Search results for "Connexins"
showing 7 items of 37 documents
Expression of Cx36 in mammalian neurons
2000
Cx36 is the first mammalian member of a novel subgroup of the connexin family, characterized by a long cytoplasmic loop, a peculiar gene structure and a preferential expression in cell types of neural origin. In the present review we summarize the evidence in favour of its predominant expression in neuronal cells in the mammalian central nervous system, such as results from experiments with specific neurotoxins and co-localization of Cx36 mRNA and a neuronal marker. We also report a detailed description of Cx36 mRNA distribution in the rat and human central nervous system by in situ hybridization and, for each brain region, we correlate the novel findings with previous morphological or func…
Identification and functional expression of HCx31.9, a novel gap junction gene
2002
By combining in silico and bench molecular biology methods we have identified a novel human gap junction gene that encodes a protein designated HCx31.9. We have determined its human chromosomal location and gene structure, and we have identified a putative mouse ortholog, mCx30.2. We have observed the presence of HCx31.9 in human cerebral cortex, liver, heart, spleen, lung, and kidney and the presence of mCx30.2 in mouse cerebral cortex, liver and lung. Moreover, preliminary data on the electrophysiological properties of HCx31.9 have been obtained by functional expression in paired Xenopus oocytes and in transfected N2A cells.
Oligodendrocytes in mouse corpus callosum are coupled via gap junction channels formed by connexin47 and connexin32.
2010
According to previously published ultrastructural studies, oligodendrocytes in white matter exhibit gap junctions with astrocytes, but not among each other, while in vitro oligodendrocytes form functional gap junctions. We have studied functional coupling among oligodendrocytes in acute slices of postnatal mouse corpus callosum. By whole-cell patch clamp we dialyzed oligodendrocytes with biocytin, a gap junction-permeable tracer. On average 61 cells were positive for biocytin detected by labeling with streptavidin-Cy3. About 77% of the coupled cells stained positively for the oligodendrocyte marker protein CNPase, 9% for the astrocyte marker GFAP and 14% were negative for both CNPase and GF…
A genotype-phenotype correlation in Sicilian patients with GJB2 biallelic mutations
2015
The aim of this work was to study the genotype distribution of Sicilian patients with biallelic GJB2 mutations; to correlate genotype classes and/or specific mutations of GJB2 gene (35delG-non-35delG) with audiologic profiles. A total of 10 different mutations and 11 different genotypes were evidenced in 73 SNHL subjects; 35delG (90.36 % of cases) and IVS1+1 (13.69 %) were the most common mutations found in the cohort with a significant difference in the distribution between North and South Sicily. Audiological evaluation revealed a severe (16/73) to profound (47/73) hearing loss (HL) in 86.13 % of cases without significant difference between the degree of HL and the province of origin of t…
Astrocytes and hypothalamic glucose sensing: metabolic role and involvement of astroglial connexins
2012
The hypothalamus plays a pivotal role in the nervous control of glucose homeostasis. This area contains gluco-sensitive neurons. Some of them detect increases in glucose levels and regulate glucose homeostasis by stimulating insulin secretion or inhibiting food intake. It is widely accepted that astrocytes are metabolically coupled to neurons. Lactate, resulting from the metabolism of glucose by astrocytes, is transported via the monocarboxylate transporters (MCTs). In addition, gap junctions (GJ), that form networks within astrocytes, are essential to transfer glucose from the bloodstream to the active neurons. These astroglial GJ mainly consist of connexins 43 and 30 (Cxs).The aims of my …
Role of genetic polymorphisms in myocardial infarction at young age
2010
Acute myocardial infarction (AMI) in young adult presents a typical pattern of risk factors, clinical, angiographic and prognostic characteristics. In the last years we demonstrated that hemorheological profile is altered in these patients in a persistent way and independently of the number of risk factors and of the extent of coronary lesions. Thus, the hyperviscosity syndrome following AMI could be considered an intrinsic characteristic of these patients. Consequently it is possible to hypothesise the presence of a genetic background at the origin of this predisposition. If this background is able to influence the risk of ischemic heart disease, this should be particularly evident in youn…
Gap junctions and connexin hemichannels both contribute to the electrical properties of retinal pigment epithelium.
2022
Gap junctions are intercellular channels that permit the transfer of ions and small molecules between adjacent cells. These cellular junctions are particularly dense in the retinal pigment epithelium (RPE), and their contribution to many retinal diseases has been recognized. While gap junctions have been implicated in several aspects of RPE physiology, their role in shaping the electrical properties of these cells has not been characterized in mammals. The role of gap junctions in the electrical properties of the RPE is particularly important considering the growing appreciation of RPE as excitable cells containing various voltage-gated channels. We used a whole-cell patch clamp to measure …