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1.
BMC Nephrol ; 24(1): 280, 2023 09 22.
Article in English | MEDLINE | ID: mdl-37740193

ABSTRACT

Rituximab (RTX) and cyclophosphamide (CYC) based treatments are both recommended as first-line therapies in idiopathic membranous nephropathy (IMN) by KDIGO 2021 guideline. However, the efficacy of RTX vs. CYC-based treatments in IMN is still controversial. We performed this systemic review and meta-analysis registered in PROSPERO (CRD 42,022,355,717) by pooling data from randomized controlled trials or cohort studies in IMN patients using the EMBASE, PubMed, and Cochrane libraries (till Orc 1, 2022). The primary outcomes were the complete remission (CR) rate + partial remission (PR) rate. CR rate, immunologic response rate, relapse rate, and the risk of serious adverse events (SAE) were secondary outcomes. Eight studies involving 600 adult patients with IMN were included with a median follow-up duration of 12 to 60 months. RTX induced a similar overall remission rate compared with CYC (RR 0.88, 95% CI: 0.71, 1.09, P = 0.23). At the follow-up time of 6 months, RTX was associated with a lower CR + PR rate compared with CYC (RR 0.67, 95% CI: 0.52, 0.88, P = 0.003). Moreover, RTX might be less effective in inducing CR + PR than CYC treatment in IMN patients with high antiPLA2R antibody levels (RR 0.67, 95% CI: 0.48, 0.94, P = 0.02). The occurrences of CRs, relapse rates, immunologic response rates, and SAE were not significantly different between RTX and CYC, respectively. In conclusion, although the long-term efficacy and safety of CYC compared to RTX were comparable, CYC might respond faster and be more advantageous in IMN patients with high antiPLA2R antibody titers.


Subject(s)
Glomerulonephritis, Membranous , Adult , Humans , Glomerulonephritis, Membranous/drug therapy , Rituximab/therapeutic use , Cyclophosphamide/therapeutic use , Patients
2.
Kidney Blood Press Res ; 46(3): 377-386, 2021.
Article in English | MEDLINE | ID: mdl-34044409

ABSTRACT

INTRODUCTION: Cardiovascular disease is the most common cause of morbidity and mortality in patients with ESRD. In addition to phosphate overload, oxalate, a common uremic toxin, is also involved in vascular calcification in patients with ESRD. The present study investigated the role and mechanism of hyperoxalemia in vascular calcification in mice with uremia. METHODS: A uremic atherosclerosis (UA) model was established by left renal excision and right renal electrocoagulation in apoE-/- mice to investigate the relationship between oxalate loading and vascular calcification. After 12 weeks, serum and vascular levels of oxalate, vascular calcification, inflammatory factors (TNF-α and IL-6), oxidative stress markers (malondialdehyde [MDA], and advanced oxidation protein products [AOPP]) were assessed in UA mice. The oral oxalate-degrading microbe Oxalobacter formigenes (O. formigenes) was used to evaluate the effect of a reduction in oxalate levels on vascular calcification. The mechanism underlying the effect of oxalate loading on vascular calcification was assessed in cultured human aortic endothelial cells (HAECs) and human aortic smooth muscle cells (HASMCs). RESULTS: Serum oxalate levels were significantly increased in UA mice. Compared to the control mice, UA mice developed more areas of aortic calcification and showed significant increases in aortic oxalate levels and serum levels of oxidative stress markers and inflammatory factors. The correlation analysis showed that serum oxalate levels were positively correlated with the vascular oxalate levels and serum MDA, AOPP, and TNF-α levels, and negatively correlated with superoxide dismutase activity. The O. formigenes intervention decreased serum and vascular oxalate levels, while did not improve vascular calcification significantly. In addition, systemic inflammation and oxidative stress were also improved in the O. formigenes group. In vitro, high concentrations of oxalate dose-dependently increased oxidative stress and inflammatory factor expression in HAECs, but not in HASMCs. CONCLUSIONS: Our results indicated that hyperoxalemia led to the systemic inflammation and the activation of oxidative stress. The reduction in oxalate levels by O. formigenes might be a promising treatment for the prevention of oxalate deposition in calcified areas of patients with ESRD.


Subject(s)
Endothelial Cells/pathology , Oxalates/metabolism , Oxidative Stress , Renal Insufficiency, Chronic/pathology , Animals , Atherosclerosis/metabolism , Atherosclerosis/pathology , Cell Line , Disease Models, Animal , Endothelial Cells/metabolism , Humans , Male , Mice , Renal Insufficiency, Chronic/metabolism , Uremia/metabolism , Uremia/pathology , Vascular Calcification/metabolism , Vascular Calcification/pathology
3.
Kidney Blood Press Res ; 44(4): 533-552, 2019.
Article in English | MEDLINE | ID: mdl-31330507

ABSTRACT

BACKGROUND/AIMS: Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic form of kidney disease. High-throughput microarray analysis has been applied for elucidating key genes and pathways associated with ADPKD. Most genetic profiling data from ADPKD patients have been uploaded to public databases but not thoroughly analyzed. This study integrated 2 human microarray profile datasets to elucidate the potential pathways and protein-protein interactions (PPIs) involved in ADPKD via bioinformatics analysis in order to identify possible therapeutic targets. METHODS: The kidney tissue microarray data of ADPKD patients and normal individuals were searched and obtained from NCBI Gene Expression Omnibus. Differentially expressed genes (DEGs) were identified, and enriched pathways and central node genes were elucidated using related websites and software according to bioinformatics analysis protocols. Seven DEGs were validated between polycystic kidney disease and control kidney samples by quantitative real-time polymerase chain reaction. RESULTS: Two original human microarray datasets, GSE7869 and GSE35831, were integrated and thoroughly analyzed. In total, 6,422 and 1,152 DEGs were extracted from GSE7869 and GSE35831, respectively, and of these, 561 DEGs were consistent between the databases (291 upregulated genes and 270 downregulated genes). From 421 nodes, 34 central node genes were obtained from a PPI network complex of DEGs. Two significant modules were selected from the PPI network complex by using Cytotype MCODE. Most of the identified genes are involved in protein binding, extracellular region or space, platelet degranulation, mitochondrion, and metabolic pathways. CONCLUSIONS: The DEGs and related enriched pathways in ADPKD identified through this integrated bioinformatics analysis provide insights into the molecular mechanisms of ADPKD and potential therapeutic strategies. Specifically, abnormal decorin expression in different stages of ADPKD may represent a new therapeutic target in ADPKD, and regulation of metabolism and mitochondrial function in ADPKD may become a focus of future research.


Subject(s)
Computational Biology/methods , Polycystic Kidney, Autosomal Dominant/genetics , Animals , Case-Control Studies , Datasets as Topic , Decorin/genetics , Gene Expression Profiling , Gene Expression Regulation , Humans , Metabolic Networks and Pathways , Mice , Microarray Analysis , Polycystic Kidney, Autosomal Dominant/metabolism , Zebrafish
4.
J Am Soc Nephrol ; 29(9): 2310-2325, 2018 09.
Article in English | MEDLINE | ID: mdl-30042193

ABSTRACT

BACKGROUND: Autosomal-dominant polycystic kidney disease (ADPKD) is the leading inherited renal disease worldwide. The proproliferative function of macrophages is associated with late-stage cyst enlargement in mice with PKD; however, the way in which macrophages act on cyst-lining epithelial cells (CLECs) has not been well elucidated. METHODS: We generated a rapid-onset PKD mouse model by inactivating Pkd1 on postnatal day 10 (P10) and compared cell proliferation and differential gene expression in kidney tissues of the PKD mice and wild-type (WT) littermates. RESULTS: The cystic phenotype was dominant from P18. A distinct peak in cell proliferation in polycystic kidneys during P22-P30 was closely related to late-stage cyst growth. Comparisons of gene expression profiles in kidney tissues at P22 and P30 in PKD and WT mice revealed that arginine metabolism was significantly activated; 204 differentially expressed genes (DEGs), including Arg1, an arginine metabolism-associated gene, were identified in late-stage polycystic kidneys. The Arg1-encoded protein, arginase-1 (ARG1), was predominantly expressed in macrophages in a time-dependent manner. Multiple-stage macrophage depletion verified that macrophages expressing high ARG1 levels accounted for late-stage cyst enlargement, and inhibiting ARG1 activity significantly retarded cyst growth and effectively lowered the proliferative indices in polycystic kidneys. In vitro experiments revealed that macrophages stimulated CLEC proliferation, and that L-lactic acid, primarily generated by CLECs, significantly upregulated ARG1 expression and increased polyamine synthesis in macrophages. CONCLUSIONS: Interactions between macrophages and CLECs promote cyst growth. ARG1 is a key molecule involved in this process and is a potential therapeutic target to help delay ADPKD progression.


Subject(s)
Cell Communication/genetics , Epithelial Cells/metabolism , Macrophages/metabolism , Polycystic Kidney, Autosomal Dominant/genetics , Protein Kinase C/genetics , Animals , Blotting, Western , Cell Proliferation/genetics , Cells, Cultured , Disease Models, Animal , Disease Progression , Mice , Mice, Inbred C57BL , Mice, Transgenic , Microscopy, Confocal/methods , Phenotype , Polycystic Kidney, Autosomal Dominant/physiopathology , Protein Kinase C/deficiency , Random Allocation , Real-Time Polymerase Chain Reaction/methods , Reference Values , Sensitivity and Specificity
5.
Mol Cell Biochem ; 449(1-2): 219-226, 2018 Dec.
Article in English | MEDLINE | ID: mdl-29675630

ABSTRACT

Autosomal dominant polycystic kidney disease (ADPKD) is a common heritable human disease. Recently, the role of repressed autophagy in ADPKD has drawn increasing attention. Here, we investigate the mechanism underlying the effect of Saikosaponin-d (SSd), a sarcoplasmic/endoplasmic reticulum Ca2+ ATPase pump (SERCA) inhibitor. We show that SSd suppresses proliferation in ADPKD cells by up-regulating autophagy. We found that treatment with SSd results in the accumulation of intracellular calcium, which in turn activates the CaMKKß-AMPK signalling cascade, inhibits mTOR signalling and induces autophagy. Conversely, we also found that treatment with an autophagy inhibitor (3-methyladenine), AMPK inhibitor (Compound C), CaMKKß inhibitor (STO-609) and intracellular calcium chelator (BAPTA/AM) could reduce autophagy puncta formation mediated by SSd. Our results demonstrated that SSd induces autophagy through the CaMKKß-AMPK-mTOR signalling pathway in ADPKD cells, indicating that SSd might be a potential therapy for ADPKD and that SERCA might be a new target for ADPKD treatment.


Subject(s)
AMP-Activated Protein Kinases/biosynthesis , Autophagy/drug effects , Calcium-Calmodulin-Dependent Protein Kinase Kinase/biosynthesis , Cell Proliferation/drug effects , Gene Expression Regulation, Enzymologic/drug effects , Oleanolic Acid/analogs & derivatives , Saponins/pharmacokinetics , Signal Transduction/drug effects , TOR Serine-Threonine Kinases/biosynthesis , AMP-Activated Protein Kinases/genetics , Calcium-Calmodulin-Dependent Protein Kinase Kinase/genetics , Cell Line, Transformed , Humans , Oleanolic Acid/pharmacokinetics , Polycystic Kidney, Autosomal Dominant/drug therapy , Polycystic Kidney, Autosomal Dominant/genetics , Polycystic Kidney, Autosomal Dominant/metabolism , Polycystic Kidney, Autosomal Dominant/pathology , Signal Transduction/genetics , TOR Serine-Threonine Kinases/genetics
6.
Kidney Blood Press Res ; 41(6): 848-864, 2016.
Article in English | MEDLINE | ID: mdl-27871084

ABSTRACT

BACKGROUND/AIMS: Blockage of the renin-angiotensin II system (RAS) prevents or delays albuminuria in diabetic patients. The aim of this study was to investigate the inhibitory mechanism of the angiotensin receptor blocker olmesartan on albuminuria in a murine model of diabetic nephropathy. METHODS: Male db/db diabetic mice were fed with placebo or 20 mg/kg olmesartan by daily gavage for 12 weeks. Conditionally immortalized mouse podocytes were treated with glucose, angiotensin II, olmesartan or p38 inhibitor s8307 in different experimental conditions after differentiation. RESULTS: Olmesartan reduced albuminuria in db/db mice without change in body weight and glycemia. The increase of apoptotic cells and decrease of podocytes in the diabetic glomerulus were prevented by olmesartan. Moreover, olmesartan restored silent mating type information regulation 1 (SIRT1) expression in diabetic glomeruli. Furthermore, olmesartan treatment suppressed p38 phosphorylation but did not restore adenosine 5'-monophosphate-activated protein kinase (AMPK) phosphorylation in the diabetic glomerulus. In vitro study revealed that olmesartan prevented angiotensin II/p38/SIRT1 induced podocyte apoptosis, but it only slightly prevented high glucose/AMPK/SIRT1 induced podocyte apoptosis. In addition, the p38 inhibitor s8307 reversed SIRT1 expression and angiotensin II induced podocyte apoptosis. CONCLUSIONS: Olmesartan reduced albuminuria in diabetic nephropathy through inhibiting angiotensin II/p38/SIRT1 triggered podocyte apoptosis.


Subject(s)
Albuminuria/prevention & control , Apoptosis/drug effects , Diabetic Nephropathies/drug therapy , Imidazoles/pharmacology , Podocytes/pathology , Tetrazoles/pharmacology , Albuminuria/drug therapy , Angiotensin II/drug effects , Animals , Cell Line , Disease Models, Animal , Male , Mice , Mice, Inbred Strains , Sirtuin 1/drug effects , p38 Mitogen-Activated Protein Kinases/drug effects
7.
Eur Heart J ; 34(30): 2412-20, 2013 Aug.
Article in English | MEDLINE | ID: mdl-21849351

ABSTRACT

AIMS: Angiogenesis is critical for re-establishing blood supply to ischaemic myocardium after myocardial infarction (MI). Human studies have associated arterial baroreflex (ABR) deficiency with higher rate of sudden death after MI. The present work was designed to examine whether ABR deficiency affects angiogenesis in MI rats. METHODS AND RESULTS: Baroreflex sensitivity (BRS) was determined in conscious rats at 1 month after occlusion of the left anterior descending coronary artery. The survival time was significantly shorter in Sprague-Dawley rats with BRS <0.60 ms/mmHg vs. those with BRS ≥0.60 ms/mmHg. Sinoaortic denervation destroyed ABR, and decreased capillary density, regional blood flow and vascular endothelial growth factor (VEGF) concentration after MI. Ketanserin (0.6 mg/kg/day) enhanced BRS, and increased capillary density, regional blood flow, and VEGF. Sinoaortic denervation also reduced the expression of vesicular acetylcholine (ACh) transporter and α7-nicotinic ACh receptor (α7-nAChR). Angiogenesis after MI was significantly attenuated in α7-nAChR knockout mice. In contrast, increase in endogenous ACh with cholinesterase inhibitor pyridostigmine (30 mg/kg/day) increased angiogenesis after MI. In cultured cardiac microvascular endothelial cells, ACh stimulated the expression of VEGF, phosphorylation of VEGF receptor 2, and tube formation in a manner dependent upon α7-nAChR. CONCLUSION: Our results demonstrated that ABR deficiency could attenuate angiogenesis in ischaemic myocardium. These findings provide further mechanistic basis for enhancing baroreflex function in the treatment of MI.


Subject(s)
Acetylcholine/physiology , Baroreflex/physiology , Myocardial Infarction/physiopathology , Neovascularization, Physiologic/physiology , alpha7 Nicotinic Acetylcholine Receptor/physiology , Acetylcholine/pharmacology , Angiogenesis Inducing Agents/pharmacology , Animals , Blood Pressure/physiology , Capillaries/physiology , Cholinergic Agonists/pharmacology , Cholinesterase Inhibitors/pharmacology , Coronary Vessels/physiology , Denervation/methods , Ketanserin/pharmacology , Mice , Mice, Knockout , Pyridostigmine Bromide/pharmacology , Rats , Rats, Sprague-Dawley , alpha7 Nicotinic Acetylcholine Receptor/metabolism
8.
Inflammation ; 46(4): 1272-1289, 2023 Aug.
Article in English | MEDLINE | ID: mdl-36997763

ABSTRACT

Adult autosomal dominant polycystic kidney disease (ADPKD) has been shown to be related as a "third hit" to the occurrence of acute or chronic kidney injury. Here, we examined whether dehydration, as a common kidney risk factor, could cause cystogenesis in chronic-onset Pkd1-/- mice by regulating macrophage activation. First, we confirmed that dehydration accelerated cytogenesis in Pkd1-/- mice and that macrophages infiltrated the kidney tissues even earlier than macroscopic cyst formation. Then, microarray analysis suggested that glycolysis pathway may be involved in macrophage activation in Pkd1-/- kidneys under conditions of dehydration. Further, we confirmed glycolysis pathway was activated and lactic acid (L-LA) was overproduced in the Pkd1-/- kidney under conditions of dehydration. We have already proved that L-LA strongly stimulated M2 macrophage polarization and overproduction of polyamine in macrophage in vitro, and in the present study, we further discovered that M2 polarization-induced polyamine production shortened the primary cilia length by disrupting the PC1/PC2 complex. Finally, the activation of L-LA-arginase 1-polyamine pathway contributed to cystogenesis and progressive cyst growth in Pkd1-/- mice recurrently exposed to dehydration.


Subject(s)
Cysts , Macrophage Activation , Polycystic Kidney Diseases , Animals , Mice , Cysts/metabolism , Dehydration/metabolism , Disease Models, Animal , Kidney/pathology , Macrophages , Polycystic Kidney Diseases/pathology
9.
J Infect Dis ; 204(10): 1605-12, 2011 Nov 15.
Article in English | MEDLINE | ID: mdl-21917879

ABSTRACT

BACKGROUND: Ketanserin, a 5-hydroxytryptamine receptor antagonist, is clinically used as an antihypertensive agent and could enhance baroreflex function. The present work tested the hypothesis that restoration of baroreflex function is an effective treatment for lipopolysaccharide (LPS)-induced shock. METHODS: Kunming mice were injected with LPS (30 mg/kg; intraperitoneal) to induce endotoxic shock. Ketanserin (0.3, 1, 3, or 10 mg/kg; intraperitoneal) was administered immediately after LPS injection. Survival time was monitored, and serum cytokines were analyzed after the onset of LPS. Effects of ketanserin were also examined in IL-10-deficient mice and mice with sinoaortic denervation. Finally, effects of ketanserin on blood pressure, heart rate, and baroreflex sensitivity were examined in Wistar-Kyoto (WKY) rats with endotoxic shock. RESULTS: Ketanserin significantly increased survival time and decreased serum levels of tumor necrosis factor α and interleukin (IL) 1ß in mice with endotoxic shock. At a dose of 10 mg/kg, ketanserin also significantly increased serum IL-10 concentration. The antishock effect of ketanserin was also apparent in IL-10-knockout mice. In mice with sinoaortic denervation, however, ketanserin had little antishock effects. In WKY rats, ketanserin significantly prevented the baroreflex impairment induced by LPS and prolonged the survival time. CONCLUSIONS: Ketanserin could ameliorate endotoxic shock by restoring baroreflex function.


Subject(s)
Baroreflex/drug effects , Ketanserin/pharmacology , Ketanserin/therapeutic use , Serotonin Antagonists/pharmacology , Serotonin Antagonists/therapeutic use , Shock, Septic/drug therapy , Animals , Blood Pressure/drug effects , Dose-Response Relationship, Drug , Heart Rate/drug effects , Interleukin-10/blood , Interleukin-1beta/blood , Lipopolysaccharides , Male , Mice , Rats , Rats, Inbred WKY , Shock, Septic/blood , Shock, Septic/chemically induced , Survival Analysis , Tumor Necrosis Factor-alpha/blood
10.
J Cardiovasc Pharmacol ; 57(3): 308-16, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21266915

ABSTRACT

AIM: This study was designed to investigate the effects of telmisartan and amlodipine on reduction of blood pressure (BP), myocardial hypertrophy, and renal injury in hypertensive rats. METHOD: In acute experiments, the BP was measured in conscious freely moving rats. Spontaneously hypertensive rats were treated with intragastric administration of amlodipine (1, 2, 4 mg/kg), telmisartan (4, 8, 12, 16, 20 mg/kg), and their different combinations (4 + 4, 2 + 4, 4 + 8, 4 + 12, 1 + 4, 2 + 8, 4 + 16, 2 + 12, 1 + 8, 2 + 16, 2 + 20, 1 + 12, 1 + 16, 1 + 20 mg/kg). The probability sum test (q test) was used to evaluate the synergistic action on BP reduction. In two-kidney, one-clip rats, the effects of amlodipine (1 mg/kg), telmisartan (6 mg/kg) and their combination on BP reduction were observed. In the chronic study, spontaneously hypertensive rats were treated with amlodipine (1 mg/kg), telmisartan (6 mg/kg), and their combination for 4 months. Histopathologic examinations were performed after the determination of BP and BP variability. RESULTS: There is a synergistic interaction between amlodipine and telmisartan on BP reduction. The optimal dose ratio was found at 1:6. The synergistic effect of this dose ratio (1:6) was also seen in two-kidney, one-clip rats. Long-term treatment with this combination results in a beneficial effect on the reduction of BP and BP variability. The end-organ damage, including myocardial hypertrophy, glomerular atrophy, and fibrosis, was significantly attenuated by this combination. CONCLUSION: The optimal dose ratio of amlodipine and telmisartan on BP was 1:6. This combination is beneficial for the BP and BP variability reduction and end-organ damage prevention.


Subject(s)
Amlodipine/therapeutic use , Angiotensin-Converting Enzyme Inhibitors/therapeutic use , Antihypertensive Agents/therapeutic use , Benzimidazoles/therapeutic use , Benzoates/therapeutic use , Calcium Channel Blockers/therapeutic use , Cardiotonic Agents/therapeutic use , Hypertension/drug therapy , Animals , Blood Pressure/drug effects , Blood Pressure/physiology , Disease Models, Animal , Dose-Response Relationship, Drug , Drug Synergism , Drug Therapy, Combination , Hypertension/physiopathology , Kidney/drug effects , Kidney/physiopathology , Kidney Diseases/prevention & control , Kidney Glomerulus/drug effects , Male , Rats , Rats, Inbred SHR , Rats, Sprague-Dawley , Telmisartan , Time Factors
11.
Acta Pharmacol Sin ; 31(8): 938-43, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20686519

ABSTRACT

AIM: To reinvestigate the characteristics of reserpine-induced gastric mucosal lesions (GMLs). METHODS: The GML-inducing effect of reserpine and the time-course of recovery from reserpine-induced GMLs were examined in Sprague-Dawley (SD) rats. The GML-inducing and blood pressure-decreasing effects of Compound Hypotensive Tablets (CHTs) were investigated in spontaneously hypertensive rats (SHRs). Intracerebroventricular (icv) injection and vagotomy were performed to verify the central vagal mechanism in reserpine-induced GMLs. RESULTS: Single intraperitoneal (ip) injections of reserpine (0.25, 0.5, 1, 2, 4, and 6 mg/kg) dose-dependently induced GMLs in SD rats. Both single and repeated (2 weeks) oral administrations of reserpine led to slight GMLs at doses of 24 mg/kg and 10 mg/kg, respectively. Blood pressure was significantly decreased in SHRs after 2 months of CHT administration (0.01 and 0.03 mg/kg; doses were expressed as the amount of reserpine in the CHT). CHT doses of 0.3 mg/kg induced GMLs, but 0.1 mg/kg did not. Examining the time course of recovery from GMLs, severe GMLs occurred 18 h after ip reserpine (4 mg/kg), obviously lessened at 1 week and healed spontaneously at 3 weeks. Intracerebroventricular injections of reserpine caused GMLs at much lower doses (0.08 and 0.4 mg/kg), and reserpine-induced GMLs were greatly inhibited by vagotomy, suggesting the involvement of a central vagal mechanism. CONCLUSION: Reserpine-induced GMLs were dose-dependent, and the lesions healed spontaneously within 3 weeks. Long-term treatment with CHT at doses adequate to decrease blood pressure will not induce GMLs. A central vagal mechanism was involved in reserpine-induced GMLs.


Subject(s)
Antihypertensive Agents/toxicity , Gastric Mucosa/drug effects , Hypertension/drug therapy , Reserpine/toxicity , Animals , Antihypertensive Agents/administration & dosage , Antihypertensive Agents/pharmacology , Blood Pressure/drug effects , Dose-Response Relationship, Drug , Drug Administration Schedule , Gastric Mucosa/pathology , Hypertension/physiopathology , Injections, Intraperitoneal , Injections, Intraventricular , Male , Rats , Rats, Inbred SHR , Rats, Sprague-Dawley , Reserpine/administration & dosage , Reserpine/pharmacology , Time Factors
12.
Can J Physiol Pharmacol ; 88(11): 1054-60, 2010 Nov.
Article in English | MEDLINE | ID: mdl-21076493

ABSTRACT

The present study was designed to test the hypothesis that a small dose of ketanserin, which enhances baroreflex activity, prevents the early lesions of atherosclerosis. In experiment 1, baroreflex sensitivity (BRS) was measured in 31 spontaneously hypertensive rats (SHRs) in a conscious state using a computerized blood pressure monitoring system. Four weeks later, the rats were administered vitamin D3 and fed a high-cholesterol diet for 8 weeks to induce atherosclerosis. Then their hearts and aortae were removed for pathological examination. A negative correlation was found between BRS and the scores of coronary (r = -0.460, P < 0.01) and aortic atherosclerosis (r = -0.448, P < 0.05) in SHR. In experiment 2, SHRs were divided into 3 groups (n = 10 in each group) and received a dose of ketanserin of 0.3, 1.0, and 3.0 mg/kg (i.g.), respectively. At the smallest dose (0.3 mg/kg), ketanserin did not lower blood pressure but enhanced BRS. In experiment 3, SHRs were administered vitamin D3, fed a high-cholesterol diet, and simultaneously treated with low-dose ketanserin. The atherosclerosis scores of the treatment group were significantly lower than those of the control group (coronary score: 0.90 ± 0.14 vs. 1.76 ± 0.27, P < 0.05; aortic scores: 1.00 ± 0.39 vs. 2.18 ± 0.41, P < 0.05). In experiment 4, male New Zealand White rabbits were fed a high-cholesterol diet and treated with low-dose ketanserin at the same time. The atherosclerosis scores of the treatment group were significantly lower than those of the control group (aortic scores: 0.26 ± 0.20 vs. 0.60 ± 0.31, P < 0.05). In conclusion, the present study demonstrated, for the first time, that low-dose ketanserin prevented the development of atherosclerosis independent of its blood pressure lowering action in SHRs and New Zealand White rabbits at least in part via enhancement of arterial baroreflex function.


Subject(s)
Antihypertensive Agents/therapeutic use , Atherosclerosis/prevention & control , Ketanserin/therapeutic use , Serotonin Antagonists/therapeutic use , Animals , Atherosclerosis/physiopathology , Baroreflex/drug effects , Blood Pressure/drug effects , Female , Male , Rabbits , Rats , Rats, Inbred SHR
13.
Polymers (Basel) ; 12(1)2020 Jan 05.
Article in English | MEDLINE | ID: mdl-31948084

ABSTRACT

Nanocomposite dielectrics show a great potential application in high voltage direct current cables for their obvious improvements in electrical properties. In the present manuscript, nanocomposite composed of low-density polyethylene and nanoscale polystyrene particles is studied by using low-density polyethylene grafted with polystyrene molecule. Fourier-transform infrared spectra reveal successful grafting of the polystyrene molecule onto the low-density polyethylene chain and the scanning electron microscope image shows the homogeneously dispersed nanoscale polystyrene particles. The presence of the polystyrene nanoparticles obviously improves the dielectric properties, such as the direct current breakdown strength and space charge inhibition. The conductivity and thermally stimulated current characteristics imply the deep traps in the composite increase obviously. Density functional theory calculation reveals that the grafted polystyrene can accommodate both shallow and deep electron carriers, and the depth of the hole traps are as deep as 2.07 eV.

14.
R Soc Open Sci ; 5(2): 170772, 2018 Feb.
Article in English | MEDLINE | ID: mdl-29515821

ABSTRACT

The role of a series of functionalized graphene additives in power cable insulation in suppressing the growth of electrical treeing and preventing the degradation of the polymer matrix has been investigated by density functional theory calculations. Bader charge analysis indicates that pristine, doped or defect graphene could effectively capture hot electrons to block their attack on cross-linked polyethylene (XLPE) because of the π-π conjugated unsaturated structures. Further exploration of the electronic properties in the interfacial region between the additives and XLPE shows that N-doped single-vacancy graphene, graphene oxide and B-, N-, Si- or P-doped graphene oxide have relatively strong physical interaction with XLPE to restrict its mobility and rather weak chemical activity to prevent the cleavage of the C-H or C-C bond, suggesting that they are all potential candidates as effective additives. The understanding of the features of functionalized graphene additives in trapping electrons and interfacial interaction will assist in the screening of promising additives as voltage stabilizers in power cables.

15.
J Clin Invest ; 128(12): 5448-5464, 2018 12 03.
Article in English | MEDLINE | ID: mdl-30325740

ABSTRACT

The pathogenesis of ischemic diseases remains unclear. Here we demonstrate the induction of microRNA-668 (miR-668) in ischemic acute kidney injury (AKI) in human patients, mice, and renal tubular cells. The induction was HIF-1 dependent, as HIF-1 deficiency in cells and kidney proximal tubules attenuated miR-668 expression. We further identified a functional HIF-1 binding site in the miR-668 gene promoter. Anti-miR-668 increased apoptosis in renal tubular cells and enhanced ischemic AKI in mice, whereas miR-668 mimic was protective. Mechanistically, anti-miR-668 induced mitochondrial fragmentation, whereas miR-668 blocked mitochondrial fragmentation during hypoxia. We analyzed miR-668 target genes through immunoprecipitation of microRNA-induced silencing complexes followed by RNA deep sequencing and identified 124 protein-coding genes as likely targets of miR-668. Among these genes, only mitochondrial protein 18 kDa (MTP18) has been implicated in mitochondrial dynamics. In renal cells and mouse kidneys, miR-668 mimic suppressed MTP18, whereas anti-miR-668 increased MTP18 expression. Luciferase microRNA target reporter assay further verified MTP18 as a direct target of miR-668. In renal tubular cells, knockdown of MTP18 suppressed mitochondrial fragmentation and apoptosis. Together, the results suggest that miR-668 is induced via HIF-1 in ischemic AKI and that, upon induction, miR-668 represses MTP18 to preserve mitochondrial dynamics for renal tubular cell survival and kidney protection.


Subject(s)
Acute Kidney Injury/metabolism , Hypoxia/metabolism , Membrane Proteins/metabolism , MicroRNAs/metabolism , Mitochondria/metabolism , Mitochondrial Dynamics , Mitochondrial Proteins/metabolism , Acute Kidney Injury/genetics , Acute Kidney Injury/pathology , Animals , Apoptosis/genetics , Female , Humans , Hypoxia/genetics , Hypoxia/pathology , Male , Membrane Proteins/genetics , Mice , Mice, Knockout , MicroRNAs/genetics , Mitochondria/genetics , Mitochondria/pathology , Mitochondrial Proteins/genetics
16.
Int J Biol Sci ; 11(8): 935-47, 2015.
Article in English | MEDLINE | ID: mdl-26157348

ABSTRACT

The Hippo signaling pathway and its transcriptional co-activator Yap are known as essential regulators for cell proliferation and organ size. However, little is known about their roles in kidney development and ciliogenesis. We examined expression of Yap during zebrafish embryogenesis, and its transcripts were detected in pronephric duct, while Yap protein was found to be localized in the cytoplasm and apical membrane in kidney epithelium cells. By morpholino (MO) knockdown of yap expression in zebrafish, the injected larve exhibits pronephic cysts and many aspects of ciliopathy, which can be rescued by full-length yap mRNA, but not yap (S127A) mRNA. With transgenic Tg(Na(+)/K(+) ATPase:EGFP), we found that lacking Yap led to expansion and discontinuities of pronephric duct, as well as disorganization of cloaca during pronephros morphogenesis. Mis-located Na(+)/K(+) ATPase and ciliary abnormalities are also detected in pronephric duct of yap morphants. In addition, genetic analysis suggests that yap interacts with ift20, ift88 and arl13b in pronephric cyst formation. Taken together, our data reveals that Yap is required for pronephric duct integrity, maintenance of baso-lateral cell polarity, and ciliogenesis during zebrafish kidney development.


Subject(s)
Ciliary Body/embryology , Kidney/embryology , Trans-Activators/physiology , Zebrafish Proteins/physiology , Zebrafish/embryology , Animals , Gene Knockdown Techniques , Morphogenesis , Sodium-Potassium-Exchanging ATPase/metabolism , Subcellular Fractions/metabolism , Trans-Activators/genetics , Trans-Activators/metabolism , YAP-Signaling Proteins , Zebrafish Proteins/genetics , Zebrafish Proteins/metabolism
17.
Sci Rep ; 4: 4992, 2014 May 27.
Article in English | MEDLINE | ID: mdl-24862314

ABSTRACT

The confinement induced resonance provides an indispensable tool for the realization of the low-dimensional strongly interacting quantum system. Here, we investigate the confinement induced resonance in spin-orbit coupled cold atoms with Raman coupling. We find that the quasi-bound levels induced by the spin-orbit coupling and Raman coupling result in the Feshbach-type resonances. For sufficiently large Raman coupling, the bound states in one dimension exist only for sufficiently strong attractive interaction. Furthermore, the bound states in quasi-one dimension exist only for sufficient large ratio of the length scale of confinement to three dimensional s-wave scattering length. The Raman coupling substantially changes the confinement-induced resonance position. We give a proposal to realize confinement induced resonance through increasing Raman coupling strength in experiments.

18.
J Am Heart Assoc ; 3(3): e000804, 2014 May 12.
Article in English | MEDLINE | ID: mdl-24820655

ABSTRACT

BACKGROUND: Endothelium-derived acetylcholine (eACh) plays an important role in the regulation of vascular actions in response to hypoxia, whereas arterial baroreflex (ABR) dysfunction impairs the eACh system. We investigated the effects of ABR dysfunction on ischemia-induced angiogenesis in animal models of hindlimb ischemia with a special focus on eACh/nicotinic ACh receptor (nAChR) signaling activation. METHODS AND RESULTS: Male Sprague-Dawley rats were randomly assigned to 1 of 3 groups that received (1) sham operation (control group), (2) sinoaortic denervation (SAD)-induced ABR dysfunction (SAD group), or (3) SAD rats on diet with an acetylcholinesterase inhibitor pyridostigmine (30 mg/kg per day, SAD+Pyr group). After 4 weeks of the SAD intervention, unilateral limb ischemia was surgically induced in all animals. At postoperative day 14, SAD rats exhibited impaired angiogenic action (skin temperature and capillary density) and decreased angiogenic factor expressions (vascular endothelial growth factor [VEGF] and hypoxic inducible factor [HIF]-1α) in ischemic muscles. These changes were restored by acetylcholinesterase inhibition. Rats with ABR dysfunction had lower eACh levels than did control rats, and this effect was recovered in SAD+Pyr rats. In α7-nAChR knockout mice, pyridostigmine improved ischemia-induced angiogenic responses and increased the levels of VEGF and HIF-1α. Moreover, nicotinic receptor blocker inhibited VEGF expression and VEGF receptor 2 phosphorylation (p-VEGFR2) induced by ACh analog. CONCLUSIONS: Thus, ABR dysfunction appears to impair ischemia-induced angiogenesis through the reduction of eACh/α7-nAChR-dependent and -independent HIF-1α/VEGF-VEGFR2 signaling activation.


Subject(s)
Arteries/physiology , Baroreflex/physiology , Ischemia/physiopathology , Neovascularization, Physiologic/physiology , Animals , Cholinesterase Inhibitors/pharmacology , Disease Models, Animal , Extremities/blood supply , Hypoxia-Inducible Factor 1, alpha Subunit/physiology , Male , Mice, Inbred C57BL , Mice, Knockout , Neovascularization, Physiologic/drug effects , Pyridostigmine Bromide/pharmacology , Rats, Sprague-Dawley , Signal Transduction/drug effects , Signal Transduction/physiology , Vascular Endothelial Growth Factor A/physiology
19.
CNS Neurosci Ther ; 18(4): 343-9, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22486847

ABSTRACT

BACKGROUND: Stroke is the second most common cause of death and a major cause of disability worldwide. Risperidone is an atypical antipsychotic drug that may increase the risk of stroke. The present work examined whether risperidone enhances the vulnerability to stroke in hypertensive rats and the potential mechanisms underlying such action. METHODS: Experiment 1: Wistar-Kyoto (WKY) rats, spontaneously hypertensive rats (SHRs) and stroke-prone SHRs (SHR-SPs) were treated with risperidone (0.8 and 2.4 mg/kg/d) or vehicle for 30 consecutive days. Tissue damage in response to middle cerebral artery occlusion (MCAO) was measured microscopically. The activity of superoxide dismutase, glutathione peroxidase, the levels of malondialdehyde were also determined. Experiment 2: Survival data were recorded in SHR-SPs that received daily risperidone perpetually. Experiment 3: Effect of risperidone on interleukin-6 and tumor necrosis factor-α was examined in quiescent or LPS-activated cortical microglias from WKY rats. Experiment 4: Potential damage of risperidone exposure to neurons was examined in primary neuronal culture obtained from WKY rats, SHRs, and SHR-SPs. RESULTS: Risperidone increased infarct areas upon MCAO in SHR-SPs and SHRs, but not in WKY rats. Survival time in SHR-SPs was shortened by risperidone. Apoptosis was augmented by risperidone through enhanced Bax. Risperidone also increased endothelial injury. CONCLUSIONS: Risperidone enhances the vulnerability to stroke in hypertensive rats through increasing neuronal apoptosis and endothelial injury.


Subject(s)
Hypertension/pathology , Risperidone/toxicity , Stroke/chemically induced , Stroke/pathology , Animals , Apoptosis/drug effects , Apoptosis/physiology , Cells, Cultured , Hypertension/complications , Neurons/drug effects , Neurons/pathology , Rats , Rats, Inbred SHR , Rats, Inbred WKY , Stroke/etiology
20.
Hypertension ; 57(2): 298-307, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21173343

ABSTRACT

Inflammatory responses are associated with the genesis and progression of end-organ damage (EOD) in hypertension. A role for the α7 nicotinic acetylcholine receptor (α7nAChR) in inflammation has recently been identified. We tested the hypothesis that α7nAChR dysfunction contributes to hypertensive EOD. In both spontaneously hypertensive rats (SHRs) and rats with abdominal aorta coarctation-induced hypertension, atropine-induced tachycardia was blunted compared with normotensive controls. Both models of hypertension were associated with deficits in expression of the vesicular acetylcholine transporter and the α7nAChR in cardiovascular tissues. In hypertension induced by abdominal aorta coarctation, deficits in aortic vesicular acetylcholine transporter and α7nAChR were present both above and below the coarctation site, indicating that they were independent of the level of arterial pressure itself. Hypertension in 40-week-old SHRs was associated with cardiac and aortic hypertrophy. Morphological abnormalities consistent with EOD, along with elevated tissue levels of proinflammatory cytokines (tumor necrosis factor-α, interleukin-1ß, and interleukin-6) were observed in the heart, kidney, and aorta. Chronic treatment of SHRs with the α7nAChR agonist PNU-282987 relieved EOD and inhibited tissue levels of proinflammatory cytokines and activation of nuclear factor κB. Greater serum levels of proinflammatory cytokines and more severe damage in the heart, aorta, and kidney were seen in α7nAChR(-/-) mice subjected to 2-kidney-1-clip surgery than in wild-type mice. A deficit in the cholinergic anti-inflammatory pathway appears to contribute to the pathogenesis of EOD in models of hypertension of varying etiology. This pathway may provide a new target for preventing cardiovascular disease resulting from hypertension.


Subject(s)
Hypertension, Renovascular/physiopathology , Inflammation/physiopathology , Multiple Organ Failure/physiopathology , Receptors, Nicotinic/physiology , Animals , Aorta/metabolism , Aorta/pathology , Aorta/ultrastructure , Atropine/pharmacology , Benzamides/pharmacology , Blood Pressure/drug effects , Blotting, Western , Bridged Bicyclo Compounds/pharmacology , Hypertension, Renovascular/genetics , Hypertension, Renovascular/metabolism , Inflammation/metabolism , Inflammation Mediators/blood , Inflammation Mediators/metabolism , Kidney/metabolism , Kidney/pathology , Kidney/ultrastructure , Male , Mice , Mice, Knockout , Microscopy, Electron , Multiple Organ Failure/blood , Multiple Organ Failure/metabolism , Muscarinic Antagonists/pharmacology , Myocardium/metabolism , Myocardium/pathology , Myocardium/ultrastructure , NF-kappa B/metabolism , Rats , Rats, Inbred SHR , Rats, Inbred WKY , Rats, Sprague-Dawley , Receptors, Nicotinic/genetics , Receptors, Nicotinic/metabolism , Signal Transduction/drug effects , Signal Transduction/physiology , Vesicular Acetylcholine Transport Proteins/genetics , Vesicular Acetylcholine Transport Proteins/metabolism , alpha7 Nicotinic Acetylcholine Receptor
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