological structure of neurons in dorsal root ganglion (DRG), and the expressions of myelin proteins were assessed. The ATP content and the mitochondrial ultrastructure were measured. Furthermore, key proteins in the AMPK/PGC-1α pathway were determined. As a result, quercetin administration at both doses improved the paw withdrawal threshold, nerve conduction velocity, and the pathologic changes in SN and DRG of DPN rats. The expressions of myelin basic protein and myelin protein zero were also increased by quercetin. The oxidative stress, decreased ATP generation, and morphological changes of mitochondria were corrected by quercetin. In vitro study found that quercetin treatment significantly decreased the high-glucose-induced generation of reactive oxygen species, as well as attenuated the mitochondrial morphologic injuries and oxidative DNA damages of RSC96 cells. Quercetin treatment promoted the expressions of phosphorylated AMPK, PGC-1α, SIRT1, NRF1, and TFAM under hyperglycemic state in vivo and in vitro. This study revealed that the neuroprotective effect of quercetin was mainly related to mitochondrial protection by activation of the AMPK/PGC-1α pathway for the first time and proved quercetin as a potential therapeutic agent in the management of diabetic neuropathy.

Jinmaitong ameliorates diabetes-induced peripheral neuropathy in rats through Wnt/ß-catenin signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Jinmaitong (JMT) is a prescription of Traditional Chinese Medicine, which is composed of ten herbal drugs and two animal drugs. It has long been used for the treatment of diabetic peripheral neuropathy (DPN). AIM OF STUDY: Wnt/ß-catenin pathway is considered as an essential and direct driver of myelinogenesis. This study aims to evaluate the protective effect of JMT against DPN dynamically during a 16-weeks' treatment, and to investigate the underlying mechanism in which the Wnt/ß-catenin pathway is involved. MATERIALS AND METHODS: Diabetic model was induced by single intraperitoneal injection of Streptozotocin (STZ) using male Sprague-Dawley rats. The model rats were divided into five groups and administrated with JMT at three doses (0.437, 0.875, and 1.75 g/kg per day), neurotropin (positive drug, 2.67 NU/kg per day), and placebo (deionized water), respectively, for continuous 8 weeks (n = 9-10), 12 weeks (n = 8-10), or 16 weeks (n = 7-9). Meanwhile, rats in control group were administrated with placebo (n = 10 for 8 weeks, n = 9 for 12 and 16 weeks, respectively). Blood glucose and body weight were monitored every four weeks. Mechanical allodynia was assessed using mechanical withdrawal threshold (MWT) test. The morphological change of sciatic nerves were observed by transmission electron microscope (TEM) and hematoxylin and eosin (HE) stain. The mRNA and protein levels of targeted genes were evaluated by quantitative real time-PCR and western bolt, respectively. Myelin protein zero (MPZ) and mediators involved in Wnt/ß-catenin pathway, such as ß-catenin, glycogen synthase kinase 3ß (GSK-3ß), and WNT inhibitory factor-1 (WIF-1), were compared among different groups after treatment of 8, 12, and 16 weeks, respectively. RESULTS: The mechanical allodynia and peripheral nerve morphology were degenerated in DPN rats over time, and notably improved after JMT-treatment of 12 and 16 weeks. The decreased MPZ level in DPN rats were also significantly amended by JMT. More importantly, we found that the suppressed Wnt/ß-catenin pathway in sciatic nerves of DPN rats was overtly up-regulated by JMT in a time-dependent manner. Among the three doses, JMT at the middle dose showed the best effect. CONCLUSIONS: JMT effectively ameliorated diabetic-induced peripheral neuropathy, which was mediated by the activation of Wnt/ß-catenin signaling pathway. This study provided new perspective to understand the neuroprotective mechanism of JMT.

Serum Adiponectin Levels Are Positively Associated With Diabetic Peripheral Neuropathy in Chinese Patients With Type 2 Diabetes.

Objective: To investigate the association between serum adiponectin levels and diabetic peripheral neuropathy (DPN) in Chinese type 2 diabetes (T2D) patients. Design and Methods: Two hundred nineteen T2D patients aged 40-79 years were divided into two groups according to whether they had DPN. The systemic levels of five biomarkers were measured using a human adipokine multiplexed bead-based immunoassay. Diabetic peripheral neuropathy diagnostic criteria included both common DPN symptoms and neurological screening tests. Results: Most features of DPN (n=98) and non-DPN patients (n=121) are similar, but the DPN patients were slightly older, had longer diabetes duration, higher hemoglobin (Hb) A1c, lower estimated glomerular filtration rates (eGFR), less exercise, and used lipid-lowering drugs more often. Serum adiponectin levels of DPN patients were higher than that of non-DPN patients (8.13 vs. 9.63 mg/ml, P = 0.004). Serum adiponectin levels were positively associated with DPN after adjusting for age, gender, body mass index, hypertension, HbA1c, alcohol intake, smoking status, physical activity, log-transformed low density lipoprotein cholesterol, lipid-lowering drug usage, eGFR, and diabetes duration {odds ratio (OR) 1.72 [95% confidence interval (CI) 1.02-2.89], P = 0.041}. The OR refers to a doubling in biomarkers. Conclusions: Serum adiponectin levels were higher in DPN patients compared to non­DPN patients in this Chinese T2D population. Serum adiponectin levels were positively associated with DPN presence, independent of multiple confounders.

Jinmaitong ameliorates diabetic peripheral neuropathy in streptozotocin-induced diabetic rats by modulating gut microbiota and neuregulin 1.

Jinmaitong (JMT), a compound prescription of traditional Chinese medicine, has long been used as a therapy for diabetic peripheral neuropathy (DPN). However, the neuroprotective mechanisms of JMT and its effect on gut microbiota remained unknown. Here, we examined the effects of JMT on behavior, pathomorphology and gut microbiota in streptozotocin (STZ)-induced DPN rats. Compared to distilled water administration, JMT reversed decreases in mechanical withdraw threshold and intraepidermal nerve fiber density, improved neurological morphology of sciatic nerves, increased serum neuregulin 1 (NRG1) level and contactin-associated protein (Caspr)-positive paranodes, and decreased amyloid precursor protein (APP) accumulation in DPN rats. More importantly, JMT enriched nine species of the gut microbiota of DPN rats, helping to prevent dysbiosis. Among these species, p_Actinobacteria, p_Proteobacteria and c_Actinobacteria were negatively correlated with DPN phenotypes and positively correlated with serum NRG1 level. These results indicate that JMT may exert a neuroprotective effect by modulating phenotype-associated gut microbiota and increasing serum NRG1 level in STZ-induced DPN rats. JMT may therefore be an effective complementary and alternative anti-DPN therapy.

Combination of Quercetin, Hirudin and Cinnamaldehyde Promotes Schwann Cell Differentiation and Myelination against High Glucose by Inhibiting ERK Signaling Pathway.

OBJECTIVE: To investigate the therapeutic and synergistic effects of QHC (combination of quercetin (Q), hirudin (H) and cinnamaldehyd (C)) on Schwann cell differentiation and myelination against high glucose (HG) induced injury. METHODS: Primary-culture Schwann cells exposed to HG (50 mmol/L) for 72 h and Schwann cell-dorsal root ganglion (DRG) neuron cocultures exposed to HG (50 mmol/L) for 7 days were employed as in vitro model of diabetic neuropathy. The cells were randomly divided into 10 groups: control (CON, 25 mmol/L glucose), HG (50 mmol/L glucose), HG plus 10 µmol/L quercetin (Q), HG plus 0.04 IU/mL hirudin (H), HG plus 100 nmol/L cinnamaldehyd (C), HG plus 10 µmol/L quercetin and 0.04 IU/mL hirudin (QH), HG plus 10 µmol/L quercetin and 50 nmol/L cinnamaldehyd (QC), HG plus 0.04 IU/mL hirudin and 50 nmol/L cinnamaldehyd (HC), HG plus 10 µmol/L quercetin, 0.04 IU/mL hirudin and 50 nmol/L cinnamaldehyd (QHC) or 10 µmol/L U0126. Cell differentiation was evaluated by periaxin immunofluorescence staining. The protein expression levels of myelin protein zero (P0), myelin basic protein (MBP), myelin-associated glycoprotein (MAG), extracellular signal-regulated kinase (ERK), p-ERK, p-c-Jun, c-Jun, notch intracellular domain (NICD) and the mRNA expression levels of P0, MBP, MAG, Krox-20, Notch1 and Jagged1 were detected by Western blotting and real-time quantitative PCR analysis. The secretion of ciliary neurotrophic factor (CNTF) was determined by enzyme-linked immunosorbent assay (ELISA). The number and length of the myelin segments were evaluated by MBP immunofluorescence staining. The expression and the location of p-ERK in cocultures were detected by MAG and p-ERK immunofluorescence double staining. RESULTS: Co-treatment with Q, C, H and their combination promoted Schwann cell differentiation, increased CNTF secretion, up-regulated the protein and mRNA expressions of myelin, and increased the number and length of the myelin segments (P<0.01 or P<0.05). In particular, the combination therapy of Q, H and C was superior to the respective monotherapy (P<0.01). Combination therapy of QHC exhibited higher inhibitory activities for ERK signaling related molecules than each monomer or the combination of the two monomers (P<0.01). CONCLUSION: QHC combination yielded synergy in promoting Schwann cell differentiation and myelination and the protective effect may involve in the inhibition of ERK signaling pathway, providing scientific evidence for better understanding of combination of Q, H and C in clinical applications.

Protective effect of quercetin on streptozotocin-induced diabetic peripheral neuropathy rats through modulating gut microbiota and reactive oxygen species level.

OBJECTIVE: Diabetic peripheral neuropathy (DPN) is a prevalent complication of diabetes with no effective drug currently. As a powerful antioxidant, the flavonoid quercetin has been demonstrated to have potential neuroprotective and prebiotic capacity. But the mechanism of its neuroprotective function and the link to the gut microbiota remains to be elucidated. METHODS: The neuroprotective effect of quercetin was evaluated on streptozotocin(STZ)-induced DPN rats through electrophysiology, behavioristic, and pathomorphology studies. Serum and urine reactive oxygen species (ROS) production levels and fecal gut microbiota compositions were detected, and the relationship between them was analyzed by Spearman's correlation. RESULTS: Quercetin not only reversed the decreased mechanical withdraw thresholds and intraepidermal nerve fiber densities in DPN rats, but also improved neurological morphology of sciatic nerves, accompanied with up-regulated percentage of paranodes at paranodal junctions, and down-regulated amyloid precursor protein and ionized calcium-binding adaptor molecule 1 in DPN rats. More importantly, quercetin rescued gut dysbiosis in DPN rats by decreasing four potential pathogenic species and enriching two prebiotic species associated with DPN phenotypes and ROS production levels. CONCLUSIONS: Quercetin exerts neuroprotective effect and modulates gut microbiota associated with DPN phenotypes and ROS production levels in STZ-induced DPN rats, suggesting the therapeutic application of quercetin for DPN prevention and treatment.

A Metabolic Insight Into the Neuroprotective Effect of Jin-Mai-Tong (JMT) Decoction on Diabetic Rats With Peripheral Neuropathy Using Untargeted Metabolomics Strategy.

Jin-Mai-Tong (JMT) decoction is a traditional Chinese compound prescription for treating diabetic peripheral neuropathy (DPN). The aim of this study is to investigate the neuroprotective effect of JMT decoction on diabetic rats with peripheral neuropathy and to elucidate the potential mechanism based on a metabolomics approach. Sprague-Dawley (SD) rats were randomly divided into four groups: control group, Streptozotocin (STZ) induced model group, JMT low dose (JMT-L) treated group and JMT high dose (JMT-H) treated group. After 12 weeks of treatment, behavioral changes, small fiber loss, and histopathological damages of sciatic nerves were estimated. Serum samples were collected for untargeted metabolomics analysis based on UPLC/QTOF-MS and multivariate statistics. As a result, JMT treatment at two dosages (13.9 and 27.8 g/kg⋅d) evidently improved the mechanical pain threshold (P < 0.05), increased the intraepidermal nerve fiber density (IENFD) and subepidermal nerve fiber density (SNFD) (P < 0.05), and renovated the demyelination and axonal atrophy of sciatic nerves on DPN rats. Furthermore, metabolomics study revealed that the serum metabolic profiles altered significantly among the control group and the STZ-induced model group. A total of 21 metabolites were identified as potential biomarkers related to the therapeutic effect of JMT decoction. Among them, 16 biomarkers were found in both JMT-H and JMT-L treated groups, while the five others were specific to JMT-H group. These metabolites mainly involved in lipid metabolism, tricarboxylic acid (TCA) cycle, amino acid metabolism, and so on. Besides, correlation analysis indicated that both mechanical pain threshold and distal nerve fiber density were negatively correlated with the serum levels of metabolites from lipid metabolism and TCA cycle. In conclusion, the results demonstrated that JMT decoction has an obvious protective effect against DPN, which could be mediated via ameliorating the metabolic disorders in diabetic rats with peripheral neuropathy.

Effects of Hirudin on High Glucose-Induced Oxidative Stress and Inflammatory Pathway in Rat Dorsal Root Ganglion Neurons.

OBJECTIVE: To investigate protective effects of hirudin on oxidative stress and apoptosis of spinal dorsal root ganglion cells in high-glucose rats at the cellular and molecular level. METHODS: Dorsal root ganglion neurons (DRGn) were harvested from embryonic day in 15 SD rats, purified and identificated after primary culture. They were divided into the normal control group, high-glucose (HG) group, positive control (alpha-lipoic acid, ALA) group, low-dose hirudin group (H1), medium-dose hirudin group (H2) and high-dose hirudin group (H3). The control group was cultured by neuron specific culture medium, while the HG group was cultured by neuron specific culture medium and 20 mmol/L glucose (HG medium). The hirudin groups were cultured by HG medium+0.25 IU/mL hirudin (H1), HG medium+0.5 IU/mL hirudin (H2) and HG medium+1 IU/mL hirudin (H3). The ALA group was cultured by HG medium+100 µ mol/L ALA. 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenylt etrazolium bromide (MTT) assay was used to explore the optimum concentration and intervention time. Flow cytometry assay was used to detect the level of reactive oxygen series (ROS). Western blot and quantificational realtime polymerase chain reaction (qRT-PCR) were used to detect the expression of protein and mRNA of nuclear factor erythroid 2-related factor 2 (Nrf-2), hemeoxygence-1 (HO-1), nuclear factor-κ B (NF-κ B) and Caspase-3. TUNEL assay was used to test the apoptosis rate of different groups. RESULTS: After 24 h of culture, the cell activity of hirudin and ALA groups were higher than that of HG group, and there was a statistical difference between the H1 group and HG group (P<0.05). In hirudin groups, the apoptosis rate of cells, the expression of activated Caspase-3 protein and Caspase-3 mRNA were lower than those of HG group (P<0.01), higher than those of ALA group (P<0.01 or P<0.05). The ROS level of hirudin groups was higher than that of ALA group (P<0.01), lower than that of HG group (P<0.01 or P<0.05). The expression of NF-κ B (P65) protein in H3 group were lower than those of HG group (P<0.05). The expression of Nrf-2 protein in hirudin groups was higher than that of HG group (P<0.01), lower than that of ALA group (P<0.01 or P<0.05). The expression of HO-1 protein in hirudin groups was lower than that of ALA group (P<0.01 or P<0.05), higher than that of HG group (P<0.01 or P<0.05). CONCLUSIONS: The activity of DRGn cells can be promoted by hirudin under HG conditions. The effects of hirudin on the inhibition of HG on DRGn cells damage mainly include scavenging ROS, up-regulating Nrf-2/HO-1 pathway, inhibiting activation of NF-κ B pathway, down-regulating the expression of and Caspase-3 and reducing DRGn cell apoptosis.

Corrigendum: Gene-Related Cerebellar Neurodegeneration in SCA3/MJD: A Case-Controlled Imaging-Genetic Study.

[This corrects the article DOI: 10.3389/fneur.2019.01025.].

Jinmaitong Ameliorates Diabetic Peripheral Neuropathy Through Suppressing TXNIP/NLRP3 Inflammasome Activation In The Streptozotocin-Induced Diabetic Rat Model.

BACKGROUND: Jinmaitong (JMT) has been used to prevent and treat diabetic peripheral neuropathy (DPN) for decades. The present study aimed to elucidate the effects of JMT on thioredoxin-interacting protein (TXNIP) and Nod-like receptor protein 3 (NLRP3) inflammasome activation in the streptozotocin (STZ)-induced rat model. METHODS: The diabetic rat model was induced by a single intraperitoneal injection of 55 mg/kg STZ. The rats were divided into 3 groups (n = 8-10 per group): diabetic control, JMT (0.876 g/kg/d), and alpha-lipoic acid (ALA; 100 mg/kg/d). Body weight and blood glucose levels were monitored every 4 weeks for 12 weeks. Mechanical allodynia and myelin sheath injury of sciatic nerves (SNs) were assessed using the mechanical withdrawal threshold (MWT) test and Luxol fast blue staining. Serum T-superoxide dismutase (T-SOD), malondialdehyde (MDA), and catalase (CAT) levels were measured using commercially available kits. TXNIP/NLRP3 inflammasome proteins, including TXNIP, NLRP3, pro-caspase-1, and cleaved -caspase-1, and the downstream protein interleukin (IL)-1ß, were measured using immunohistochemistry and Western blot. Gasdermin D (GSDMDC1) protein expression was analyzed using Western blot, and serum IL-1ß and IL-18 levels were detected using ELISA. RESULTS: JMT did not significantly affect body weight or level of fasting blood glucose but improved mechanical allodynia and myelin sheath injury of SNs at 12 weeks following treatment. Moreover, JMT increased serum levels of the anti-oxidative enzymes CAT and T-SOD, and decreased MDA levels. Both JMT and ALA decreased expression of TXNIP, NLRP3, and cleaved-caspase-1 protein. JMT and ALA also decreased IL-1ß, IL-18, and GSDMDC1 protein expression. CONCLUSION: The current study demonstrated that TXNIP/NLRP3 inflammasome activation is involved in the molecular mechanisms underlying JMT's protective effects in the STZ-induced diabetic rat model, which provides novel evidence to support the future clinical use of JMT.

Gene-Related Cerebellar Neurodegeneration in SCA3/MJD: A Case-Controlled Imaging-Genetic Study.

Background: Spinocerebellar ataxia type 3/Machado-Joseph disease (SCA3/MJD) is one of the nine polyglutamine (polyQ) diseases and is caused by a CAG repeat expansion within the coding sequence of the ATXN3 gene. Few multimodal imaging analyses of the macro- and micro-structural changes have been performed. Methods: In the present study, we recruited 31 genetically-confirmed symptomatic SCA3/MJD patients and 31 healthy subjects as controls for a multimodal neuroimaging study using structural magnetic resonance imaging (sMRI), proton magnetic resonance spectroscopy (1H-MRS) and diffusion tensor imaging (DTI). Results: The SCA3/MJD patients displayed a significantly reduced of gray matter volume in the cerebellum, pons, midbrain and medulla, as well as inferior frontal gyrus and insula, and left superior frontal gyrus. The total International Cooperative Ataxia Rating Scale (ICARS) score was inversely correlated with the gray matter volume in the cerebellar culmen, pons and midbrain. The numbers of CAG repeats in the expanded alleles were inversely correlated with the gray matter in the cerebellar culmen. NAA/Cr and NAA/Cho ratio in the middle cerebellar peduncles, dentate nucleus, cerebellar vermis, and thalamus in the SCA3/MJD patients were significantly reduced when compared to that in the normal controls, suggesting neurochemical alterations in cerebellum in the SCA3/MJD patients. Tract-Based Spatial Statistics (TBSS) analysis revealed significant lower volume and mean FA values of the cerebellar peduncles, which inversely correlated with the total scores of ICARS in our patients. Conclusions: In this study, we demonstrated cerebellar degeneration in SCA3/MJD based on tissue volume, neurochemistry, and tissue microstructure. Moreover, the associations between the clinical measures, cerebellar degeneration and genetic variation support a distinct genotype-phenotype relationship in SCA3/MJD.