Characteristics of intestinal microbiota in C57BL/6 mice with non-alcoholic fatty liver induced by high-fat diet

Introduction

As a representation of the gut microbiota, fecal and cecal samples are most often used in human and animal studies, including in non-alcoholic fatty liver disease (NAFLD) research. However, due to the regional structure and function of intestinal microbiota, whether it is representative to use cecal or fecal contents to study intestinal microbiota in the study of NAFLD remains to be shown.

Methods

The NAFLD mouse model was established by high-fat diet induction, and the contents of the jejunum, ileum, cecum, and colon (formed fecal balls) were collected for 16S rRNA gene analysis.

Results

Compared with normal mice, the diversity and the relative abundance of major bacteria and functional genes of the ileum, cecum and colon were significantly changed, but not in the jejunum. In NAFLD mice, the variation characteristics of microbiota in the cecum and colon (feces) were similar. However, the variation characteristics of intestinal microbiota in the ileum and large intestine segments (cecum and colon) were quite different.

Discussion

Therefore, the study results of cecal and colonic (fecal) microbiota cannot completely represent the results of jejunal and ileal microbiota.

XBP1 increases transactivation of somatic mutants of ESR1 and loss of XBP1 reverses endocrine resistance conferred by gain-of-function Y537S ESR1 mutation

Somatic mutations of the estrogen receptor 1 gene (ESR1) is an emerging mechanism of acquired resistance to endocrine therapy in hormonal breast cancers. Hotspot point mutations in the ligand- binding domain of estrogen receptor α (ER) and genomic rearrangements producing ESR1 fusion genes are the two major types of mutations that are associated with endocrine resistance. The crosstalk between X-box binding protein 1 (XBP1), a key transcription factor of the unfolded protein response (UPR) and ER signalling creates a positive feedback loop that results in increased expression of XBP1 in ER-positive breast cancer. Here we report that XBP1 co-operated with point mutants (Y537S, D538G) and fusion mutants (ESR1-YAP1, ESR1-DAB2) of ESR1 to increase their transcriptional activity. XBP1 was required for optimal expression of estrogen-regulated genes, and up to 40% of XBP1-dependent genes were estrogen-responsive genes. Knockdown of XBP1 in genome-edited MCF7 cells expressing Y537S mutant reduced their growth, re-sensitized them to anti-estrogens and attenuated the constitutive and estrogen-stimulated expression of estrogen-regulated genes. Our study provides a rationale for overcoming endocrine resistance in breast cancers expressing ESR1 mutation by combining the XBP1 targeting agents with anti-estrogen agents.

Microcystin-LR exposure results in aberrant spindles and induces apoptosis in porcine oocytes

Microcystin-LR (MC-LR), as a well-known hepatotoxin, was recently found to accumulate in gonads and induce a variety of reproductive damages in zebrafish, mice and other model organisms, however, little information is available on whether MC-LR has toxic effects on the mammalian oocytes, especially in livestock species. In this study, the effects of MC-LR on meiotic maturation of porcine oocytes were investigated, and the potential mechanism of MC-LR toxicity was explored. Germinal vesicle (GV)-stage oocytes were exposed to 0, 20, 40 and 60 μM MC-LR, respectively, during the in vitro maturation for 44 h, and the results showed that the first polar body (PbI) extrusion rate of the oocytes decreased significantly when the MC-LR concentration reached 40 (P < 0.01) or 60 μM (P < 0.001). After treated with 60 μM MC-LR for 44 h, a significant higher percentage of the oocytes arrested at anaphase-telophase I (ATI) stage (P < 0.01). Laser scanning confocal results further confirmed that a significantly larger proportion of the 60 μM MC-LR-treated oocytes exhibited aberrant spindles and misaligned chromosomes, suggesting a failure of spindle assembly and homologous chromosome segregation during the ATI stage. Furthermore, the ROS levels in the 60 μM MC-LR-exposed oocytes were significantly higher than the control group (P < 0.01), while the expression of antioxidant related genes (SOD1, CAT and GPX) were much lower compared with control group, indicating that oxidative stress was induced and the antioxidant capacity of oocytes was depleted by 60 μM MC-LR treatment. Additionally, markedly decreased mitochondrial membrane potential (MMP) (P < 0.01) and significantly higher incidence of early apoptosis (P < 0.01) were observed in the 60 μM MC-LR-treated oocytes, suggesting that MC-LR exposure induced apoptosis in porcine oocytes. Moreover, the protein expression of PP2A was remarkably inhibited, whereas the expression of p53, BAX, Caspase3 and Cleaved-caspase3 were prominently increased in the 60 μM MC-LR-exposed oocytes. Together, these results suggested that 60 μM of MC-LR exposure can induce oxidative stress, and lead to aberrant spindles, impaired MMP, and trigger apoptosis, which eventually result in failure of porcine oocyte maturation.

Aurora A inhibition disrupts chromosome condensation and spindle assembly during the first embryonic division in pigs

As common overexpression of Aurora A in various tumours, much attention has focused on its function in inducing cancer, and its value in cancer therapeutics, considerably less is known regarding its role in the first cleavage division of mammalian embryos. Here, we highlight an indispensable role of Aurora A during the first mitotic division progression of pig embryos just after meiosis. The expression and spatiotemporal localization of Aurora A were initially assessed in pig embryos during the first mitotic division by Western blot analysis and indirect immunofluorescent staining. Then, the potential role of Aurora A was further evaluated using a highly selective Aurora A inhibitor, MLN8054, during this mitotic progression in pig embryos. Aurora A was found to express and exhibit a specific dynamic intracellular localization pattern during the first mitotic division in pig embryos. Aurora A was diffused in the cytoplasm at the prophase stage, and then exhibited a dynamic intracellular localization which was tightly associated with the chromosome and spindle dynamics throughout subsequent mitotic phases. Inhibition of Aurora A by MLN8054 treatment led to the failure of the first cleavage, with the majority of embryos being arrested in prophase of the mitotic division. Further subcellular structure examination showed that Aurora A inhibition not only led to the failure of spindle microtubule assembly, but also resulted in severe defects in chromosome condensation, accompanied by an obvious decrease in p-TACC3(S558) expression during the prophase of the first mitosis. Together, these results illustrated that Aurora A is crucial for both spindle assembly and chromosome condensation during the first mitotic division in pig embryos, and that the regulation of Aurora A may be associated with its effects on p-TACC3(S558) expression.

Polo-like kinase 1 inhibition results in misaligned chromosomes and aberrant spindles in porcine oocytes during the first meiotic division

Polo-like kinase 1 (Plk1), a type of serine/threonine protein kinase, has been implicated in various functions in the regulation of mitotic processes. However, these kinase's roles in meiotic division are not fully understood, particularly in the meiotic maturation of porcine oocytes. In this study, the expression and spatiotemporal localization of Plk1 were initially assessed in the meiotic process of pig oocytes by utilizing Western blotting with immunofluorescent staining combined with confocal microscopy imaging technique. The results showed that Plk1 was expressed and exhibited a dynamic subcellular localization throughout the meiotic process. After germinal vesicle breakdown (GVBD), Plk1 was detected prominently around the condensed chromosomes and subsequently exhibited a similar subcellular localization to α-tubulin throughout subsequent meiotic phases, with particular enrichment being observed near spindle poles at MI and MII. Inhibition of Plk1 via a highly selective inhibitor, GSK461364, led to the failure of first polar body extrusion in porcine oocytes, with the majority of the treated oocytes being arrested in GVBD. Further subcellular structure examination results indicated that Plk1 inhibition caused the great majority of oocytes with spindle abnormalities and chromosome misalignment during the first meiotic division. The results of this study illustrate that Plk1 is critical for the first meiotic division in porcine oocytes through its influence on spindle organization and chromosome alignment, which further affects the ensuing meiotic cell cycle progression.

Plk1 is essential for proper chromosome segregation during meiosis I/meiosis II transition in pig oocytes

BACKGROUND

Polo-like kinase 1 (Plk1), as a characteristic regulator in meiosis, organizes multiple biological events of cell division. Although Plk1 has been implicated in various functions in somatic cell mitotic processes, considerably less is known regarding its function during the transition from metaphase I (MI) to metaphase II (MII) stage in oocyte meiotic progression.

METHODS

In this study, the possible role of Plk1 during the MI-to-MII stage transition in pig oocytes was addressed. Initially, the spatiotemporal expression and subcellular localization pattern of Plk1 were revealed in pig oocytes from MI to MII stage using indirect immunofluorescence and confocal microscopy imaging techniques combined with western blot analyses. Moreover, a highly selective Plk1 inhibitor, GSK461364, was used to determine the potential role of Plk1 during this MI-to-MII transition progression.

RESULTS

Upon expression, Plk1 exhibited a specific dynamic intracellular localization, and co-localization of Plk1 with α-tubulin was revealed in the meiotic spindle of pig oocyte during the transition from MI to MII stage. GSK461364 treatment significantly blocked the first polar body (pbI) emission in a dose-dependent manner and resulted in a failure of meiotic maturation, with a larger percentage of the GSK461364-treated oocytes arresting in the anaphase-telophase I (ATI) stage. Further subcellular structure examination results showed that inhibition of Plk1 with GSK461364 had no visible effect on spindle assembly but caused a significantly higher proportion of the treated oocytes to have obvious defects in homologous chromosome segregation at ATI stage.

CONCLUSIONS

Thus, these results indicate that Plk1 plays an essential role during the meiosis I/meiosis II transition in porcine oocytes, and the regulation is associated with Plk1's effects on homologous chromosome segregation in the ATI stage.

The effect of hydroxyzine on treating bruxism of 2- to 14-year-old children admitted to the clinic of Bandar Abbas Children Hospital in 2013-2014

Introduction. Bruxism is to press or grind teeth against each other in non-physiologic cases, when an individual does not swallow or chew. If not treated, teeth problems, stress, mental disorders, frequent night waking, and headache is expected. This research aimed to study the effect of hydroxyzine on treating bruxism of 2- to 14-year-old children admitted to the clinic of Bandar Abbas Children Hospital. Methodology. In this clinical trial, 143 children with the ages between 4-12 years were admitted to the Children Hospital and were divided randomly into test and control groups. The test group consisted of 88 hydroxyzine-treated children and the control group consisted of 55 children who used hot towels. Both groups were examined in some stages including the pre-test stages or the stage before starting treatments at two, four, and six weeks and four months after stopping the treatment. The effects of each treatment on reducing bruxism symptoms were assessed by a questionnaire. The data were analyzed by using SPSS in descriptive statistics, t-test, and ANOVA. Results. As far as bruxism severity was concerned, the results showed a significant difference between the test group members who received hydroxyzine and the control group members who received no medication. T-test results showed a statistically significant difference between the test and the control groups in the second post-test (four weeks later) (p. value ≤ 0.05). Mean of the scores of bruxism severity in the test group has changed significantly in the post-test (at two weeks, four weeks, and six weeks later) as compared to the pre-test. Whereas, as far as the response to the treatment, no significant difference was recorded between the control group and the test group 4 weeks after the treatment. Discussion. The results showed that prescribing hydroxyzine for 4 weeks had a considerable effect in diminishing bruxism severity between the test groups.

Is there any correlation between high sensitive CRP and disease activity in systemic lupus erythematosus?

The role of C-reactive protein (CRP) in systemic lupus erythematosus (SLE) as an inflammatory marker is still controversial. Recently, more sensitive methods, such as high sensitive CRP (hs-CRP) have been used to detect micro-inflammation. The role of hs-CRP in lupus flare has not been documented well. We conducted this study to examine the correlation between hs-CRP serum concentrations and disease activity in lupus. Ninety-two SLE patients and 49 healthy controls contributed to our study. Most confounding factors influencing the hs-CRP values were excluded. Disease activity was estimated using the SLE Disease Activity Index (SLEDAI-2K). hs-CRP values were determined using an enzyme-linked immunosorbent assay (ELISA) kit. Serum values of hs-CRP were significantly higher (p < 0.001, z = 3.29) in patients compared with healthy controls. The cutoff point for hs-CRP between patients and controls was 0.93 mg/L (Youden's Index = 0.39). There was no correlation between hs-CRP serum levels and disease activity. Furthermore, hs-CRP values did not correlate with any of the laboratory parameters, except for C3 (p = 0.003, r(s)  = -0.2) and C4 (p = 0.02, r(s) = -0.1). Although hs-CRP serum levels were significantly higher in lupus patients compared with healthy controls, it seems that this marker is not a good indicator for disease activity.

Clinical course and outcome of snake envenomation at a hospital in Karachi

INTRODUCTION

Snake envenomation is a frequently reported medical emergency at the Civil Hospital Karachi, Pakistan, [corrected] thus obviating the need to assess the patterns of the clinical course and outcome of snake envenomation cases.

METHODS

The demographic characteristics, clinical signs and symptoms, laboratory findings, treatment and outcome of 80 victims of snake bite were recorded. These patients were admitted to the Civil Hospital Karachi between January 2006 and September 2007. The data of all the cases was analysed statistically using the Statistical Package for the Social Sciences version 11.0.

RESULTS

The majority of the 80 victims of snake bite were male (80 percent) and 20 percent were female. The mean age of the patients was 33.3 years. The main type of envenomation was vasculotoxic (92.5 percent), and none were neurotoxic or myotoxic. Both local and systemic clinical features of envenomation were present. Bleeding was reported in 43.8 percent of the patients. 71.3 percent of the patients showed coagulopathy of defibrination and the anti-coagulant type. All patients received anti-snake venom. Five (6.3 percent) patients in the study died.

CONCLUSION

The most common type of snake envenomation in this part of the province of Sindh is vasculotoxic due to the high inhabitancy of Viperidae. High morbidity and mortality rates can be reduced significantly through patient education on the precautions that need to be taken by farmers and field workers against snake bite. Early referral to a well-equipped health facility is necessary, as the mortality rate was high among those patients who arrived late.