Type 2 diabetes mellitus(T2DM)is a lifelong condition and a threat to human health.Thorough understanding of its pathogenesis is acutely needed in order to devise innovative,preventative,and potentially curative pharm...Type 2 diabetes mellitus(T2DM)is a lifelong condition and a threat to human health.Thorough understanding of its pathogenesis is acutely needed in order to devise innovative,preventative,and potentially curative pharmacological interventions.MicroRNAs(miRNA),are small,non-coding,one-stranded RNA molecules,that can target and silence around 60%of all human genes through translational repression.MiR-155 is an ancient,evolutionarily well-conserved miRNA,with distinct expression profiles and multifunctionality,and a target repertoire of over 241 genes involved in numerous physiological and pathological processes including hematopoietic lineage differentiation,immunity,inflammation,viral infections,cancer,cardiovascular conditions,and particularly diabetes mellitus.MiR-155 Levels are progressively reduced in aging,obesity,sarcopenia,and T2DM.Thus,the loss of coordinated repression of multiple miR-155 targets acting as negative regulators,such as C/EBPβ,HDAC4,and SOCS1 impacts insulin signaling,deteriorating glucose homeostasis,and causing insulin resistance(IR).Moreover,deranged regulation of the renin angiotensin aldosterone system(RAAS)through loss of Angiotensin II Type 1 receptor downregulation,and negated repression of ETS-1,results in unopposed detrimental Angiotensin II effects,further promoting IR.Finally,loss of BACH1 and SOCS1 repression abolishes cytoprotective,anti-oxidant,anti-apoptotic,and anti-inflam matory cellular pathways,and promotesβ-cell loss.In contrast to RAAS inhibitor treatments that further decrease already reduced miR-155 Levels,strategies to increase an ailing miR-155 production in T2DM,e.g.,the use of metformin,mineralocorticoid receptor blockers(spironolactone,eplerenone,finerenone),and verapamil,alone or in various combinations,represent current treatment options.In the future,direct tissue delivery of miRNA analogs is likely.展开更多
The emergence of coronavirus disease-2019 induced by a newly identified bcoronavirus, namely severe acute respiratory syndrome coronavirus 2(SARSCoV-2) has constituted a public health emergency. Even though it was con...The emergence of coronavirus disease-2019 induced by a newly identified bcoronavirus, namely severe acute respiratory syndrome coronavirus 2(SARSCoV-2) has constituted a public health emergency. Even though it was considered a zoonotic disease, the virus has also spread among humans via respiratory secretions. The expression and distribution of angiotensin converting enzyme type 2(ACE2) in various human organs might also show other possible infection routes. High ACE2 ribonucleic acid expression has been identified in the gastrointestinal tract(GI) indicating its importance as a possible infection pathway of SARS-CoV-2. ACE2 induces viral entry into the host and most importantly has been found to be associated with the function of the gut. Its deficiency has been implicated in several pathologies such as colorectal inflammation. The renin-angiotensin system(RAS) is an essential regulatory cascade operating both at a local tissue level and at the systemic or circulatory level. The RAS may be important in the pathogenesis of chronic liver disease and is associated with the up-regulation of ACE2. Thus, the aim of this review is firstly, the analysis of some important general and genome characteristics of SARS-CoV-2 and secondly, and most importantly, to focus on the utility of ACE2 receptors in both SARS-CoV-2 replication and pathogenesis, especially in the GI tract.展开更多
BACKGROUND Recent studies have revealed that sustained ingestion of angiotensin converting enzymes inhibitors or angiotensin receptor blockers(ACEIs/ARBs)had no harmful effects on coronavirus disease 2019(COVID-19)pat...BACKGROUND Recent studies have revealed that sustained ingestion of angiotensin converting enzymes inhibitors or angiotensin receptor blockers(ACEIs/ARBs)had no harmful effects on coronavirus disease 2019(COVID-19)patients complicated with hypertension.AIM To investigate the impact on COVID-19 patients complicated with hypertension who discontinued using ACEIs/ARBs.METHODS All COVID-19 patients complicated with hypertension admitted to our isolated unit were consecutively recruited in this study.Some patients switched from ACEIs/ARBs to calcium channel blocker(CCBs)after admission,while others continued using non-ACEIs/ARBs.We compared characteristics and clinical outcomes between these two groups of patients.RESULTS A total of 53 patients were enrolled,27 patients switched from ACEIs/ARBs to CCBs while 26 patients continued with non-ACEIs/ARBs.After controlling potential confounding factors using the Cox proportional hazards model,hospital stay was longer in patients who discontinued ACEIs/ARBs,with a hazard ratio of 0.424(95%confidence interval:0.187-0.962;P=0.040),upon discharge than patients using other anti-hypertensive drugs.A sub-group analysis showed that the effect of discontinuing use of ACEIs/ARBs was stronger in moderate cases[hazard ratio=0.224(95%confidence interval:0.005-0.998;P=0.0497)].CONCLUSION Patients in the discontinued ACEIs/ARBs group had longer hospital stays.Our findings suggest that COVID-19 patients complicated with hypertension should continue to use ACEIs/ARBs.展开更多
Background: Breast cancer is the most common type of cancer among women. Diagnosed and treated timely, patients may have good prognostics. In Brazil, in 2012, the estimate of new cases was 52,680 and the number of reg...Background: Breast cancer is the most common type of cancer among women. Diagnosed and treated timely, patients may have good prognostics. In Brazil, in 2012, the estimate of new cases was 52,680 and the number of registered deaths in 2012 was 12,852. The Renin-Angiotensin System (RAS) is known for its role in arterial hypertension and in other cardiovascular diseases. Angiotensin-Converting Enzyme 2 (ACE2) is the key to Ang-(1-7) formation, and counterbalances the ACE1/AngII/AGTR1 axis actions. RAS components have complex interactions with different tissues and their actions are not restricted to the cardiovascular system. Recently, the RAS has been associated with different types of cancers and in particular with gynecological cancers. Objectives: Our aim is to investigate possible associations between allelic distribution of two genetic polymorphisms in the AGTR2 receptor with ACEs 1 and 2 plasma levels among women with breast cancer. Patients and Methods: Patients with breast cancer were genotyped for two polymorphisms of the AGTR2 (T1247G and A5235G). Genotyping assays (TaqMan) were performed with genomic DNA extracted from blood cells. ACEs plasma level measurements were conducted in women from the breast-cancer group (N = 53). ACEs were measured in the plasma of these patients using ELISA kits. Results: SNPs genotype distribution is correlated with ACEs plasma levels. ACEs plasma levels are also correlated with clinical variables and ACE2 high levels are associated with better prognostics. Conclusions: Changes in circulating levels of ECA1/AngII ECA2/ Ang-(1-7) determine the magnitude of the inflammatory response that an individual can trigger and the variation in ACE 1 and 2 plasma level measurements in the blood of breast cancer patients suggests an association with the process of mammary carcinogenesis. Thus, the RAS may be associated with the process of mammary carcinogenesis by both genotypic variations of RAS components and by circulating levels of ACEs.展开更多
Previous voltage clamp studies have demonstrated the modulation of sperm Ca 2+ activated K + (KCa) channels expressed in Xenopus oocytes by angiotensin II (Ang II) and extracellular ATP via AT 1 receptor and ...Previous voltage clamp studies have demonstrated the modulation of sperm Ca 2+ activated K + (KCa) channels expressed in Xenopus oocytes by angiotensin II (Ang II) and extracellular ATP via AT 1 receptor and P 2U receptor, respectively. In the present study, we investigated the involvement of KCa channels in receptor regulated sperm motility of the rat using a computer aided sperm analysis system, HTM IVOS, in conjunction with Ca 2+ mobilizing agents, receptor agonists/antagonists and KCa channels blockers. The percentage of motile sperm was increased by ionomycin (0.5 μmol/L), which could be inhibited by K + channel blockers, tetraethylammonium (TEA 1 μmol/L ) or charybdotoxin (ChTX, 300 nmol/L) indicating the presence of KCa channels. Ang II, at low concentration, 10 nmol/L, was found to increase motility, however, at higher concentration, 1 μmol/L, percentage of motility was found to be suppressed. Both stimulatory and inhibitory effects of Ang II could be reversed by losartan, a specific antagonist of AT 1 receptors, but not AT 2 antagonist PD123177, indicating the involvement of AT 1 but not AT2 receptor in mediating both effects. ChTX also abolished both stimulatory and inhibitory effects of Ang II, suggesting the involvement of KCa channels. The percentage of motility was also enhanced by extracellular ATP, a factor known to be involved in sperm activation. The ATP enhanced sperm motility was mimicked by UTP, and inhibited by ChTX and reactive blue, an antagonist of P 2 receptor, indicating the involvement of both P 2U and KCa channels. RT PCR study was also conducted to confirm the expression of KCa channels, AT 1 receptors and P 2U receptor, but not AT 2 receptor, in rat caudal epididymal sperm. The present findings suggest an important role of KCa channels in the regulation of sperm motility by AT 1 and P 2U receptors.展开更多
There is a pathophysiological correlation between arterial hypertension and diabetes mellitus, established since the pre-diabetic state in the entity known as insulin resistance. It is known that high concentrations o...There is a pathophysiological correlation between arterial hypertension and diabetes mellitus, established since the pre-diabetic state in the entity known as insulin resistance. It is known that high concentrations of angiotensin-Ⅱ enable chronic activation of the AT1 receptor, promoting sustained vasoconstriction and the consequent development of high blood pressure. Furthermore, the chronic activation of the AT1 receptor has been associated with the development of insulin resistance. From a molecular outlook, the AT1 receptor signaling pathway can activate the JNK kinase. Once activated, this kinase can block the insulin signaling pathway, favoring the resistance to this hormone. In accordance with the previously mentioned mechanisms, the negative regulation of the AT1receptor could have beneficial effects in treating metabolic syndrome and type 2diabetes mellitus. This review explains the clinical correlation of the metabolic response that diabetic patients present when receiving negatively regulatory drugs of the AT1 receptor.展开更多
文摘Type 2 diabetes mellitus(T2DM)is a lifelong condition and a threat to human health.Thorough understanding of its pathogenesis is acutely needed in order to devise innovative,preventative,and potentially curative pharmacological interventions.MicroRNAs(miRNA),are small,non-coding,one-stranded RNA molecules,that can target and silence around 60%of all human genes through translational repression.MiR-155 is an ancient,evolutionarily well-conserved miRNA,with distinct expression profiles and multifunctionality,and a target repertoire of over 241 genes involved in numerous physiological and pathological processes including hematopoietic lineage differentiation,immunity,inflammation,viral infections,cancer,cardiovascular conditions,and particularly diabetes mellitus.MiR-155 Levels are progressively reduced in aging,obesity,sarcopenia,and T2DM.Thus,the loss of coordinated repression of multiple miR-155 targets acting as negative regulators,such as C/EBPβ,HDAC4,and SOCS1 impacts insulin signaling,deteriorating glucose homeostasis,and causing insulin resistance(IR).Moreover,deranged regulation of the renin angiotensin aldosterone system(RAAS)through loss of Angiotensin II Type 1 receptor downregulation,and negated repression of ETS-1,results in unopposed detrimental Angiotensin II effects,further promoting IR.Finally,loss of BACH1 and SOCS1 repression abolishes cytoprotective,anti-oxidant,anti-apoptotic,and anti-inflam matory cellular pathways,and promotesβ-cell loss.In contrast to RAAS inhibitor treatments that further decrease already reduced miR-155 Levels,strategies to increase an ailing miR-155 production in T2DM,e.g.,the use of metformin,mineralocorticoid receptor blockers(spironolactone,eplerenone,finerenone),and verapamil,alone or in various combinations,represent current treatment options.In the future,direct tissue delivery of miRNA analogs is likely.
文摘The emergence of coronavirus disease-2019 induced by a newly identified bcoronavirus, namely severe acute respiratory syndrome coronavirus 2(SARSCoV-2) has constituted a public health emergency. Even though it was considered a zoonotic disease, the virus has also spread among humans via respiratory secretions. The expression and distribution of angiotensin converting enzyme type 2(ACE2) in various human organs might also show other possible infection routes. High ACE2 ribonucleic acid expression has been identified in the gastrointestinal tract(GI) indicating its importance as a possible infection pathway of SARS-CoV-2. ACE2 induces viral entry into the host and most importantly has been found to be associated with the function of the gut. Its deficiency has been implicated in several pathologies such as colorectal inflammation. The renin-angiotensin system(RAS) is an essential regulatory cascade operating both at a local tissue level and at the systemic or circulatory level. The RAS may be important in the pathogenesis of chronic liver disease and is associated with the up-regulation of ACE2. Thus, the aim of this review is firstly, the analysis of some important general and genome characteristics of SARS-CoV-2 and secondly, and most importantly, to focus on the utility of ACE2 receptors in both SARS-CoV-2 replication and pathogenesis, especially in the GI tract.
文摘BACKGROUND Recent studies have revealed that sustained ingestion of angiotensin converting enzymes inhibitors or angiotensin receptor blockers(ACEIs/ARBs)had no harmful effects on coronavirus disease 2019(COVID-19)patients complicated with hypertension.AIM To investigate the impact on COVID-19 patients complicated with hypertension who discontinued using ACEIs/ARBs.METHODS All COVID-19 patients complicated with hypertension admitted to our isolated unit were consecutively recruited in this study.Some patients switched from ACEIs/ARBs to calcium channel blocker(CCBs)after admission,while others continued using non-ACEIs/ARBs.We compared characteristics and clinical outcomes between these two groups of patients.RESULTS A total of 53 patients were enrolled,27 patients switched from ACEIs/ARBs to CCBs while 26 patients continued with non-ACEIs/ARBs.After controlling potential confounding factors using the Cox proportional hazards model,hospital stay was longer in patients who discontinued ACEIs/ARBs,with a hazard ratio of 0.424(95%confidence interval:0.187-0.962;P=0.040),upon discharge than patients using other anti-hypertensive drugs.A sub-group analysis showed that the effect of discontinuing use of ACEIs/ARBs was stronger in moderate cases[hazard ratio=0.224(95%confidence interval:0.005-0.998;P=0.0497)].CONCLUSION Patients in the discontinued ACEIs/ARBs group had longer hospital stays.Our findings suggest that COVID-19 patients complicated with hypertension should continue to use ACEIs/ARBs.
文摘Background: Breast cancer is the most common type of cancer among women. Diagnosed and treated timely, patients may have good prognostics. In Brazil, in 2012, the estimate of new cases was 52,680 and the number of registered deaths in 2012 was 12,852. The Renin-Angiotensin System (RAS) is known for its role in arterial hypertension and in other cardiovascular diseases. Angiotensin-Converting Enzyme 2 (ACE2) is the key to Ang-(1-7) formation, and counterbalances the ACE1/AngII/AGTR1 axis actions. RAS components have complex interactions with different tissues and their actions are not restricted to the cardiovascular system. Recently, the RAS has been associated with different types of cancers and in particular with gynecological cancers. Objectives: Our aim is to investigate possible associations between allelic distribution of two genetic polymorphisms in the AGTR2 receptor with ACEs 1 and 2 plasma levels among women with breast cancer. Patients and Methods: Patients with breast cancer were genotyped for two polymorphisms of the AGTR2 (T1247G and A5235G). Genotyping assays (TaqMan) were performed with genomic DNA extracted from blood cells. ACEs plasma level measurements were conducted in women from the breast-cancer group (N = 53). ACEs were measured in the plasma of these patients using ELISA kits. Results: SNPs genotype distribution is correlated with ACEs plasma levels. ACEs plasma levels are also correlated with clinical variables and ACE2 high levels are associated with better prognostics. Conclusions: Changes in circulating levels of ECA1/AngII ECA2/ Ang-(1-7) determine the magnitude of the inflammatory response that an individual can trigger and the variation in ACE 1 and 2 plasma level measurements in the blood of breast cancer patients suggests an association with the process of mammary carcinogenesis. Thus, the RAS may be associated with the process of mammary carcinogenesis by both genotypic variations of RAS components and by circulating levels of ACEs.
基金Direct Grant of the Chinese University of Hong Kong to Dr. HC Chan
文摘Previous voltage clamp studies have demonstrated the modulation of sperm Ca 2+ activated K + (KCa) channels expressed in Xenopus oocytes by angiotensin II (Ang II) and extracellular ATP via AT 1 receptor and P 2U receptor, respectively. In the present study, we investigated the involvement of KCa channels in receptor regulated sperm motility of the rat using a computer aided sperm analysis system, HTM IVOS, in conjunction with Ca 2+ mobilizing agents, receptor agonists/antagonists and KCa channels blockers. The percentage of motile sperm was increased by ionomycin (0.5 μmol/L), which could be inhibited by K + channel blockers, tetraethylammonium (TEA 1 μmol/L ) or charybdotoxin (ChTX, 300 nmol/L) indicating the presence of KCa channels. Ang II, at low concentration, 10 nmol/L, was found to increase motility, however, at higher concentration, 1 μmol/L, percentage of motility was found to be suppressed. Both stimulatory and inhibitory effects of Ang II could be reversed by losartan, a specific antagonist of AT 1 receptors, but not AT 2 antagonist PD123177, indicating the involvement of AT 1 but not AT2 receptor in mediating both effects. ChTX also abolished both stimulatory and inhibitory effects of Ang II, suggesting the involvement of KCa channels. The percentage of motility was also enhanced by extracellular ATP, a factor known to be involved in sperm activation. The ATP enhanced sperm motility was mimicked by UTP, and inhibited by ChTX and reactive blue, an antagonist of P 2 receptor, indicating the involvement of both P 2U and KCa channels. RT PCR study was also conducted to confirm the expression of KCa channels, AT 1 receptors and P 2U receptor, but not AT 2 receptor, in rat caudal epididymal sperm. The present findings suggest an important role of KCa channels in the regulation of sperm motility by AT 1 and P 2U receptors.
文摘There is a pathophysiological correlation between arterial hypertension and diabetes mellitus, established since the pre-diabetic state in the entity known as insulin resistance. It is known that high concentrations of angiotensin-Ⅱ enable chronic activation of the AT1 receptor, promoting sustained vasoconstriction and the consequent development of high blood pressure. Furthermore, the chronic activation of the AT1 receptor has been associated with the development of insulin resistance. From a molecular outlook, the AT1 receptor signaling pathway can activate the JNK kinase. Once activated, this kinase can block the insulin signaling pathway, favoring the resistance to this hormone. In accordance with the previously mentioned mechanisms, the negative regulation of the AT1receptor could have beneficial effects in treating metabolic syndrome and type 2diabetes mellitus. This review explains the clinical correlation of the metabolic response that diabetic patients present when receiving negatively regulatory drugs of the AT1 receptor.
