Molecular Characterization, Tissue Distribution, Subcellular Localization and Actin-Sequestering Function of a Thymosin Protein from Silkworm

We identified a novel gene encoding a Bombyx mori thymosin (BmTHY) protein from a cDNA library of silkworm pupae, which has an open reading frame (ORF) of 399 bp encoding 132 amino acids. It was found by bioinformatics that BmTHY gene consisted of three exons and two introns and BmTHY was highly homologous to thymosin betas (Tβ). BmTHY has a conserved motif LKHTET with only one amino acid difference from LKKTET, which is involved in Tβ binding to actin. A His-tagged BmTHY fusion protein (rBmTHY) with a molecular weight of approximately 18.4 kDa was expressed and purified to homogeneity. The purified fusion protein was used to produce anti-rBmTHY polyclonal antibodies in a New Zealand rabbit. Subcellular localization revealed that BmTHY can be found in both Bm5 cell (a silkworm ovary cell line) nucleus and cytoplasm but is primarily located in the nucleus. Western blotting and real-time RT-PCR showed that during silkworm developmental stages, BmTHY expression levels are highest in moth, followed by instar larvae, and are lowest in pupa and egg. BmTHY mRNA was universally distributed in most of fifth-instar larvae tissues (except testis). However, BmTHY was expressed in the head, ovary and epidermis during the larvae stage. BmTHY formed complexes with actin monomer, inhibited actin polymerization and cross-linked to actin. All the results indicated BmTHY might be an actin-sequestering protein and participate in silkworm development

Psychosocial aspects and support networks associated with disability in two longevous populations in Brazil: a cross-sectional study

© 2022 The Authors. Published by Springer. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.1186/s12877-022-02810-4Background Among the oldest old, aged 80 years and over, the prevalence of disability is higher than in other age groups and can be considered a predictor of mortality. Objective To evaluate how psychosocial aspects and support networks influence the disability of these oldest-old individuals, performing a comparison between two longevous populations, one living in one of the poorest regions of Brazil, in the backlands of Paraíba, and another living in one of the largest urban centres in Latin America. Method A cross-sectional study in which 417 oldest-old persons aged 80 years and older were interviewed, with data collected through the “Health, Welfare and Ageing” survey conducted in two Brazilian cities. Disability was assessed by reporting the need for assistance in Activities of Daily Living (ADLs) and Instrumental Activities of Daily Living (IADLs). Bivariate and multiple analyses were performed using R statistical software. Results Food insufficiency in the first years of life had negative repercussions on the disability of oldest old people living in the northeast. On the other hand, in this region, older people have a higher rate of support and live longer with their peers, which may contribute to reducing feelings of loneliness, depressive symptoms, and worse self-perception of health. In the Southeast, financial constraints, subjective poverty, and unmet needs may favour the development of functional limitations between long-lived people. Conclusion Our findings indicate that regional differences in Brazil may influence the disability of older people aged 80 and older. In northeast Brazil, having no partner may contribute to disability for ADLs and IADLs; while, in the longevous population of São Paulo, having a worse self-rated health may contribute to disability for IADLs.The current study was funded by Universidade Estadual da Paraíba (PROPESQ) and Fundação de Apoio à Pesquisa do Estado da Paraíba (FAPESQ/CNPq— PPSUS 015/2014); CAPES (INCT 14/50931–3), Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP-CEPID 2013/08028–1; 1999/ 05125, 2005/54947–2, 2009/53778–3).Published onlin

Distinct Regulatory Functions of Calpain 1 and 2 during Neural Stem Cell Self-Renewal and Differentiation

Calpains are calcium regulated cysteine proteases that have been described in a wide range of cellular processes, including apoptosis, migration and cell cycle regulation. In addition, calpains have been implicated in differentiation, but their impact on neural differentiation requires further investigation. Here, we addressed the role of calpain 1 and calpain 2 in neural stem cell (NSC) self-renewal and differentiation. We found that calpain inhibition using either the chemical inhibitor calpeptin or the endogenous calpain inhibitor calpastatin favored differentiation of NSCs. This effect was associated with significant changes in cell cycle-related proteins and may be regulated by calcium. Interestingly, calpain 1 and calpain 2 were found to play distinct roles in NSC fate decision. Calpain 1 expression levels were higher in self-renewing NSC and decreased with differentiation, while calpain 2 increased throughout differentiation. In addition, calpain 1 silencing resulted in increased levels of both neuronal and glial markers, β-III Tubulin and glial fibrillary acidic protein (GFAP). Calpain 2 silencing elicited decreased levels of GFAP. These results support a role for calpain 1 in repressing differentiation, thus maintaining a proliferative NSC pool, and suggest that calpain 2 is involved in glial differentiation

CHRONIC NITRIC-OXIDE SYNTHASE INHIBITION AGGRAVATES GLOMERULAR INJURY IN RATS WITH SUBTOTAL NEPHRECTOMY

Besides its glomerular hemodynamic effects, nitric oxide (NO) inhibits platelet aggregation and mesangial cell proliferation, two mechanisms possibly involved in the pathogenesis of glomerulosclerosis (GS). Chronic NO synthase inhibition in the rat leads to marked arterial hypertension and promotes glomerular and interstitial injury, but only mild GS. In this study, NO synthase blockade by nitro-L-arginine methyl ester (L-NAME) was associated with 5/6 nephrectomy, a well-known model of GS. Sixty-eight adult male Munich-Wistar rats were distributed among four groups: SHAM (no renal ablation or drug treatment), NX (5/6 nephrectomy), NX+NAME (5/6 nephrectomy and chronic treatment with L-NAME, 5 mg/dL in drinking water) and NX+NAME+L (as in group NX+NAME but also receiving the angiotensin II receptor inhibitor Losartan potassium (L), 25 mg/dL in drinking water), One week after ablation, rats of Group NX showed moderate glomerular hypertension and hypertrophy. Although glomerular enlargement was also modest in Group NX+NAME, glomerular hypertension was particularly severe in this group. Both alterations were absent in Group NX+NAME+L. Only incipient glomerular and interstitial injury occurred at this phase. Three weeks after ablation, renal structural injury was still modest in Group NX. By contrast, Group NX+NAME exhibited marked GS, glomerular ischemic injury, interstitial expansion, and creatinine retention. Renal injury was largely prevented in Group NX+NAME+L, Tuft enlargement occurred in all groups but was most prominent in Group NX. NO synthase inhibition aggravates parenchymal injury and functional impairment in the remnant kidney by mechanisms that may involve glomerular hypertension and renin-angiotensin activation but that appear to be unrelated to glomerular enlargement.571498150