Associations between cytokines,endocrine stress response,and gastrointestinal symptoms in autism spectrum disorder

Many children and adolescents with autism spectrum disorder (ASD) have significant gastrointestinal (GI) symptoms, but the etiology is currently unknown. Some individuals with ASD show altered reactivity to stress and altered immune markers relative to typically-developing individuals, particularly stress-responsive cytokines including tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6). Acute and chronic stress is associated with the onset and exacerbation of GI symptoms in those without ASD. The present study examined whether GI symptoms in ASD were associated with increases in cortisol, a stress-associated endocrine marker, and TNF-α and IL-6 in response to stress. As hypothesized, a greater amount of lower GI tract symptoms were significantly associated with post-stress cortisol concentration. The relationship between cortisol response to stress and GI functioning was greater for children who had a history of regressive autism. Exploratory analyses revealed significant correlations between cortisol response, intelligence, and inappropriate speech. In contrast, symptoms of the lower GI tract were not associated with levels of TNF-α or IL-6. Significant correlations were found, however, between TNF-α and IL-6 and irritability, socialization, and intelligence. These findings suggest that individuals with ASD and symptoms of the lower GI tract may have an increased response to stress, but this effect is not associated with concomitant changes in TNF-α and IL-6. The relationship between cortisol stress response and lower GI tract symptoms in children with regressive autism, as well as the relationships between cortisol, IL-6, and intelligence in ASD, warrant further investigation.     

Primary murine microglia are resistant to nitric oxide inhibition of indoleamine 2,3-dioxygenase

Indoleamine 2,3-dioxygenase (IDO) is an intracellular heme-containing enzyme that is activated by proinflammatory cytokines, including interferon-γ (IFNγ), and metabolizes tryptophan along the kynurenine pathway. Activation of murine macrophages induces not only IDO but also nitric oxide synthase (iNOS), and the ensuing production of nitric oxide (NO) inhibits IDO. To determine the sensitivity of primary cultures of murine microglia to NO, microglia were stimulated with recombinant murine IFNγ (1 ng/ml) and lipopolysaccharide (LPS) (10 ng/ml). This combination of IFNγ + LPS synergized to produce maximal amounts of nitrite as early as 16 h. Steady-state mRNAs for both iNOS and IDO were significantly increased by IFNγ + LPS at 4 h post-treatment, followed by an increase in IDO enzymatic activity at 24 h. Murine microglia (>95% CD11b⁺) were pretreated with the iNOS inhibitor, L-NIL hydrochloride, at a dose (30 μM) that completely abrogated production of nitrite. L-NIL had no effect on IDO mRNA at 4 h or IDO enzymatic activity at 24 h following stimulation with IFNγ + LPS. These data establish that IDO regulation in murine microglia is not restrained by NO, thereby permitting the accumulation of kynurenine and its downstream metabolites in the central nervous system.     

黄萸方对大鼠糖尿病早期肾脏保护作用的研究

目的:观察中药复方黄萸方对实验性糖尿病大鼠微量白蛋白尿的疗效。方法:采用高糖高脂喂饲加低剂量STZ建立伴胰岛素抵抗的大鼠2型糖尿病模型,给予黄萸方治疗12周,动态观察血糖及尿微量白蛋白等指标。结果:黄萸方可降低血糖、减少尿微量白蛋白、减轻肾脏肥大、改善尿多症状、降低血清甘油三酯水平,疗效优于血管紧张素Ⅱ受体拮抗剂(ARB)氯沙坦。结论:黄萸方可改善实验性大鼠2型糖尿病肾脏病变,主要是减少微量白蛋白尿的作用。     

凉血通瘀方对脑出血大鼠脑水肿及基质金属蛋白酶9和金属蛋白酶组织抑制剂1表达的影响

目的：探讨中药凉血通瘀方对脑出血大鼠脑水肿的作用及其机制。方法：采用自体血纹状体注射方法制备大鼠脑出血模型。实验大鼠分为假手术组、模型组和凉血通瘀方组。凉血通瘀方组给予凉血通瘀煎剂灌胃,余两组给予生理盐水灌胃,每日1次。脑出血后24、48、72和120 h观察大鼠脑水肿情况,明胶酶谱法检测脑血肿周围组织内基质金属蛋白酶9（matrix metalloproteinase-9,MMP-9）活性,荧光定量实时聚合酶链式反应法检测MMP-9和基质金属蛋白酶组织抑制剂1（tissueinhibitor ofmetalloproteinase-1,TIMP-1）的表达水平。结果：凉血通瘀方组大鼠脑水肿程度在各时间点均显著低于模型组（P〈0.01）,仅在72 h其脑组织含水量高于假手术组（P〈0.01）。与模型组相比,凉血通瘀方组的MMP-9酶原水平及活性均显著降低,其mRNA水平亦在脑出血后48、72、120 h低于模型组（P〈0.01）,而TIMP-1 mRNA水平在各时间点均显著升高（P〈0.01）。结论：凉血通瘀方可能通过上调TIMP-1表达来抑制MMP-9水平,从而减轻脑出血大鼠脑水肿。     

siRNA技术在哮喘治疗中的应用

RNA干扰是由双链RNA引发的序列特异的基因沉默现象,其中长度为21～23nt的小RNA分子（small inter-fering RNA,siRNA）是引起RNA干扰现象的直接原因。利用siRNA使基因沉寂从而调节目的蛋白的表达,在疾病的基因治疗中有巨大的应用价值。哮喘是一种常见的多发病,在治疗上仍面临极大的挑战。利用siRNA技术治疗哮喘是当今最新的一种治疗手段,虽然应用才刚刚起步,但其革命性的治疗理念,无疑给哮喘患者带来了新的希望。     

Thrombin inhibits aquaporin 4 expression through protein kinase C-dependent pathway in cultured astrocytes

Aquaporin 4 (AQP4) is a key molecule for maintaining water balance in the central nervous system, and its dysfunction might cause brain edema. However, little is known about the regulation of AQP4 expression. Because thrombin has been implicated in brain edema formation, the purpose of this study is to determine whether thrombin affects expression of AQP4 in astrocytes. Here, the effect of thrombin on AQP4 expression in vitro was evaluated using Western blot analysis and RT-PCR. Meanwhile, we investigated whether the effect of thrombin on AQP4 expression was due to protease-activated receptor 1 (PAR-1). In addition, we examined the role of protein kinase C (PKC) in the effect of thrombin on AQP4 expression using Western blot analysis. We found that thrombin did not affect cell viability at concentrations of 0.05, 0.5, 5, or 50 nM but killed astrocytes at concentrations of 500 nM, with approx 72% of astrocytes surviving at 500 nM thrombin. Our data showed that AQP4 protein expression achieved only 28% of controls in 500 nM thrombin treatment, even if astrocytes survived approx 72% of controls at 500 nM thrombin. Thrombin significantly inhibited AQP4 in a time- and dose dependent manner in vitro (p<0.05). Cathepsin-G, a thrombin PAR-1 inhibitor, reversed significantly (p<0.05) the effect of thrombin on AQP4 mRNA and protein expression in astrocytes. We also observed that PKC inhibitor H-7 or prolonged pretreatment with TPA can rapidly increase AQP4 expression (p<0.05). Thrombin might inhibit AQP4 expression in rat astrocytes, and this effect is possibly mediated by the PKC pathway.     

Characterization and immunostimulatory activity of a polysaccharide from the spores of Ganoderma lucidum

Spores of Ganoderma lucidum contain a large amount of bioactive substances and have a higher bioactivity than the fruit bodies of G. lucidum. However, ingredients from spores are less studied due to the difficulties in collecting the spores and breaking the rigid shell. In this study, a water-soluble polysaccharide named GSG was extracted from the spores of G. lucidum. GSG is characterized to be a branched glucan that contains several different kinds of linkages. It was an effective inducer of MAPKs- and Syk-dependent TNF-α and IL-6 secretion in murine resident peritoneal macrophages. Dectin-1 could recognize GSG and partially mediate its biological activities. Additionally, in vivo administration of GSG potentiated the Con A-induced proliferative response of splenocytes and induced anti-tumor activity against Lewis lung cancer in mice. Therefore, these results suggest that GSG is an effective immunomodulator and may be a promising adjuvant remedy for anti-tumor therapies.     

Very early premature ovarian failure in two sisters compound heterozygous for the FMR1 premutation

Expansion of the CGG trinucleotide repeat in the 5′ untranslated region of the fragile X mental retardation 1 (FMR1) gene within the premutation range is one of the known genetic factors associated with premature ovarian failure and earlier age at menopause. Studies have shown that approximately 16–26% of female carriers will develop premature ovarian failure, and current research is focussed on the identification of molecular factors that predict its occurrence in female carriers. In this report we present two sisters who are compound heterozygous for a premutation, and who were referred because of very early menopause, occurring at the age of 17 years in the youngest sister. Premature ovarian failure associated with FMR1 premutation at such an early age has not been reported in the literature before.