Metabolism alteration in follicular niche: The nexus among intermediary metabolism,mitochondrial function,and classic polycystic ovary syndrome

Classic polycystic ovary syndrome (PCOS) is a high-risk phenotype accompanied by increased risks of reproductive and metabolic abnormalities; however, the local metabolism characteristics of the ovaries and their effects on germ cell development are unclear. The present study used targeted metabolomics to detect alterations in the intermediate metabolites of follicular fluid from classic PCOS patients, and the results indicated that hyperandrogenism but not obesity induced the changed intermediate metabolites in classic PCOS patients. Regarding the direct contact, we identified mitochondrial function, redox potential, and oxidative stress in cumulus cells which were necessary to support oocyte growth before fertilization, and suggested dysfunction of mitochondria, imbalanced redox potential, and increased oxidative stress in cumulus cells of classic PCOS patients. Follicular fluid intermediary metabolic profiles provide signatures of classic PCOS ovary local metabolism and establish a close link with mitochondria dysfunction of cumulus cells, highlighting the role of metabolic signal and mitochondrial cross talk involved in the pathogenesis of classic PCOS.     

Influence of long term treatment with 3-methylcholanthrene or carbaryl on mixed-function oxidase activity in 3T3 fibroblasts: Studies by microspectrofluorimetry on single cells

Using benzo(a)pyrene (BaP) as a probe for aryl hydrocarbon hydroxylase (AHH) activity, differences in mixed-function oxidase (MFO) activity were observed using microspectrofluorimetry in single living cells during long term treatment with 3-methylcholanthrene (3-MC) or carbaryl. Although these two compounds differ in chemical structure, similar effects were observed in 3T3 cell populations. The results suggest that the two compounds activate the same enzymatic system and that individual cells of a supposed homogeneous cell population are not equally sensitive to xenobiotics, i.e. subpopulations were observed which have differences in AHH activity.     

Modulation of Coordinated Activity across Cortical Layers by Plasticity of Inhibitory Synapses

1. Download : Download high-res image (118KB)
2. Download : Download full-size image

     

Microbial production of d-amino acids

The production of d-aminoacylase by Alcaligenes denitrificans and Alcaligenes faecalis has been studied. The enzyme was inducibly produced and N-acetyl-d-leucine and N-acetyl-d-valine were the most effective inducers. d-methionine, d-valine, d-phenylalamine and d-leucine were produced by the enzymic hydrolysis of the appropriate N-acetyl-d-amino-acids with whole cell biomass. The hydrolysis of N-acetyl-d-methionine by A. denitrificans and N-acetyl-d-valine by A. faecalis was preferential. Maximum yields of d-methionine and d-valine were 94.3 and 84.7% at a specific product formation rate of 20.10 and 19.19 μmol min⁻¹ mg⁻¹ of wet cells at 20 mM substrate concentration and 5 mg ml⁻¹ of cell density.     

Vesicle Shrinking and Enlargement Play Opposing Roles in the Release of Exocytotic Contents

1. Download : Download high-res image (176KB)
2. Download : Download full-size image

     

Rat Sertoli and spermatogenic cells express a similar gene, and its product is antigenically related to an outer dense fiber-associated protein.

We have previously reported that a heterodimeric protein secreted by rat Sertoli cells is antigenically related to a protein associated with outer dense fibers of the sperm tail. Therefore, we have explored the possibility that Sertoli and spermatogenic cells express a similar gene encoding a homologous protein. A Sertoli cell heterodimeric protein cDNA probe recognizes specific mRNA in pachytene and round spermatids fractionated by centrifugal elutriation; however, this specific mRNA was less prominent than in cultured Sertoli cells. In agreement with these observations, in situ hybridization experiments show that Sertoli cells are predominantly engaged in active heterodimeric protein mRNA synthesis, while meiotic prophase spermatocytes and spermatids also show significant but less abundant specific mRNA. Immunoblotting experiments demonstrate that, while Sertoli cells synthesize a heterodimeric protein consisting of two disulfide-linked components with molecular masses of 45 and 35 kD, both primary spermatocytes and round spermatids synthesize single 30 kD monomers not associated by disulfide linkage but recognized by antisera to Sertoli cell heterodimeric protein. Immunoblotting and immunogold electron microscopic studies show that antisera to Sertoli cell heterodimeric protein recognize a protein associated with outer dense fibers. This immunoreactivity was abolished by a 5-min pronase treatment, without affecting the integrity of outer dense fibers. Results of this study and previous studies demonstrate that both Sertoli and spermatogenic cells express a similar gene and that an antigenically related product encoded by this gene becomes associated with outer dense fibers during their assembly at spermiogenesis.     

The Amount of BCL6 in B Cells Shortly after Antigen Engagement Determines Their Representation in Subsequent Germinal Centers

1. Download : Download high-res image (102KB)
2. Download : Download full-size image

     

Astrocyte–neuron interactions in neurological disorders

Astrocytes have long been considered as just providing trophic support for neurons in the central nervous system, but recently several studies have highlighted their importance in many functions such as neurotransmission, metabolite and electrolyte homeostasis, cell signaling, inflammation, and synapse modulation. Astrocytes are, in fact, part of a bidirectional crosstalk with neurons. Moreover, increasing evidence is stressing the emerging role of astrocyte dysfunction in the pathophysiology of neurological disorders, including neurodegenerative disease, stroke, epilepsy, migraine, and neuroinflammatory diseases.     

Localisation autoradiographique des ions Cl− et Na+ dans les cellules à chlorure de la branchie d'anguille (Anguilla anguilla L.) adaptée à l'eau de mer

Résumé Nous avons montré par une technique autoradiographique que les ions Cl^– et Na⁺ sont concentrés dans les cellules à chlorure de la branchie d'anguille adaptée à l'eau de mer. La signification de cette accumulation ionique plus marquée vers le pôle apical de ces cellules a été discutée par rapport à l'excrétion branchiale de ces ions en eau de mer.

---

Autoradiographic localization of Cl^– and Na⁺ ions in the chloride cells of sea water adapted eel (Anguilla anguilla L.) gills

Summary With an autoradiographic technique Cl^– and Na⁺ ions have been shown to be localized in the chloride cells of sea water eel gills. The significance of this accumulation, more marked towards the apical pole of these cells, is discussed with regard to branchial excretion of these ions in sea water.