Human intestinal anion exchanger isoforms: expression, distribution, and membrane localization

AbstractA family of anion exchangers (AEs) including AE1, AE2 and AE3 has been described. AE3 gene has been shown to encode two alternatively spliced isoforms termed as bAE3 (brain subtype) and cAE3 (cardiac subtype). The identity of the AE(s) involved in the human intestinal NaCl absorption is not fully understood. Current studies were undertaken to identify the AE isoforms expressed in the human intestine, to define their regional and vertical axis (crypt vs. surface cells) distribution, and to elucidate their membrane localization in the epithelial cells along the entire length of the human intestine. Our studies utilizing reverse transcription (RT)-PCR with total RNA extracted from pinch biopsies from various regions of the human intestine demonstrate that AE2 and bAE3 but not AE1 or cAE3 were expressed in all the regions of the human intestine. Utilizing in situ RT-PCR, we demonstrated that the message of AE2 was expressed throughout the vertical surface–crypt axis of the colon. Our Western blotting studies demonstrated that AE2 and bAE3 are localized to the basolateral but not the apical membranes of the intestinal epithelial cells from the human ileum and colon. In conclusion, our results demonstrated that in the human intestine, AE2 and bAE3, but not AE1 or cAE3, are expressed throughout the tract with the highest expression in the colon compared to the ileum and jejunum. Both the isoforms were found to be localized to the basolateral but not the apical membranes of the epithelial cells. We speculate that, in the human intestine, AE2 and bAE3 may be the ‘housekeeping’ isoforms, and the apical AE, the potential candidate for chloride absorption, remains to be identified

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Not AvailableThe Potyviridae family is one of the largest and economically most significant families of plant viruses, owing to their effects on crops globally. Sugarcane streak mosaic virus (SCSMV), a member of the genus Poacevirus, of this family, an important viral pathogen affects the sugarcane production in India. The genome has a single open reading frame that is translated in to a large polypeptide and consequently cleaved into functional proteins. This virus causes mosaic of sugarcane along with the Sugarcane mosaic virus (SCMV) which is a serious disease causing varietal degeneration reported from India in 1999 and later has been reported from geographically different Asian countries. The coding region for P1 peptidase is located at the very beginning of the viral genome of the family Potyviridae. P1 was thought of as serine peptidase with RNA-binding activity and with possible influence in cell-to-cell viral spreading. In order to unveil its mechanism of evolution we initiated the study by characterizing 10 P1 gene of Indian isolates and the sequences were compared with previously reported SCSMV isolates from different countries. Comparison of all of the sequenced virus isolates revealed a high level of diversity in the P1 gene (83–98% nt sequence identity; 87–100% aa sequence identity), and the Indian isolates were found to be the most divergent (up to 9% variation at the amino acid level). Phylogenetic analysis revealed clustering of 17 SCSMV isolates into two groups. Group I included isolates from India (except SCSMV-TPT) and Pakistan, and group II consisted of isolates from Japan, Indonesia, Thailand and SCSMV-TPT. The results obtained from phylogenetic study were further supported with the SNPs (single nucleotide polymorphism), INDELs (insertion and deletion) and evolutionary distance analysis. A significant proportion of recombination sites were found at the N terminal region of P1 gene of Indian isolates. Analysis of selection pressure indicated that the P1 gene of Indian SCSMV isolates is under strong negative selection. It is likely that recombination, along with strong negative selection, enhances the speed of elimination of lethal mutations in the P1 gene of Indian SCSMV isolates.Not Availabl

Prevalence of overweight and obesity in adults from North Africa

The share of North African immigrants in Europe is growing continuously. In this review, we aimed to systematically analyse and describe the literature on weight status and physical activity in North African adults, both in their home country and after immigration to Europe. Existing data on North African residents and on North African immigrants in Europe were analysed by a systematic search on PUBMED. There is a wide variation among countries in the prevalence of overweight/obesity, with immigrants showing higher values. The overall results revealed a higher prevalence of overweight and obesity in females than in males in North African residents. Females also show higher levels of obesity among immigrants. In particular, literature reports indicate that 1.3-47.8% of North African residents and 3.6-49.4% of North African immigrants in adult age are overweight or obese. Physical inactivity is higher than 20% in males and 40% in females in North African residents. The highest frequency of physically inactive or lightly active people among immigrants was observed in first-generation Sudanese and Moroccans in Amsterdam (males: 57.1%; females: 74.2%), with increasing rates in second-generation females. The results underline a higher health risk in North African immigrants than in residents. Specific public health strategies should be adopted in various populations of North African origin to control the obesity epidemic

Spontaneous superconducting diode effect in nonmagnetic Nb/Ru/Sr2RuO4 topological junctions

Non-reciprocal electronic transport in a material occurs if both time reversal and inversion symmetries are broken. The superconducting diode effect (SDE) is an exotic manifestation of this type of behavior where the critical current for positive and negative currents are mismatched, as recently observed in some non-centrosymmetric superconductors with a magnetic field. Here, we demonstrate a SDE in non-magnetic Nb/Ru/Sr2RuO4 Josephson junctions without applying an external magnetic field. The cooling history dependence of the SDE suggests that time-reversal symmetry is intrinsically broken by the superconducting phase of Sr2RuO4. Applied magnetic fields modify the SDE dynamically by randomly changing the sign of the non-reciprocity. We propose a model for such a topological junction with a conventional superconductor surrounded by a chiral superconductor with broken time reversal symmetry.ISSN:2399-365