Difference in mitochondrial gene expression in granulosa cells between recombinant FSH and hMG cycles under in vitro fertilization and transfer

Purpose

Examination of the mitochondrial mRNA expression in granulosa cells from an unspecified population of infertile patients to evaluate whether recombinant follicle stimulating hormone (recFSH) is more effective in producing higher quality embryo rates compared with human menopausal gonadotropin (hMG).

Method

Thirty-nine patients who underwent the in vitro fertilization and embryo transfer program were retrospectively examined. Patients were administered recFSH (n = 18) or hMG (n = 20) in a long protocol where GnRH agonist was used. Granulosa cells were obtained during oocyte retrieval and examined for mitochondria mRNA expression ratio against GAPDH. Expressions of mitochondria mRNA were evaluated by real-time PCR analysis.

Results

The high-quality embryo rate in the hMG cycle was higher than in the recFSH cycle, and the total dose of hMG showed a positive correlation with the expression level of mitochondrial genes in granulosa cells. Moreover, mitochondria mRNA expression was higher in the hMG cycle than in the recFSH cycle.

Conclusions

Compared with recFSH, hMG induces a higher mitochondrial gene expression ratio in granulosa cells at the time of oocyte retrieval and, therefore, may lead to higher quality embryo rates.     

Brush border myosin Ia inactivation in gastric but not endometrial tumors

Brush border Myosin Ia (MYO1A) has been shown to be frequently mutated in colorectal tumors with microsatellite instability (MSI) and to have tumor suppressor activity in intestinal tumors. Here, we investigated the frequency of frameshift mutations in the A8 microsatellite in exon 28 of MYO1A in MSI gastric and endometrial tumors and found a high mutation rate in gastric (22/47; 46.8%) but not endometrial (3/48; 6.2%) tumors. Using a regression model, we show that MYO1A mutations are likely to confer a growth advantage to gastric, but not endometrial tumors. The mutant MYO1A^7A protein was shown to lose its membrane localization in gastric cancer cells and a cycloheximide‐chase assay demonstrated that the mutant MYO1A^7A protein has reduced stability compared to the wild type MYO1A. Frequent MYO1A promoter hypermethylation was also found in gastric tumors. Promoter methylation negatively correlates with MYO1A mRNA expression in a series of 58 non‐MSI gastric primary tumors (Pearson's r = ?0.46; p = 0.0003) but not in a cohort of 54 non‐MSI endometrial tumors and treatment of gastric cancer cells showing high MYO1A promoter methylation with the demethylating agent 5‐aza‐2′‐deoxycytidine, resulted in a significant increase of MYO1A mRNA levels. We found that normal gastric epithelial cells, but not normal endometrial cells, express high levels of MYO1A. Therefore, when considered together, our findings suggest that MYO1A has tumor suppressor activity in the normal gastric epithelium but not in the normal endometrium and inactivation of MYO1A either genetically or epigenetically may confer gastric epithelial cells a growth advantage.     

Melanocortin 4 receptor-deficient mice as a novel mouse model of nonalcoholic steatohepatitis

Obesity may be viewed as a state of chronic low-grade inflammation that participates in the development of the metabolic syndrome. Nonalcoholic steatohepatitis (NASH) is considered a hepatic phenotype of the metabolic syndrome and a high risk for progression to cirrhosis and hepatocellular carcinoma. Although the "two hit" hypothesis suggests involvement of excessive hepatic lipid accumulation and chronic inflammation, the molecular mechanisms underlying the development of NASH remain unclear, in part because of lack of appropriate animal models. Herein we report that melanocortin 4 receptor-deficient mice (MC4R-KO) develop steatohepatitis when fed a high-fat diet, which is associated with obesity, insulin resistance, and dyslipidemia. Histologic analysis reveals inflammatory cell infiltration, hepatocyte ballooning, and pericellular fibrosis in the liver in MC4R-KO mice. Of note, all of the MC4R-KO mice examined developed well-differentiated hepatocellular carcinoma after being fed a high-fat diet for 1 year. They also demonstrated enhanced adipose tissue inflammation, ie, increased macrophage infiltration and fibrotic changes, which may contribute to excessive lipid accumulation and enhanced fibrosis in the liver. Thus, MC4R-KO mice provide a novel mouse model of NASH with which to investigate the sequence of events that make up diet-induced hepatic steatosis, liver fibrosis, and hepatocellular carcinoma and to aid in understanding the pathogenesis of NASH, pursuing specific biomarkers, and evaluating potential therapeutic strategies.     

Involvement of hypothalamic periventricular GABAergic nerves in the central pressor response to clonidine in freely-moving conscious rats

Microinjection of the α(2)-adrenoceptor agonist clonidine into the hypothalamic periventricular nuclei (PVN) induces the pressor response associated with bradycardia in freely-moving conscious rats. This study investigated the involvement of γ-aminobutyric acid nerves (GABAergic nerves) and glutamatergic nerves in the cardiovascular response to microinjection of clonidine in the PVN. Male Wistar rats were chronically implanted with a microinjection cannula into the PVN and an arterial catheter into the abdominal aorta through the femoral artery. Blood pressure and heart rate were measured under a conscious unrestrained state. PVN injection of clonidine induced a dose-dependent pressor response concomitant with bradycardia. PVN pretreatment with GABA, muscimol (GABA(A)-receptor agonist), or bicuculline (GABA(A)-receptor antagonist) significantly inhibited the pressor response to PVN-injected clonidine without affecting bradycardia. PVN pretreatment with baclofen (GABA(B)-receptor agonist), 2-hydroxysaclofen (GABA(B)-receptor antagonist), or kynurenic acid (non-selective NMDA-type glutamate-receptor and ionotropic glutamate-receptor antagonist) did not affect the pressor response to PVN-injected clonidine. These results suggest that clonidine induces a pressor response by stimulating the presynaptic α(2)-adrenoceptor of GABAergic nerves in the PVN, thereby inhibiting GABAergic nerve activity.     

The mechanism of calcitonin gene-related peptide-containing nerve innervation

Calcitonin gene-related peptide (CGRP) is a major neurotransmitter and CGRP-containing primary sensory neurons play an important role in nociception and potent vasodilation. CGRP-containing nerves in mesenteric arteries are decreased in pathological animal models (hypertension, diabetes, and atherosclerosis). In apolipoprotein E–knockout mice, which have atherosclerosis and peripheral sensory nerve defects, nerve growth factor (NGF)-mediated CGRP nerve facilitation was down-regulated, which may have been caused by the impairment of the Akt–NO–cGMP pathway. In addition, NGF-mediated CGRP neurite outgrowth was decreased in fructose-induced insulin-resistant rats. We recently discovered that renin–angiotensin inhibitors improved CGRP innervation in spontaneously hypertensive rats, indicating that rescuing CGRP nerve innervation might improve pathophysiological conditions. To find a novel reagent that facilitates CGRP nerves, a new model, phenol-injured perivascular nerve model rats, was established. Adrenomedullin, hepatocyte growth factor, and angiotensin II type 2 receptor activation induced CGRP nerve distribution in phenol-injured rats. Furthermore, in insulin-resistant model rats, the down-regulation of CGRP nerves was likely due to the depression of phosphoinositide 3-kinase (PI3K)-dependent Akt activation. Administration of candesartan improves CGRPergic function via the PI3K–Akt pathway in insulin-resistant rats. Thus, clarification of the mechanisms of CGRP nerve defects may constitute future therapeutic targets.     

Lineage analysis of newly generated neurons in organotypic culture of rat hippocampus

New neurons are continuously generated in the hippocampus at the subgranular zone of the dentate granule cell layer throughout life. However, the lineage of newly generated neurons is unknown in detail. Here, using a retrovirus vector encoding EGFP, we labeled proliferating cells in an organotypic slice culture of the postnatal hippocampus of rat, and tracked their descendents over a long period. At 28 days post-inoculation, the phenotypes of the cells were immunohistochemically identified using specific antibodies to cell-type markers such as HuC/D (pan-neuronal marker), GFAP (astrocyte marker), Prox1 (dentate granule cell marker) or NeuN (mature neuronal marker). We found that the cells were mostly GFAP-negative in the HuC/D-positive lineages. The EGFP-expressing cells were often untraceable shortly after cell division in the HuC/D-positive lineages. The postmitotic periods of these cells distributed between 2 and 14 days. For the lineages expressing both Prox1 and NeuN the newborn cells became untraceable in a similar period (2-10 days). It is suggested that the newly generated neurons differentiate to mature dentate granule cells in the slice culture once they have survived over this critical traceability period.     

Evaluation of a Sindbis virus vector displaying an immunoglobulin-binding domain: antibody-dependent infection of neurons in living mice

Viral vectors that genetically incorporate an immunoglobulin-binding domain on their surfaces provide many advantages because of the availability of a spectrum of antibodies that allow the selection of a wide range of target cells. However, the specificity and the effectiveness of this system have not been evaluated in the field of neuroscience. We investigated the effectiveness and specificity of a recombinant Sindbis virus displaying an antibody-binding domain of bacterial protein A (ZZ Sindbis). We found that the ZZ Sindbis virus vector specifically infected hippocampal neurons in an antibody-specific manner in living mice, although the efficiency of the gene transduction was not high. However, the ZZ Sindbis virus vector that did not display any specific antibodies continued to exhibit intrinsic tropism toward Bergmann glial cells in the cerebellum. These data indicate that the antibody-displaying viral vectors are potentially useful for delivering a gene of interest to a specific subset of neurons in the central nervous system with the help of neuron type-specific antibodies.     

Immune recovery after autologous PBSC transplantation without in vitro graft manipulation for refractory systemic lupus erythematosus

Autologous hematopoietic SCT (ASCT) has been investigated as salvage therapy for refractory systemic lupus erythematosus (SLE). Although immune recovery after ASCT with in vitro purging of lymphocytes has been extensively studied, little information is available about immune recovery after ASCT without in vitro purging. Therefore, we analyzed the immune recovery of a patient who successfully underwent ASCT without in vitro purging for refractory SLE. In addition to the numbers of PBL subsets, T-cell receptor rearrangement excision circles (TRECs) and the T-cell receptor repertoire diversity of both CD4+ and CD8+ T cells were sequentially analyzed. All SLE-related symptoms disappeared within 3 months after ASCT and the serum anti-dsDNA Ab became undetectable. The number of CD4+CD45RO+ memory T cells remained lower than that in healthy adult controls, but the number of CD4+CD45RA+ na?ve T cells showed a rapid increase after ASCT. TRECs of both CD4+ and CD8+ T cells were strongly suppressed before ASCT, but consistently increased after ASCT. The T-cell receptor repertoire of CD8+ T cells was skewed before ASCT, but the diversity recovered after ASCT. ASCT with the reinfusion of a large number of autologous T cells did not impair the recovery of naive T cells or resetting of the immune system.