Adipose tissue macrophage-derived microRNA-210-3p disrupts systemic insulin sensitivity by silencing GLUT4 in obesity.

Management of chronic obesity-associated metabolic disorders is a key challenge for biomedical researchers. During chronic obesity, visceral adipose tissue (VAT) undergoes substantial transformation characterized by a unique lipid-rich hypoxic AT microenvironment which plays a crucial role in VAT dysfunction, leading to insulin resistance (IR) and type 2 diabetes. Here, we demonstrate that obese AT microenvironment triggers the release of miR-210-3p microRNA-loaded extracellular vesicles from adipose tissue macrophages, which disseminate miR-210-3p to neighboring adipocytes, skeletal muscle cells, and hepatocytes through paracrine and endocrine actions, thereby influencing insulin sensitivity. Moreover, EVs collected from Dicer-silenced miR-210-3p-overexpressed bone marrow-derived macrophages induce glucose intolerance and IR in lean mice. Mechanistically, miR-210-3p interacts with the 3'-UTR of GLUT4 mRNA and silences its expression, compromising cellular glucose uptake and insulin sensitivity. Therapeutic inhibition of miR-210-3p in VAT notably rescues high-fat diet-fed mice from obesity-induced systemic glucose intolerance. Thus, targeting adipose tissue macrophage-specific miR-210-3p during obesity could be a promising strategy for managing IR and type 2 diabetes.

Amphiregulin from regulatory T cells promotes liver fibrosis and insulin resistance in non-alcoholic steatohepatitis.

Production of amphiregulin (Areg) by regulatory T (Treg) cells promotes repair after acute tissue injury. Here, we examined the function of Treg cells in non-alcoholic steatohepatitis (NASH), a setting of chronic liver injury. Areg-producing Treg cells were enriched in the livers of mice and humans with NASH. Deletion of Areg in Treg cells, but not in myeloid cells, reduced NASH-induced liver fibrosis. Chronic liver damage induced transcriptional changes associated with Treg cell activation. Mechanistically, Treg cell-derived Areg activated pro-fibrotic transcriptional programs in hepatic stellate cells via epidermal growth factor receptor (EGFR) signaling. Deletion of Areg in Treg cells protected mice from NASH-dependent glucose intolerance, which also was dependent on EGFR signaling on hepatic stellate cells. Areg from Treg cells promoted hepatocyte gluconeogenesis through hepatocyte detection of hepatic stellate cell-derived interleukin-6. Our findings reveal a maladaptive role for Treg cell-mediated tissue repair functions in chronic liver disease and link liver damage to NASH-dependent glucose intolerance.

Preditores da dessaturação do oxigênio no teste da caminhada de seis minutos em pacientes com fibrose cística / Predictors of oxygen desaturation during the six-minute walk test in patients with cystic fibrosis

OBJETIVO: Identificar os fatores preditores de dessaturação de oxigênio durante o teste de caminhada de seis minutos (TC6) em pacientes com fibrose cística (FC). MÉTODOS: Estudo transversal e prospectivo em pacientes com FC clinicamente estáveis com idade superior a 10 anos. Os pacientes foram submetidos à avaliação nutricional, teste oral de tolerância à glicose, testes de função pulmonar, exame radiológico do tórax e TC6. RESULTADOS: Foram incluídos 88 pacientes (43 femininos e 45 masculinos) com média de idade de 19,9 ± 7,2 anos e média de VEF1 de 65,4 ± 28,4 por cento. Observamos que 75 pacientes apresentaram-se sem dessaturação de oxigênio (SD) e 13 com dessaturação (CD). Os pacientes do grupo CD apresentaram maior média de idade (p = 0,004), pior escore clínico (p < 0,001), pior escore radiológico (p < 0,001), maior frequência de intolerância à glicose (p = 0,004), menor frequência de infecção bacteriana por Staphylococcus aureus sensível à meticilina (p < 0,001), maior frequência de infecção por S. aureus resistente à meticilina (p = 0,016) e por Pseudomonas aeruginosa (p = 0,008) e menor valor médio de SpO2 em repouso (p < 0,001) e de VEF1 (p < 0,001) do que os pacientes do grupo SD. Na análise de regressão logística, SpO2 em repouso (OR = 0,305, p < 0,001) e VEF1 (OR = 0,882, p = 0,025) se associaram com a dessaturação de oxigênio no TC6. Os parâmetros que maximizaram o valor preditivo para dessaturação de oxigênio foram SpO2 em repouso < 96 por cento e VEF1 < 40 por cento. Nessa amostra, 15 por cento dos pacientes com FC com mais de 10 anos apresentaram dessaturação de oxigênio no TC6. CONCLUSÕES: Os parâmetros SpO2 em repouso < 96 por cento e VEF1 < 40 por cento contribuem como preditores de dessaturação no TC6.

OBJECTIVE: To identify the predictive factors of oxygen desaturation during the six-minute walk test (6MWT) in patients with cystic fibrosis (CF). METHODS: Prospective cross-sectional study involving clinically stable patients with CF aged > 10 years. The patients were submitted to nutritional evaluations, oral glucose tolerance tests, pulmonary function tests, chest X-rays and 6MWTs. RESULTS: The study included 88 patients (43 females and 45 males; mean age, 19.9 ± 7.2 years; mean FEV1, 65.4 ± 28.4 percent). We observed oxygen desaturation in 13 patients (OD+ group) and no oxygen desaturation in 75 (ODµ group). In comparison with ODµ group patients, OD+ group patients presented higher mean age (p = 0.004), worse clinical score (p < 0.001), worse radiological score (p < 0.001), higher incidence of glucose intolerance (p = 0.004), lower incidence of methicillin-sensitive Staphylococcus aureus infection (p < 0.001), higher incidence of methicillin-resistant S. aureus infection (p = 0.016), higher incidence of Pseudomonas aeruginosa infection (p = 0.008), lower mean resting SpO2 (p < 0.001) and lower mean FEV1 (p < 0.001). In the logistic regression analysis, oxygen desaturation during the 6MWT correlated with resting SpO2 (OR = 0.305, p < 0.001) and FEV1 (OR = 0.882, p = 0.025). The parameters maximizing the predictive value for oxygen desaturation were resting SpO2 < 96 percent and FEV1 < 40 percent. In this sample, 15 percent of the patients with CF aged > 10 years presented oxygen desaturation during the 6MWT. CONCLUSIONS: Resting SpO2 < 96 percent and FEV1 < 40 percent can predict oxygen desaturation during the 6MWT.

An Evaluation of Glucose Tolerance in Essential Hypertension

PURPOSE: This study aimed to determine the impaired glucose tolerance and diabetes prevalence in patients with essential hypertension (HT) and to compare the developed microvascular complications of these groups. MATERIALS AND METHODS: An oral glucose tolerance test (OGTT) was performed on 338 essential hypertensive cases and glucose tolerances were classified according to ADA-2002 criteria. RESULTS: Of the 338 cases, 32 people had diabetes (DM, 9.46%), 78 people had glucose intolerance (IGT, 23.1%), and 228 people had only hypertension but not IGT and DM (67.4%). Both the mean ages of the DM group (56.9 +/- 6.7 years, p = 0.002) and IGT group (56.3 +/- 8.4 years, p = 0.003) were older than the mean age of the control group (51.1 +/- 6.4 years). The risk of IGT development was found to be four times greater in male cases than female cases when compared to the control group (p = 0.004, add ratio = 4.194). There were no significant differences in the body mass indexes (BMI's), hypertension durations, and microvascular complications between the groups. CONCLUSION: In conclusion, the risk of IGT and DM development in hypertensive cases increases with aging and longer hypertension duration. The risk of IGT development in hypertensive cases is four times more in males.