Central GLP-1 Resistance Induced by Severe Traumatic Brain Injury Was Associated with Persistent Hyperglycemia in Humans.

INTRODUCTION: Whether central glucagon-like peptide 1 (GLP-1)/GLP-1 receptor system mediated peripheral glucose homeostasis in patients with traumatic brain injury (TBI) is not clear. We aim to determine if plasma GLP-1 level could distinguish the non-survivors from the survivors during the first 14 days after TBI that could prognose 6 months mortality. METHODS: Metabolic, inflammatory, and hematologic profiles were examined in 73 patients with TBI in neurological intensive care unit. Factors that discriminate non-survivors from survivors were determined by two-way ANOVA. Biomarkers associated with mortality were determined by binary logistic regression and Cox proportional hazard regression. RESULTS: The non-survivors had higher infectious SOFA scores (p < 0.001), lower first 3 days' body temperature (p = 0.017), greater chance of cerebral hernia (p = 0.048), and decompressive craniectomy (p = 0.001) than the survivors. Higher 14-day plasma GLP-1 (p < 0.0001), glucose (p = 0.002), and IL-6 (p = 0.005) levels, in contrast with lower insulin level at days 4-7 (p = 0.020) were found in non-survivors than in survivors. Except the survivors who had an increased 14-day platelet number (p < 0.001), the two groups did not differ in hematological profile and intestinal barrier function. Although GLP-1 correlated closely with IL-6 in both the groups, it correlated with neither insulin nor glucose in each group. GLP-1 on days 8-10 and IL-6 on days 1-3 were positively, while insulin on days 4-7 was negatively associated with mortality. CONCLUSION: Persistent higher GLP-1 level in non-survivors over the survivors may present more severe central resistance to endogenous GLP-1 in non-survivors, which may be associated with progressive hyperglycemia with increased mortality in TBI.

Prognostic Significance of Plasma Insulin Level for Deep Venous Thrombosis in Patients with Severe Traumatic Brain Injury in Critical Care.

BACKGROUND: Whether insulin resistance underlies deep venous thrombosis (DVT) development in patients with severe traumatic brain injury (TBI) is unclear. In this study, the association between plasma insulin levels and DVT was analyzed in patients with severe TBI. METHODS: A prospective observational study of 73 patients measured insulin, glucose, glucagon-like peptide 1 (GLP-1), inflammatory factors, and hematological profiles within four preset times during the first 14 days after TBI. Ultrasonic surveillance of DVT was tracked. Two-way analysis of variance was used to determine the factors that discriminated between patients with and without DVT or with and without insulin therapy. Partial correlations of insulin level with all the variables were conducted separately in patients with DVT or patients without DVT. Factors associated with DVT were analyzed by multivariable logistic regression. Neurological outcomes 6 months after TBI were assessed. RESULTS: Among patients with a mean (± standard deviation) age of 53 (± 16 years), DVT developed in 20 patients (27%) on median 10.4 days (range 4-22), with higher Acute Physiology and Chronic Health Evaluation II scores but similar Sequential Organ Failure Assessment scores and TBI severity. Patients with DVT were more likely to receive insulin therapy than patients without DVT (60% vs. 28%; P = 0.012); hence, they had higher 14-day insulin levels. However, insulin levels were comparable between patients with DVT and patients without DVT in the subgroups of patients with insulin therapy (n = 27) and patients without insulin therapy (n = 46). The platelet profile significantly discriminated between patients with and without DVT. Surprisingly, none of the coagulation profiles, blood cell counts, or inflammatory mediators differed between the two groups. Patients with insulin therapy had significantly higher insulin (P = 0.006), glucose (P < 0.001), and GLP-1 (P = 0.01) levels and were more likely to develop DVT (60% vs. 15%; P < 0.001) along with concomitant platelet depletion. Insulin levels correlated with glucose, GLP-1 levels, and platelet count exclusively in patients without DVT. Conversely, in patients with DVT, insulin correlated negatively with GLP-1 levels (P = 0.016). Age (P = 0.01) and elevated insulin levels at days 4-7 (P = 0.04) were independently associated with DVT. Patients with insulin therapy also showed worse Glasgow Outcome Scale scores (P = 0.001). CONCLUSIONS: Elevated insulin levels in the first 14 days after TBI may indicate insulin resistance, which is associated with platelet hyperactivity, and thus increasing the risk of DVT.

Differentiated expressed miRNAs in splenic monocyte induced by burn injury in mice.

To find potential biomarkers based on miRNA and their potential targets in splenic monocytes in burn-injured mice. Male Balb/c mice were subjected to sham or scalding injury of 15% total body surface area. Spenic CD11b+ monocytes were purified with magnetic beads. The monocytes were cultured in the presence of lipopolysaccharide. The proliferation of monocytes was detected by MTT assay, and the cytokines in the supernatant were examined by enzyme linked immunosorbent assay. The purified monocytes were also under total RNA extraction. The differential monocytic miRNAs expression between the sham and burn-injured mice was analysed by miRNA microarray. The activity of monocytes was comparable between the two groups (p > 0.05). However, monocytes from burn-injured mice secreted higher levels of tumour necrosis factor (TNF)-α and transforming growth factor-ß, but lower level of monocyte chemoattratctant protein-1. A total of 54 miRNAs were differentially expressed in monocytes from burn relative to sham-injured mice (fold >3). Further quantitative reverse transcription polymerase chain reaction confirmed that the expression of miR-146a was significantly down-regulated, while miR-3091-6p was up-regulated after burn injury. Using the combination of Miranda and TargetScan softwares, we found that mir-146a may regulate 180 potential target genes including TNF receptor related factor 6 (TRAF6), interleukin-1 receptor related kinase 1 (IRAK1) and CD28. Mir-3091-6p may regulate 39 potential targets, including SOCS7 (cytokine signal transduction inhibitor 7) and ARRB2 (arrestin, ß 2). The miRNAs expressed by monocytes after burn injury may be involved in the regulation of innate immune response in burn injury.

Exendin-4 Exacerbates Burn-Induced Mortality in Mice by Switching to Th2 Response.

INTRODUCTION: To determine if Exendin-4 could be a therapeutic agent for burn-induced hyperglycemia. MATERIALS AND METHODS: Male Balb/c mice received a bolus of Exendin-4 intraperitoneally immediately after 15% total body surface area scald injury. Tail glucose levels were recorded and T-cell functions were analyzed at 4 h and 24 h postburn (pb). Pancreatic pathology was observed consecutively. The secretions of cytokines were detected in serum, spleen, and lung. Apoptosis of splenic CD3+ T-cells was examined by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling and flow cytometry. RESULTS: Although Exendin-4 could attenuate burn-induced hyperglycemia in mice at 4 h pb, it accelerated their survival dose dependently with progressive depletion of splenocyte number. T-cell function underwent two-phasic changes following Exendin-4 treatment. Compared to placebo mice, T-cell from Exendin-4-treated mice was manifested with increased proliferation, while decreased IL-2 secretion and lower ratio of IL-4/IFN-γ at 4 h pb. However, at 24 h pb, it showed decreased proliferation, while increased IL-2 secretion and higher ratio of IL-4/IFN-γ. Exendin-4 could elicit higher circulating IL-6 and IL-10 levels at 4 h pb, which were pronounced in the lung at 24 h pb. In the meanwhile, severe inflammation could be found in the pancreas. At 24 h pb, the numbers of terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling or caspase-3 positive cells and the apoptosis of CD3+ T-cells were significantly increased in the spleens of Exendin-4 mice relative to placebo mice. CONCLUSIONS: These data support a pathogenic role of Exendin-4 signaling during thermal injury, warning against its clinical application in acute insults.

Exendin-4 Exacerbates Burn-Induced Morbidity in Mice by Activation of the Sympathetic Nervous System.

BACKGROUND: Although glucagon-like peptide 1- (GLP-1-) based therapy of hyperglycemia in burn injury has shown great potential in clinical trials, its safety is seldom evaluated. We hypothesize that exendin-4, a GLP-1 analogue, might affect the immune response via the activation of the sympathetic nervous system in burn injury. METHODS: Male Balb/c mice were subjected to sham or thermal injury of 15% total body surface area. Exendin-4 on T cell function in vitro was examined in cultured splenocytes in the presence of ß-adrenoceptor antagonist propranolol (1 nmol/L) or GLP-1R antagonist exendin (9-39) (1 µmol/L), whereas its in vivo effect was determined by i.p. injection of exendin-4 (2.4 nmol/kg) in mice. To further elucidate the sympathetic mechanism, propranolol (30 mg/kg) or vehicle was applied 30 min prior to injury. RESULTS: Although the exacerbated burn-induced mortality by exendin-4 was worsened by propranolol pretreatment, the inhibition of T cell proliferation by exendin-4 in vitro could be restored by propranolol instead of exendin (9-39). However, a Th2 switch by exendin-4 in vitro could only be reversed by exendin (9-39). Likewise, the inhibition of splenic T cell function and NFAT activity by exendin-4 in vivo was restored by propranolol. By contrast, the increased splenic NF-κB translocation by exendin-4 in vivo was potentiated by propranolol in sham mice but suppressed in burn mice. Accordingly, propranolol abrogated the heightened inflammatory response in the lung and the accelerated organ injuries by exendin-4 in burn mice. On the contrary, a Th2 switch and higher serum levels of inflammatory mediators by exendin-4 were potentiated by propranolol in burn mice. Lastly, exendin-4 raised serum stress hormones which could be remarkably augmented by propranolol. CONCLUSIONS: Exendin-4 suppresses T cell function and promotes organ inflammation through the activation of the sympathetic nervous system, while elicits Th2 switch via GLP-1R in burn injury.

Proinflammatory switch from Gαs to Gαi signaling by Glucagon-like peptide-1 receptor in murine splenic monocyte following burn injury.

OBJECTIVE: Glucagon-like peptide-1 (GLP-1)-based therapy via G protein-coupled receptor (GPCR) GLP-1R, to attenuate hyperglycemia in critical care has attracted great attention. However, the exaggerated inflammation by GLP-1R agonist, Exendin-4, in a mouse model of burn injury was quite unexpected. Recent studies found that GPCR might elicit proinflammatory effects by switching from Gαs to Gαi signaling in the immune system. Thus, we aimed to investigate the possible Gαs to Gαi switch in GLP-1R signaling in monocyte following burn injury. MATERIALS AND METHODS: Splenic monocytes from sham and burn mice 24 h following burn injury were treated with consecutive doses of Exendin-4 alone or in combination with an inhibitor of Gαi signaling (pertussis toxin, PTX), or a blocker of protein kinase A (H89). Cell viability was assessed by CCK-8, and the supernatant was collected for cytokine measurement by ELISA. Intracellular cAMP level, phosphorylated PKA activity, and nuclear NF-κB p65 were determined by ELISA, ERK1/2 activation was analyzed by Western blot. The expression of GLP-1R downstream molecules, Gαs, Gαi and G-protein coupled receptor kinase 2 (GRK2) were examined by immunofluorescence staining and Western blot. RESULTS: Exendin-4 could inhibit the viability of monocyte from sham rather than burn mice. Unexpectedly, it could also reduce TNF-α secretion from sham monocyte while increase it from burn monocyte. The increased secretion of TNF-α by Exendin-4 from burn monocyte could be reversed by pretreatment of PTX or H89. Accordingly, Exendin-4 could stimulates cAMP production dose dependently from sham instead of burn monocyte. However, the blunt cAMP production from burn monocyte was further suppressed by pretreatment of PTX or H89 after 6-h incubation. Nevertheless, phosphorylated PKA activity was significantly increased by low dose of Exendin-4 in sham monocyte, by contrast, it was enhanced by high dose of Exendin-4 in burn monocyte after 1-h incubation. Following Exendin-4 treatment for 2 h ex vivo, total nuclear NF-κB and phosphorylated NF-κB activity, as well as cytoplasmic pERK1/2 expressions were reduced in sham monocyte, however, only pERK1/2 was increased by Exendin-4 in burn monocytes. Moreover, reduced expressions of GLP-1R, GRK-2 and Gαs in contrast with increased expression of Gαi were identified in burn monocyte relative to sham monocyte. CONCLUSIONS: This study presents an unexpected proinflammatory switch from Gαs to Gαi signaling in burn monocyte, which promotes ERK1/2 and NF-κB activation and the downstream TNF-α secretion. This phenomenon is most probably responsible for proinflammatory response evoked by Gαs agonist Exendin-4 following burn injury.

Incidence and mortality prognosis of dysnatremias in neurologic critically ill patients.

BACKGROUND: Dysnatremia, which is associated with increased mortality in general intensive care units (ICU), has not been thoroughly studied in neurologic ICU (NICU). METHODS: Prevalence of dysnatremia was retrospectively assessed. The multivariable binary logistic regression model was used to determine the influence of dysnatremia on mortality. RESULTS: Of 519 patients, 106 (20.4%) were admitted with hyponatremia and 177 (34.10%) with hypernatremia. Hypernatremia was detected in 69 (13.29%) patients on admission to NICU and in 108 patients (20.81%) during the ICU stay. However, the incidence of dysnatremia did not differ across the neurological categories (p = 0.4690). ICU stay in patients with acquired hypernatremia (22.3 ± 25.35 days) was longer than those with admission hypernatremia (13.5 ± 12.8 days) or with consistent normonatremia (16.16 ± 20.06 days). The other indicators such as Acute Physiology and Chronic Health Evaluation II, Glasgow Coma Scale score, urinary catheterization, and incidence of pneumonia were also associated with the serum sodium concentrations. Hypernatremia both on admission and acquired in NICU could significantly differentiate between survivors and nonsurvivors (p = 0.002 and <0.0001). However, only NICU-acquired hypernatremia was the independent risk factor for mortality with high sensitivity (p = 0.000). CONCLUSIONS: Dysnatremia is more common in NICU, whereas only acquired-hypernatremia was independently associated with outcome.

Identification and Treatment of the Early Form of Neurogenic Pulmonary Edema in Emergency Room.

OBJECTIVE: To improve the management of the early neurogenic pulmonary edema(NPE)in patients with non-traumatic cerebral hemorrhage. METHODS: Totally 140 eligible patients with non-traumatic cerebral hemorrhage who were treated in the emergency department of our hospital from October 2008 to October 2014 were divided into two groups:NPE group(n=25)and non-NPE group(n=115). The clinical data were analyzed and compared. RESULTS: Although the mean arterial pressure was similar between these two groups,the median pH and the bicarbonate ion(HCO(3)(-))were significantly lower in the NPE group than in the non-NPE group(pH:7.32 vs.7.39,P=0.002;HCO(3)(-),20.6 mmol/L vs.22.7 mmol/L,P=0.01). Multivariate regression analysis indicated that younger age and higher glucose level were significantly correlated with the early onset of NPE in the NPE group than in the non-NPE group(age:50.1 years vs.65.1 years,P=0.0008;glucose,15.4 mmol/L vs.10.78 mmol/L,P=0.001).There were only 3 patients in all with non-traumatic cerebral hemorrhage happened the fulminant NPE in 1 hour. Within 24 hours after patients visited the emergency room,the condition was improved in 20 of 25 patients in the NPE group. However,5 patients died,among whom 3 patients with fulminant NPE(onset within 1 hour)died due to acute respiratory distress syndrome and complicated with multiple organ failure,and 2 died of cerebral hernia. CONCLUSIONS: NPE is a rare and severe complication in patients with non traumatic cerebral hemorrhage. The possibility of NPE should be considered in relatively young patients with higher glucose and lower blood pH value. Timely prevention and treatment can improve the outcomes.

Role of mitofusin-2 in high mobility group box-1 protein-mediated apoptosis of T cells in vitro.

BACKGROUND: High mobility group box-1 protein (HMGB1), a ubiquitous nuclear protein, which is recognized as a danger-associated molecular pattern (DAMP) triggering activation of the innate immune system. Previous studies have shown that HMGB1 also plays a role in T cell-mediated immunity, but the effect of HMGB1 on apoptosis of T cells and its precise mechanism remain to be determined. METHODS: Two kinds of apoptosis assay techniques were used, i.e., Annexin V-FITC conjunction with PI to identify early apoptotic cells, Hoechst 33342 staining for double-stranded DNA to observe nuclear fragmentation or apoptotic body. The activation status of caspase-3, caspase-8, as well as caspase-9 was examined by colorimetric assay. The dynamic changes in intracellular calcium concentration ([Ca(2+)]i) was monitored by flow cytometry. Overexpression of Mfn2 was preformed by lentiviral vector transfection. The mRNA and protein levels of Mfn2 were determined by RT-PCR and Western-blotting. RESULTS: Treatment of Jurkat T cells with recombinant human HMGB1 (rhHMGB1) causes a significant dose-dependent increase in percentage of apoptotic cells. When T cells are incubated with HMGB1 they express decreased mitochondria fusion-related protein mitofusin-2 (Mfn2) and activate mitochondrial apoptotic pathway via elevation of [Ca(2+)]i, Bax insertion, and activation of caspase. Furthermore, overexpression of Mfn2 ameliorates the apoptosis of T cells induced by HMGB1. This occurs at least partly through Mfn2 keeps Ca(2+) homeostasis in T cells evidenced by monitoring [Ca(2+)]i dynamics. CONCLUSION: HMGB1 can trigger apoptosis of T lymphocytes through mitochondrial death pathway associated with [Ca(2+)]i elevation. Mfn2 plays a pivotal role in this process, and it might be a novel therapeutic target in T cell apoptosis related disorders.

Citrus pectin protects mice from burn injury by modulating intestinal microbiota, GLP-1 secretion and immune response.

Water-soluble rhamnogalacturonan-I enriched citrus pectin (WRP) has promising effect on antimicrobial defense. We aim to determine whether the modified acidic (A) or neutral (B) WRP solutions can improve intestinal microbial dysbiosis in burn-injured mice. Male Balb/c mice were gavaged with WRPs at 80, 160, 320 mg/kg. Body weight daily for 21 days before exposed to thermal injury of 15 % total body surface area and mortality was monitored. Mice with 80 mg/kg WRPs were also subjected to fecal DNAs and T cell metabonomics analysis, intestinal and plasma glucagon-like peptide 1 (GLP-1) detection, plasma defensin, immunoglobin and intestinal barrier examinations at 1 and 3d postburn (p.b.). Burn-induced mortality was only improved by low dose WRP-A (P = 0.039). Both WRPs could prevent the dysbiosis of gut microbiota in burn injury by reducing the expansion of inflammation-promoting bacteria. Both WRPs suppressed ileum GLP-1 production at 1d p.b. (P = 0.002) and plasma GLP-1 levels at 3d p.b. (P = 0.013). Plasma GLP-1 level correlated closely with ileum GLP-1 production (P = 0.019) but negatively with microbiota diversity at 1d p.b. (P = 0.003). Intestinal T cell number was increased by both WRPs in jejunum at 3d p.b. However, the exaggerated splenic T cell metabolism in burn injury was reversed by both WRPs at 1d p.b. The burn-increased plasma defensin ß1 level was only reduced by WRP-B. Similarly, the intestinal barrier permeability was only rescued by WRP-B at 1d p.b. WRP-A rather than WRP-B could reduce burn-induced mortality in mice by suppressing intestinal GLP-1 secretion, restoring gut microbiota dysbiosis and improving adaptive immune response.

Effect of Jianpi Shengxue Tablet on Iron Metabolism and Nutritional Status in Patients with Renal Anemia: A Prospective, Randomized, Open, Parallel Controlled and Multicenter Clinical Study.

OBJECTIVE: This study aimed to analyze the clinical efficacy of the Jianpi Shengxue tablet for treating renal anemia. METHODS: A total of 200 patients with renal anemia from December 2020 to December 2022 were enrolled and randomly divided into two groups. Patients in the control group were treated with polysaccharide-iron complex, and those in the experimental group were administered Jianpi Shengxue tablet. After 8 weeks of continuous treatment, the therapeutic outcomes regarding anemia were compared between the two groups. RESULTS: After treatment, the red blood cell (RBC) count, hematocrit (HCT), reticulocyte percentage (RET), ferritin (SF), serum iron (SI), transferrin saturation (TSAT), and serum albumin (ALB) all increased (P<0.01), and the clinical symptom score and total iron binding capacity decreased (P<0.01) in the experimental group. Moreover, the improvements in RBC, HCT, RET, SF, SI, TAST, ALB, and clinical symptoms (fatigue, anorexia, dull skin complexion, numbness of hands and feet) in the experimental group were significantly greater than those in the control group (P<0.05). The total effective rate for treating renal anemia was significantly higher in the experimental group than in the control group (P<0.01). CONCLUSION: The Jianpi Shengxue tablet demonstrates efficacy in treating renal anemia, leading to significant improvements in the laboratory examination results and clinical symptoms of patients with renal anemia.

Distinctive biochemistry profiles associated with hyperuricemia between Tibetans and Hans in China.

Purpose: We sought to identify distinct risk factors for hyperuricemia in native Tibetan and immigrant Han populations in Tibet, China. Methods: Three cohorts of male participants aged between 20 and 40 years were enrolled in this study. Biochemical parameters including serum uric acid (UA), fasting plasma glucose, insulin, lactate dehydrogenase (LDH), thyroxin, blood cell count, aminotransferase, and lipid profiles were analyzed. The association of risk factors with UA levels was evaluated using a multivariable line regression model. The effect of UA level on the biochemical parameters between the Hans and Tibetans was evaluated by two-way ANOVA. Results: The prevalence of hyperuricemia (≥420 µmol/L) was 24.8% (62/250) in the Hans, similar to 23.8% (29/136) in the Tibetans. In the regression analysis, the risk factors that were significantly associated with UA in Hans did not apply to Tibetans. Tibetans had higher fasting insulin (P<0.05) and LDH (P<0.01) levels, in contrast with lower levels of triglycerides (P<0.05), total cholesterol (P<0.01), and low-density lipoprotein-cholesterol (P<0.01) than Hans in normal UA populations. Biochemistry analysis revealed lower albumin levels (P<0.001) and higher levels of all aminotransaminase and especially alkaline phosphatase (P<0.01) in Tibetans than in Hans in both populations. Compared with Hans, Tibetans had lower serum levels of urea, creatinine, and electrolytes in the normal UA population, which were further exacerbated in the high UA population. Tibetans had comparable white blood cell counts as Hans in both normal and high UA populations. In contrast, the red blood cell count and hemoglobin concentration were much lower in Tibetans than in Hans under high UA conditions. Conclusions: The distinctive biochemistry between Tibetans and Hans may underlie the different etiologies of hyperuricemia in Tibet, China.

Treatment with gelsolin reduces brain inflammation and apoptotic signaling in mice following thermal injury.

BACKGROUND: Burn survivors develop long-term cognitive impairment with increased inflammation and apoptosis in the brain. Gelsolin, an actin-binding protein with capping and severing activities, plays a crucial role in the septic response. We investigated if gelsolin infusion could attenuate neural damage in burned mice. METHODS: Mice with 15% total body surface area burns were injected intravenously with bovine serum albumin as placebo (2 mg/kg), or with low (2 mg/kg) or high doses (20 mg/kg) of gelsolin. Samples were harvested at 8, 24, 48 and 72 hours postburn. The immune function of splenic T cells was analyzed. Cerebral pathology was examined by hematoxylin/eosin staining, while activated glial cells and infiltrating leukocytes were detected by immunohistochemistry. Cerebral cytokine mRNAs were further assessed by quantitative real-time PCR, while apoptosis was evaluated by caspase-3. Neural damage was determined using enzyme-linked immunosorbent assay of neuron-specific enolase (NSE) and soluble protein-100 (S-100). Finally, cerebral phospho-ERK expression was measured by western blot. RESULTS: Gelsolin significantly improved the outcomes of mice following major burns in a dose-dependent manner. The survival rate was improved by high dose gelsolin treatment compared with the placebo group (56.67% vs. 30%). Although there was no significant improvement in outcome in mice receiving low dose gelsolin (30%), survival time was prolonged against the placebo control (43.1 ± 4.5 h vs. 35.5 ± 5.0 h; P < 0.05). Burn-induced T cell suppression was greatly alleviated by high dose gelsolin treatment. Concurrently, cerebral abnormalities were greatly ameliorated as shown by reduced NSE and S-100 content of brain, decreased cytokine mRNA expressions, suppressed microglial activation, and enhanced infiltration of CD11b+ and CD45+ cells into the brain. Furthermore, the elevated caspase-3 activity seen following burn injury was remarkably reduced by high dose gelsolin treatment along with down-regulation of phospho-ERK expression. CONCLUSION: Exogenous gelsolin infusion improves survival of mice following major burn injury by partially attenuating inflammation and apoptosis in brain, and by enhancing peripheral T lymphocyte function as well. These data suggest a novel and effective strategy to combat excessive neuroinflammation and to preserve cognition in the setting of major burns.

[Construction and analysis of one kind of chitosan-coated BMP-2 nanoparticles as genetic carrier].

OBJECTIVE: To construct an excellent kind of chitosan-coated BMP-2 nanoparticles as genetic carrier. METHODS: Chitosan-coated BMP-2 nanoparticles as genetic carrier, including C-B50 group, C-B100 group and C-B200 group, were constructed through re-coacervation and gene recombination methods. This carrier was studied by using morphological observation, enveloping test, anti- DNase I digested test and MTT assay. RESULTS: One kind of excellent chitosan-coated BMP-2 nanoparticles as genetic carrier was constructed. Particle diameter was about (90 +/- 20) nm. Enveloping ratio of C-B50 group, C-B100 group and C-B200 group was 76.31% + 1.58%, 84.49% + 1.81% and 81.69% + 1.77%, respectively. Genetic carrier could prevent objective gene from DNase I digestion. The growth inhibiting ratio to bone marrow stem cells was increased as the increase of genetic carrier dose and contact time (P < 0.05), but maximal dose of carrier had no obvious toxic effect on cells growth in vitro. CONCLUSION: The constructed chitosan-coated BMP-2 nanoparticle material was a promising genetic carrier in bone tissue engineering.

The management of vascular access in hemodialysis patients during the coronavirus disease 2019 epidemic: A multicenter cross-sectional study.

BACKGROUND: Coronavirus disease 2019 is an epidemic disease throughout the world. The management of vascular access during the epidemic is currently unknown. METHODS: In this multicenter cross-sectional study, we collected vascular access data from hemodialysis patients treated at 44 hospitals in Hubei from 22 January to 10 March 2020. We estimated the management of vascular access during the coronavirus disease 2019 outbreak. RESULTS: Of the 9231 hemodialysis patients included, 5387 patients (58.4%) were men and 2959 patients (32.1%) were older than 65 years. Arteriovenous fistula was the predominant type of vascular access, accounting for 76.5%; 496 patients (5.4%) developed vascular access complications; catheter flow reduction was the most common vascular access complication, and stenosis was the predominant complication among those with arteriovenous access. Overall, 280 vascular access sites were placed in patients newly diagnosed with uremia, of whom 260 (92.8%) underwent catheter insertion; 149 rescue procedures were carried out to treat the vascular access complications, which consisted of 132 catheters, 7 percutaneous transluminal angioplasties, 6 arteriovenous fistula repairs, and 4 arteriovenous fistulas. Occlusion of the arteriovenous access had the highest rescue rate (92.7%), while many other vascular access complications remained untreated; 69 and 142 patients were diagnosed with confirmed and suspected coronavirus disease 2019, respectively. A total of 146 patients died, of whom 29 patients (19.9%) died due to vascular access complications. CONCLUSION: Catheter flow reduction and stenosis of arteriovenous access were the major vascular access complications. Most of the vascular access sites established were catheters, and many of the vascular access complications remained untreated.

Genistein reduced the neural apoptosis in the brain of ovariectomised rats by modulating mitochondrial oxidative stress.

The present study was undertaken to investigate the antioxidant effect of chronic ingestion of genistein (Gen) against neural death in the brain of ovariectomised (Ovx) rats. The rats were randomly divided into five groups, i.e. sham-operated (sham), Ovx-only, Ovx with 17ß-oestradiol, Ovx with low (15 mg/kg) and high (30 mg/kg) doses of Gen (Gen-L and Gen-H), and were orally administered daily with drugs or vehicle for 6 weeks. The learning and memory abilities were measured by Morris water maze test. Oxidative damages in the brain were evaluated by the level of superoxide dismutase (SOD), malondialdehyde (MDA) and monoamine oxidase (MAO) activities. Neural apoptosis was shown by terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) staining and caspase-3 activity. In the visual learning and memory test, there were no significant differences among the population means of the five groups. While in the probe trial test, the Gen-L group instead of the Gen-H group exhibited reduced escape latency and increased memory frequency than the Ovx group. Although both doses of Gen could reduce acetylcholinesterase activity, only a low dose of Gen could diminish MDA activity significantly in frontal cortex and enhance SOD content in the hippocampus. In contrast, MAO content was decreased in the cortex by either dose of Gen, while in the hippocampus, only a high dose of Gen appeared to be effective. Interestingly, Gen at both the doses could attenuate the increased number of TUNEL-positive neurons and caspase-3 activity in Ovx rats. These results suggest that Gen confers protection against Ovx-induced neurodegeneration by attenuating oxidative stress, lipid peroxidation and the mitochondria-mediated apoptotic pathway in a region- and dose-dependent manner.

Beta cell-specific deficiency of the stimulatory G protein alpha-subunit Gsalpha leads to reduced beta cell mass and insulin-deficient diabetes.

The G protein alpha-subunit G(s)alpha is required for hormone-stimulated cAMP generation. In pancreatic beta cells, G(s)alpha mediates the signaling of glucagon-like peptide 1 and other incretin hormones, which are implicated as important regulators of beta cell survival and insulin release. Studies have suggested that G(s)alpha/cAMP mediates these actions by stimulating insulin receptor substrate 2 (IRS2) expression. Mice with beta cell-specific G(s)alpha deficiency (betaGsKO) were generated by mating G(s)alpha-floxed mice to rat insulin II promoter-cre recombinase mice. betaGsKO mice had poor survival and postnatal growth with low serum insulin-like growth factor 1 levels. betaGsKO mice also developed severe hyperglycemia and glucose intolerance with severe hypoinsulinemia and reduced islet insulin content and glucose-stimulated insulin release. betaGsKO mice had markedly reduced average islet size and beta cell mass, which was partially explained by reduced beta cell size. In addition, betaGsKO mice had significantly reduced beta cell proliferation and increased beta cell apoptosis and markedly reduced expression of the cell cycle protein cyclin D2. The effects on beta cell mass and proliferation, but not apoptosis, were present from birth. Unexpectedly expression of Irs2 and the downstream gene Pdx1 were unaffected. These results show that G(s)alpha/cAMP pathways are critical regulators of beta cell function and proliferation that can work through IRS2-independent mechanisms.

[The central mechanism for estrogen receptor to mediate nutrients and energy metabolism].

Estrogen is demonstrated to be involved in the development and progress of diabetes mellitus. Recently studies have indicated that estrogen receptor (ER) play a crucial role in the modulation of nutrients and energy metabolism. Estrogen could regulate the expressions of anorexia and hyperphagic neuropeptide in the hypothalamus by genomic actions via nuclear ER, or via membrane ER linking to the phosphatidylinositol 3-kinase (PI3-K)/Akt and ERK1/2 mitogen-activated protein kinase (MAPK) pathways. The mice with hypothalamic ERalpha silencing exhibited the features of typical metabolic syndrome, suggesting the role of ERalpha in peripheral nutrient metabolism. Further studies showed that the central ERalpha interacts with both insulin and leptin signaling pathways. The elucidation of the mechanism of central ER in energy balance and nutrient metabolism would provide the novel strategy to overcome the abnormality of glucose metabolism and energy imbalance induced by estrogen disorder in clinical settings.

Long-lasting neurobehavioral alterations in burn-injured mice resembling post-traumatic stress disorder in humans.

OBJECTIVE: To establish an animal model for posttraumatic stress disorder in burn-injured patients. METHODS: Thermal-injured mice with 15% total body surface area were subjected to a series of neurobehavioral tests at 1 and 3 months postburn. Brains were collected for analysis of key molecules expression, spleens for T cell function analysis, and blood for biochemistry and hormones detection. RESULTS: Comparison with sham mice, burn mice showed extremely high locomotion in homecage, open field, and forced swimming tests, indicating a hyper-arousal state. Burn mice exhibited improved spatial memory in Morris Water Maze test and heightened context fear memory in context fear conditioning, suggesting re-experiencing behavior. Although burn mice showed pronounced passive avoidance in the step-through test, their active avoidance capability in response to the conditional stimulus in the shuttle box test was relatively deteriorated. Likewise, the retention of cue-feared memory was impaired in fear conditioning test. The above negative alterations in mood were recapitulated in open-field test, in which the burn mice displayed an anxiety-like behavior with less time spent in the center. However, no sign of depression was found in the forced swimming and sucrose preference tests. The negative mood of burn mice was reinforced by a deficit in sociality and preference for social novelty in social interaction test. These neurobehavioral alterations were associated with an increased expression of brain-derived neurotrophic factor along with a remarkable microgliosis and a moderate astrocytosis in the brain of burn vs. sham mice. Moreover, a prominent Th2 switch and consequent increased nuclear NF-κB translocation were seen in the splenic T cells from burn relative to sham mice. CONCLUSIONS: We conclude that even mild burn injury could lead to long-lasting cognitive and effective alterations in mice. These findings shed light on the interactions among neuropsychology, neurobiology, and immunology throughout the recovery period of burn injury.