PKD2 regulates autophagy and forms a protein complex with BECN1 at the primary cilium of hypothalamic neuronal cells.

The primary cilium, hereafter cilium, is an antenna-like organelle that modulates intracellular responses, including autophagy, a lysosomal degradation process essential for cell homeostasis. Dysfunction of the cilium is associated with impairment of autophagy and diseases known as "ciliopathies". The discovery of autophagy-related proteins at the base of the cilium suggests its potential role in coordinating autophagy initiation in response to physiopathological stimuli. One of these proteins, beclin-1 (BECN1), it which is necessary for autophagosome biogenesis. Additionally, polycystin-2 (PKD2), a calcium channel enriched at the cilium, is required and sufficient to induce autophagy in renal and cancer cells. We previously demonstrated that PKD2 and BECN1 form a protein complex at the endoplasmic reticulum in non-ciliated cells, where it initiates autophagy, but whether this protein complex is present at the cilium remains unknown. Anorexigenic pro-opiomelanocortin (POMC) neurons are ciliated cells that require autophagy to maintain intracellular homeostasis. POMC neurons are sensitive to metabolic changes, modulating signaling pathways crucial for controlling food intake. Exposure to the saturated fatty acid palmitic acid (PA) reduces ciliogenesis and inhibits autophagy in these cells. Here, we show that PKD2 and BECN1 form a protein complex in N43/5 cells, an in vitro model of POMC neurons, and that both PKD2 and BECN1 locate at the cilium. In addition, our data show that the cilium is required for PKD2-BECN1 protein complex formation and that PA disrupts the PKD2-BECN1 complex, suppressing autophagy. Our findings provide new insights into the mechanisms by which the cilium controls autophagy in hypothalamic neuronal cells.

Methods for studying primary cilia in heart tissue after ischemia-reperfusion injury.

Cardiovascular diseases are the leading cause of death and disability worldwide. After heart injury triggered by myocardial ischemia or myocardial infarction, extensive zones of tissue are damaged and some of the tissue dies by necrosis and/or apoptosis. The loss of contractile mass activates a series of biochemical mechanisms that allow, through cardiac remodeling, the replacement of the dysfunctional heart tissue by fibrotic material. Our previous studies have shown that primary cilia, non-motile antenna-like structures at the cell surface required for the activation of specific signaling pathways, are present in cardiac fibroblasts and required for cardiac fibrosis induced by ischemia/reperfusion (I/R) in mice. I/R-induced myocardial fibrosis promotes the enrichment of ciliated cardiac fibroblasts where the myocardial injury occurs. Given discussions about the existence of cilia in specific cardiac cell types, as well as the functional relevance of studying cilia-dependent signaling in cardiac fibrosis after I/R, here we describe our methods to evaluate the presence and roles of primary cilia in cardiac fibrosis after I/R in mice.

Association between cardiovascular mortality and STOP-Bang questionnaire scores in a cohort of hospitalized patients: a prospective study.

OBJECTIVE: Obstructive sleep apnea (OSA) is associated with an increased risk of mortality and cardiometabolic diseases. The STOP-Bang questionnaire is a tool to screen populations at risk of OSA and prioritize complementary studies. Our objective was to evaluate the clinical utility of this questionnaire in identifying patients at an increased risk of mortality after discharge in a cohort of hospitalized patients. METHODS: This was a prospective cohort study involving consecutive patients admitted to an internal medicine unit between May and June of 2017 who were reevaluated three years after discharge. At baseline, we collected data on comorbidities (hypertension, obesity, diabetes, and fasting lipid profile) and calculated STOP-Bang scores, defining the risk of OSA (0-2 score, no risk; ≥ 3 score, risk of OSA; and ≥ 5 score, risk of moderate-to-severe OSA), which determined the study groups. We also recorded data regarding all-cause and cardiovascular mortality at the end of the follow-up period. RESULTS: The sample comprised 435 patients. Of those, 352 (80.9%) and 182 (41.8%) had STOP-Bang scores ≥ 3 and ≥ 5, respectively. When compared with the group with STOP-Bang scores of 0-2, the two groups showed higher prevalences of obesity, hypertension, diabetes, and dyslipidemia. Multivariate analysis showed an independent association between cardiovascular mortality and STOP-Bang score ≥ 5 (adjusted hazard ratio = 3.12 [95% CI, 1.39-7.03]; p = 0.01). Additionally, previous coronary heart disease was also associated with cardiovascular mortality. CONCLUSIONS: In this cohort of hospitalized patients, STOP-Bang scores ≥ 5 were able to identify patients at an increased risk of cardiovascular mortality three years after discharge.

Association between cardiovascular mortality and STOP-Bang questionnaire scores in a cohort of hospitalized patients: a prospective study / Associação entre mortalidade cardiovascular e pontuação do questionário STOP-Bang em uma coorte de pacientes hospitalizados: um estudo prospectivo

ABSTRACT Objective: Obstructive sleep apnea (OSA) is associated with an increased risk of mortality and cardiometabolic diseases. The STOP-Bang questionnaire is a tool to screen populations at risk of OSA and prioritize complementary studies. Our objective was to evaluate the clinical utility of this questionnaire in identifying patients at an increased risk of mortality after discharge in a cohort of hospitalized patients. Methods: This was a prospective cohort study involving consecutive patients admitted to an internal medicine unit between May and June of 2017 who were reevaluated three years after discharge. At baseline, we collected data on comorbidities (hypertension, obesity, diabetes, and fasting lipid profile) and calculated STOP-Bang scores, defining the risk of OSA (0-2 score, no risk; ≥ 3 score, risk of OSA; and ≥ 5 score, risk of moderate-to-severe OSA), which determined the study groups. We also recorded data regarding all-cause and cardiovascular mortality at the end of the follow-up period. Results: The sample comprised 435 patients. Of those, 352 (80.9%) and 182 (41.8%) had STOP-Bang scores ≥ 3 and ≥ 5, respectively. When compared with the group with STOP-Bang scores of 0-2, the two groups showed higher prevalences of obesity, hypertension, diabetes, and dyslipidemia. Multivariate analysis showed an independent association between cardiovascular mortality and STOP-Bang score ≥ 5 (adjusted hazard ratio = 3.12 [95% CI, 1.39-7.03]; p = 0.01). Additionally, previous coronary heart disease was also associated with cardiovascular mortality. Conclusions: In this cohort of hospitalized patients, STOP-Bang scores ≥ 5 were able to identify patients at an increased risk of cardiovascular mortality three years after discharge.

RESUMO Objetivo: A apneia obstrutiva do sono (AOS) está associada a um risco maior de mortalidade e doenças cardiometabólicas. O questionário STOP-Bang é uma ferramenta para rastrear populações em risco de AOS e assim priorizar estudos complementares. Nosso objetivo foi avaliar a utilidade clínica desse questionário na identificação de pacientes com risco aumentado de mortalidade após a alta em uma coorte de pacientes hospitalizados. Métodos: Estudo de coorte prospectivo com pacientes consecutivos internados em uma unidade de medicina interna entre maio e junho de 2017 que foram reavaliados três anos após a alta. No momento basal, coletamos dados sobre comorbidades (hipertensão, obesidade, diabetes e perfil lipídico em jejum) e calculamos as pontuações no STOP-Bang, definindo o risco de OSA (pontuação 0-2, sem risco; pontuação ≥ 3, risco de AOS; e pontuação ≥ 5, risco de AOS moderada a grave), que determinou os grupos de estudo. Também registramos dados sobre mortalidade por todas as causas e mortalidade cardiovascular ao final do período de acompanhamento. Resultados: Foram incluídos 435 pacientes. Desses, 352 (80,9%) e 182 (41,8%) apresentaram pontuações no STOP-Bang ≥ 3 e ≥ 5, respectivamente. Quando comparados com o grupo com pontuação no STOP-Bang de 0-2, os outros dois grupos apresentaram prevalências mais elevadas de obesidade, hipertensão, diabetes e dislipidemia. A análise multivariada mostrou uma associação independente entre mortalidade cardiovascular e pontuação no STOP-Bang ≥ 5 (razão de risco ajustada = 3,12 [IC95%, 1,39-7,03]; p = 0,01). Além disso, doença coronariana prévia também foi associada à mortalidade cardiovascular. Conclusões: Nesta coorte de pacientes hospitalizados, pontuações no STOP-Bang ≥ 5 foram capazes de identificar pacientes com risco aumentado de mortalidade cardiovascular três anos após a alta.

[Association between high vitamin B12 levels and one year mortality in older people admitted to the hospital]. / Asociación entre niveles de vitamina B-12 y mortalidad en pacientes hospitalizados adultos mayores.

BACKGROUND: Supplementation of vitamin B12 in older adults is a common practice to avoid vitamin B12 insufficiency. However, there is a paucity of information about the effects of cobalamin excess. AIM: To asses any potential effects of high levels vitamin B12 on mortality on adults aged ≥ 65 years admitted to an internal medicine service. MATERIAL AND METHODS: We Prospectively studied patients admitted to an internal medicine service of an academic hospital from September 2017 to September 2018, who were able to give their consent and answer questionnaires. We tabulated age, gender, medical history, comorbidity index (Charlson), frailty score (Fried scale), admission diagnosis and blood tests performed within 48 hours of admission. The primary outcome was death by any cause in less of 30 days or after one of year follow up, determined according to death certificates. RESULTS: We included 93 patients aged 65 to 94 years (53% males). Fifteen patients died during the year of follow up (five within 30 days of admission). Those who died had higher cobalamin levels than survivors (1080.07 ± 788.09 and 656.68 ± 497.33 pg/mL respectively, p = 0.02). Patients who died had also a significantly lower corrected serum calcium, sodium (p = 0.04) and a medical history of chronic liver disease (p = 0.03). In the multivariable analysis, only vitamin B12 preserved the association with mortality (p = 0.009). CONCLUSIONS: There was a significant association between high levels of cobalamin and all-cause mortality in this group of patients aged ≥ 65 years-old.

Insights into the Mn2+ Binding Site in the Agmatinase-Like Protein (ALP): A Critical Enzyme for the Regulation of Agmatine Levels in Mammals.

Agmatine is a neurotransmitter with anticonvulsant, anti-neurotoxic and antidepressant-like effects, in addition it has hypoglycemic actions. Agmatine is converted to putrescine and urea by agmatinase (AGM) and by an agmatinase-like protein (ALP), a new type of enzyme which is present in human and rodent brain tissues. Recombinant rat brain ALP is the only mammalian protein that exhibits significant agmatinase activity in vitro and generates putrescine under in vivo conditions. ALP, despite differing in amino acid sequence from all members of the ureohydrolase family, is strictly dependent on Mn2+ for catalytic activity. However, the Mn2+ ligands have not yet been identified due to the lack of structural information coupled with the low sequence identity that ALPs display with known ureohydrolases. In this work, we generated a structural model of the Mn2+ binding site of the ALP and we propose new putative Mn2+ ligands. Then, we cloned and expressed a sequence of 210 amino acids, here called the "central-ALP", which include the putative ligands of Mn2+. The results suggest that the central-ALP is catalytically active, as agmatinase, with an unaltered Km for agmatine and a decreased kcat. Similar to wild-type ALP, central-ALP is activated by Mn2+ with a similar affinity. Besides, a simple mutant D217A, a double mutant E288A/K290A, and a triple mutant N213A/Q215A/D217A of these putative Mn2+ ligands result on the loss of ALP agmatinase activity. Our results indicate that the central-ALP contains the active site for agmatine hydrolysis, as well as that the residues identified are relevant for the ALP catalysis.

Asociación entre niveles de vitamina B-12 y mortalidad en pacientes hospitalizados adultos mayores / Association between high vitamin B12 levels and one year mortality in older people admitted to the hospital

Background: Supplementation of vitamin B12 in older adults is a common practice to avoid vitamin B12 insufficiency. However, there is a paucity of information about the effects of cobalamin excess. Aim: To asses any potential effects of high levels vitamin B12 on mortality on adults aged ≥ 65 years admitted to an internal medicine service. Material and Methods: We Prospectively studied patients admitted to an internal medicine service of an academic hospital from September 2017 to September 2018, who were able to give their consent and answer questionnaires. We tabulated age, gender, medical history, comorbidity index (Charlson), frailty score (Fried scale), admission diagnosis and blood tests performed within 48 hours of admission. The primary outcome was death by any cause in less of 30 days or after one of year follow up, determined according to death certificates. Results: We included 93 patients aged 65 to 94 years (53% males). Fifteen patients died during the year of follow up (five within 30 days of admission). Those who died had higher cobalamin levels than survivors (1080.07 ± 788.09 and 656.68 ± 497.33 pg/mL respectively, p = 0.02). Patients who died had also a significantly lower corrected serum calcium, sodium (p = 0.04) and a medical history of chronic liver disease (p = 0.03). In the multivariable analysis, only vitamin B12 preserved the association with mortality (p = 0.009). Conclusions: There was a significant association between high levels of cobalamin and all-cause mortality in this group of patients aged ≥ 65 years-old.

Prevalence of STOP BANG questionnaire and association with major cardiovascular events in hospitalized population: is it enough with currently used cardiovascular risk measurements?

Cardiovascular risk (CR) is associated with obstructive sleep apnea hypopnea syndrome (OSAHS). This association enhances the risk of major adverse cardiovascular events (MACE); nevertheless, data from hospitalized populations and interactions among these conditions remain unclear. PURPOSE: To evaluate the risk of MACE in the population with risk of OSAHS using the STOP-BANG questionnaire. METHODS: We performed a prospective study in an academic hospital from 2017 to 2018. Data included demography, admissions, STOP-BANG score and CR using AHA scores. The primary outcome was risk of MACE in participants with low risk of OSAHS (STOP-BANG 0-2 points), risk of OSAHS (≥3 points) and risk of moderate/severe OSAHS (≥5 points). Risk of MACE was evaluated using odds ratios (OR), and average CR was evaluated using the t-test. RESULTS: A total of 441 participants were included. The cumulative prevalence of STOP BANG ≥3 points was 80.9%, and that of ≥5 points was 41.6%. OR of MACE ≥3 points was 3.93 (CI 2.08-7.24) (p < 0.001) compared with <3 points, and Average CR was 10.91% (SD ± 2.13) at <3 points versus 24.3% (SD ± 1.24) for ≥3 points for ≥5 points OR of MACE was 1.72 (CI 1.18-2.59) (p = 0.005) and average CR was 26.14% (SD ± 1.63). However, after multivariable analysis, gender differences and previous heart failure were independently associated to MACE. CONCLUSION: The risk of OSAHS in the hospitalized population is high. This population has a higher risk of MACE and higher CRs than do low-risk participants. Conversely, gender and heart failure are potential cofounders.