唑来膦酸联合胰岛素促进2型糖尿病并发雌激素缺乏大鼠骨折早期愈合

目的探讨唑来膦酸联合胰岛素对于2型糖尿病并发雌激素缺乏大鼠早期骨折愈合的影响。方法 32只雌性SD大鼠随机分为CF、DOF、DOFI和DOFIZ 4组。除CF组外,其余3组建立2型糖尿病并发雌激素缺乏动物模型,其中DOFI组和DOFIZ组分别给予单独胰岛素或联合唑来膦酸治疗,骨折后3周取材。通过对骨痂X线片、Micro-CT、番红O-固绿染色、TRAP阳性破骨细胞密度、OCN和Caspase-3的表达进行分析,评价单独应用胰岛素或联合唑来膦酸对其早期骨折愈合的影响。结果DOF组骨痂的骨折愈合X线评分、Tb.N、BV/TV、骨性骨痂面积比和OCN表达均显著低于CF组(P0.05),Th.Sp、TRAP阳性破骨细胞密度和Caspase-3表达均显著高于CF组(P0.05)。胰岛素干预后,DOFI组以上各受损指标中除了Th.Sp外均得到显著改善(P0.05)。联合唑来膦酸干预后,DOFIZ组骨痂面积、Tb.N、BV/TV和骨性骨痂面积比显著高于DOFI组(P0.05),Th.Sp和TRAP阳性破骨细胞密度显著低于DOFI组(P0.05)。结论胰岛素联合早期单剂量唑来膦酸干预可促进2型糖尿病并发雌激素缺乏大鼠骨折早期愈合。     

两种不同药物对骨质疏松性椎体骨折术后老年患者疗效的影响

目的研究丹参注射液联合仙灵骨葆胶囊对骨质疏松性椎体骨折术后老年患者血清胰岛素生长因子-1(insulin growth factor-1,IGF-1)及碱性成纤维细胞生长因子(basic fibroblast growth factor,b FGF)水平的影响。方法选取我院于2017年6月至2018年10月收治的123例老年骨质疏松性椎体骨折患者,依据随机数字表法分为观察(62例)和对照(61例)两组。两组患者均行经皮椎体成形术(PVP)治疗,对照组患者服用仙灵骨葆胶囊(持续用药3个月),观察组患者在对照组基础上使用丹参注射液(持续用药1周)。比较两组患者的治疗效果、骨折愈合情况,以及VAS评分和血清b FGF及IGF-1在不同时间点水平变化,统计两组并发症发生情况。结果观察组患者治疗有效率(95.00%)显著高于对照组(83.33%),差异有统计学意义(P0.05)。治疗后6个月两组患者骨密度显著增加,而椎体后凸Cobb角显著降低,且观察组患者改善情况显著优于对照组(P0.05)。两组患者经治疗后VAS评分显著降低,血清b FGF、IGF-1水平显著增加,其中观察组患者VAS评分、血清b FGF、IGF-1水平在治疗2周、4周、6周的改善程度均优于对照组(P0.05)。两组患者并发症发生率的差异无统计学意义(P0.05)。结论丹参注射液联合仙灵骨葆胶囊可增强PVP对老年骨质疏松性椎体骨折患者的疗效,可通过提高血清b FGF及IGF-1水平促进骨折修复,从而加快骨折愈合,降低疼痛。     

胃转流术对非肥胖型2型糖尿病大鼠骨骼肌组织中MG53蛋白表达的影响

目的研究胃转流术对非肥胖型2型糖尿病(T2DM)大鼠骨骼肌组织中E3泛素连接酶—mitsugumin53(MG53)蛋白及其mRNA,以及胰岛素受体底物1(IRS-1)mRNA表达的影响,探讨胃转流术改善骨骼肌胰岛素抵抗的可能机制。方法将24只雄性GK大鼠随机分为糖尿病手术组、糖尿病假手术组及糖尿病对照组,每组8只,若大鼠死亡,则重新制备模型补充;另外以8只Wistar大鼠作为正常对照组。应用Westem blot技术检测4组大鼠术后第8周时骨骼肌组织中MG53蛋白的表达水平,应用RT-PCR技术检测4组大鼠术后第8周时骨骼肌组织中IRS-1 mRNA和MG53 mRNA的表达水平。结果①糖尿病假手术组及糖尿病对照组大鼠的MG53 mRNA及其蛋白的表达水平均高于正常对照组和糖尿病手术组(P<0.05),但糖尿病手术组和正常对照组间比较、糖尿病假手术组和糖尿病对照组间比较差异均无统计学意义(P>0.05)。②与正常对照组比较,糖尿病手术组、糖尿病假手术组及糖尿病对照组大鼠的IRS-1 mRNA的表达水平均较低(P<0.05),但糖尿病手术组、糖尿病假手术组及糖尿病对照组大鼠的IRS-1 mRNA的表达水平比较差异无统计学意义(P>0.05)。结论胃转流术降低了非肥胖型T2DM大鼠骨骼肌组织中IRS-1蛋白的E3泛素连接酶—MG53蛋白的表达水平,减少了IRS-1蛋白的泛素化降解,这可能是骨骼肌胰岛素信号通路中IRS-1蛋白表达上调的主要机制之一,从而改善了骨骼肌的胰岛素抵抗,降低了血糖。     

柴胡疏肝散对肝郁型代谢综合征大鼠糖脂代谢及胰岛素抵抗的影响

目的:观察柴胡疏肝散对肝郁型代谢综合征大鼠糖脂代谢及胰岛素抵抗的影响。方法:将40只大鼠随机分为普通饲料空白组和高脂饲料造模组,每组各20只。高脂饲料造模组给予高脂饲料喂养,采用束缚情志应激法造模。造模成功后,将普通饲料空白组随机分为普通饲料生理盐水组和普通饲料药物干预组,每组各10只;将高脂饲料造模组随机分为造模生理盐水组和造模药物干预组,每组各10只。高脂饲料造模组继续予高脂饲料喂养。普通饲料生理盐水组和高脂造模生理盐水组予0.01 ml·g~(-1)生理盐水灌胃;普通饲料药物干预组和高脂饲料造模药物干预组予柴胡疏肝散,按0.01 m L·g~(-1)灌胃,每日2次,连续4周。大鼠禁食12 h后,从眼眶静脉采血,离心取上清,测定三酰甘油(three acyl glycerin,TG)、血清总胆固醇(total cholesterol,TC)、低密度脂蛋白(low density lipoprotein cholesterol,LDL-C)和高密度脂蛋白(high density lipoprotein cholesterol,HDL-C)、空腹血糖(fasting plasma glucose,FBG)、空腹胰岛素(fasting insulin,FIN)。结果:高脂饲料造模组与空白组比较,HDL-C、TC、TG、FBG、FIN、胰岛素抵抗指数、体质量及腹围差异有统计学意义(P0.05)。造模药物干预组与造模生理盐水组大鼠比较,LDL-C、TC、FBG、FIN、胰岛素抵抗指数差异有统计学意义(P0.05)。结论:柴胡疏肝散能改善肝郁型代谢综合征大鼠的胰岛素抵抗,从而影响其糖脂代谢。     

The Effect of Dexamethasone on Postoperative Blood Glucose in Patients With Type 2 Diabetes Mellitus Undergoing Total Joint Arthroplasty

BackgroundPerioperative glucocorticoids are routinely administered to patients undergoing total joint arthroplasty (TJA) to decrease postoperative pain and nausea. However, there is concern regarding the effects of glucocorticoids on perioperative glucose control in diabetes. The goal of this study is to determine if administration of preoperative dexamethasone to diabetic patients is significantly associated with hyperglycemia and increased insulin requirements in the immediate postoperative period after TJA and to identify risk factors for postoperative hyperglycemia immediately after TJA.MethodsA retrospective review of type 2 diabetic patients undergoing TJA from 2010 to 2015 (n = 285) was undertaken to evaluate the effect of dexamethasone on postoperative glucose control. Preoperative baseline characteristics were compared between patients who did and did not receive 8 mg of intravenous dexamethasone preoperatively. Postoperative glucose and insulin requirements were evaluated with respect to dexamethasone dosing. Statistical analysis was performed using logistic regression models.ResultsDexamethasone administration did not correlate with the maximum postoperative blood glucose (P = .78). There was a significantly higher initial postoperative blood glucose after intravenous dexamethasone administration (P < .01). Dexamethasone administration was associated with increased aspart insulin requirements on postoperative day 0 (P = .04). However, preoperative hemoglobin A1c was most strongly associated with postoperative glucose control.ConclusionPreoperative dexamethasone administration to diabetic patients was associated with an initial increase in blood glucose and increased insulin requirement on postoperative day 0. Yet the observed effect on glucose control in diabetic patients may not outweigh the known clinical benefits of perioperative glucocorticoids.     

Novel non‐alcoholic steatohepatitis model with histopathological and insulin‐resistant features

Although several non‐alcoholic steatohepatitis (NASH) models have been reported to date, few of these models fully reflect the histopathology and pathophysiology of human NASH. The aim of this study was to establish a novel NASH model by feeding a high‐fat (HF) diet and administering both carbon tetrachloride (CCl₄) and the Liver X receptor agonist T0901317. Male C57BL/6J mice were divided into four groups (each n = 5): HF, HF + CCl₄, HF + T0901317, and the novel NASH model (HF + CCl₄ + T0901317). CCl₄ (0.1 mL/kg) and T0901317 (2.5 mg/kg) were intraperitoneally administered four times and five times, respectively. The livers of the novel NASH model group presented a whitish colour. The serum levels of TNF‐α and IL‐6 were significantly increased in the novel NASH model group, and mice in this group exhibited histopathological features and insulin resistance reflective of NASH, i.e., macrovesicular hepatic steatosis, ballooning hepatocytes, Mallory‐Denk bodies, lobular inflammation and fibrosis. The novel NASH model group presented significantly upregulated expression levels of mRNAs related to lipogenesis, oxidative stress, fibrosis and steatosis and significantly downregulated expression levels of mRNAs related to triglyceride export. We successfully established a novel experimental NASH model that exhibits similar histopathology and pathophysiology to human NASH.     

Catecholamine-induced lipolysis causes mTOR complex dissociation and inhibits glucose uptake in adipocytes

Anabolic and catabolic signaling oppose one another in adipose tissue to maintain cellular and organismal homeostasis, but these pathways are often dysregulated in metabolic disorders. Although it has long been established that stimulation of the β-adrenergic receptor inhibits insulin-stimulated glucose uptake in adipocytes, the mechanism has remained unclear. Here we report that β-adrenergic–mediated inhibition of glucose uptake requires lipolysis. We also show that lipolysis suppresses glucose uptake by inhibiting the mammalian target of rapamycin (mTOR) complexes 1 and 2 through complex dissociation. In addition, we show that products of lipolysis inhibit mTOR through complex dissociation in vitro. These findings reveal a previously unrecognized intracellular signaling mechanism whereby lipolysis blocks the phosphoinositide 3-kinase–Akt–mTOR pathway, resulting in decreased glucose uptake. This previously unidentified mechanism of mTOR regulation likely contributes to the development of insulin resistance.Adipose tissue plays an essential role in maintaining whole-body energy homeostasis by storing or releasing nutrients. This balance is controlled by opposing signaling pathways where anabolic processes are activated by insulin (INS) and catabolic actions are activated by catecholamines. An important unanswered question in adipose biology is how catecholamine-induced β-adrenergic signaling opposes insulin-stimulated glucose uptake (1–6). Surprisingly, the underlying mechanism for this well-established physiological response in adipocytes is still unknown.When nutrients are plentiful, insulin is released by the pancreas and stimulates the absorption of glucose and fatty acids in adipose tissue, where they are packaged and stored as triacylglycerol (TAG) in cellular lipid droplets. Insulin signaling in adipocytes is mediated by the phosphoinositide 3-kinase (PI3K)–Akt–mTOR pathway. mTOR is a highly conserved serine/threonine protein kinase that functions in either of two distinct multiprotein complexes, mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). mTORC1 is defined primarily by the association of mTOR with raptor, whereas mTORC2 includes mTOR with rictor (7). Importantly, mTORC2 phosphorylation of Akt at S473 is required for Akt activity on AS160, which is necessary for glucose uptake in response to insulin (8–11). Of note, for both mTORC1 and mTORC2, the integrity of these protein complexes is essential for kinase substrate specificity and proper signaling (12, 13).During periods of fasting or stress, catecholamines are released by the sympathetic nervous system to activate lipolysis. Stimulation of the β-adrenergic receptor on adipocytes activates adenylyl cyclase (AC), leading to elevated cAMP and protein kinase A (PKA) activity. PKA initiates lipolysis by direct phosphorylation of hormone-sensitive lipase (HSL) and perilipin (14–16) and indirect activation of adipose triglyceride lipase (ATGL) (17–19). Lipolysis involves hydrolysis of TAG stored in the lipid droplet to produce diacylglycerol (DAG), monoacylglycerol (MAG), fatty acids, and glycerol. These lipolytic products are important energy substrates that can act as precursors for other lipids and impact cellular signaling. However, their potential role as signaling molecules has been underappreciated (20).In this study, we provide insight into the mechanisms that link β-adrenergic stimulation to the inhibition of insulin-stimulated glucose uptake. Namely, we show that activation of lipolysis is crucial. Moreover, we find that products of lipolysis themselves cause mTOR inhibition by complex dissociation, which inhibits glucose uptake in adipocytes. This mechanism of mTOR regulation (i.e., by complex dissociation) has major implications in the regulation of cellular metabolism and likely contributes to stress-induced hyperglycemia and obesity-induced insulin resistance.     

Periodontal Status and High‐Sensitivity C‐Reactive Protein Levels in Polycystic Ovary Syndrome With and Without Medical Treatment

Background: Recently, some studies have revealed the effect of polycystic ovary syndrome (PCOS) on gingival inflammation. This cross‐sectional study attempts to assess the periodontal status and systemic inflammation of women receiving medical treatment for PCOS and women newly diagnosed with PCOS. Methods: A total of 126 participants comprising 41 newly diagnosed patients with PCOS (PCOS‐N), 45 patients with PCOS on medical treatment (PCOS‐MT), and 40 systemically healthy controls (control group [CG]) were examined. Periodontal parameters, anthropometric parameters, and serum levels of high‐sensitivity C‐reactive protein (hsCRP) were recorded. Results: Women with newly diagnosed PCOS had increased sites with bleeding on probing (BOP), probing depth, clinical attachment level (CAL), waist circumference (WC), hsCRP, and prevalence of periodontitis compared with control and PCOS‐MT groups (P ≤0.05). On partial correlation analysis after controlling for confounders, BOP and CAL correlated positively and significantly with hsCRP (P = 0.01 and P = 0.005). Multivariate linear regression analysis revealed that BOP and CAL (dependent variable) (P = 0.009/R² = 0.05 and P = 0.005/R² = 0.07, respectively) had significant association with hsCRP. Furthermore, hsCRP, when considered as outcome, also exhibited association with CAL and WC (P = 0.002/R² = 0.07 and P = 0.04/R² = 0.106). Logistic regression analysis demonstrated that the PCOS‐N group had 2.88 times increased likelihood of having moderate periodontitis (adjusted odds ratio 2.88, 95% confidence interval 1.18 to 6.98). Conclusions: Women with newly diagnosed PCOS may have increased prevalence and likelihood for periodontitis, with higher measures of periodontal inflammation and breakdown than those on medical treatment for PCOS and systemically healthy females. Furthermore, periodontal breakdown might depend on systemic inflammation and vice versa.     

Porphyromonas gingivalis Lipopolysaccharide Upregulates Insulin Secretion From Pancreatic β Cell Line MIN6

Background: A close association between periodontitis and diabetes has been demonstrated in human cross‐sectional studies, but an exact relationship between periodontitis and prediabetes has not been established. Previous studies using animal model systems consistently have shown that hyperinsulinemia occurs in animals with periodontitis compared to animals with healthy periodontium (while maintaining normoglycemia). Because bacterial lipopolysaccharide (LPS) plays an important role in the pathogenesis of periodontitis, we hypothesized that LPS may stimulate insulin secretion through a direct effect on β cell function. To test this hypothesis, pancreatic β cell line MIN6 cells were used to determine the effect of Porphyromonas gingivalis (Pg) LPS on insulin secretion. Furthermore, expression of genes altered by Pg LPS in innate immunity and insulin‐signaling pathways was determined. Methods: MIN6 cells were grown in medium with glucose concentration of normoglycemia (5.5 mM). Pg LPS was added to each well at final concentrations of 50, 200, and 500 ng/mL. Insulin secretion was measured using enzyme‐linked immunosorbent assay. Gene expression levels altered by Pg LPS were determined by polymerase chain reaction (PCR) array for mouse innate and adaptive immunity response and mouse insulin‐signaling pathways, and results were confirmed for specific genes of interest by quantitative PCR. Results: Pg LPS stimulated insulin secretion in the normoglycemic condition by ≈1.5‐ to 3.0‐fold depending on the concentration of LPS. Pg LPS treatment altered the expression of several genes involved in innate and adaptive immune response and insulin‐signaling pathway. Pg LPS upregulated the expression of the immune response–related genes cluster of differentiation 8a (Cd8a), Cd14, and intercellular adhesion molecule‐1 (Icam1) by about two‐fold. LPS also increased the expression of two insulin signaling–related genes, glucose‐6‐phosphatase catalytic subunit (G6pc) and insulin‐like 3 (Insl3), by three‐ to four‐fold. Conclusions: We have demonstrated for the first time that Pg LPS stimulates insulin secretion by pancreatic β cell line MIN cells. Pg LPS may have significant implications on the development of β cell compensation and insulin resistance in prediabetes in individuals with periodontitis.