NIELS OLSEN SARAIVA CAMARA
Projetos de Pesquisa
Unidades Organizacionais
BMI, ICB - Docente
LIM/05 - Laboratório de Poluição Atmosférica Experimental, Hospital das Clínicas, Faculdade de Medicina
LIM/05 - Laboratório de Poluição Atmosférica Experimental, Hospital das Clínicas, Faculdade de Medicina
3 resultados
Resultados de Busca
Agora exibindo 1 - 3 de 3
- Hypoxia enhances ILC3 responses through HIF-1 alpha-dependent mechanism(2021) FACHI, J. L.; PRAL, L. P.; SANTOS, J. A. C. dos; CODO, A. C.; OLIVEIRA, S. de; FELIPE, J. S.; ZAMBOM, F. F. F.; CAMARA, N. O. S.; VIEIRA, P. M. M. M.; COLONNA, M.; VINOLO, M. A. R.Group 3 innate lymphoid cells (ILC3) have a prominent role in the maintenance of intestine mucosa homeostasis. The hypoxia-inducible factor (HIF) is an important modulator of immune cell activation and a key mechanism for cellular adaptation to oxygen deprivation. However, its role on ILC3 is not well known. In this study, we investigated how a hypoxic environment modulates ILC3 response and the subsequent participation of HIF-1 signaling in this process. We found increased proliferation and activation of intestinal ILC3 at low oxygen levels, a response that was phenocopied when HIF-1 alpha was chemically stabilized and was reversed when HIF-1 was blocked. The increased activation of ILC3 relied on a HIF-1 alpha-dependent transcriptional program, but not on mTOR-signaling or a switch to glycolysis. HIF-1 alpha deficiency in RORyt compartment resulted in impaired IL-17 and IL-22 production by ILC3 in vivo, which reflected in a lower expression of their target genes in the intestinal epithelium and an increased susceptibility to Clostridiodes difficile infection. Taken together, our results show that HIF-1 alpha activation in intestinal ILC3 is relevant for their functions in steady state and infectious conditions.
- Sensing soluble uric acid by Naip1-Nlrp3 platform(2021) BRAGA, Tarcio Teodoro; DAVANSO, Mariana Rodrigues; MENDES, Davi; SOUZA, Tiago Antonio de; BRITO, Anderson Fernandes de; CRUZ, Mario Costa; HIYANE, Meire Ioshie; LIMA, Dhemerson Souza de; NUNES, Vinicius; GIAROLA, Juliana de Fatima; SOUTO, Denio Emanuel Pires; PROCHNICKI, Tomasz; LAUTERBACH, Mario; BISCAIA, Stellee Marcela Petris; FREITAS, Rilton Alves de; CURI, Rui; PONTILLO, Alessandra; LATZ, Eicke; CAMARA, Niels Olsen SaraivaUric acid (UA), a product of purine nucleotide degradation able to initiate an immune response, represents a breakpoint in the evolutionary history of humans, when uricase, the enzyme required for UA cleavage, was lost. Despite being inert in human cells, UA in its soluble form (sUA) can increase the level of interleukin-1 beta (IL-1 beta) in murine macrophages. We, therefore, hypothesized that the recognition of sUA is achieved by the Naip1-Nlrp3 inflammasome platform. Through structural modelling predictions and transcriptome and functional analyses, we found that murine Naip1 expression in human macrophages induces IL-1 beta expression, fatty acid production and an inflammation-related response upon sUA stimulation, a process reversed by the pharmacological and genetic inhibition of Nlrp3. Moreover, molecular interaction experiments showed that Naip1 directly recognizes sUA. Accordingly, Naip may be the sUA receptor lost through the human evolutionary process, and a better understanding of its recognition may lead to novel anti-hyperuricaemia therapies.
- Renal Inflammation and Innate Immune Activation Underlie the Transition From Gentamicin-Induced Acute Kidney Injury to Renal Fibrosis(2021) ALBINO, Amanda Helen; ZAMBOM, Fernanda Florencia Fregnan; FORESTO-NETO, Orestes; OLIVEIRA, Karin Carneiro; AVILA, Victor Ferreira; ARIAS, Simone Costa Alarcon; SEGURO, Antonio Carlos; MALHEIROS, Denise Maria Avancini Costa; CAMARA, Niels Olsen Saraiva; FUJIHARA, Clarice Kazue; ZATZ, RobertoSubjects recovering from acute kidney injury (AKI) are at risk of developing chronic kidney disease (CKD). The mechanisms underlying this transition are unclear and may involve sustained activation of renal innate immunity, with resulting renal inflammation and fibrosis. We investigated whether the NF-kappa B system and/or the NLRP3 inflammasome pathway remain activated after the resolution of AKI induced by gentamicin (GT) treatment, thus favoring the development of CKD. Male Munich-Wistar rats received daily subcutaneous injections of GT, 80 mg/kg, for 9 days. Control rats received vehicle only (NC). Rats were studied at 1, 30, and 180 days after GT treatment was ceased. On Day 1, glomerular ischemia (ISCH), tubular necrosis, albuminuria, creatinine retention, and tubular dysfunction were noted, in association with prominent renal infiltration by macrophages and myofibroblasts, along with increased renal abundance of TLR4, IL-6, and IL1 beta. Regression of functional and structural changes occurred on Day 30. However, the renal content of IL-1 beta was still elevated at this time, while the local renin-angiotensin system remained activated, and interstitial fibrosis became evident. On Day 180, recurring albuminuria and mild glomerulosclerosis were seen, along with ISCH and unabated interstitial fibrosis, whereas macrophage infiltration was still evident. GT-induced AKI activates innate immunity and promotes renal inflammation. Persistence of these abnormalities provides a plausible explanation for the transition of AKI to CKD observed in a growing number of patients.