Putative neurotransmitters in three experimental filariasis models

Some putative neurotransmitters in three experimental filariasis models were investigated by a new relevant chromatographic method, sensitive and specific. No catecholaminergic compounds have been detected, but serotonin was found in Dipetalonema vitae. However, further investigations revealed very high levels of gamma amino butyric acid (GABA) in the macro-filariae. These data allow us to foresee new fields in filariasis therapeutics.     

Nematocide activity of 6,7-diarylpteridines in three experimental models

The in vitro nematocide activity of seventeen 6,7-diarylpteridines has been tested using three different experimental models, Caenorhabditis elegans, Nippostrongylus brasiliensis and Heligmosomoides polygyrus. The method of evaluation of inhibition in the secretion of acetylcholinesterase by H. polygyrus seems to be the most indicated to avoid false positives. The in vivo activities, against Trichinella spiralis, of the most in vitro active pteridines have been assayed. All pteridine derivatives bearing 6,7-di-p-bromophenyl substituents have shown in vitro nematocide activities in the three experimental models used. Amongst all the pteridines tested in vivo, only 2,4-pteridinedithione derivatives exhibited moderate activity.     

Differential expression of microRNAs in mouse pain models

Background

MicroRNAs (miRNAs) are short non-coding RNAs that inhibit translation of target genes by binding to their mRNAs. The expression of numerous brain-specific miRNAs with a high degree of temporal and spatial specificity suggests that miRNAs play an important role in gene regulation in health and disease. Here we investigate the time course gene expression profile of miR-1, -16, and -206 in mouse dorsal root ganglion (DRG), and spinal cord dorsal horn under inflammatory and neuropathic pain conditions as well as following acute noxious stimulation.

Results

Quantitative real-time polymerase chain reaction analyses showed that the mature form of miR-1, -16 and -206, is expressed in DRG and the dorsal horn of the spinal cord. Moreover, CFA-induced inflammation significantly reduced miRs-1 and -16 expression in DRG whereas miR-206 was downregulated in a time dependent manner. Conversely, in the spinal dorsal horn all three miRNAs monitored were upregulated. After sciatic nerve partial ligation, miR-1 and -206 were downregulated in DRG with no change in the spinal dorsal horn. On the other hand, axotomy increases the relative expression of miR-1, -16, and 206 in a time-dependent fashion while in the dorsal horn there was a significant downregulation of miR-1. Acute noxious stimulation with capsaicin also increased the expression of miR-1 and -16 in DRG cells but, on the other hand, in the spinal dorsal horn only a high dose of capsaicin was able to downregulate miR-206 expression.

Conclusions

Our results indicate that miRNAs may participate in the regulatory mechanisms of genes associated with the pathophysiology of chronic pain as well as the nociceptive processing following acute noxious stimulation. We found substantial evidence that miRNAs are differentially regulated in DRG and the dorsal horn of the spinal cord under different pain states. Therefore, miRNA expression in the nociceptive system shows not only temporal and spatial specificity but is also stimulus-dependent.

     

Caspase-1 is not involved in experimental hepatitis in mouse

Experimental hepatitis induced by tumor necrosis factor in D-(+)-galactosamine-sensitized mice or by an agonistic anti-Fas antibody in normal mice is accompanied by dramatic apoptosis of hepatocytes. Apoptosis is the final result of activation of a cascade of caspases. We used caspase-1-/- mice, generated by gene targeting, to study the role of this protease in TNF- and anti-Fas-induced lethal hepatitis. We found that mutant mice exhibited the typical caspase-1-/- phenotype, since they resisted to a lethal injection of LPS and released no interleukin-1beta in the circulation, in contrast to wild-type littermates. When caspase-1-/- mice were challenged with different doses of tumor necrosis factor/D-(+)-galactosamine or with anti-Fas, no increased survival was observed compared with control mice. Furthermore, apoptosis in the livers of these mice and serum levels of alanine aminotransferase were not reduced. These data indicate that caspase-1 deficiency does not lead to reduced apoptosis in these models, either because caspase-1 is irrelevant in this model or because of functional redundancy.     

Cytokine expression during chronic versus occult hepatitis B virus infection in HIV co-infected individuals

Chronic hepatitis B virus infection is characterized by persistent detectable levels of hepatitis B surface antigen (HBsAg) and HBV DNA in the serum. In contrast, HBsAg is not detectable during occult HBV infection, despite the presence of HBV DNA. An altered host immune response could play a role in the development of occult HBV infection; however, potential differences in immune responses among chronic and occult HBV-infected patients have not been evaluated in vivo. In the current study, we evaluated serum levels of regulatory, apoptotic, and fibrotic/anti-fibrotic cytokines/markers as indicators of immune responses in 25 chronic and 12 occult HBV-infected patients. More than half of the patients in both chronic and occult HBV infection groups had IL-2, IL-4, IL-13, and IFN-γ levels below detectable limits. In contrast, most patients had detectable levels of IL-8, IL-10, IP-10, sFas, sFasL, and TGF-β1. Of these, only sFas was significantly different between the two groups, with lower levels observed during occult compared to chronic HBV infection (p = 0.01). As a surrogate marker of apoptotic inhibition, decreased sFas during occult HBV infection suggests that apoptosis occurs at different rates in occult compared to chronic HBV infection and therefore, may contribute to persistence of occult HBV infection.     

Cytokine characteristics of jaundice in mouse liver

OBJECTIVE: The aim of this study is to clarify the perioperative cytokine changes and their mechanism in jaundiced liver. MATERIALS AND METHODS: Obstructive jaundice was induced using a common bile duct ligation (CBDL) and a two-thirds hepatectomy (HEP) was performed in six- to seven-week-old male C3H/HeN mice. When hepatectomy was added to CBDL, it was carried out 2 to 5 days after CBDL. The serum interleukin 6 (IL-6) levels and heat shock protein (HSP)-70 expression were evaluated. One mg per mouse of methylprednisolone (MPL) was intraperitonealy administered in some mice of CBDL+HEP group. RESULTS: The post-hepatectomy IL-6 values at 2 and 3 days after CBDL were significantly lower than those in the HEP group, while those at 5 days after CBDL were significantly higher than those in HEP group. The serum IL-6 value of the steroid group was significantly lower than that of non-steroid group in HEP group. However, no steroid effects were recognized on post-hepatectomy IL-6 values at 3 days after CBDL, steroid inhibited post-hepatectomy IL-6 production at 5 days after CBDL. No expression of HSP70 protein was observed in the control group, but HSP70 protein was expressed in both the hepatocytes and Kupffer cells 3 days after CBDL, then at 5 days after CBDL, no HSP70 protein was expressed in the Kupffer cells. CONCLUSIONS: In the early period of obstructive jaundice, the IL-6 level after hepatectomy did not increase in comparison to HEP group, and steroid had no effect on IL-6 level. According to the progression of obstructive jaundice, the IL-6 level after hepatectomy increased to a higher level than before, and the effect of MPL was restored. HSP70 is thus suggested to have an important role in cytokine production.     

小鼠溃疡性结肠炎模型的建立及病理组织学比较

目的建立乙酸,右旋葡聚糖硫酸钠（dextran sodium sulfate,DSS）,幽门螺杆菌（Helicobacter pyliri）小鼠溃疡性结肠炎（ulcerative colitis）动物模型,通过病理学对比观察,选择最佳的小鼠溃疡性结肠炎动物模型。方法将40只清洁级BALB/c小鼠随机分为4组,实验组中Ⅰ组采用乙酸刺激法诱发溃疡性结肠炎,Ⅱ组采用饮用3.5%DSS溶液诱发结肠炎,Ⅲ组采用幽门螺杆菌感染小鼠诱发溃疡性结肠炎,对照组饮用蒸馏水。观察小鼠每日的体重,大便性状和隐血情况,以及结肠大体形态和组织病理学改变。结果乙酸,右旋葡聚糖硫酸钠均可引起小鼠疡性结肠炎。结论 DSS诱发的小鼠溃疡性结肠炎是一种较理想的UC动物模型,可作为研究UC发病机制和药物治疗较理想的工具。     

Kupffer cells hasten resolution of liver immunopathology in mouse models of viral hepatitis

Kupffer cells (KCs) are widely considered important contributors to liver injury during viral hepatitis due to their pro-inflammatory activity. Herein we utilized hepatitis B virus (HBV)-replication competent transgenic mice and wild-type mice infected with a hepatotropic adenovirus to demonstrate that KCs do not directly induce hepatocellular injury nor do they affect the pathogenic potential of virus-specific CD8 T cells. Instead, KCs limit the severity of liver immunopathology. Mechanistically, our results are most compatible with the hypothesis that KCs contain liver immunopathology by removing apoptotic hepatocytes in a manner largely dependent on scavenger receptors. Apoptotic hepatocytes not readily removed by KCs become secondarily necrotic and release high-mobility group box 1 (HMGB-1) protein, promoting organ infiltration by inflammatory cells, particularly neutrophils. Overall, these results indicate that KCs resolve rather than worsen liver immunopathology.     

模式小鼠总DNA三种提取方法比较

目的：建立简便、快捷、经济的模式小鼠总DNA提取方法,以快速鉴定大批量模式小鼠基因型。方法采用苯酚抽提法、异丙醇沉淀法、鼠耳煮沸法提取同种模式小鼠总DNA,对比DNA纯度、得率、耗费时间,并比较基因型鉴定结果。结果苯酚抽提法得率最高,异丙醇沉淀法最低;而纯度则按照苯酚抽提法、异丙醇沉淀法、鼠耳煮沸法顺序递减;在耗时上鼠耳煮沸法最短。三种方法提取的DNA均可做模版用于基因型鉴定。结论鼠耳煮沸法操作简单、成本最低,快速、基因型鉴定结果可靠,可用于规模化的基因型鉴定实验中。     

Contributions of experimental mouse models to the understanding of African trypanosomiasis

African trypanosomiasis is the collective name for a wide variety of trypanosome infections that affect humans and livestock. In recent years, experimental mice infection models have provided new insights into both human and animal trypanosomiasis. Mouse models seem to be a valuable and versatile tool in trypanosomiasis-associated pathology and immunology research and highlight the variety shown by African trypanosomiases. Indeed, inbred mouse strains have enabled the study of genetic determinants of susceptibility and of the roles of anti-parasite antibodies, inflammatory mediators and anti-inflammatory mediators for each trypanosome species. Remarkable advances relating to the encephalitic stage of sleeping sickness have also been achieved thanks to murine models. The different contributions of murine models to the African trypanosomiases knowledge are presented here. Future search directions are finally proposed, with respect to mouse model opportunities and limitations.     

Cytokine regulatory effects on alpha-1 proteinase inhibitor expression in NOD mouse islet endothelial cells

Human microvascular islet endothelial cells (IEC) exhibit specific morphological and functional characteristics that differ from endothelia derived from other organs. One of these characteristics is the expression of alpha-1 proteinase inhibitor (Api). In this study, we observed its expression in nonobese diabetic (NOD) mouse IEC, in relation to the occurrence of type 1 diabetes and in response to cytokines, namely IL-1 beta and IL-10. In addition, IL-10-deficient NOD mice as well as IL-10 transgenic NODs were studied. Results have demonstrated that Api expression is: (i) highly specific for IEC in NOD mouse islets, as for humans; (ii) linked to the occurrence of early type 1 diabetes, and iii) strongly modulated by Th1 and Th2 cytokines. In fact, Api mRNA found in pre-diabetic NOD animals is significantly reduced when they become hyperglycemic and disappears by 25 weeks of age, when mice are diabetic. Moreover, Api mRNAs are never seen in nondiabetic controls. Furthermore, in cultured NOD IEC, Api expression is downregulated by the addition of IL-1 beta and is upregulated by IL-10; it is always absent in IL-10-deficient NOD mice and overexpressed in IL-10 transgenic NODs, thus further supporting that this cytokine upregulates Api expression.     

Effect of methadone administration on MHV-3 virus-induced experimental hepatitis in the mouse

Mice treated with 15 mg/Kg/day methadone and infected with MHV-3 virus after 7 days did not show increased susceptibility to MHV-3 virus infection, did not develop more serious forms of hepatitis and not mortality did not increase with respect to the controls. Drug administration was continued for the duration of the experiment.     

Microarray analysis of gene expression by skeletal muscle of three mouse models of Kennedy disease/spinal bulbar muscular atrophy

Background

Emerging evidence implicates altered gene expression within skeletal muscle in the pathogenesis of Kennedy disease/spinal bulbar muscular atrophy (KD/SBMA). We therefore broadly characterized gene expression in skeletal muscle of three independently generated mouse models of this disease. The mouse models included a polyglutamine expanded (polyQ) AR knock-in model (AR113Q), a polyQ AR transgenic model (AR97Q), and a transgenic mouse that overexpresses wild type AR solely in skeletal muscle (HSA-AR). HSA-AR mice were included because they substantially reproduce the KD/SBMA phenotype despite the absence of polyQ AR.

Methodology/Principal Findings

We performed microarray analysis of lower hindlimb muscles taken from these three models relative to wild type controls using high density oligonucleotide arrays. All microarray comparisons were made with at least 3 animals in each condition, and only those genes having at least 2-fold difference and whose coefficient of variance was less than 100% were considered to be differentially expressed. When considered globally, there was a similar overlap in gene changes between the 3 models: 19% between HSA-AR and AR97Q, 21% between AR97Q and AR113Q, and 17% between HSA-AR and AR113Q, with 8% shared by all models. Several patterns of gene expression relevant to the disease process were observed. Notably, patterns of gene expression typical of loss of AR function were observed in all three models, as were alterations in genes involved in cell adhesion, energy balance, muscle atrophy and myogenesis. We additionally measured changes similar to those observed in skeletal muscle of a mouse model of Huntington''s Disease, and to those common to muscle atrophy from diverse causes.

Conclusions/Significance

By comparing patterns of gene expression in three independent models of KD/SBMA, we have been able to identify candidate genes that might mediate the core myogenic features of KD/SBMA.     

Adipokine expression profile in adipocytes of different mouse models of obesity.

Adipose tissue produces and secretes multiple adipokines. Most studies on adipokine production/expression have been performed on whole adipose tissue. In addition, data concerning an overall of adipokine expression are scarce and can be heterogeneous depending on the obesity model studied. Our first aim was to compare the expression of adipokines involved in the interplay between obesity and insulin resistance in isolated adipocytes from different mouse models of obesity displaying different levels of weight gain and insulin sensitivity. The second aim was to determine perigonadal/subcutaneous ratio of each adipokine. Only resistin expression was decreased in obese mice without modifications in glucose and insulin blood levels. In addition to decreased levels of resistin, obesity models associated with hyperglycemia and hyperinsulinemia presented an increased expression of leptin and tumor necrosis factor-alpha (TNFalpha). Obese and diabetic mice were the only animals to exhibit high expression of plasminogen activator inhibitor type-1 and interleukin-6. All adipokines except TNFalpha were more heavily expressed in perigonadal than in subcutaneous adipocytes. Interestingly, fat-enriched diet and overweight on their own did not modify the distribution of adipokines between the two fat depots. However, severe obesity modified the distribution of proinflammatory adipokines. In conclusion, the level and number of adipokines with altered expression increased with obesity and hyperinsulinemia in mice. The physiopathological impact of depot-specific differences of adipokine expression in adipocytes remains to be clarified.     

Choosing a mouse model: experimental biology in context--the utility and limitations of mouse models of breast cancer

Genetically engineered mice are critical experimental models for the study of breast cancer biology. Transgenic mice, employing strong mammary epithelial promoters to drive oncogenes, develop carcinomas with phenotypes corresponding to the molecular pathway activated. Gene-targeted (knockout) mice, in which tumor suppressors are deleted, develop mammary neoplasms with phenotypes primarily including patterns seen in spontaneous mouse mammary tumors, albeit at higher rates. Improved genetic engineering, using inducible gene expression, somatic gene transduction, conditional alleles, and crossbreeding for combined/compound genetic engineering yields precise molecular models with exquisite experimental control and phenotypes with comparative pathologic validity. Mammary gland transplantation technology adds a practical and validated method for assessing biologic behavior of selected mammary tissues. Overall, the many mouse models available are a rich resource for experimental biology with phenocopies of breast cancer subtypes, and a variety of practical advantages. The challenge is matching the model to the experimental question.     

Cytokine mediation of experimental heart failure-induced anhedonia

Immune system dysfunction is hypothesized to influence several disease states, including cardiovascular disease and psychological depression. The comorbidity of depression and coronary artery disease may be influenced by immune system-brain interactions involving proinflammatory cytokines. The present studies evaluated an index of depression in a rodent model of heart failure by measuring responses to rewarding electrical brain stimulation, which provides an experimental procedure to operationally define anhedonia in rats. Heart failure led to a rightward shift in the current-response relationship in the brain stimulation paradigm, indicative of reduced rewarding properties of the brain stimulation (i.e., anhedonia). Acute treatment with a tumor necrosis factor antagonist, etanercept, reduced circulating tumor necrosis factor- levels in rats with heart failure and restored responding for electrical brain stimulation. The current findings have implications for the study of pathophysiological mechanisms underlying the association of cardiovascular disease and depression.