Tonabersat breaks the cycle of Cx43- hemichannel mediated activity and NLRP3 inflammasome activation in a model of diabetic nephropathy

Introduction: Our previous findings link connexin-43 (Cx43)-hemichannel mediated ATP release to an increase in the nod-like receptor protein-3 (NLRP3) inflammasome, via nuclear factor kappa-B (NFκB)-mediated priming and purinergic P2X7 receptor (P2X7R) activation. Evidence from studies examining diabetic retinopathy suggests that NLRP3 priming indirectly regulates Cx43-hemichannel activity through increased NFκB binding to the Cx43 promoter. In the diabetic kidney, this feedback loop remains to be established. Method: Human primary proximal tubule epithelial cells (hPTECs) were cultured in 5mM or 25mM D-glucose and treated with interleukin (IL)1β (10ng) and tumour necrosis factor-alpha (TNFα; 10ng) ± Cx43 hemichannel blocker Tonabersat (50μM), ± Caspase-1 inhibitor YVAD-CMK (10μM/mL), ± NFκB inhibitor BAY117082 (5μM) for 48hrs (n=3-6). Real-time qPCR and western blotting examined mRNA and protein expression respectively, whilst carboxyfluorescein dye-uptake and ATP release assessed Cx43-hemichannel activity. Results: Inhibition of NLRP3 priming and activation decreases interleukin (IL)1α (35±13%; P<0.01 and 55±10%; P<0.001 respectively) and generates a priming-dependent reduction in granulocyte-colony stimulating factor (G-CSF) expression (40±10%; P<0.001). Similarly, blocking Cx43-hemichannels with Tonabersat reduced IL1α (61±5.5%; P<0.001) and G-CSF (52±7.9%; P<0.001) expression, with inhibition of NLRP3 reducing Cx43 mRNA and protein expression (29±5.0%; P<0.01 and 34±9.1%; P<0.01 respectively), hemichannel-mediated dye-uptake (37±2.7%; P<0.001) and ATP release (32±8.7%; P<0.05). Discussion: In combination with previous data demonstrating a role for Cx43-hemichannel activity in mediating NLRP3 priming and activation, we establish the presence of a cycle of events in which NLRP3-induced inflammation and Cx43-hemichannel mediated activity reciprocally exacerbate the activation of each other. This vicious cycle is blocked by Tonabersat

Blocking connexin-43 hemichannels dampens tubulointerstitial inflammation and fibrosis in models of diabetic nephropathy

Aims:Increased connexin-43 (Cx43)-hemichannel activity exacerbates inflammation in diabetic retinopathy, effects dampened by the hemichannel blocker Tonabersat. In the kidney, tubulointerstitial inflammation and fibrosis contribute to diabetic nephropathy and develop in response to activation of multiple cell types. A role for tubuleCx43 in mediating this damage remains to be determined. Methods:Using the Nephroseq database, transcriptomic analysis examined gene expression in kidneys with and without diabetic nephropathy. The unilateral ureteral obstruction (UUO) mouse model of advanced interstitial inflammation and fibrosis was used in the presence of a tubule- specific Cx43 (Pax8- rtTA-cre:cx43 flox Cx43−/−)knockout (n = 6– 12). Human primary proximal tubule epithelial cells (hPTECs) were cultured in 5 mM/25 mM glucose ± interleukin (IL)1β (10 ng) and tumour necrosis factor- alpha (TNFα; 10 ng) ± Tonabersat (50 μM), for 48 h(n = 3– 5). Real- time qPCR examined mRNA expression, whilst immunostaining assessed macrophage and fibroblast accumulation. Results:Renal Cx43 mRNA expression was upregulated in diabetic nephropathy from 1.65 ± 0.42 to 2.80 ± 0.31; (p < 0.05; n = 12) as compared to control (n = 10). Tubule- specific Cx43 knockout (Cx43−/−) reduced UUO- induced increases in IL1β (25 ± 1.4; p < 0.05), IL6 (59 ± 4.9 p < 0.01) and monocyte chemoattractant protein 1 (MCP1) (52 ± 12.5; p < 0.001) expression. This paralleled reduced fibroblast accumulation (135 ± 11.4; p < 0.001) and macrophage infiltration (2.3 ± 0.1; p < 0.001). Tonabersat reduced upregulation of IL1β (57 ± 5.3%; p < 0.001), IL6 (49 ± 3.7%; p < 0.001) and MCP1 (44 ± 7.8%; p < 0.001) in glucose/cytokine treated hPTECs in vitro. Conclusion:Renal tubule inflammation is driven by aberrant Cx43- hemichannel activity, which when blocked reduces the release of chemo- attractants, dampening immune cell recruitment and activation. These data highlight the therapeutic potential for targeting Cx43- hemichannels in diabetic nephropathy

Progresso científico em equideocultura na 1ª década do século XXI Scientific progress in equine production at 1st decade of the XXI century

No Brasil, como nos demais países, os investimentos em pesquisa com equinos estão relacionados às perspectivas dos segmentos da indústria equina no país. Este trabalho foi conduzido com o objetivo de revisar a literatura corrente com a perspectiva de avaliar o recente desenvolvimento científico e tecnológico na produção de equídeos. As pesquisas estão relacionadas às diversas áreas da equideocultura, como produção e manejo, genética e melhoramento, nutrição e alimentação, reprodução, medicina e cirurgia, doenças, sanidade e defesa sanitária. Há ainda pesquisas em áreas relacionadas ao hipismo, envolvendo fisiologia esportiva, equitação e treinamento de equinos e também, além de estudos sobre o comércio nacional e internacional de equinos. Considerando todas as áreas da equideocultura, o maior número de artigos publicados está relacionado às áreas da medicina e cirurgia e doenças e sanidade. Na área da Zootecnia, predominam as publicações de artigos associados à nutrição e alimentação dos equinos. No entanto, deve-se considerar que os interesses do agronegócio do cavalo, das associações de criadores, dos governos e da sociedade em geral influenciam as pesquisas e, consequentemente, as publicações dos artigos e trabalhos técnicos sobre equídeos.<br>In Brazil, as in other countries, investments in research with horses are related to the objectives of the equine industry in the country. This study aimed to review the current literature with the purpose of assessing the latest scientific and technological development in horse's production. Researchers are related to many areas as in production and management, genetics and breeding, nutrition and feeding, reproduction, medicine and surgery, diseases and health protection. There is still research in areas related to equestrian sports, involving equine exercise physiology, riding and training horses and also studies on national and international equine trade. Considering all areas of interest of horse production the largest number of published articles is related to the medicine and surgery and diseases and health. In Animal Science, the largest number of articles is related to nutrition and feeding of horses. However, must be consider that interests of agribusiness, horse's breeders associations, governments and society in general, influence the research and consequently the publication of papers about horses

A Call for Deep-Ocean Stewardship

Covering more than half the planet, the deep ocean sequesters atmospheric CO2 and recycles major nutrients; is predicted to hold millions of yet-to-be-described species; and stores mind-boggling quantities of untapped energy resources, precious metals, and minerals (1). It is an immense, remote biome, critical to the health of the planet and human well-being. The deep ocean (defined here as below a typical continental shelf break, &gt;200 m) faces mounting challenges as technological advances—including robotics, imaging, and structural engineering—greatly improve access. We recommend a move from a frontier mentality of exploitation and single-sector management to a precautionary system that balances use of living marine resources, energy, and minerals from the deep ocean with maintenance of a productive and healthy marine environment, while improving knowledge and collaboration