Targeting GATA1 and p2x7r Locus Binding in Spinal Astrocytes Suppresses Chronic Visceral Pain by Promoting DNA Demethylation / 神经科学通报·英文版

Irritable bowel syndrome is a gastrointestinal disorder of unknown etiology characterized by widespread, chronic abdominal pain associated with altered bowel movements. Increasing amounts of evidence indicate that injury and inflammation during the neonatal period have long-term effects on tissue structure and function in the adult that may predispose to gastrointestinal diseases. In this study we aimed to investigate how the epigenetic regulation of DNA demethylation of the p2x7r locus guided by the transcription factor GATA binding protein 1 (GATA1) in spinal astrocytes affects chronic visceral pain in adult rats with neonatal colonic inflammation (NCI). The spinal GATA1 targeting to DNA demethylation of p2x7r locus in these rats was assessed by assessing GATA1 function with luciferase assay, chromatin immunoprecipitation, patch clamp, and interference in vitro and in vivo. In addition, a decoy oligodeoxynucleotide was designed and applied to determine the influence of GATA1 on the DNA methylation of a p2x7r CpG island. We showed that NCI caused the induction of GATA1, Ten-eleven translocation 3 (TET3), and purinergic receptors (P2X7Rs) in astrocytes of the spinal dorsal horn, and demonstrated that inhibiting these molecules markedly increased the pain threshold, inhibited the activation of astrocytes, and decreased the spinal sEPSC frequency. NCI also markedly demethylated the p2x7r locus in a manner dependent on the enhancement of both a GATA1-TET3 physical interaction and GATA1 binding at the p2x7r promoter. Importantly, we showed that demethylation of the p2x7r locus (and the attendant increase in P2X7R expression) was reversed upon knockdown of GATA1 or TET3 expression, and demonstrated that a decoy oligodeoxynucleotide that selectively blocked the GATA1 binding site increased the methylation of a CpG island in the p2x7r promoter. These results demonstrate that chronic visceral pain is mediated synergistically by GATA1 and TET3 via a DNA-demethylation mechanism that controls p2x7r transcription in spinal dorsal horn astrocytes, and provide a potential therapeutic strategy by targeting GATA1 and p2x7r locus binding.

Role of Autophagy in Granulocyte-Colony Stimulating Factor Induced Anti-Apoptotic Effects in Diabetic Cardiomyopathy

Background@#We previously, reported that granulocyte-colony stimulating factor (G-CSF) reduces cardiomyocyte apoptosis in diabetic cardiomyopathy. However, the underlying mechanisms are not yet fully understood. Therefore, we investigated whether the mechanisms underlying of the anti-apoptotic effects of G-CSF were associated with autophagy using a rat model of diabetic cardiomyopathy. @*Methods@#Diabetic cardiomyopathy was induced in rats through a high-fat diet combined with low-dose streptozotocin and the rats were then treated with G-CSF for 5 days. Rat H9c2 cardiac cells were cultured under high glucose conditions as an in vitro model of diabetic cardiomyopathy. The extent of apoptosis and protein levels related to autophagy (Beclin-1, microtubule-binding protein light chain 3 [LC3]-II/LC3-I ratio, and P62) were determined for both models. Autophagy determination was performed using an Autophagy Detection kit. @*Results@#G-CSF significantly reduced cardiomyocyte apoptosis in the diabetic myocardium in vivo and led to an increase in Beclin-1 level and the LC3-II/LC3-I ratio, and decreased P62 level. Similarly, G-CSF suppressed apoptosis, increased Beclin-1 level and LC3-II/LC3-I ratio, and decreased P62 level in high glucose-induced H9c2 cardiac cells in vitro. These effects of G-CSF were abrogated by 3-methyladenine, an autophagy inhibitor. In addition, G-CSF significantly increased autophagic flux in vitro. @*Conclusion@#Our results suggest that the anti-apoptotic effect of G-CSF might be significantly associated with the up-regulation of autophagy in diabetic cardiomyopathy.

Application value of totally laparoscopic transabdominal-hiatal approach in the radical resec-tion of Siewert type Ⅱ adenocarcinoma of esophagogastric junction / 中华消化外科杂志

Objective:To investigate the application value of totally laparoscopic trans-abdominal-hiatal approach in the radical resection of Siewert type Ⅱ adenocarcinoma of esophago-gastric junction (AEG).Methods:The retrospective and descriptive study was conducted. The clinicopathological data of 45 patients with Siewert type Ⅱ AEG who were admitted to the Affiliated Hangzhou First People′s Hospital, Zhejiang University School of Medicine from May 2017 to December 2020 were collected. There were 28 males and 17 females, aged from 35 to 85 years, with a median age of 64 years. All patients underwent radical resection of AEG by totally laparoscopic trans-abdominal-hiatal approach with gastrointestinal anastomosis using proximal gastrectomy with double-tract anastomosis or total gastrectomy with esophagojejunointestinal anastomosis and digestive reconstruction using transdiaphragmatic-hiatal superior overlap esophagojejunostomy. Observation indicators: (1) surgical and postoperative situations; (2) postoperative histopathological examination; (3) follow-up and survival situations. Follow-up using outpatient examination and telephone interview was performed to detect survival of patients and tumor recurrence and metastasis up to March 2021. Measurement data with normal distribution were presented as Mean± SD and measure-ment data with skewed distribution were presented as M(range). Results:(1) Surgical and post-operative situations: all 45 patients underwent radical resection of AEG by totally laparoscopic transabdominal-hiatal approach successfully, including 35 cases undergoing total gastrectomy with esophagojejunointestinal anastomosis and 10 cases undergoing proximal gastrectomy with double-tract anastomosis. The total operation time, time of lower mediastinal lymph node dissection, time of superior overlap esophagojejunostomy, volume of intraoperative blood loss, time for initial out-of-bed activities, time to first flatus, time to initial liquid diet intake, time to drainage tube removal of the 45 patients were (235±32)minutes, (25±8)minutes, (45±10)minutes, (70±13)mL, (20±8)hours, (2.3±0.2)days, (2.6±0.8)days and (6.2±1.1)days, respectively. Eleven of 45 patients under-went postoperative complications and none of patient died during perioperative period. The post-operative duration of hospital stay of 45 patients was (10±3)days. (2) Postoperative histopatho-logical examination: all 45 patients had negative upper surgical margin. The length of proximal margin, tumor diameter, total number of lymph lodes harvested and number of lower mediastinal lymph nodes harvested were (2.5±0.5)cm, (2.9±0.8)cm, 35.0±4.0 and 2.4±0.8, respectively. Patholo-gical examination showed adenocarcinoma in all 45 patients with pTNM staging as 5 cases of stage ⅠB, 8 cases of stage ⅡA, 21 cases of stage ⅡB and 11 cases of stage ⅢA. (3) Follow-up and survival situations: 45 patients were followed up for 3 to 46 months, with a median follow-up time of 26 months. During follow-up, 8 of 45 patients died. Of the 37 patients survived, 3 cases underwent liver metastasis and 3 cases underwent bone metastasis, lung metastasis or peritoneal metastasis respec-tively.Conclusion:Total laparoscopic transabdominal-hiatal approach is safe and feasible in the treatment of Siewert type II AEG with a satisfactory clinical efficacy.

Role of Autophagy in Granulocyte-Colony Stimulating Factor Induced Anti-Apoptotic Effects in Diabetic Cardiomyopathy

Background@#We previously, reported that granulocyte-colony stimulating factor (G-CSF) reduces cardiomyocyte apoptosis in diabetic cardiomyopathy. However, the underlying mechanisms are not yet fully understood. Therefore, we investigated whether the mechanisms underlying of the anti-apoptotic effects of G-CSF were associated with autophagy using a rat model of diabetic cardiomyopathy. @*Methods@#Diabetic cardiomyopathy was induced in rats through a high-fat diet combined with low-dose streptozotocin and the rats were then treated with G-CSF for 5 days. Rat H9c2 cardiac cells were cultured under high glucose conditions as an in vitro model of diabetic cardiomyopathy. The extent of apoptosis and protein levels related to autophagy (Beclin-1, microtubule-binding protein light chain 3 [LC3]-II/LC3-I ratio, and P62) were determined for both models. Autophagy determination was performed using an Autophagy Detection kit. @*Results@#G-CSF significantly reduced cardiomyocyte apoptosis in the diabetic myocardium in vivo and led to an increase in Beclin-1 level and the LC3-II/LC3-I ratio, and decreased P62 level. Similarly, G-CSF suppressed apoptosis, increased Beclin-1 level and LC3-II/LC3-I ratio, and decreased P62 level in high glucose-induced H9c2 cardiac cells in vitro. These effects of G-CSF were abrogated by 3-methyladenine, an autophagy inhibitor. In addition, G-CSF significantly increased autophagic flux in vitro. @*Conclusion@#Our results suggest that the anti-apoptotic effect of G-CSF might be significantly associated with the up-regulation of autophagy in diabetic cardiomyopathy.

Role of MicroRNA-34a in Anti-Apoptotic Effects of Granulocyte-Colony Stimulating Factor in Diabetic Cardiomyopathy

BACKGROUND: Recent studies have shown that microRNAs (miRNAs) are involved in the process of cardiomyocyte apoptosis. We have previously reported that granulocyte-colony stimulating factor (G-CSF) ameliorated diastolic dysfunction and attenuated cardiomyocyte apoptosis in a rat model of diabetic cardiomyopathy. In this study, we hypothesized a regulatory role of cardiac miRNAs in the mechanism of the anti-apoptotic effect of G-CSF in a diabetic cardiomyopathy rat model.METHODS: Rats were given a high-fat diet and low-dose streptozotocin injection and then randomly allocated to receive treatment with either G-CSF or saline. H9c2 rat cardiomyocytes were cultured under a high glucose (HG) condition to induce diabetic cardiomyopathy in vitro. We examined the extent of apoptosis, miRNA expression, and miRNA target genes in the myocardium and H9c2 cells.RESULTS: G-CSF treatment significantly decreased apoptosis and reduced miR-34a expression in diabetic myocardium and H9c2 cells under the HG condition. G-CSF treatment also significantly increased B-cell lymphoma 2 (Bcl-2) protein expression as a target for miR-34a. In addition, transfection with an miR-34a mimic significantly increased apoptosis and decreased Bcl-2 luciferase activity in H9c2 cells.CONCLUSION: Our results indicate that G-CSF might have an anti-apoptotic effect through down-regulation of miR-34a in a diabetic cardiomyopathy rat model.

Overexpression of Purinergic P2X4 Receptors in Hippocampus Rescues Memory Impairment in Rats with Type 2 Diabetes / 神经科学通报·英文版

Purinergic receptors have been reported to be involved in brain disorders. In this study, we explored their roles and mechanisms underlying the memory impairment in rats with type 2 diabetes mellitus (T2DM). T2DM rats exhibited a worse performance in the T-maze and Morris water maze (MWM) than controls. Microglia positive for P2X purinoceptor 4 (P2X4R) in the hippocampus were reduced and activated microglia were increased in T2DM rats. Long Amplicon PCR (LA-PCR) showed that DNA amplification of the p2x4r gene in the hippocampus was lower in T2DM rats. Minocycline significantly reduced the number of activated microglia and the mean distance traveled by T2DM rats in the MWM. Most importantly, P2X4R overexpression suppressed the activated microglia and rescued the memory impairment of T2DM rats. Overall, T2DM led to excessive activation of microglia in the hippocampus, partly through the DNA damage-mediated downregulation of P2X4Rs, thus contributing to memory impairment.

Decreased miR-325-5p Contributes to Visceral Hypersensitivity Through Post-transcriptional Upregulation of CCL2 in Rat Dorsal Root Ganglia / 神经科学通报·英文版

Chronic visceral hypersensitivity is an important type of chronic pain with unknown etiology and pathophysiology. Recent studies have shown that epigenetic regulation plays an important role in the development of chronic pain conditions. However, the role of miRNA-325-5p in chronic visceral pain remains unknown. The present study was designed to determine the roles and mechanism of miRNA-325-5p in a rat model of chronic visceral pain. This model was induced by neonatal colonic inflammation (NCI). In adulthood, NCI led to a significant reduction in the expression of miRNA-325-5p in colon-related dorsal root ganglia (DRGs), starting to decrease at the age of 4 weeks and being maintained to 8 weeks. Intrathecal administration of miRNA-325-5p agomir significantly enhanced the colorectal distention (CRD) threshold in a time-dependent manner. NCI also markedly increased the expression of CCL2 (C-C motif chemokine ligand 2) in colon-related DRGs at the mRNA and protein levels relative to age-matched control rats. The expression of CXCL12, IL33, SFRS7, and LGI1 was not significantly altered in NCI rats. CCL2 was co-expressed in NeuN-positive DRG neurons but not in glutamine synthetase-positive glial cells. Furthermore, CCL2 was mainly expressed in isolectin B4-binding- and calcitonin gene-related peptide-positive DRG neurons but in few NF-200-positive cells. More importantly, CCL2 was expressed in miR-325-5p-positive DRG neurons. Intrathecal injection of miRNA-325-5p agomir remarkably reduced the upregulation of CCL2 in NCI rats. Administration of Bindarit, an inhibitor of CCL2, markedly raised the CRD threshold in NCI rats in a dose- and time-dependent manner. These data suggest that NCI suppresses miRNA-325-5p expression and enhances CCL2 expression, thus contributing to visceral hypersensitivity in adult rats.

Neonatal Maternal Deprivation Followed by Adult Stress Enhances Adrenergic Signaling to Advance Visceral Hypersensitivity / 神经科学通报·英文版

The pathophysiology of visceral pain in patients with irritable bowel syndrome remains largely unknown. Our previous study showed that neonatal maternal deprivation (NMD) does not induce visceral hypersensitivity at the age of 6 weeks in rats. The aim of this study was to determine whether NMD followed by adult stress at the age of 6 weeks induces visceral pain in rats and to investigate the roles of adrenergic signaling in visceral pain. Here we showed that NMD rats exhibited visceral hypersensitivity 6 h and 24 h after the termination of adult multiple stressors (AMSs). The plasma level of norepinephrine was significantly increased in NMD rats after AMSs. Whole-cell patch-clamp recording showed that the excitability of dorsal root ganglion (DRG) neurons from NMD rats with AMSs was remarkably increased. The expression of β adrenergic receptors at the protein and mRNA levels was markedly higher in NMD rats with AMSs than in rats with NMD alone. Inhibition of β adrenergic receptors with propranolol or butoxamine enhanced the colorectal distention threshold and application of butoxamine also reversed the enhanced hypersensitivity of DRG neurons. Overall, our data demonstrate that AMS induces visceral hypersensitivity in NMD rats, in part due to enhanced NE-β adrenergic signaling in DRGs.

Modified overlap esophagojejunostomy in digestive tract reconstruction after laparoscopic total gastrectomy for gastric carcinoma / 中华普通外科杂志

Objective@#To evaluate modified overlap esophagojejunostomy in digestive tract reconstruction of totally laparoscopie total gastrectomy(TLTG)in patients of gastric carcinoma.@*Methods@#The clinicalpathological data of 68 patients admitted to Hangzhou First People′s Hospital from Jun 2015 to Aug 2018 Undergoing totally laparoscopie total gastrectomy and modified overlap esophagojejunostomy were analyzed retrospectively.@*Results@#Procedures were successful in all 68 patients without conversion to open surgery and no perioperative death.The operation time, esophagojejunostomy time, volume of intraoperative blood loss and incision length were respectively (210±30)min, (25±12)min, (50±20)ml and(3.5±1.1)cm. Time for initial out of bed activity, time of initial anal exsufflation, time for postoperative fluid diet intake and duration of postoperative hospital stay were (24±8)h, (2.4±0.5)d, (3.1±0.8)d, and (8±3.6)d. There was anastomotic fistula in one and recovered by conservative treatment, total number of harvested LNs in 68 patients were (38.9±2.3). By pTNM staging: 6 cases in stage ⅠB, 10 cases in stage ⅡA, 20 cases in stage ⅡB , 15 cases in stage ⅢA, 12 cases in stage ⅢB, 5 cases in stage ⅢC. 59 patients were followed up from 3 to 42 months. One with liver metastasis after 22 months, others were all tumor-free.@*Conclusion@#The modified overlap esophagojejunostomy method is safe and feasible in digestive tract reconstruction of totally laparoscopie total gastrectomy for gastric carcinoma.

Fecal microbiota transplantation as a novel therapy for severe psoriasis / 中华内科杂志

To explore the therapeutic effect of fecal microbiota transplantation (FMT) for severe psoriasis. A patient, male, 36 years old, diagnosed as severe plaque psoriasis for 10 years and irritable bowel syndrome (IBS) for 15 years, was administrated twice FMT via both upper endoscopy and colonoscopy with a 5-week interval. The following items were used to evaluate responses: body surface area (BSA), psoriasis area and severity index (PASI), dermatology life quality index (DLQI), histological examination, intestinal symptoms, adverse reactions and serum level of tumor necrosis factor (TNF)-α. After second FMT treatment for 5 weeks, aforementioned items were improved greatly compared with those before treatment. Moreover, IBS was completely relieved and no adverse reactions were observed during the treatment and follow-up. In conclusion, FMT could be a novel therapy for psoriasis. Further clinical trials are needed to provide solid evidences.

Modified overlap esophagojejunostomy in digestive tract reconstruction after laparoscopic total gastrectomy for gastric carcinoma / 中华普通外科杂志

Objective To evaluate modified overlap esophagojejunostomy in digestive tract reconstruction of totally laparoscopie total gastrectomy (TLTG) in patients of gastric carcinoma.Methods The clinicalpathological data of 68 patients admitted to Hangzhou First People's Hospital from Jun 2015 to Aug 2018 Undergoing totally laparoscopie total gastrectomy and modified overlap esophagojejunostomy were analyzed retrospectively.Results Procedures were successful in all 68 patients without conversion to open surgery and no perioperative death.The operation time,esophagojejunostomy time,volume of intraoperative blood loss and incision length were respectively (210 ±30)min,(25 ± 12)min,(50 ±20)ml and(3.5 ± 1.1) cm.Time for initial out of bed activity,time of initial anal exsufflation,time for postoperative fluid diet intake and duration of postoperative hospital stay were (24 ± 8) h,(2.4 ± 0.5) d,(3.1 ± 0.8) d,and (8 ± 3.6) d.There was anastomotic fistula in one and recovered by conservative treatment,total number of harvested LNs in 68 patients were (38.9 ±2.3).By pTNM staging:6 cases in stage Ⅰ B,10 cases in stage ⅡA,20 cases in stage ⅡB,15 cases in stage ⅢA,12 cases in stage ⅢB,5 cases in stage ⅢC.59 patients were followed up from 3 to 42 months.One with liver metastasis after 22 months,others were all tumor-free.Conclusion The modified overlap esophagojejunostomy method is safe and feasible in digestive tract reconstruction of totally laparoscopie total gastrectomy for gastric carcinoma.

Fecal microbiota transplantation as a novel therapy for severe psoriasis / 中华内科杂志

[Summary] To explore the therapeutic effect of fecal microbiota transplantation (FMT) for severe psoriasis. A patient, male, 36 years old, diagnosed as severe plaque psoriasis for 10 years and irritable bowel syndrome (IBS) for 15 years, was administrated twice FMT via both upper endoscopy and colonoscopy with a 5‐week interval. The following items were used to evaluate responses: body surface area (BSA), psoriasis area and severity index (PASI), dermatology life quality index (DLQI), histological examination, intestinal symptoms, adverse reactions and serum level of tumor necrosis factor (TNF)‐α. After second FMT treatment for 5 weeks, aforementioned items were improved greatly compared with those before treatment. Moreover, IBS was completely relieved and no adverse reactions were observed during the treatment and follow‐up. In conclusion, FMT could be a novel therapy for psoriasis. Further clinical trials are needed to provide solid evidences.

Application value of totally laparoscopic transabdominal-hiatal approach in the radical resection of Siewert type Ⅱ adenocarcinoma of esophagogastric junction / 中华消化外科杂志

Objective To investigate the safety and feasibility of totally laparoscopic transabdominalhiatal approach in the treatment of Siewert type Ⅱ adenocarcinoma of esophagogastric junction (AEG).Methods The retrospective and descriptive study was conducted.The clinicopathological data of 11 patients with Siewert type Ⅱ AEG who were admitted to Affiliated Hangzhou First People's Hospital of Zhejiang University School of Medicine from May 2017 to July 2018 were collected.There were 8 males and 3 females,aged 56-72 years,with an average age of 63 years.Patients underwent radical resection of AEG by totally laparoscopic transabdominalhiatal approach.Observation indicators:(1) surgical situations and postoperative recovery;(2) postoperative pathological examination;(3) follow-up and survival situations.Follow-up using outpatient examination and telephone interview was performed to detect postoperative adjuvant chemotherapy,complications,food intake,anastomosis patency,tumor recurrence and metastasis,and survival up to December 2018.Measurement data with normal distribution were presented as Mean±SD,measurement data with skewed distribution were presented as M (range),and count data were represented as absolute number or percentage.Results (1) Surgical situations and postoperative recovery:all the patients underwent totally laparoscopic radical resection of Siewert type Ⅱ AEG by transabdominal-hiatal approach,without conversion to open surgery or perioperative death.Of the 11 patients,8 underwent total gastrectony including 3 combined with splenic hilar lymph node dissection and 3 underwent proximal gastrectomy with double-tract reconstruction.Operation time,time of superior overlap esophagojejunostomy,volume of intraoperative blood loss,time for initial out-of-bed activities,time to first flatus,time to initial liquid diet intake,time of drainage tube removal were respectively (245± 39)minutes,(60± 12) minutes,(75±23) mL,(24± 8) hours,(2.4± 0.5) days,(3.5 ± 0.8) days,(8.2 ± 1.3) days respectively.There was no serious complication including postoperative hemorrhage,anatomotic fistula or death.Three patients had left pleural effusion,and were cured after thoracic drainage.The duration of postoperative hospital stay was (11.0±3.0) days.(2) Postoperative pathological examination:all the 11 patients had negative upper surgical margin.The length of proximal margin,tumor diameter,total number of lymph lodes harvested,and number of lower mediastinal lymph lodes harvested were (2.1 ±0.2) cm,(2.6±0.9) cm,(36.0±4.0)/case and (2.3± 0.8)/case.Pathological examination showed adenocarcinoma in all the 11 patients.pTNM staging:2 cases were in stage Ⅰ B,4 cases in stage Ⅱ A,3 cases in stage Ⅱ B and 2 cases in stage Ⅲ A.(3) Follow-up and survival situations:11 patients were follow-up for 6-19 months,with a median time of 9 months.Chemotherapy regimeus were formulated according to the pathological examination.Nine patients received postoperative adjuvant chemotherapy,and 2 in stage Ⅱ B received no postoperative adjuvant chemotherapy.During the follow-up,11 patients had no obvious reflux symptom or choking feeling,and the anastomosis was patent as evaluated by oral contrast agent and gastroscopy.There was no tumor recurrence and metastasis or death in the 11 patients.Conclusion Totally laparoscopic transabdominal-hiatal approach applied in the radical resection is safe and feasible for the treatment of Siewert type Ⅱ AEG,with good short-term outcomes.

Analysis on the specificity of the relevant points along the governor vessel in chronic gastritis based on tenderness reaction and tenderness threshold / 中国针灸

OBJECTIVE@#To explore the specificity of the relevant points along the governor vessel in chronic gastritis through the synchronous observation of the tenderness reaction and tenderness threshold on the back along the governor vessel in the volunteers with chronic gastritis and make the comparison with healthy volunteers.@*METHODS@#A chronic gastritis group and a healthy volunteer group were prepared, 30 cases in each one. Using synchronous comparison, the tenderness reaction at the point inferior to each of the spinous processes from T to L along the governor vessel was observed. The mechanical pressure pain threshold was determined.@*RESULTS@#Regarding the tenderness reaction at the point inferior to each spinous process on the back along the governor vessel, the occurrence rate was different significantly between the chronic gastritis group and the healthy volunteer group (0.05).@*CONCLUSION@#The point inferior to the spoinous process of T on the governor vessel, Shendao (GV 11, T) and Lingtai (GV 10, T) are the points with the high specificity in chronic gastritis, which provides the reference to clinical treatment with acupuncture and moxibustion. The occurrence rate of high tenderness reaction and the low tenderness threshold may be the important manifestation of the point specificity on the back along the governor vessel in chronic gastritis.

The glymphatic system: concept, function and research progresses / 生理学报

The glymphatic system is a cerebrospinal fluid-interstitial fluid exchange system dependent on the water channel aquaporin-4 polarized on astrocyte endfeet, which is proposed to account for the clearance of abnormal proteins (e.g. β-amyloid) and metabolites (e.g. lactate) from the brain. Accumulating studies have revealed that glymphatic activity during sleep and general anesthesia is dramatically enhanced, while its function is significantly damaged during aging, traumatic brain injury, Alzheimer's disease, stroke, and diabetes. The glymphatic hypothesis is a breakthrough in the field of neuroscience recently, which would considerably enhance our comprehension on the cerebrospinal fluid circulation and its role in the maintenance of brain homeostasis. In this review, we briefly introduced the conceptualization of glymphatic system, summarized the recent progresses, and prospected its future investigation and potential clinical application.

Protein Kinase C Mediates the Corticosterone-induced Sensitization of Dorsal Root Ganglion Neurons Innervating the Rat Stomach

BACKGROUND/AIMS: Gastric hypersensitivity contributes to abdominal pain in patients with functional dyspepsia. Recent studies showed that hormones induced by stress are correlated with visceral hypersensitivity. However, the precise mechanisms underlying gastric hypersensitivity remain largely unknown. The aim of the present study was designed to investigate the roles of corticosterone (CORT) on excitability of dorsal root ganglion (DRG) neurons innervating the stomach. METHODS: DRG neurons innervating the stomach were labeled by DiI injection into the stomach wall. Patch clamp recordings were employed to examine neural excitability and voltage-gated sodium channel currents. Electromyograph technique was used to determine the responses of neck muscles to gastric distension. RESULTS: Incubation of acutely isolated DRG neurons with CORT significantly depolarized action potential threshold and enhanced the number of action potentials induced by current stimulation of the neuron. Under voltage-clamp mode, incubation of CORT enhanced voltage-gated sodium current density of the recorded neurons. Pre-incubation of GF109203X, an inhibitor of protein kinase C, blocked the CORT-induced hyperexcitability and potentiation of sodium currents. However, pre-incubation of H-89, an inhibitor of protein kinase A, did not alter the sodium current density. More importantly, intraperitoneal injection of CORT produced gastric hypersensitivity of healthy rats, which was blocked by pre-administration of GF109203X but not H-89. CONCLUSIONS: Our data strongly suggest that CORT rapidly enhanced neuronal excitability and sodium channel functions, which is most likely mediated by protein kinase C but not protein kinase A signaling pathway in DRG neurons innervating the stomach, thus underlying the gastric hypersensitivity induced by CORT injection.

Local Injection of Granulocyte-Colony Stimulating Factor Accelerates Wound Healing in a Rat Excisional Wound Model

A systemic treatment of granulocyte-colony stimulating factor (G-CSF) is known to improve healings of damaged tissues. However, recent studies suggested local actions of G-CSF on the healing processes of damaged tissues. We investigated the treatment effect of locally injected G-CSF and compared to that of systemically injected G-CSF in a rat model. A wound was created on the rat dorsum and treated either by local injection or by systemic injection of G-CSF. Wound healing rate, deposition of collagen, and gene expression were evaluated. G-CSF receptor (G-CSFR) protein was detected by Western blotting. The wound healing rate in the local injection group was significantly higher than that in the systemic injection group at days 9 and 15; it was also significantly higher than that in the control group at days 3, 9, and 15. The expression of G-CSFR protein in wound tissues was higher than in normal skin tissues. The local injection of G-CSF is more effective than systemic injection of G-CSF in promoting wound healing, which may implicate the local action of G-CSF treatment in wound healing processes.

Upregulation of cystathionine β-synthetase in the arcuate nucleus produces pain hypersensitivity via PKC upregulation and GluN2B phosphorylation in rats with chronic pancreatitis / 生理学报

Hydrogen sulfide (HS) contributes to visceral hyperalgesia in primary sensory neurons, but its role in central nervous system remains largely unknown. This study was to investigate the roles and underlying mechanisms of HS and its endogenous synthesis enzymes in the arcuate nucleus (ARC) in rat pancreatic hyperalgesia. Chronic pancreatitis (CP) was induced in male adult Sprague-Dawley rats by intra-pancreatic ductal injection of trinitrobenzene sulfonic acid (TNBS). Abdominal hyperalgesia was assessed by referred somatic behaviors to mechanical stimulation of rat abdomen. Western blot analysis was performed to detect protein expression in the ARC. CP markedly upregulated cystathionine β-synthetase (CBS) expression but did not alter cystathionine-γ-lyase level in the ARC at 4 weeks after TNBS injection. Although the expression of total GluN2B was not altered, CP greatly enhanced the phosphorylation level of GluN2B in the ARC when compared with age- and sex-matched control rats. CP also significantly increased expression of protein kinase Cγ (PKCγ) in the ARC. Arcuate microinjection of O-(Carboxymethyl) hydroxylamine hemihydrochloride (AOAA, an inhibitor of CBS) significantly attenuated abdominal pain in CP rats in a dose-dependent manner and reversed the CP-induced upregulation of p-GluN2B and PKCγ in the ARC. Furthermore, the GluN2B inhibitor or specific PKC inhibitor chelerythrine significantly attenuated abdominal hyperalgesia in CP rats. The p-GluN2B expression was also suppressed by PKC inhibitor. Taken together, our results suggest that the upregulation of CBS in the ARC leads to an activation of GluN2B via PKCγ, which may play an important role in generation of pain hypersensitivity of CP.

Colonic Hypersensitivity and Sensitization of Voltage-gated Sodium Channels in Primary Sensory Neurons in Rats with Diabetes

BACKGROUND/AIMS: Patients with long-standing diabetes often demonstrate intestinal dysfunction and abdominal pain. However, the pathophysiology of abdominal pain in diabetic patients remains elusive. The purpose of study was to determine roles of voltage-gated sodium channels in dorsal root ganglion (DRG) in colonic hypersensitivity of rats with diabetes. METHODS: Diabetic models were induced by a single intraperitoneal injection of streptozotocin (STZ; 65 mg/kg) in adult female rats, while the control rats received citrate buffer only. Behavioral responses to colorectal distention were used to determine colonic sensitivity in rats. Colon projection DRG neurons labeled with DiI were acutely dissociated for measuring excitability and sodium channel currents by whole-cell patch clamp recordings. Western blot analysis was employed to measure the expression of NaV1.7 and NaV1.8 of colon DRGs. RESULTS: STZ injection produced a significantly lower distention threshold than control rats in responding to colorectal distention. STZ injection also depolarized the resting membrane potentials, hyperpolarized action potential threshold, decreased rheobase and increased frequency of action potentials evoked by 2 and 3 times rheobase and ramp current stimulation. Furthermore, STZ injection enhanced neuronal sodium current densities of DRG neurons innervating the colon. STZ injection also led to a significant upregulation of NaV1.7 and NaV1.8 expression in colon DRGs compared with age and sex-matched control rats. CONCLUSIONS: Our results suggest that enhanced neuronal excitability following STZ injection, which may be mediated by upregulation of NaV1.7 and NaV1.8 expression in DRGs, may play an important role in colonic hypersensitivity in rats with diabetes.

Acute Effects of Transforming Growth Factor-β1 on Neuronal Excitability and Involvement in the Pain of Rats with Chronic Pancreatitis

BACKGROUND/AIMS: This study was to investigate whether transforming growth factor-β1 (TGF-β1) plays a role in hyperalgesia in chronic pancreatitis (CP) and the underlying mechanisms. METHODS: CP was induced in male adult rats by intraductal injection of trinitrobenzene sulfonic acid (TNBS). Abdominal hyperalgesia was assessed by referred somatic behaviors to mechanical stimulation of rat abdomen. Dil dye injected into the pancreas was used to label pancreas-specific dorsal root ganglion (DRG) neurons. Whole cell patch clamp recordings and calcium imaging were performed to examine the effect of TGF-β1 on acutely isolated pancreas-specific DRG neurons. Western blot analysis was carried out to measure the expression of TGF-β1 and its receptors. RESULTS: TNBS injection significantly upregulated expression of TGF-β1 in the pancreas and DRGs, and TGF-β1 receptors in DRGs (T9-T13) in CP rats. Intrathecal injection of TGF-β receptor I antagonist SB431542 attenuated abdominal hyperalgesia in CP rats. TGF-β1 application depolarized the membrane potential and caused firing activity of DRG neurons. TGF-β1 application also reduced rheobase, hyperpolarized action potential threshold, and increased numbers of action potentials evoked by current injection of pancreas-specific DRG neurons. TGF-β1 application also increased the concentration of intracellular calcium of DRG neurons, which was inhibited by SB431542. Furthermore, intrathecal injection of TGF-β1 produced abdominal hyperalgesia in healthy rats. CONCLUSIONS: These results suggest that TGF-β1 enhances neuronal excitability and increases the concentration of intracellular calcium. TGF-β1 and its receptors are involved in abdominal hyperalgesia in CP. This and future study might identify a potentially novel target for the treatment of abdominal pain in CP.