Publications by authors named "Haixia Huang"

43 Publications

ASIC2 Synergizes with TRPV1 in the Mechano-Electrical Transduction of Arterial Baroreceptors.

Neurosci Bull 2021 Jul 2. Epub 2021 Jul 2.

Department of Neurobiology, School of Basic Medical Sciences, Beijing Key Laboratory of Neural Regeneration and Repair, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, 100069, China.

Mechanosensitive ion channels (MSCs) are key molecules in the mechano-electrical transduction of arterial baroreceptors. Among them, acid-sensing ion channel 2 (ASIC2) and transient receptor potential vanilloid subfamily member 1 (TRPV1) have been studied extensively and documented to play important roles. In this study, experiments using aortic arch-aortic nerve preparations isolated from rats revealed that both ASIC2 and TRPV1 are functionally necessary, as blocking either abrogated nearly all pressure-dependent neural discharge. However, whether ASIC2 and TRPV1 work in coordination remained unclear. So we carried out cell-attached patch-clamp recordings in HEK293T cells co-expressing ASIC2 and TRPV1 and found that inhibition of ASIC2 completely blocked stretch-activated currents while inhibition of TRPV1 only partially blocked these currents. Immunofluorescence staining of aortic arch-aortic adventitia from rats showed that ASIC2 and TRPV1 are co-localized in the aortic nerve endings, and co-immunoprecipitation assays confirmed that the two proteins form a compact complex in HEK293T cells and in baroreceptors. Moreover, protein modeling analysis, exogenous co-immunoprecipitation assays, and biotin pull-down assays indicated that ASIC2 and TRPV1 interact directly. In summary, our research suggests that ASIC2 and TRPV1 form a compact complex and function synergistically in the mechano-electrical transduction of arterial baroreceptors. The model of synergism between MSCs may have important biological significance beyond ASIC2 and TRPV1.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s12264-021-00737-1DOI Listing
July 2021

Reversible GABAergic dysfunction involved in hippocampal hyperactivity predicts early-stage Alzheimer disease in a mouse model.

Alzheimers Res Ther 2021 06 14;13(1):114. Epub 2021 Jun 14.

Key Laboratory for Neurodegenerative Disorders of the Ministry of Education, Capital Medical University, Beijing, 100069, China.

Background: Neuronal hyperactivity related to β-amyloid (Aβ) is considered an early warning sign of Alzheimer disease (AD). Although increasing evidence supports this opinion, the underlying mechanisms are still unknown.

Methods: Here, we recorded whole-cell synaptic currents and membrane potentials using patch clamping of acute hippocampal slices from human amyloid precursor protein (APP)/presenilin-1 transgenic (5XFAD) mice and their wild-type littermates. Biochemical methods, electron microscopic imaging, behavioral tests, and intraventricular drug delivery applied with osmotic pumps were used in this study.

Results: We confirmed hyperactivity of hippocampal CA1 pyramidal neurons in 5XFAD mice using whole-cell electrophysiological recording at 2.5 months old, when local Aβ-positive plaques had not developed and only mild cognitive dysfunction occurred. We further discovered attenuated inhibitory postsynaptic currents and unchanged excitatory postsynaptic currents in CA1 pyramidal neurons, in which the intrinsic excitability was unchanged. Moreover, the density of both γ-aminobutyric acid A (GABA) receptor subunits, α1 and γ2, was reduced in synapses of the hippocampus in transgenic mice. Intriguingly, early intervention with the GABA receptor agonist gaboxadol reversed the hippocampal hyperactivity and modestly ameliorated cognitive performance in 5XFAD mice under our experimental conditions.

Conclusions: Inhibitory postsynaptic disruption critically contributes to abnormalities in the hippocampal network and cognition in 5XFAD mice and possibly in AD. Therefore, strengthening the GABAergic system could be a promising therapy for AD in the early stages.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s13195-021-00859-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8204558PMC
June 2021

Targeting cancer epigenetic pathways with small-molecule compounds: Therapeutic efficacy and combination therapies.

Pharmacol Res 2021 Jun 5:105702. Epub 2021 Jun 5.

State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu 610041, PR China. Electronic address:

Epigenetics mainly refers to covalent modifications to DNA or histones without affecting genomes, which ultimately lead to phenotypic changes in cells or organisms. Given the abundance of regulatory targets in epigenetic pathways and their pivotal roles in tumorigenesis and drug resistance, the development of epigenetic drugs holds a great promise for the current cancer therapy. However, lack of potent, selective, and clinically tractable small-molecule compounds makes the strategy to target cancer epigenetic pathways still challenging. Therefore, this review focuses on epigenetic pathways, small molecule inhibitors targeting DNA methyltransferase (DNMT) and small molecule inhibitors targeting histone modification (the main regulatory targets are histone acetyltransferases (HAT), histone deacetylases (HDACs) and histone methyltransferases (HMTS)), as well as the combination strategies of the existing epigenetic therapeutic drugs and more new therapies to improve the efficacy, which will shed light on a new clue on discovery of more small-molecule drugs targeting cancer epigenetic pathways as promising strategies in the future.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.phrs.2021.105702DOI Listing
June 2021

Glial Fibrillary Acidic Protein Astrocytopathy in Pediatric Patients: A Retrospective Study.

Front Pediatr 2020 25;8:626564. Epub 2021 Jan 25.

Intensive Care Unit, Key Medical Laboratory of Pediatrics, Chongqing Health Bureau, Ministry of Education, Chongqing, China.

Autoimmune glial fibrillary acidic protein astrocytopathy is a novel form of autoimmune meningoencephalitis related to GFAP autoantibodies. This condition is still being characterized, and few pediatric patients have been identified. Here, we report three patients presenting with fever, nausea, and headache, following progressive disturbance of consciousness, limb weakness, dyspnea, or urine retention. MRI analysis revealed that T2-hyperintense lesions, or enhancement of the meninges and spinal cord. CSF and serum analyses revealed they were positive for GFAP antibody, confirming GFAP astrocytopathy diagnosis. Treating the patients with IVIG, with or without intravenous steroids, gradually improved their clinical symptoms. Our findings indicate that GFAP astrocytopathy should be considered in children who are clinically diagnosed with meningoencephalitis, whether or not myelitis is present, and if the MRI reveals enhancement of meninges or spinal cord, T2-hyperintense lesions, or a pattern of linear perivascular gadolinium enhancement. Suspected cases should be tested for GFAP antibody as soon as possible because these patients may benefit from immunotherapy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fped.2020.626564DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7868541PMC
January 2021

Apelin/APJ relieve diabetic cardiomyopathy by reducing microvascular dysfunction.

J Endocrinol 2021 04;249(1):1-18

School of Basic Medical Sciences, Capital Medical University, Beijing, China.

Microcirculatory injuries had been reported to be involved in diabetic cardiomyopathy, which was mainly related to endothelial cell dysfunction. Apelin, an adipokine that is upregulated in diabetes mellitus, was reported to improve endothelial cell dysfunction and attenuate cardiac insufficiency induced by ischemia and reperfusion. Therefore, it is hypothesized that apelin might be involved in alleviating endothelial cell dysfunction and followed cardiomyopathy in diabetes mellitus. The results showed that apelin improved endothelial cell dysfunction via decreasing apoptosis and expression of adhesion molecules and increasing proliferation, angiogenesis, and expression of E-cadherin, VEGFR 2 and Tie-2 in endothelial cells, which resulted in the attenuation of the capillary permeability in cardiac tissues and following diabetic cardiomyopathy. Meanwhile, the results from endothelial cell-specific APJ knockout mice and cultured endothelial cells confirmed that the effects of apelin on endothelial cells were dependent on APJ and the downstream NFκB pathways. In conclusion, apelin might reduce microvascular dysfunction induced by diabetes mellitus via improving endothelial dysfunction dependent on APJ activated NFκB pathways.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1530/JOE-20-0398DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8052525PMC
April 2021

BK channel participates in insulin-induced lipid deposition in adipocytes by increasing intracellular calcium.

J Cell Physiol 2021 Aug 11;236(8):5818-5831. Epub 2021 Jan 11.

Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, China.

Storing energy in the form of triglyceride (TG) is one of the basic functions of adipose tissue. Large-conductance calcium-activated potassium channels (BK channels) are expressed in adipose tissue and adipocyte-specific BK deficiency resists obesity in mice, but the role of BK channels in lipid deposition and the underlying mechanisms have not been elucidated. In the present study, we generated BK knockout (KO) rats and performed a transcriptome analysis of adipose tissue. We found that the phosphoinositide 3-kinase (PI3K)-protein kinase B (Akt) signaling pathway, which is important for lipid deposition, exhibited the most notable reduction among various signaling pathways in BK KO rats compared to wild-type rats. Insulin-induced TG deposition, glucose uptake, and Akt (Ser473) phosphorylation were significantly reduced in cultured adipocytes differentiated from adipose-derived stem cells of BK KO rats. Furthermore, we found that the insulin-induced increase of intracellular calcium resulting from extracellular calcium influx was significantly impaired in BK KO adipocytes. Finally, insulin activated BK currents through PI3K, which was independent of Akt and intracellular calcium. The results of this study suggested that BK channels participate in the insulin signaling pathway and promote TG deposition by increasing extracellular calcium influx in adipocytes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jcp.30266DOI Listing
August 2021

Ubiquitin-Like Modifier Activating Enzyme 1 as a Novel Diagnostic and Prognostic Indicator That Correlates With Ferroptosis and the Malignant Phenotypes of Liver Cancer Cells.

Front Oncol 2020 3;10:592413. Epub 2020 Dec 3.

Department of Dermatology, Chongqing Traditional Chinese Medicine Hospital, Chongqing, China.

Purpose: Ferroptosis is a type of cell death that is iron dependent, a characteristic that distinguishes it from necrosis, apoptosis, and autophagy. However, the ferroptotic mechanisms for hepatitis B virus-associated hepatocellular carcinoma (HCC) remain incompletely described.

Methods: Two hepatitis B virus-associated HCC public datasets, GSE22058 (n=192) and GSE54238 (n=23), were obtained from the NCBI Gene Expression Omnibus (GEO) database. Bioinformatics methods, including weighted gene coexpression network analysis (WGCNA), Cox regression, and LASSO analysis, were used to identify signature markers for diagnosis and prognosis. CCK8, wound healing, Transwell migration/invasion, and ferroptosis assays were employed to explore the biological function of novel candidate markers weight gene coexpression network analysis.

Results: In total, 926 differentially expressed genes (DEGs) were common between the GSE22058 and GSE54238 datasets. Following WGCNA, 515 DEGs derived from the MEturquoise gene module were employed to establish diagnosis and prognosis models in The Cancer Genome Atlas (TCGA) HCC RNA-Seq cohort (n=423). The score of the diagnostic model was strikingly upregulated in the TCGA HCC group (<2.2e-16). The prognostic model exhibited high specificity and sensitivity in both training and validation (AUC=0.835 and 0.626, respectively), and the high-risk group showed dismal prognostic outcomes compared with the low-risk group (training: =1.416e-10; validation: =4.495e-02). Ubiquitin-like modifier activating enzyme 1 () was identified among both diagnosis and prognosis signature genes, and its overexpression was associated with poor survival. We validated the expression level of in eight pairs of HCC patient tissues and liver cancer cell lines. silencing decreased proliferation, migration, and invasion in Huh7 cells while elevating the Fe and malondialdehyde (MDA) levels. Additionally, these biological effects were recovered by oltipraz (an activator). Furthermore, blocking strikingly repressed the protein expression levels of , , , and in the signal transduction pathway.

Conclusion: Our findings demonstrated that participates in the development of HCC by modulating Huh7 phenotypes and ferroptosis the signal transduction pathway and might be a promising diagnostic and prognostic indicator for HCC.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fonc.2020.592413DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7744729PMC
December 2020

Ecthyma gangrenosum due to Pseudomonas aeruginosa sepsis as initial manifestation of X-linked agammaglobulinemia: a case report.

BMC Pediatr 2020 12 1;20(1):540. Epub 2020 Dec 1.

Intensive Care Unit, Key Medical Laboratory of Pediatrics, Key Laboratory of Child Development and Disorders, Chongqing Health Bureau, Ministry of Education, Children's Hospital of Chongqing Medical University, 136#, Zhong Shan 2nd Rord, Yuzhong District, Chongqing, People's Republic of China.

Background: X-linked agammaglobulinemia (XLA, OMIM#300,300), caused by mutations in the Bruton tyrosine kinase (BTK) gene, is a rare monogenic inheritable immunodeficiency disorder. Ecthyma gangrenosum is a cutaneous lesion caused by Pseudomonas aeruginosa that typically occurs in patients with XLA and other immunodeficiencies.

Case Presentation: We report the case of a 20-month-old boy who presented with fever, vomiting, diarrhea, and ecthyma gangrenosum. Blood, stool, and skin lesion culture samples were positive for P. aeruginosa. A diagnosis of XLA was established, and the c.262G > T mutation in exon 4 of BTK was identified with Sanger sequencing. Symptoms improved following treatment with antibiotics and immunoglobulin infusion.

Conclusions: Primary immunodeficiency (i.e., XLA) should be suspected in male infants with P. aeruginosa sepsis, highlighting the importance of genetic and immune testing in these patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12887-020-02436-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7704585PMC
December 2020

Identification of Pannexin 2 as a Novel Marker Correlating with Ferroptosis and Malignant Phenotypes of Prostate Cancer Cells.

Onco Targets Ther 2020 19;13:4411-4421. Epub 2020 May 19.

Department of Dermatology, Chongqing Traditional Chinese Medicine Hospital, Chongqing, People's Republic of China.

Purpose: Prostate cancer (PCa) is a widespread urinary neoplasm and one of the most prevalent and second most frequent malignancies diagnosed in males worldwide. This study aimed to identify a candidate marker and explore its molecular mechanism in PCa.

Methods: Gene expression datasets, GSE55945 (n=21) and GSE46602 (n=50), were downloaded from the Gene Expression Omnibus database. Bioinformatic approaches were applied to identify potential markers. Effects of the candidate marker on proliferation, migration, invasion, and ferroptosis (ferrous iron and malondialdehyde (MDA)) in PCa cells and its mechanism were assessed after performing cell transfection.

Results: A total of 1435 common differentially expressed genes were identified in GSE55945 and GSE46602. Five key gene modules were listed based on a protein-protein interaction network, containing five hub genes. Pannexin 2 (), a candidate marker was identified, and findings revealed substantial upregulation of its expression levels in PCa cell lines. Blocking expression of resulted in suppression of proliferation, migration, and invasion in PCa cells, while increasing ferrous iron and MDA levels. However, these effects were rescued by activator, oltipraz. The signaling pathway was consequently applied to determine underlying mechanism of in PCa cells. We established that silencing remarkably reduced protein expression levels in members of signaling pathway ( and ).

Conclusion: Our study demonstrated that is implicated in the pathogenesis of PCa, which regulates malignant phenotypes and ferroptosis through signaling pathway, and maybe a potential therapeutic target for PCa.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2147/OTT.S249752DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7245471PMC
May 2020

Specific Knockdown of α-Synuclein by Peptide-Directed Proteasome Degradation Rescued Its Associated Neurotoxicity.

Cell Chem Biol 2020 06 30;27(6):751-762.e4. Epub 2020 Apr 30.

Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Institute of Brain Disorders, Key Laboratory for Neurodegenerative Disease of the Ministry of Education, Capital Medical University, #10 Xitoutiao, Youanmenwai, Beijing 100069, China. Electronic address:

α-Synuclein (α-syn) overload is strongly associated with Parkinson disease (PD), and reduction of the α-syn level by targeting the peptide-based system through the autophagy-lysosomal pathway (ALP) is a promising strategy to delay PD progression. However, if the ALP is comprised, targeting the peptide-based proteasomal degradation system would be a good alternative. In this study, we designed a fusion peptide containing an α-syn-binding domain and a short strong proteasome-targeting motif. Our results reveal that this peptide could specifically bind to α-syn, and direct it to the proteasomes for degradation in a recombinant expression system. Furthermore, by adding a membrane-penetrating motif to this fusion peptide, we demonstrated that it could penetrate into cells and consequently suppress the cellular α-syn level through proteasome degradation in a dose- and time-dependent manner. Functionally, these effects rescued the mitochondrial dysfunction and cellular defects caused by α-syn overexpression in the cultured cells and primary neurons.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.chembiol.2020.03.010DOI Listing
June 2020

A lipid-soluble extract of Pinellia pedatisecta Schott orchestrates intratumoral dendritic cell-driven immune activation through SOCS1 signaling in cervical cancer.

J Ethnopharmacol 2021 Mar 7;267:112837. Epub 2020 Apr 7.

Department of Integration of Western and Traditional Medicine, Obstetrics and Gynecology Hospital of Fudan University, Shanghai, 200090, China; Shanghai Key Laboratory of Female Reproductive Endocrine Related Diseases, Fudan University, Shanghai, 200011, China. Electronic address:

Ethnopharmacological Relevance: Pinellia pedatisecta Schott extract (PE) is generated from Pinellia pedatisecta Schott, a traditional Chinese medicinal plant. PE suppresses cervical tumor growth and exhibits effects on dendritic cells (DCs) that lead to modulation of antitumor CD4 and CD8 responses.

Aims: To explore the underlying mechanisms by which PE modulates tumor-associated dendritic cell (TADC) activation and function.

Methods: DCs and TADCs were generated from murine bone marrow and exposed to PE solutions at different doses, as well as to repeated doses separated at different time intervals. Quantitative PCR, Western blot analysis, flow cytometry, and gene silencing were used to analyze the modulatory effects of PE on the SOCS1/JAK2/STAT pathways. Furthermore, we separated human cervical tumor-infiltrated DCs (TIDCs) and conducted an ex-vivo stimulation model to observe the effect of PE. For phenotypic analysis of cultured DCs and ex vivo human specimens, we used flow cytometry to detect the molecular markers associated with cell function.

Results: In cultured TADCs and human cervical TIDCs, maturation- and functional markers (MHCII, CD80, CD83, CD86, and IL-12) were downregulated, whereas SOCS1 was upregulated. PE enhanced the expression of CD80, CD86, and IL-12 in cervical TIDCs, which induced increased expression of CD107a, GZMB, and perforin in CTLs, and furthermore induced apoptosis in a larger number of tumor cells. In cultured TADCs, PE downregulated SOCS1 expression and activated the phosphorylation of JAK2, STAT1, STAT4, and STAT5 in both dose- and time-dependent manners. The effects of PE upregulating MHCII, CD80, CD86, IL-12 on TADCs were blocked after SOCS1 silencing.

Conclusions: In this study, PE restored the impaired function of cervical TIDCs, thereby eliciting further antitumor CTL responses. The effects of PE on TADCs were mediated through inhibition of SOCS1 and activation of downstream JAK2-STAT1/STAT4/STAT5 pathways. PE may be a potent and effective immunomodulatory drug for antitumor treatment via the blockade of SOCS1 signaling in DCs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jep.2020.112837DOI Listing
March 2021

Exosomal DNA Aptamer Targeting α-Synuclein Aggregates Reduced Neuropathological Deficits in a Mouse Parkinson's Disease Model.

Mol Ther Nucleic Acids 2019 Sep 23;17:726-740. Epub 2019 Jul 23.

Department of Neurobiology, Beijing Key Laboratory of Neural Regeneration and Repair, Beijing Institute of Brain Disorders, Key Laboratory for Neurodegenerative Disease of the Ministry of Education, Capital Medical University, Beijing 100069, China. Electronic address:

The α-synuclein aggregates are the main component of Lewy bodies in Parkinson's disease (PD) brain, and they showed immunotherapy could be employed to alleviate α-synuclein aggregate pathology in PD. Recently we have generated DNA aptamers that specifically recognize α-synuclein. In this study, we further investigated the in vivo effect of these aptamers on the neuropathological deficits associated with PD. For efficient delivery of the aptamers into the mouse brain, we employed modified exosomes with the neuron-specific rabies viral glycoprotein (RVG) peptide on the membrane surface. We demonstrated that the aptamers were efficiently packaged into the RVG-exosomes and delivered into neurons in vitro and in vivo. Functionally, the aptamer-loaded RVG-exosomes significantly reduced the α-synuclein preformed fibril (PFF)-induced pathological aggregates, and rescued synaptic protein loss and neuronal death. Moreover, intraperitoneal administration of these exosomes into the mice with intra-striatally injected α-synuclein PFF reduced the pathological α-synuclein aggregates and improved motor impairments. In conclusion, we demonstrated that the aptamers targeting α-synuclein aggregates could be effectively delivered into the mouse brain by the RVG-exosomes and reduce the neuropathological and behavioral deficits in the mouse PD model. This study highlights the therapeutic potential of the RVG-exosome delivery of aptamer to alleviate the brain α-synuclein pathology.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.omtn.2019.07.008DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6709346PMC
September 2019

A lipid-soluble extract of Pinellia pedatisecta Schott enhances antitumor T cell responses by restoring tumor-associated dendritic cell activation and maturation.

J Ethnopharmacol 2019 Sep 28;241:111980. Epub 2019 May 28.

Department of Integration of Western and Traditional Medicine, Obstetrics and Gynecology Hospital of Fudan University, Shanghai, 200090, China; Shanghai Key Laboratory of Female Reproductive Endocrine Related Diseases, Fudan University, Shanghai, 200011, China.

Ethnopharmacological Relevance: Pinellia pedatisecta Schott (PPS)is a traditional Chinese medicine functioning as reducing swelling and drying dampness. Pinellia pedatisecta Schott extract (PE) has been confirmed to suppress cervical tumor growth and modulate the antitumor CD4T helper immunity towards Th1.

Aims: To explore the roles of PE in modulating tumor-associated dendritic cell (TADC) activation and function.

Methods: For in vivo studies, HPVTC-1 mouse tumor models were conducted and treated with PE for 3 weeks (10 mg/kg/d or 20 mg/kg/day). The immune profiles of spleen, tumor-draining lymph nodes (TDLNs), tumor and serum were analyzed by flow cytometry and multiplexed bead-based immunoassay. For in vitro studies, TADCs were generated by tumor-conditioned medium and treated with PE solution. The maturation and function of TADCs were evaluated by flow cytometry, ELISA, mixed lymphocyte reaction (MLR) and cytotoxic T lymphocyte (CTL) assay. Furthermore, the effect of PE on SOCS1 pathway was examined by western blotting and real time PCR.

Results: PE upregulated the expression of major histocompatibility complex class II (MHCII) and costimulatory molecules CD80 and CD86 on TADCs and promoted IL-12 secretion from TADCs. In addition, PE-treated TADCs promoted the proliferation of CD4 and CD8 T cells and induced the differentiation of IFN-γCD4 and GZMBCD8 T cells. PE-treated TADCs also elicited a more powerful antigen-specific cytotoxic T lymphocyte (CTL) response. Furthermore, PE treatment in vivo enhanced the proliferation, activated the functional ability (increased Ki67, CD137, GZMB or IFN-γ, TNF-α expression) and reversed the exhaustion (impaired CD95 or PD-1 expression) of antitumor T cells. Mechanistically, PE inhibited SOCS1-restrained JAK2 activation in TADCs.

Conclusions: PE efficiently restored the immature status of TADCs and enhanced their function as antigen-presenting cells to further elicit antitumor Th1 and CTL responses, suggesting that PE may be a potential immunomodulatory drug for cancer treatment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jep.2019.111980DOI Listing
September 2019

The extracellular loop of the auxiliary β-subunit is involved in the regulation of BK channel mechanosensitivity.

Am J Physiol Cell Physiol 2018 10 20;315(4):C485-C493. Epub 2018 Jun 20.

Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University , Beijing , People's Republic of China.

The large conductance Ca-activated potassium (BK) channel is activated by stretch. The stress-regulated exon (STREX) in α-subunits is known to affect the mechanosensitivity of BK channels. However, in human colonic smooth muscle cells (HCoSMCs), we found that the α-subunits without STREX (ZERO-BK) and β-subunits could be detected yet the cells were mechanosensitive. Whether the β-subunit is involved in the regulation of BK mechanosensitivity is unclear. In the present study, ZERO-BK and β-subunits were individually expressed or coexpressed in HEK293 cells and cell-attached patch-clamp techniques were used to measure BK currents defining mechanosensitivity. Single-channel patch-clamp recordings from HEK293 cells cotransfected with ZERO-BK and β-subunits showed stretch sensitivity, but there was no mechanosensitivity in HEK293 cells transfected only with ZERO-BK. We also showed that expression of the β-subunit could increase mechanosensitivity of the STREX-type α-subunits (STREX-BK). To identify the domain in β-subunits responsible for affecting stretch sensitivity, we expressed β- Loop (chimeric β-subunits without the extracellular loop) or β- C Term (chimeric β-subunits without COOH terminus) with ZERO-BK in HEK293 cells. The data showed that deletion of the extracellular loop but not the COOH terminus of β-subunits virtually abolished the mechanosensitivity. These results suggest that the extracellular loop of the β-subunit is involved in the regulation of BK channel mechanosensitivity and that role is independent of STREX.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1152/ajpcell.00037.2018DOI Listing
October 2018

Immune modulation of a lipid-soluble extract of Pinellia pedatisecta Schott in the tumor microenvironment of an HPV tumor-burdened mouse model.

J Ethnopharmacol 2018 Oct 19;225:103-115. Epub 2018 May 19.

Department of Obstetrics and Gynecology of Shanghai Medical School, Fudan University, Shanghai 200032.

Ethnopharmacological Relevance: Pinellia pedatisecta Schott extract (PE), a traditional Chinese medicine, has been used to reduce swelling, dry dampness and suppress cervical tumors.

Aims: To evaluate the roles of PE in the regulation of anti-tumor effects and the cellular immune response in the tumor microenvironment.

Methods: The immune microenvironment of HPVTC-1 tumors was examined by immunohistochemistry, real-time PCR and flow cytometry.

Results: Our study demonstrated that PE in vitro could significantly increase the percentage of apoptosis and necrosis in HPVTC-1 cells and block the cell cycle phase. In vivo treatment with PE eradicated established subcutaneous HPVTC-1 tumors in wild-type C57BL/6 mice by infiltrating CD8 T cells and CD4 T cells and by directly suppressing tumor growth and resistance to avascular necrosis. The key factors in the canonical Wnt signaling pathway in the experimental group (PE+mDC+naive CD4T cells) were challenged, and the levels of beta-catenin, C-myc, cyclin D1 and PPAR1 were significantly enhanced at the 5 day. In particular, the subset proportion of Th1 cells (characterized by IFNγ production and the transcription factor Tbet) increased significantly, and both Th2 cells (characterized by IL-4 production and the transcription factor GATA3) and Th17 cells (characterized by IL-17 production and the transcription factor RoRγt) decreased profoundly.

Conclusions: These findings linked the anti-tumor properties of PE with the immune microenvironment to present a reliable basis for the future practical application of PE in cervical cancer as a novel and pharmacologically safe immunotherapy strategy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jep.2018.04.037DOI Listing
October 2018

Beclin-1 suppresses gastric cancer progression by promoting apoptosis and reducing cell migration.

Oncol Lett 2017 Dec 25;14(6):6857-6862. Epub 2017 Sep 25.

Department of Pathology, King Medical Diagnostics Center, Shanghai 201321, P.R. China.

To investigate Beclin-1 expression in gastric cancer and its clinical relevance, 60 samples were collected from patients with gastric carcinoma, which were subjected to immunohistochemical staining and analysis. Associations of Beclin-1 expression with the clinical parameters of the patients, including tumor size, histological differentiation and metastatic status, were examined by statistical analysis. The results demonstrated that Beclin-1 expression in gastric carcinoma tissue was significantly associated with the tumor, node, metastasis stage and tumor invasion status. Further experiments indicated that Beclin-1 overexpression promoted MKN-45 gastric cancer cell apoptosis and inhibited their migration. These data suggested that Beclin-1 was a suppressor of tumorigenesis in gastric cancer and a potential therapeutic target for patients with gastric cancer.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3892/ol.2017.7046DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5691380PMC
December 2017

Sitagliptin Attenuates Endothelial Dysfunction of Zucker Diabetic Fatty Rats: Implication of the Antiperoxynitrite and Autophagy.

J Cardiovasc Pharmacol Ther 2018 Jan 15;23(1):66-78. Epub 2017 Jun 15.

1 Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, China.

Although the contributions of sitagliptin to endothelial function in diabetes mellitus were previously reported, the potential mechanisms still remain undefined. Our research was intended to explore the underlying mechanisms of protective effects of sitagliptin treatment on endothelial dysfunction in Zucker diabetic fatty (ZDF) rats. Male lean nondiabetic Zucker rats were used as control and male obese ZDF rats were randomly divided into ZDF and ZDF + sitagliptin groups. The significant decrease in endothelium-dependent relaxation induced by acetylcholine was observed in mesenteric arteries and thoracic aorta rings of ZDF rats. The administration of sitagliptin restored the vascular function effectively. The morphology study showed severe endothelial injuries in thoracic aortas of ZDF rats, and sitagliptin treatment attenuated these changes. The increased malondialdehyde levels and decreased superoxide dismutase activities in serum of ZDF rats were reversed by sitagliptin treatment. Sitagliptin also increased the expression of endothelial nitric oxide synthase and microtubule-associated protein 1 light chain 3 (LC3) and decreased the expression of inducible nitric oxide synthase, 3-nitrotyrosine, and p62 in ZDF rats. After giving Fe (III) tetrakis (1-methyl-4-pyridyl) porphyrin pentachloride porphyrin pentachloride (FeTMPyP, a peroxynitrite [ONOO] scavenger) or sitagliptin to high-glucose (30 mmol/L, 48 hours) cultured human umbilical vein endothelial cells (HUVECs), the increased levels of Beclin-1 and lysosome-associated membrane protein type 2 were detected. Both FeTMPyP and sitagliptin also significantly increased the number of mRFP-GFP-LC3 dots per cell, suggesting that autophagic flux was increased in HUVECs. Our study indicated that sitagliptin treatment can improve the endothelium-dependent relaxation and attenuate the endothelial impairment of ZDF rats. The protective effects of sitagliptin are possibly related to antiperoxynitrite and promoting autophagy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/1074248417715001DOI Listing
January 2018

Synergistic cytotoxic effects of a combined treatment of a lipid-soluble extract and cisplatin on human cervical carcinoma .

Oncol Lett 2017 Jun 25;13(6):4748-4754. Epub 2017 Apr 25.

Department of Integration of Western and Traditional Medicine, Obstetrics and Gynecology Hospital, Fudan University, Shanghai 200011, P.R. China.

Herbal medicines are known to have numerous benefits, including lower toxicity and fewer side effects than traditional chemotherapeutic drugs. In traditional Chinese medicine, the rhizome of (PE) Schott has long been used to treat cancer, undiagnosed swelling and erythema toxicum. However, its medical benefits lack support from scientific evidence. A novel lipid-soluble extract from PE has been previously verified to enhance the cytotoxicity of cis-dichlorodiammineplatinum-II (CDDP) against human cervical cancer cells . The present study evaluated the synergistic cytotoxic effects of PE and CDDP against human cervical cancer. Combination therapy of PE with CDDP exhibited synergistic cytotoxicity towards CaSki cell growth in mouse xenograft tumors. PE exhibited a cytotoxic effect on tumor size and weight, although the inhibitory ratio of tumor weight was only 26.3% in the PE-treated group. However, when mice were co-treated with PE and CDDP, the inhibitory ratio was higher than that of mice treated with CDDP alone (50.8 vs. 68.4%, respectively). The potential synergistic mechanism was likely via inhibiting the signaling E6/p53 pathway, restoring p53 function and inducing downstream tumor suppressor chain effects on apoptosis. Western blot analysis and immunohistochemistry indicated thatE6protein expression was significantly decreased upon treatment with combined PE and CDDP. The expression of p53 was increased in the combined PE and CDDP treatment group. Upregulation of p53-dependent apoptosis-associated proteins, including Bcl-2-associated X protein and cleaved caspases-9 and -3, was observed in the combined PE and CDDP treatment group. Our results present a molecular basis for the future application of the combination of PE and CDDP in the treatment of cervical cancer as a novel and pharmacologically safe chemotherapeutic strategy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3892/ol.2017.6091DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5452894PMC
June 2017

Synergistic effects of a novel lipid-soluble extract from Schott and cisplatin on human cervical carcinoma cell lines through the regulation of DNA damage response signaling pathway.

Oncol Lett 2017 Apr 14;13(4):2121-2128. Epub 2017 Feb 14.

Department of Integration of Western and Traditional Medicine, Obstetrics and Gynecology Hospital, Fudan University, Shanghai 200011, P.R. China.

Herbal medicines have been recognized as an attractive approach for cancer therapy with minimal side effects. The present study investigated the type of interaction between a novel lipid-soluble extract from Schott (PE) and cisplatin (CDDP) on human cervical cancer SiHa and CaSki cell lines . The mechanism of this combination was studied using cell proliferation, invasion and apoptosis assays, and by analyzing cell cycle distribution and protein expression, with a focus on DNA damage response (DDR) activation. Equipotent combinations of PE and CDDP were determined by isobologram analysis, in order to evaluate potential synergy. The combination index for SiHa cells was 0.43, and the index for CaSki cells was 0.68, indicating synergy. Treatment with PE and CDDP combined resulted in a significantly greater inhibition of invasion in the two cells, compared with either drug alone (SiHa, P<0.01; CaSki, P<0.001). This co-treatment induced significantly more apoptosis in the two cell lines, and arrested cells at the G0/G1 phase and G2/M phase in SiHa and CaSki, respectively, with a significant decrease (P<0.01) in S phase cells in the two cell lines. Combined PE and CDDP targeting synergistically enhanced the expression of markers of DDR (phosphorylation of ataxia-telangiectasia mutated, checkpoint kinase (Chk)-1, Chk-2, and γ-H2A histone family member X) in cells. These results suggest that PE and cisplatin act synergistically in cervical cancer cells with high DDR activation. The approach presented in the present study may have important implications for the pharmacological mechanism of Schott and cervical cancer therapeutic strategies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3892/ol.2017.5738DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5403266PMC
April 2017

Orthostatic Hypotension Predicts Cognitive Impairment in the Elderly: Findings from a Cohort Study.

Front Neurol 2017 3;8:121. Epub 2017 Apr 3.

Department of Neurology, North Sichuan Branch of Shanghai No.1 People's Hospital, Shanghai, China.

Background: Orthostatic hypotension (OH) is a known risk factor for cerebral ischemia, but its correlation with cognitive impairment (CI) is not well established.

Objective: The aim of this study is to explore the relationship between OH and CI in the elderly.

Methods: The study group consisted of 44 OH patients who presented with drowsiness, vertigo, and fatigue between January 2009 and December 2011 (OH group). Eighty-eight healthy elderly were paired with those in the OH group in a 1:2 based on their education levels (NOH group). Baseline sociodemographic information and cognition-related measures were collected for both groups. Cognitive function was assessed 4 years later using MMSE.

Results: The overall incidence of CI was 14.0% among the 114 subjects who completed the follow-up assessment. There was a significant difference in the incidence of CI between the OH group (23.7%) and the NOH group (9.2%) (χ = 4.399,  = 0.036). After excluding the influence of age (OR = 1.199, 95% CI: 1.072-1.340,  = 0.001) and education years (OR = 0.568, 95% CI: 0.371-0.869,  = 0.009), OH (OR = 4.047, 95% CI: 1.144-14.313,  = 0.030) became an independent risk factor for CI.

Conclusion: OH can lead to CI. We suggest that future studies, with a larger sample size, use OH exposure time instead of OH exposure population to verify the conclusion of this study.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fneur.2017.00121DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5377264PMC
April 2017

Antiperoxynitrite Treatment Ameliorates Vasorelaxation of Resistance Arteries in Aging Rats: Involvement With Protection of Circulating Endothelial Progenitor Cells.

J Cardiovasc Pharmacol 2016 Nov;68(5):334-341

*Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, China; and †Beijing Key Laboratory of Metabolic Disorders Related Cardiovascular Diseases, Capital Medical University, Beijing, China.

Numerous studies have found that the age-associated structural and functional alterations in arteries were characterized by increased endothelial dysfunction. In this study, young (3 months), adult (9 months), and aging (20 months) male Sprague-Dawley rats were randomly divided into 6 groups, including control groups and FeTMPyP (peroxynitrite scavenger) groups receiving saline and FeTMPyP, respectively, for 5 administrations once every 3 days through intraperitoneal injection. The aged-related proteins beta-galactosidase, p53, and p16 as well as the nitrotyrosine and endothelial marker endothelial nitric oxide synthase and von Willebrand factor (vWF) in vascular tissues were measured by immunohistochemistry. Endothelium-dependent vasorelaxation and endothelium-independent vasorelaxation of rat thoracic aortas and mesenteric arteries were measured by acetylcholine and sodium nitroprusside, respectively. The amount of circulating endothelial progenitor cells (EPCs) was determined by flow cytometry. The endothelium-dependent/independent relaxation in mesenteric arteries and the amount of circulating EPCs (CD31/CD34) in peripheral blood of aging rats were reduced significantly compared with young and adult rats. Immunohistochemistry results showed that the nitrotyrosine levels and morphological damage in mesenteric arteries were increased significantly in aging rats. Adoption of peroxynitrite scavenger FeTMPyP intervention may not only improve the endothelium-dependent relaxation and the amount of circulating EPCs in aging rats but also reverse endothelial injury. In conclusion, this study demonstrates that enhanced nitrative stress may aggravate the endothelial injury and vascular dysfunction of resistance arteries in aging rats. Antiperoxynitrite treatment can ameliorate the vasorelaxation and may be involved with the protection of circulating EPCs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/FJC.0000000000000420DOI Listing
November 2016

Advanced Glycation End Products Impair Voltage-Gated K+ Channels-Mediated Coronary Vasodilation in Diabetic Rats.

PLoS One 2015 12;10(11):e0142865. Epub 2015 Nov 12.

Department of Cardiology, Beijing Friendship Hospital, Capital Medical University, Beijing, PR China.

Background: We have previously reported that high glucose impairs coronary vasodilation by reducing voltage-gated K+ (Kv) channel activity. However, the underlying mechanisms remain unknown. Advanced glycation end products (AGEs) are potent factors that contribute to the development of diabetic vasculopathy. The aim of this study was to investigate the role of AGEs in high glucose-induced impairment of Kv channels-mediated coronary vasodilation.

Methods: Patch-clamp recording and molecular biological techniques were used to assess the function and expression of Kv channels. Vasodilation of isolated rat small coronary arteries was measured using a pressurized myograph. Treatment of isolated coronary vascular smooth muscle cells (VSMCs) and streptozotocin-induced diabetic rats with aminoguanidine, the chemical inhibitor of AGEs formation, was performed to determine the contribution of AGEs.

Results: Incubation of VSMCs with high glucose reduced Kv current density by 60.4 ± 4.8%, and decreased expression of Kv1.2 and Kv1.5 both at the gene and protein level, whereas inhibiting AGEs formation or blocking AGEs interacting with their receptors prevented high glucose-induced impairment of Kv channels. In addition, diabetic rats manifested reduced Kv channels-mediated coronary dilation (9.3 ± 1.4% vs. 36.9 ± 1.4%, P < 0.05), which was partly corrected by the treatment with aminoguanidine (24.4 ± 2.2% vs. 9.3 ± 1.4%, P < 0.05).

Conclusions: Excessive formation of AGEs impairs Kv channels in VSMCs, then leading to attenuation of Kv channels-mediated coronary vasodilation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0142865PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4642979PMC
July 2016

An Enhanced Differential Evolution with Elite Chaotic Local Search.

Comput Intell Neurosci 2015 24;2015:583759. Epub 2015 Aug 24.

State Key Laboratory of Software Engineering, Wuhan University, Wuhan 430072, China.

Differential evolution (DE) is a simple yet efficient evolutionary algorithm for real-world engineering problems. However, its search ability should be further enhanced to obtain better solutions when DE is applied to solve complex optimization problems. This paper presents an enhanced differential evolution with elite chaotic local search (DEECL). In DEECL, it utilizes a chaotic search strategy based on the heuristic information from the elite individuals to promote the exploitation power. Moreover, DEECL employs a simple and effective parameter adaptation mechanism to enhance the robustness. Experiments are conducted on a set of classical test functions. The experimental results show that DEECL is very competitive on the majority of the test functions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1155/2015/583759DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4561320PMC
June 2016

Impact of early enteral nutrition on short term prognosis after acute stroke.

J Clin Neurosci 2015 Sep 14;22(9):1473-6. Epub 2015 Jul 14.

Department of Neurology, Branch of the People's First Hospital, 1878 North Sichuan Road, Hongkou District, Shanghai 200081, China. Electronic address:

We hypothesized that early enteral nutritional support would improve the short term prognosis of acute stroke patients with dysphagia, demonstrated by lower malnutrition rates, lower complication rates, and lower National Institutes of Health Stroke Scale (NIHSS) scores at 90 days post stroke. Nutrition support is an essential element in the care of stroke patients and many studies have investigated the effect of specific nutritional elements on stroke patients. However, few studies have looked at the impact of complete enteral nutrition on Chinese patients with acute stroke. To investigate this, we conducted a randomized controlled trial of 146 patients with acute stroke and dysphagia, among whom 75 were supported with nasogastric nutrition and 71 received family managed nutrition after randomization. Nutritional status, nosocomial infection and mortality rates were recorded on day 21 of hospitalization. Neurological deficits were evaluated by the NIHSS activities of daily living Barthel index (ADLBI) and the modified Rankin scale (mRS) and compared between the two groups. We found that the nasogastric nutrition group had a better nutritional status and reduced nosocomial infection and mortality rates after 21 days compared with patients in the family managed nutrition group. In addition, the nasogastric nutrition group showed a lower score on the NIHSS than the control group. However, the differences in the scores of the ADLBI and the 90 day mRS between the groups were not significant. Taken together, the present study shows that early enteral nutrition support improves the short term prognosis of acute stroke patients with dysphagia.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jocn.2015.03.028DOI Listing
September 2015

Age-related difference in relationships between cognitive processing speed and general cognitive status.

Appl Neuropsychol Adult 2015 13;22(2):94-9. Epub 2014 Jun 13.

a Laboratory of Neuropsychology, Laboratory of Cognitive Affective Neuroscience, and Institute of Clinical Neuropsychology , The University of Hong Kong , Hong Kong.

General cognitive status (GCS) is a composite of cognitive abilities reflecting full function. The literature suggests a relationship between cognitive processing speed and GCS, as well as age-related changes of processing speed on cognitive performance. Therefore, this study recruited 34 younger and 39 older adults to verify age-related differences in relationships between cognitive processing speed and GCS. We measured cognitive processing speed with the Processing Speed Index of the Wechsler Adult Intelligence Scale. Findings indicated that cognitive processing speed predicted GCS in older but not younger adults. Future research may be needed to verify the training effect of processing speed on GCS. This study also further examined cognitive factors related to processing speed in aging and the relationships between cognitive processing speed and verbal fluency, cognitive inhibition, and divided attention. A stepwise regression analysis indicated that only verbal fluency contributed significantly to cognitive processing speed in older adults, accounting for 21% of the variance. These observations suggest that age-related changes of prefrontal regions may not fully explain age-related decline in cognitive processing speed.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/23279095.2013.860602DOI Listing
December 2015

β1-Adrenoceptor autoantibodies affect action potential duration and delayed rectifier potassium currents in guinea pigs.

Cardiovasc Toxicol 2015 Jan;15(1):1-9

Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China.

β1-Adrenoceptor autoantibodies (β1-AAs) affect the action potential duration (APD) in cardiomyocytes and are related to ventricular arrhythmias. The delayed rectifier potassium current (I K) plays a crucial role in APD, but the effects of β1-AAs on I K have not been completely illuminated. This work aimed to observe the effects of β1-AAs on I K and APD and further explore the mechanisms of β1-AA-mediated ventricular arrhythmias. β1-AAs were obtained from sera of patients with coronary heart disease (CHD) and nonsustained ventricular tachycardia. With whole-cell patch clamp technique, action potentials and I K were recorded. The results illustrated 0.1 μmol/L β1-AAs shortened APD at 50 % (APD50) and 90 % (APD90) of the repolarization. However, at 0.01 μmol/L, β1-AAs had no effects on either APD90 or APD50 (P > 0.05). At 0.001 μmol/L, β1-AAs significantly prolonged APD90 and APD50. Moreover, β1-AAs (0.001, 0.01, 0.1 μmol/L) dose-dependently increased the rapidly activating delayed rectifier potassium current (I Kr), but similarly decreased the slowly activating delayed rectifier potassium current (I Ks) and increased L-type calcium currents at the different concentrations. Taken together, the IKr increase induced by high β1-AA concentrations is responsible for a significant APD reduction which would contribute to repolarization changes and trigger the malignant ventricular arrhythmias in CHD patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s12012-014-9261-3DOI Listing
January 2015

Expression and localization of TRPC proteins in rat ventricular myocytes at various developmental stages.

Cell Tissue Res 2014 Jan 22;355(1):201-12. Epub 2013 Oct 22.

Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, 100069, Beijing, People's Republic of China.

Growing evidence indicates that transient receptor potential canonical (TRPC) channels play important roles in various Ca(2+)-mediated physiological and pathophysiological processes, including development. Many types of TRPC proteins are expressed in the heart. However, limited data are available comparing the expression and localization among TRPC proteins in the ventricular myocyte at various developmental stages. Our purpose is to investigate the expression and localization profile of TRPC proteins in ventricular myocytes of fetal (18.5 days), neonatal (< 24 h after birth) and adult (8 week old) rats. Western blotting, immunofluorescence and confocal laser scanning microscopy were employed. TRPC1/3-6 proteins were expressed in the rat ventricle throughout the three developmental stages. The expression profile of TRPC1/3/4 in the ventricle followed an upward trend from the fetus to the adult. By contrast, TRPC6 in the ventricle was expressed at the highest level in the fetal group and was sharply down-regulated immediately after birth. TRPC5 expression in the ventricle did not change significantly during the three stages. TRPC1/3/5/6 proteins were localized to the T-tubule and TRPC1/3/4/6 to intercalated disks in adult myocytes. The wide spatiotemporal overlap and dynamic regulation of TRPC expression in ventricular myocytes indicates potential complex combinations and redundancy of native TRPC proteins in the heart and gives important clues for further investigations into the exact subunit compositions and functional properties of native TRPC channels in the heart.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00441-013-1733-4DOI Listing
January 2014

Caveolae regulation of mechanosensitive channel function in myotubes.

PLoS One 2013 30;8(8):e72894. Epub 2013 Aug 30.

Capital Medical University, Department of Physiology, Beijing, China.

Mutations that lead to muscular dystrophy often create deficiencies in cytoskeletal support of the muscle sarcolemma causing hyperactive mechanosensitive cation channel (MSC) activity and elevated intracellular Ca(2+). Caveolae are cholesterol-rich microdomains that form mechanically deformable invaginations of the sarcolemma. Mutations to caveolin-3, the main scaffolding protein of caveolae in muscle, cause Limbe-Girdle muscular dystrophy. Using genetic and acute chemical perturbations of developing myotubes we investigated whether caveolae are functionally linked to MSCs. MSC sensitivity was assayed using suction application to patches and probe-induced indentation during whole-cell recordings. Membrane mechanical stress in patches was monitored using patch capacitance/impedance. Cholesterol depletion disrupted caveolae and caused a large increase in MSC current. It also decreased the membrane mechanical relaxation time, likely reflecting cytoskeleton dissociation from the bilayer. Reduction of Cav3 expression with miRNA also increased MSC current and decreased patch relaxation time. In contrast Cav3 overexpression produced a small decrease in MSC currents. To acutely and specifically inhibit Cav3 interactions, we made a chimeric peptide containing the antennapedia membrane translocation domain and the Cav3 scaffolding domain (A-CSD3). A-CSD3 action was time dependent initially producing a mild Ca(2+) leak and increased MSC current, while longer exposures decreased MSC currents coinciding with increased patch stiffening. Images of GFP labeled Cav3 in patches showed that Cav3 doesn't enter the pipette, showing patch composition differed from the cell surface. However, disruption via cholesterol depletion caused Cav3 to become uniformly distributed over the sarcolemma and Cav3 appearance in the patch dome. The whole-cell indentation currents elicited under the different caveolae modifying conditions mirror the patch response supporting the role of caveolae in MSC function. These studies show that normal expression levels of Cav3 are mechanoprotective to the sarcolemma through multiple mechanisms, and Cav3 upregulation observed in some dystrophies may compensate for other mechanical deficiencies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0072894PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3758351PMC
April 2014

Mechanical effects on KATP channel gating in rat ventricular myocytes.

PLoS One 2013 14;8(5):e63337. Epub 2013 May 14.

Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, China.

Cardiac KATP channels link metabolism with electrical activity. They are implicated in arrhythmias, secretion of atrial natriuretic peptide and protection of the heart from hypertrophy and failure. These processes may involve mechanosensitivity. KATP channels can be activated by mechanical stimulation and disrupting the cortical actin increases the activity. We propose that KATP channels are modulated by local bilayer tension and this tension is affected by cortical F-actin. Here we measured KATP background activity and stretch sensitivity with inside-out patches of rat ventricular myocytes before and after disrupting F-actin. Disrupting F-actin potentiated background activity but did not influence the slope sensitivity in the semilog relationship of NPo vs. suction that is a measure of the change in dimensions between closed and open states. Thus actin alters prestress on the channel probably by parallel elastic sharing of mean cortical tension with the bilayer.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0063337PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3653899PMC
December 2013
-->