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1.
Heart Vessels ; 2024 May 26.
Article En | MEDLINE | ID: mdl-38797744

It remains to be elucidated whether Ca2+ antagonists induce pharmacological preconditioning to protect the heart against ischemia/reperfusion injury. The aim of this study was to determine whether and how pretreatment with a Ca2+ antagonist, azelnidipine, could protect cardiomyocytes against hypoxia/reoxygenation (H/R) injury in vitro. Using HL-1 cardiomyocytes, we studied effects of azelnidipine on NO synthase (NOS) expression, NO production, cell death and apoptosis during H/R. Action potential durations (APDs) were determined by the whole-cell patch-clamp technique. Azelnidipine enhanced endothelial NOS phosphorylation and NO production in HL-1 cells under normoxia, which was abolished by a heat shock protein 90 inhibitor, geldanamycin, and an antioxidant, N-acetylcysteine. Pretreatment with azelnidipine reduced cell death and shortened APDs during H/R. These effects of azelnidipine were diminished by a NOS inhibitor, L-NAME, but were influenced by neither a T-type Ca2+ channel inhibitor, NiCl2, nor a N-type Ca2+ channel inhibitor, ω-conotoxin. The azelnidipine-induced reduction in cell death was not significantly enhanced by either additional azelnidipine treatment during H/R or increasing extracellular Ca2+ concentrations. RNA sequence (RNA-seq) data indicated that azelnidipine-induced attenuation of cell death, which depended on enhanced NO production, did not involve any significant modifications of gene expression responsible for the NO/cGMP/PKG pathway. We conclude that pretreatment with azelnidipine protects HL-1 cardiomyocytes against H/R injury via NO-dependent APD shortening and L-type Ca2+ channel blockade independently of effects on gene expression.

2.
Clin Pharmacol Ther ; 115(6): 1358-1364, 2024 Jun.
Article En | MEDLINE | ID: mdl-38389505

A recent meta-analysis found no benefit of uric acid-lowering therapy including febuxostat on death, cardiovascular events, or renal impairment. However, there may be populations that benefit from febuxostat in reducing mortality and cerebral and cardiovascular events. The aim of the present study was to examine the clinical benefit of febuxostat in elderly patients stratified by age using Febuxostat for Cerebral and CaRdiorenovascular Events PrEvEntion StuDy (FREED) data. FREED was a randomized study involving patients aged 65 years or older with hyperuricemia and risk factors for cerebral, cardiovascular, or renal diseases. A total of 1,070 patients were included in this post hoc analysis, divided into 2 age groups: 65-74 years and ≥ 75 years. Patients were randomized into febuxostat and non-febuxostat groups, with uric acid levels monitored for 36 months. The primary composite end point included cerebral, cardiovascular, and renal events. In patients aged between 65 and 74 years, febuxostat significantly reduced the risk of future cerebral and cardiorenovascular events. However, no effects of febuxostat were found in the older population aged ≥ 75 years. Heterogeneity in potential interactions between the age and febuxostat treatment was particularly observed in non-fatal cerebral and cardiovascular events and all-cause death. Patients aged ≥ 75 years exhibited more pre-existing factors associated with cerebral and cardiorenovascular events than those aged 65-74 years. The effectiveness of febuxostat varies by age group, with potential benefits for patients aged 65-74 years. The effects of febuxostat are complex and it is important to consider patient characteristics in its clinical use.


Cardiovascular Diseases , Febuxostat , Gout Suppressants , Hyperuricemia , Uric Acid , Humans , Febuxostat/therapeutic use , Hyperuricemia/drug therapy , Hyperuricemia/blood , Aged , Male , Female , Cardiovascular Diseases/prevention & control , Cardiovascular Diseases/mortality , Gout Suppressants/therapeutic use , Gout Suppressants/adverse effects , Uric Acid/blood , Age Factors , Aged, 80 and over , Cerebrovascular Disorders/prevention & control , Risk Factors , Treatment Outcome
3.
JMA J ; 6(4): 523-526, 2023 Oct 16.
Article En | MEDLINE | ID: mdl-37941684

Clinical practice guidelines (CPGs) consist of clinical questions (CQs) and corresponding recommendations. Considering the estimation of body of evidence, patients' opinions, and medical economics, recommendations can vary depending on the votes of the committee members of CPGs. Taking this into consideration, concerns have already been raised on how financial conflict of interest (COI) potentially influences recommendations. In this study, we developed the third edition of guideline for the management of hyperuricemia and gout. This CPG was composed of seven CQs and recommendations. The direction and strength of the recommendations were determined by votes. There are three CQs. Individual questions asked whether uric acid-lowering-agents (ULAs) could be applied to hyperuricemic patients with chronic kidney disease (CKD) (CQ A), hypertension (CQ B), or heart failure (CQ C) to prevent organ damage. We examined whether the absence (18 members) or presence (8 members) of COIs of committee members could influence the votes. In total, 26 committee members with and without COI have equally determined the direction and strength of recommendations. In CQ A, members without financial COIs and those with financial COI selected conditional recommendation for the use of ULAs in patients with CKD (without COI, 17/18; with COI, 7/8). In CQ B, members without financial COIs and those with financial COI selected conditional recommendation against the use of ULAs in hypertensive patients (without COI, 14/18; with COI, 5/8). In CQ C, members without financial COIs and those with financial COIs have selected conditional recommendation against the use of ULAs in patients suffering from heart failure (without COI, 15/18; with COI, 4/8). We found that members with financial COIs have determined their recommendations in the same direction and strength as those without financial COIs.

4.
Biomolecules ; 13(10)2023 10 13.
Article En | MEDLINE | ID: mdl-37892201

The prevalence of patients with hyperuricemia or gout is increasing worldwide. Hyperuricemia and gout are primarily attributed to genetic factors, along with lifestyle factors like consuming a purine-rich diet, alcohol and/or fructose intake, and physical activity. While numerous studies have reported various comorbidities linked to hyperuricemia or gout, the range of these associations is extensive. This review article focuses on the relationship between uric acid and thirteen specific domains: transporters, genetic factors, diet, lifestyle, gout, diabetes mellitus, metabolic syndrome, atherosclerosis, hypertension, kidney diseases, cardiovascular diseases, neurological diseases, and malignancies. The present article provides a comprehensive review of recent developments in these areas, compiled by experts from the Young Committee of the Japanese Society of Gout and Uric and Nucleic Acids. The consolidated summary serves to enhance the global comprehension of uric acid-related matters.


Gout , Hyperuricemia , Metabolic Syndrome , Humans , Uric Acid , Diet
6.
J Arrhythm ; 39(4): 664-668, 2023 Aug.
Article En | MEDLINE | ID: mdl-37560272

Background: Cardiomyocytes derived from human iPS cells (hiPSCs) include cells showing SAN- and non-SAN-type spontaneous APs. Objectives: To examine whether the deep learning technology could identify hiPSC-derived SAN-like cells showing SAN-type-APs by their shape. Methods: We acquired phase-contrast images for hiPSC-derived SHOX2/HCN4 double-positive SAN-like and non-SAN-like cells and made a VGG16-based CNN model to classify an input image as SAN-like or non-SAN-like cell, compared to human discriminability. Results: All parameter values such as accuracy, recall, specificity, and precision obtained from the trained CNN model were higher than those of human classification. Conclusions: Deep learning technology could identify hiPSC-derived SAN-like cells with considerable accuracy.

7.
Hypertens Res ; 46(10): 2368-2377, 2023 10.
Article En | MEDLINE | ID: mdl-37592041

Soluble uric acid (UA) absorbed by cells through UA transporters (UATs) accumulates intracellularly, activates the NLRP3 inflammasome and thereby increases IL-1ß secretion. ABCG2 transporter excludes intracellular UA. However, it remains unknown whether ABCG2 inhibition leads to intracellular accumulation of UA and increases IL-1ß production. In this study, we examined whether genetic and pharmacological inhibition of ABCG2 could increase IL-1ß production in mouse macrophage-like J774.1 cells especially under hyperuricemic conditions. We determined mRNA and protein levels of pro-IL-1ß, mature IL-1ß, caspase-1 and several UATs in culture supernatants and lysates of J774.1 cells with or without soluble UA pretreatment. Knockdown experiments using an shRNA against ABCG2 and pharmacological experiments with an ABCG2 inhibitor were conducted. Extracellularly applied soluble UA increased protein levels of pro-IL-1ß, mature IL-1ß and caspase-1 in the culture supernatant from lipopolysaccharide (LPS)-primed and monosodium urate crystal (MSU)-stimulated J774.1 cells. J774.1 cells expressed UATs of ABCG2, GLUT9 and MRP4, and shRNA knockdown of ABCG2 increased protein levels of pro-IL-1ß and mature IL-1ß in the culture supernatant. Soluble UA increased mRNA and protein levels of ABCG2 in J774.1 cells without either LPS or MSU treatment. An ABCG2 inhibitor, febuxostat, but not a urate reabsorption inhibitor, dotinurad, enhanced IL-1ß production in cells pretreated with soluble UA. In conclusion, genetic and pharmacological inhibition of ABCG2 enhanced IL-1ß production especially under hyperuricemic conditions by increasing intracellularly accumulated soluble UA that activates the NLRP3 inflammasome and pro-IL-1ß transcription in macrophage-like J774.1 cells.


Inflammasomes , Uric Acid , Mice , Animals , Uric Acid/pharmacology , Inflammasomes/metabolism , Inflammasomes/pharmacology , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Lipopolysaccharides/pharmacology , Macrophages/metabolism , Interleukin-1beta/genetics , Interleukin-1beta/metabolism , Interleukin-1beta/pharmacology , RNA, Small Interfering/pharmacology , RNA, Messenger/pharmacology , Caspases/pharmacology
8.
Article En | MEDLINE | ID: mdl-37545323

Heart failure and pneumonia are highly prevalent in elderly patients. We conducted a study to evaluate the differences in the patterns of symptoms, laboratory findings, and computed tomography (CT) results in elderly patients with acute cardiogenic pulmonary edema (ACPE) and community-acquired pneumonia (CAP). From January 1, 2015 to December 31, 2017, we studied 140 patients aged >75 years who were diagnosed with ACPE and CAP. Symptoms, laboratory findings, mean ostial pulmonary vein (PV) diameter and patterns on CT images were assessed. The primary measures of diagnostic accuracy were assessed using the positive likelihood ratio (LR+). The cutoff value of ostial PVs for differentiating patients with ACPE from CAP was evaluated using the receiver operating characteristic (ROC) analysis. Ninety-three patients with ACPE, 36 with CAP, and 11 with complicated ACPE/CAP were included. In patients with ACPE, edema (LR+ 5.4) was a moderate factor for rule-in, and a high brain natriuretic peptide level (LR+ 4.2) was weak. In patients with CAP, cough (LR+ 5.7) and leukocytosis (LR+ 5.2) were moderate factors for rule-in, while fever (LR+ 3.8) and a high C-reactive protein level (LR+ 4.8) were weak factors. The mean diameter of ostial PVs in patients with ACPE was significantly larger than that of patients with CAP (15.8±â€Š1.8 mm vs 9.6±1.5 mm, p< 0.01). ROC analysis revealed that an ostial PV diameter cutoff of 12.5 mm was strong evidence for distinguishing ACPE from CAP with an area under the ROC curve of 0.99 and LR+ 36.0. In conclusion, as ACPE and CAP have similar symptoms and laboratory findings, dilated ostial PVs were useful in characterizing CT images to distinguish ACPE from CAP.

9.
Biomedicines ; 11(5)2023 Apr 23.
Article En | MEDLINE | ID: mdl-37238926

The importance of uric acid, the final metabolite of purines excreted by the kidneys and intestines, was not previously recognized, except for its role in forming crystals in the joints and causing gout. However, recent evidence implies that uric acid is not a biologically inactive substance and may exert a wide range of effects, including antioxidant, neurostimulatory, proinflammatory, and innate immune activities. Notably, uric acid has two contradictory properties: antioxidant and oxidative ones. In this review, we present the concept of "dysuricemia", a condition in which deviation from the appropriate range of uric acid in the living body results in disease. This concept encompasses both hyperuricemia and hypouricemia. This review draws comparisons between the biologically biphasic positive and negative effects of uric acid and discusses the impact of such effects on various diseases.

10.
Biomedicines ; 11(5)2023 Apr 24.
Article En | MEDLINE | ID: mdl-37238929

Uric acid (UA) forms monosodium urate (MSU) crystals to exert proinflammatory actions, thus causing gout arthritis, urolithiasis, kidney disease, and cardiovascular disease. UA is also one of the most potent antioxidants that suppresses oxidative stress. Hyper andhypouricemia are caused by genetic mutations or polymorphism. Hyperuricemia increases urinary UA concentration and is frequently associated with urolithiasis, which is augmented by low urinary pH. Renal hypouricemia (RHU) is associated with renal stones by increased level of urinary UA, which correlates with the impaired tubular reabsorption of UA. Hyperuricemia causes gout nephropathy, characterized by renal interstitium and tubular damage because MSU precipitates in the tubules. RHU is also frequently associated with tubular damage with elevated urinary beta2-microglobulin due to increased urinary UA concentration, which is related to impaired tubular UA reabsorption through URAT1. Hyperuricemia could induce renal arteriopathy and reduce renal blood flow, while increasing urinary albumin excretion, which is correlated with plasma xanthine oxidoreductase (XOR) activity. RHU is associated with exercise-induced kidney injury, since low levels of SUA could induce the vasoconstriction of the kidney and the enhanced urinary UA excretion could form intratubular precipitation. A U-shaped association of SUA with organ damage is observed in patients with kidney diseases related to impaired endothelial function. Under hyperuricemia, intracellular UA, MSU crystals, and XOR could reduce NO and activate several proinflammatory signals, impairing endothelial functions. Under hypouricemia, the genetic and pharmacological depletion of UA could impair the NO-dependent and independent endothelial functions, suggesting that RHU and secondary hypouricemia might be a risk factor for the loss of kidney functions. In order to protect kidney functions in hyperuricemic patients, the use of urate lowering agents could be recommended to target SUA below 6 mg/dL. In order to protect the kidney functions in RHU patients, hydration and urinary alkalization may be recommended, and in some cases an XOR inhibitor might be recommended in order to reduce oxidative stress.

11.
Hypertens Res ; 46(7): 1714-1726, 2023 07.
Article En | MEDLINE | ID: mdl-37072573

A direct relationship between serum uric acid levels and hypertension, cardiovascular, renal and metabolic diseases has been reported in many basic and epidemiological studies. Among these, high blood pression is one of the most common features associated with hyperuricemia. In this regard, several small-scale interventional studies have demonstrated a significant reduction in blood pressure in hypertensive or prehypertensive patients on uric acid-lowering drugs. These observation or intervention studies have led to affirm that there is a causal relationship between uric acid and hypertension. While the clinical association between uric acid and high blood pressure is notable, no clear conclusion has yet been reached as to whether lowering uric acid is beneficial to prevent cardiovascular and renal metabolic diseases. Recently, several prospective randomized controlled intervention trials using allopurinol and other uric acid-lowering drugs have been reported, and the results from these trials were almost negative, suggesting that the correlation between hyperuricemia and cardiovascular disease has no causality. However, it is important to note that in some of these recent studies there were high dropout rates and an important fraction of participants were not hyperuricemic. Therefore, we should carry caution in interpreting the results of these studies. This review article presents the results of recent clinical trials using uric acid-lowering drugs, focusing on hypertension and cardiovascular and renal metabolic diseases, and discusses the future of uric acid therapy.


Cardiovascular Diseases , Hypertension , Hyperuricemia , Kidney Diseases , Humans , Cardiovascular Diseases/complications , Uric Acid , Hyperuricemia/complications , Hyperuricemia/drug therapy , Prospective Studies , Hypertension/complications , Kidney Diseases/complications
12.
Hypertens Res ; 46(6): 1417-1422, 2023 06.
Article En | MEDLINE | ID: mdl-36750608

Effect of urate-lowering on renal outcomes in patients at high-risk for cardiovascular disease with hyperuricemia without gout is not known. We conducted a post hoc analysis of a randomized trial (Febuxostat for Cerebral and CaRdiorenovascular Events PrEvEntion StuDy [FREED]). The FREED trial enrolled 1070 asymptomatic, hyperuricemic elderly patients with at least one risk factor for cardiovascular disease, divided into febuxostat (n = 537) and non-febuxostat (n = 533) groups. We compared the effect of these treatments on renal outcomes including 40% decline in estimated glomerular filtration rate, new onset of microalbuminuria and development or worsening macroalbuminuria. The relative risk of developing or worsening macroalbuminuria was 56% lower in the febuxostat group (hazard ratio, 0.44; 95% CI, 0.24-0.82; P = 0.0098). However, the risks for other outcomes were comparable. In patients with asymptomatic hyperuricemia without gout, febuxostat reduces the risk of development or worsening of macroalbuminuria.


Cardiovascular Diseases , Gout , Hyperuricemia , Aged , Humans , Cardiovascular Diseases/drug therapy , Febuxostat/therapeutic use , Gout/complications , Gout/drug therapy , Gout Suppressants/therapeutic use , Hyperuricemia/complications , Hyperuricemia/drug therapy , Treatment Outcome , Uric Acid
13.
Ann Plast Surg ; 90(2): 171-179, 2023 02 01.
Article En | MEDLINE | ID: mdl-36688861

ABSTRACT: Platelet-rich plasma (PRP) and adipose-derived stem cells (ADSCs) are known to secrete angiogenic factors that contribute to the treatment of intractable ulcers. The combination of PRP and ADSCs may enhance their angiogenic effects. However, it remains unclear whether treatment of ADSCs with PRP influences angiogenesis. We studied whether the conditioned medium from PRP-treated ADSCs under hypoxic conditions exerts angiogenic effects. Although PRP stimulated the proliferation of ADSCs obtained from rats, it decreased the mRNA levels of vascular endothelial growth factor, hepatocyte growth factor, and TGF-ß1, but not of basic fibroblast growth factor, under hypoxia. The conditioned medium of PRP-treated ADSCs inhibited endothelial nitric oxide synthase phosphorylation, decreased NO production, and suppressed tube formation in human umbilical vein endothelial cells. Transplantation of ADSCs alone increased both blood flow and capillary density of the ischemic limb; however, its combination with PRP did not further improve blood flow or capillary density. This suggests that both conditioned medium of ADSCs treated with PRP and combination of PRP with ADSCs transplantation may attenuate the phosphorylation of endothelial nitric oxide synthase and angiogenesis.


Platelet-Rich Plasma , Vascular Endothelial Growth Factor A , Humans , Rats , Animals , Culture Media, Conditioned/pharmacology , Vascular Endothelial Growth Factor A/metabolism , Nitric Oxide Synthase Type III , Human Umbilical Vein Endothelial Cells/metabolism , Neovascularization, Physiologic , Stem Cells/metabolism , Platelet-Rich Plasma/metabolism , Adipose Tissue/metabolism , Cells, Cultured
15.
Intern Med ; 62(13): 1915-1920, 2023 Jul 01.
Article En | MEDLINE | ID: mdl-36418091

Objective Both renal hypouricemia (RHU) and gout are associated with renal dysfunction and urolithiasis. The difference in renal complications associated with RHU and gout, however, has not been studied. We characterized the urate metabolism and complications of patients with RHU and compared them with patients with gout. Methods Eighteen patients with RHU who had a serum uric acid (SUA) level <2 mg/dL (10 men and 8 women), 44 patients with gout (44 men) and 16 normouricemic patients (4 men and 12 women) were included. The blood and urinary biochemical data were evaluated. A genetic analysis of uric acid transporter 1 (URAT1) was also conducted in 15 cases with RHU. Results The SUA level of RHU was 0.9±0.5/mg/dL, and the Uur/Ucr and Cur/Ccr were 0.56±0.14% and 45.7±18.0%, respectively. A genetic analysis of URAT1 in 15 RHU patients showed that 13 harbored a URAT1 gene mutation, whereas 2 harbored the wild-type gene. The SUA level was significantly lower in RHU patients (n=11) than in either gout patients (n=44) or normouricemic patients (n=16). This reduction was accompanied by the elevation of Cua/Ccr. Urinary beta 2-microglobulin levels were higher in RHU patients than in gout or normouricemia patients. Cua/Ccr correlated with normalized urinary beta 2-microglobulin levels. The prevalence of urolithiasis was 18.2% in RHU cases and 6.8% in gout cases. A homozygous URAT1 mutation was associated with urolithiasis. Conclusion Besides urolithiasis, RHU can be associated with tubular dysfunction, such as elevated urinary beta 2-microglobulin levels.


Gout , Urinary Calculi , Male , Humans , Female , Uric Acid , beta 2-Microglobulin , Gout/complications , Gout/genetics , Urinary Calculi/complications , Urinary Calculi/genetics
16.
Cardiovasc Drugs Ther ; 37(5): 965-974, 2023 10.
Article En | MEDLINE | ID: mdl-35648242

PURPOSE: Inflammation plays an important role in the initiation and progression of atherosclerosis, leading to poor clinical outcomes. Hyperuricemia is associated with the activation of the Nod-like receptor protein 3 inflammasome. Here, we investigated whether inhibition of inflammation using febuxostat lowered the risk of cardiovascular events. METHODS: This is a post-hoc analysis of the randomized trial, Febuxostat for Cerebral and CaRdiorenovascular Events PrEvEntion StuDy (FREED). In total, 1067 patients (736 men and 331 women) were included in the analysis. We compared the serial changes in high-sensitivity C-reactive protein (hs-CRP) levels between febuxostat and non-febuxostat groups and assessed the correlation between the changes in uric acid (UA) and hs-CRP levels after febuxostat treatment. We also determined whether febuxostat could reduce a hard endpoint, defined as a composite of cardiovascular events and all-cause mortality. RESULTS: Serum UA levels in the febuxostat group were significantly lower than those in the non-febuxostat group after randomization (p < 0.05). However, hs-CRP levels were comparable between the two groups during the study. No significant correlation was observed between the changes in UA and hs-CRP levels after febuxostat treatment. The hard endpoints did not differ significantly between the two groups. In patients with baseline hs-CRP levels > 0.2 mg/dL or those administered 40 mg of febuxostat, the drug did not reduce hs-CRP levels or decrease the hard endpoint. CONCLUSION: Febuxostat reduced the UA levels but did not affect the CRP levels, and therefore may fail to improve cardiovascular outcomes after treatment. TRIAL REGISTRATION: ClinicalTrial.gov (NCT01984749). https://clinicaltrials.gov/ct2/show/NCT01984749.


Atherosclerosis , Hyperuricemia , Male , Humans , Female , Febuxostat/adverse effects , Hyperuricemia/diagnosis , Hyperuricemia/drug therapy , C-Reactive Protein/metabolism , Uric Acid , Atherosclerosis/drug therapy , Inflammation/drug therapy , Treatment Outcome
17.
Front Pharmacol ; 14: 1289386, 2023.
Article En | MEDLINE | ID: mdl-38259292

Objectives: This study investigates the impact of xanthine oxidase inhibitors (XOI) on mortality in patients with cardiovascular diseases. XOI withdrawal has been reported to increased mortality risk due to rapid adenosine triphosphate (ATP) deficiency. This study aims to determine whether XOI treatment reduces mortality and whether XOI withdrawal increases mortality. Methods: This is a real-world database study using the Japanese Registry of All Cardiac and Vascular Diseases (J-ROAD). We analyzed 1,648,891 hospitalized patients aged 20-90 with acute coronary syndrome or heart failure. In the first study, mortality rates were compared between patients without urate-lowering agents (n = 1,292,486) and those with XOI agents (n = 315,388, excluding 41,017 on other urate-lowering agents). In the second study, mortality rates were compared between the XOI continuous medication group (n = 226,261) and the XOI withdrawal group (n = 89,127). Results: After multiple adjustments, XOI treatment group showed significantly lower mortality compared with that without any urate-lowering agent (odds ratio (OR), 0.576, 95% confidence interval (CI), 0.567-0.587, p < .001). In the sub-analysis, the group with allopurinol (OR, 0.578; 95% CI, 0.557-0.600), febuxostat (OR, 0.610; 95% CI, 0.599-0.622), and topiroxostat (HR, 0.545; 95% CI, 0.473-0.628) showed lower OR of mortality compared with that without any urate-lowering agent. XOI withdrawal group led to significantly higher death rates compared to XOI continuous group (19.8% vs. 0.03%; p < .001). Conclusion: XOI treatment for patients with cardiovascular diseases is associated with reduced mortality. Conversely, XOI withdrawal is linked to elevated mortality risk. This emphasizes the importance of both prescribing and discontinuing XOI carefully to optimize patient outcomes.

19.
Regen Ther ; 21: 239-249, 2022 Dec.
Article En | MEDLINE | ID: mdl-36092505

Introduction: Dysfunction of the sinoatrial node (SAN) cells causes arrhythmias, and many patients require artificial cardiac pacemaker implantation. However, the mechanism of impaired SAN automaticity remains unknown, and the generation of human SAN cells in vitro may provide a platform for understanding the pathogenesis of SAN dysfunction. The short stature homeobox 2 (SHOX2) and hyperpolarization-activated cyclic nucleotide-gated cation channel 4 (HCN4) genes are specifically expressed in SAN cells and are important for SAN development and automaticity. In this study, we aimed to purify and characterize human SAN-like cells in vitro, using HCN4 and SHOX2 as SAN markers. Methods: We developed an HCN4-EGFP/SHOX2-mCherry dual reporter cell line derived from human induced pluripotent stem cells (hiPSCs), and HCN4 and SHOX2 gene expressions were visualized using the fluorescent proteins EGFP and mCherry, respectively. The dual reporter cell line was established using an HCN4-EGFP bacterial artificial chromosome-based semi-knock-in system and a CRISPR-Cas9-dependent knock-in system with a SHOX2-mCherry targeting vector. Flow cytometry, RT-PCR, and whole-cell patch-clamp analyses were performed to identify SAN-like cells. Results: Flow cytometry analysis and cell sorting isolated HCN4-EGFP single-positive (HCN4+/SHOX2-) and HCN4-EGFP/SHOX2-mCherry double-positive (HCN4+/SHOX2+) cells. RT-PCR analyses showed that SAN-related genes were enriched within the HCN4+/SHOX2+ cells. Further, electrophysiological analyses showed that approximately 70% of the HCN4+/SHOX2+ cells exhibited SAN-like electrophysiological characteristics, as defined by the action potential parameters of the maximum upstroke velocity and action potential duration. Conclusions: The HCN4-EGFP/SHOX2-mCherry dual reporter hiPSC system developed in this study enabled the enrichment of SAN-like cells within a mixed HCN4+/SHOX2+ population of differentiating cardiac cells. This novel cell line is useful for the further enrichment of human SAN-like cells. It may contribute to regenerative medicine, for example, biological pacemakers, as well as testing for cardiotoxic and chronotropic actions of novel drug candidates.

20.
Life Sci ; 301: 120604, 2022 Jul 15.
Article En | MEDLINE | ID: mdl-35526593

AIMS: This study investigated the effects of adipose-derived stem cell sheets on a rat model of detrusor underactivity. MAIN METHODS: Adipose-derived stem cell sheets were prepared from the subcutaneous adipose tissue of male Lewis rats. Female Lewis rats were assigned into four groups: control, sham operation, cryo-injury, and cryo-injury+sheet (n = 8 per group). Rats in the cryo-injury+sheet group were implanted with ASC sheets 3 days after cryo-injury induction and underwent cystometry 7 days later. Subsequently, reverse transcription-polymerase chain reaction (RT-PCR) and histopathological examinations were performed. Cell sheets expressing the green fluorescent protein were prepared and transplanted to confirm the viability and differentiation of the sheets. Fluorescence was confirmed using a fluorescence stereomicroscope on days 3, 7, 14, 21, and 28 after sheet implantation, and tissue immunostaining was performed. KEY FINDINGS: Cystometry showed that sheet implantation improved the maximum intravesical pressure (P = 0.009) and the residual urine volume (P = 0.011). Furthermore, RT-PCR indicated that the mRNA levels of the angiogenic factors vascular endothelial growth factor and hepatocyte growth factor were significantly higher in the cryo-injury+sheet group than in the cryo-injury group (P = 0.045, P = 0.037, respectively). Histologically, sheet implantation resulted in an improvement in inflammation and increased the number of blood vessels. Green fluorescent protein-positive cells fused with von Willebrand factor-positive cells and differentiated into blood vessels 7 days after sheet implantation. SIGNIFICANCE: Adipose-derived stem cell sheets transplanted into the bladder of cryo-injured rats differentiated into blood vessels and restored bladder contractile function 7 days after transplantation.


Urinary Bladder, Underactive , Adipose Tissue , Animals , Female , Green Fluorescent Proteins , Male , Rats , Rats, Inbred Lew , Stem Cell Transplantation/methods , Stem Cells , Vascular Endothelial Growth Factor A
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