To investigate the relationship between intracellular free Ca^2+ concentration ([Ca^2+ ]i ) and calcium-activated chloride (Clca) channels of pulmonary artery smooth muscle cells (PASMCs) in rats under acute a...To investigate the relationship between intracellular free Ca^2+ concentration ([Ca^2+ ]i ) and calcium-activated chloride (Clca) channels of pulmonary artery smooth muscle cells (PASMCs) in rats under acute and chronic hypoxic conditions, acute hypoxia-induced contraction was observed in rat pulmonary artery by using routine blood vascular perfusion in vitro. The fluorescence Ca^2+ indicator Fura-2/AM was used to observe [Ca^2+ ]i of rat PASMCs under normal and chronic hypoxic condition. The effect of Clca channels on PASMCs proliferation was assessed by MTT assay. The Clca channel blockers niflumic acid (NFA) and indaryloxyacetic acid (IAA-94) exerted inhibitory effects on acute hypoxia-evoked contractions in the pulmonary artery. Under chronic hypoxic condition, [Ca^2+ ]i was increased. Under normoxic condition, [Ca^2+ If was (123.634-18.98) nmol/ L, and in hypoxic condition, [Ca^2+]i wag (281. 754-16.48) nmol/L (P〈0. 01). Under normoxic condition, [Ca^2+ ]i showed no significant change and no effect on Clca channels was observed (P〉 0. 05). Chronic hypoxia increased [Ca^2+ ]i which opened Clca channels. The NFA and IAA-94 blocked the channels and decreased [Ca^2+ ]i from (281.75± 16.48) nmot/L to (117.66 ±15.36) nmol/L (P〈0.01). MTT assay showed that under chronic hypoxic condition NFA and IAA-94 decreased the value of absorbency (A value) from 0. 459±0. 058 to 0. 224±0. 025 (P〈0. 01). Hypoxia increased [Ca^2+ ]i which opened Cl~ channels and had a positive-feedback in [Ca^2+ ]i. This may play an important role in hypoxic pulmonary hypertension. Under chronic hypoxic condition, Clca channel may play a part in the regulation of proliferation of PASMCs.展开更多
Background:Tuberculosis (TB) is a chronic wasting inflammatory disease characterized by multisystem involvement,which can cause metabolic derangements in afflicted patients.Metabolic signatures have been exploited ...Background:Tuberculosis (TB) is a chronic wasting inflammatory disease characterized by multisystem involvement,which can cause metabolic derangements in afflicted patients.Metabolic signatures have been exploited in the study of several diseases.However,the serum that is successfully used in TB diagnosis on the basis of metabolic profiling is not by much.Methods:Orthogonal partial least-squares discriminant analysis was capable of distinguishing TB patients from both healthy subjects and patients with conditions other than TB.Therefore,TB-specific metabolic profiling was established.Clusters of potential biomarkers for differentiating TB active from non-TB diseases were identified using Mann-Whitney U-test.Multiple logistic regression analysis of metabolites was calculated to determine the suitable biomarker group that allows the efficient differentiation of patients with TB active from the control subjects.Results:From among 271 participants,12 metabolites were found to contribute to the distinction between the TB active group and the control groups.These metabolites were mainly involved in the metabolic pathways of the following three biomolecules:Fatty acids,amino acids,and lipids.The receiver operating characteristic curves of3D,7D,and 11D-phytanic acid,behenic acid,and threoninyl-γ-glutamate exhibited excellent efficiency with area under the curve (AUC) values of 0.904 (95% confidence interval [CI]:0.863-0.944),0.93 (95% CI:0.893-0.966),and 0.964 (95% CI:0.941-0.988),respectively.The largest and smallest resulting AUCs were 0.964 and 0.720,indicating that these biomarkers may be involved in the disease mechanisms.The combination of lysophosphatidylcholine (18∶0),behenic acid,threoninyl-γ-glutamate,and presqualene diphosphate was used to represent the most suitable biomarker group for the differentiation of patients with TB active from the control subjects,with an AUC value of 0.991.Conclusion:The metabolic analysis results identified new serum biomarkers that can distinguish TB from non-TB diseases.The metabolomics-based analysis provides specific insights into the biology of TB and may offer new avenues for TB diagnosis.展开更多
文摘To investigate the relationship between intracellular free Ca^2+ concentration ([Ca^2+ ]i ) and calcium-activated chloride (Clca) channels of pulmonary artery smooth muscle cells (PASMCs) in rats under acute and chronic hypoxic conditions, acute hypoxia-induced contraction was observed in rat pulmonary artery by using routine blood vascular perfusion in vitro. The fluorescence Ca^2+ indicator Fura-2/AM was used to observe [Ca^2+ ]i of rat PASMCs under normal and chronic hypoxic condition. The effect of Clca channels on PASMCs proliferation was assessed by MTT assay. The Clca channel blockers niflumic acid (NFA) and indaryloxyacetic acid (IAA-94) exerted inhibitory effects on acute hypoxia-evoked contractions in the pulmonary artery. Under chronic hypoxic condition, [Ca^2+ ]i was increased. Under normoxic condition, [Ca^2+ If was (123.634-18.98) nmol/ L, and in hypoxic condition, [Ca^2+]i wag (281. 754-16.48) nmol/L (P〈0. 01). Under normoxic condition, [Ca^2+ ]i showed no significant change and no effect on Clca channels was observed (P〉 0. 05). Chronic hypoxia increased [Ca^2+ ]i which opened Clca channels. The NFA and IAA-94 blocked the channels and decreased [Ca^2+ ]i from (281.75± 16.48) nmot/L to (117.66 ±15.36) nmol/L (P〈0.01). MTT assay showed that under chronic hypoxic condition NFA and IAA-94 decreased the value of absorbency (A value) from 0. 459±0. 058 to 0. 224±0. 025 (P〈0. 01). Hypoxia increased [Ca^2+ ]i which opened Cl~ channels and had a positive-feedback in [Ca^2+ ]i. This may play an important role in hypoxic pulmonary hypertension. Under chronic hypoxic condition, Clca channel may play a part in the regulation of proliferation of PASMCs.
文摘Background:Tuberculosis (TB) is a chronic wasting inflammatory disease characterized by multisystem involvement,which can cause metabolic derangements in afflicted patients.Metabolic signatures have been exploited in the study of several diseases.However,the serum that is successfully used in TB diagnosis on the basis of metabolic profiling is not by much.Methods:Orthogonal partial least-squares discriminant analysis was capable of distinguishing TB patients from both healthy subjects and patients with conditions other than TB.Therefore,TB-specific metabolic profiling was established.Clusters of potential biomarkers for differentiating TB active from non-TB diseases were identified using Mann-Whitney U-test.Multiple logistic regression analysis of metabolites was calculated to determine the suitable biomarker group that allows the efficient differentiation of patients with TB active from the control subjects.Results:From among 271 participants,12 metabolites were found to contribute to the distinction between the TB active group and the control groups.These metabolites were mainly involved in the metabolic pathways of the following three biomolecules:Fatty acids,amino acids,and lipids.The receiver operating characteristic curves of3D,7D,and 11D-phytanic acid,behenic acid,and threoninyl-γ-glutamate exhibited excellent efficiency with area under the curve (AUC) values of 0.904 (95% confidence interval [CI]:0.863-0.944),0.93 (95% CI:0.893-0.966),and 0.964 (95% CI:0.941-0.988),respectively.The largest and smallest resulting AUCs were 0.964 and 0.720,indicating that these biomarkers may be involved in the disease mechanisms.The combination of lysophosphatidylcholine (18∶0),behenic acid,threoninyl-γ-glutamate,and presqualene diphosphate was used to represent the most suitable biomarker group for the differentiation of patients with TB active from the control subjects,with an AUC value of 0.991.Conclusion:The metabolic analysis results identified new serum biomarkers that can distinguish TB from non-TB diseases.The metabolomics-based analysis provides specific insights into the biology of TB and may offer new avenues for TB diagnosis.