The greener the living environment, the better the health? Examining the effects of multiple green exposure metrics on physical activity and health among young students.

The sedentary and less active lifestyle of modern college students has a significant impact on the physical and mental well-being of the college community. Campus Green Spaces (GSs) are crucial in promoting physical activity and improving students' health. However, previous research has focused on evaluating campuses as a whole, without considering the diverse spatial scenarios within the campus environment. Accordingly, this study focused on the young people's residential scenario in university and constructed a framework including a comprehensive set of objective and subjective GSs exposure metrics. A systematic, objective exposure assessment framework ranging from 2D (GSs areas), and 2.5D (GSs visibility) to 3D (GSs volume) was innovatively developed using spatial analysis, deep learning technology, and unmanned aerial vehicle (UAV) measurement technology. Subjective exposure metrics incorporated GSs visiting frequency, GSs visiting duration, and GSs perceived quality. Our cross-sectional study was based on 820 university students in Nanjing, China. Subjective measures of GSs exposure, physical activity, and health status were obtained through self-reported questionnaires. The Generalized Linear Model (GLM) was used to evaluate the associations between GSs exposure, physical activity, and perceived health. Physical activity and social cohesion were considered as mediators, and path analysis based on Structural Equation Modeling (SEM) was used to disentangle the mechanisms linking GSs exposure to the health status of college students. We found that (1) 2D indicator suggested significant associations with health in the 100m buffer, and the potential underlying mechanisms were: GSs area → Physical activity → Social cohesion → Physical health → Mental health; GSs area → Physical activity → Social cohesion → Mental health. (2) Subjective GSs exposure indicators were more relevant in illustrating exposure-response relationships than objective ones. This study can clarify the complex nexus and mechanisms between campus GSs, physical activity, and health, and provide a practical reference for health-oriented campus GSs planning.

A membrane-associated phosphoswitch in Rad controls adrenergic regulation of cardiac calcium channels.

The ability to fight or flee from a threat relies on an acute adrenergic surge that augments cardiac output, which is dependent on increased cardiac contractility and heart rate. This cardiac response depends on ß-adrenergic-initiated reversal of the small RGK G protein Rad-mediated inhibition of voltage-gated calcium channels (CaV) acting through the Cavß subunit. Here, we investigate how Rad couples phosphorylation to augmented Ca2+ influx and increased cardiac contraction. We show that reversal required phosphorylation of Ser272 and Ser300 within Rad's polybasic, hydrophobic C-terminal domain (CTD). Phosphorylation of Ser25 and Ser38 in Rad's N-terminal domain (NTD) alone was ineffective. Phosphorylation of Ser272 and Ser300 or the addition of 4 Asp residues to the CTD reduced Rad's association with the negatively charged, cytoplasmic plasmalemmal surface and with CaVß, even in the absence of CaVα, measured here by FRET. Addition of a posttranslationally prenylated CAAX motif to Rad's C-terminus, which constitutively tethers Rad to the membrane, prevented the physiological and biochemical effects of both phosphorylation and Asp substitution. Thus, dissociation of Rad from the sarcolemma, and consequently from CaVß, is sufficient for sympathetic upregulation of Ca2+ currents.

Single-cell transcriptome sequencing reveals aberrantly activated inter-tumor cell signaling pathways in the development of clear cell renal cell carcinoma.

BACKGROUND: Aberrant intracellular or intercellular signaling pathways are important mechanisms that contribute to the development and progression of cancer. However, the intercellular communication associated with the development of ccRCC is currently unknown. The purpose of this study was to examine the aberrant tumor cell-to-cell communication signals during the development of ccRCC. METHODS: We conducted an analysis on the scRNA-seq data of 6 ccRCC and 6 normal kidney tissues. This analysis included sub clustering, CNV analysis, single-cell trajectory analysis, cell-cell communication analysis, and transcription factor analysis. Moreover, we performed validation tests on clinical samples using multiplex immunofluorescence. RESULTS: This study identified eleven aberrantly activated intercellular signaling pathways in tumor clusters from ccRCC samples. Among these, two of the majors signaling molecules, MIF and SPP1, were mainly secreted by a subpopulation of cancer stem cells. This subpopulation demonstrated high expression levels of the cancer stem cell markers POU5F1 and CD44 (POU5F1hiCD44hiE.T), with the transcription factor POU5F1 regulating the expression of SPP1. Further research demonstrated that SPP1 binds to integrin receptors on the surface of target cells and promotes ccRCC development and progression by activating potential signaling mechanisms such as ILK and JAK/STAT. CONCLUSION: Aberrantly activated tumor intercellular signaling pathways promote the development and progression of ccRCC. The cancer stem cell subpopulation (POU5F1hiCD44hiE.T) promotes malignant transformation and the development of a malignant phenotype by releasing aberrant signaling molecules and interacting with other tumor cells.

MiR-15b-5p Promotes Growth and Metastasis of Renal Clear Cell Carcinoma / MiR-15b-5p Promueve el Crecimiento y la Metástasis del Carcinoma Renal de Células Claras

SUMMARY: We investigated the expression and clinical significance of miR-15b-5p in clear cell renal cell carcinoma (RCC) through bioinformatics analysis and experimental verification. The differentially expressed miRNAs were screened in the GEO database. Venn diagram showed that there were 5 up-regulated miRNAs (has-miR-210, has-miR-142-3p, has-miR-142-5p, has-miR-15b-5p, and has-miR-193a-3p) and only 1 down-regulated miRNA (has-miR-532-3p) that were commonly expressed between GSE189331 and GSE16441 datasets. This was further confirmed in TCGA. Further analysis showed that the has-miR-193a-3p, has-miR-142-3p, has- miR-142-5p, and has-miR-15b-5p were closely related to tumor invasion, distant metastasis and survival probability. The expression of miR-15b-5p in ccRCC tissues was significantly higher than that in adjacent normal kidney tissues (P0.05). Following inhibition of miR-15b-5p expression, RCC cells had attenuated proliferation, increased apoptosis, and attenuated migration and invasion. has-miR-15b-5p-WEE1, has-miR-15b-5p-EIF4E, has-miR-15b-5p-PPP2R1B may be three potential regulatory pathways in ccRCC. miR-15b-5p is highly expressed in cancer tissues of ccRCC patients. It may promote proliferation, inhibit apoptosis and enhance cell migration and invasion of RCC cells. The has-miR-15b-5p-WEE1, has-miR-15b-5p-EIF4E, and has-miR-15b-5p-PPP2R1B may be three potential regulatory pathways in ccRCC.

Investigamos la expresión y la importancia clínica de miR-15b-5p en el carcinoma de células renales (CCR) de células claras mediante análisis bioinformático y verificación experimental. Los miARN expresados diferencialmente se examinaron en la base de datos GEO. El diagrama de Venn mostró que había 5 miARN regulados positivamente (has-miR-210, has-miR-142-3p, has-miR-142-5p, has-miR-15b-5p y has-miR-193a-3p). ) y solo 1 miARN regulado negativamente (has-miR-532-3p) que se expresaron comúnmente entre los conjuntos de datos GSE189331 y GSE16441. Esto fue confirmado aún más en TCGA. Un análisis más detallado mostró que has-miR-193a-3p, has-miR-142-3p, has- miR-142-5p y has-miR-15b-5p estaban estrechamente relacionados con la invasión tumoral, la metástasis a distancia y la probabilidad de supervivencia. La expresión de miR-15b-5p en tejidos ccRCC fue significativamente mayor que la de los tejidos renales normales adyacentes (P 0,05). Tras la inhibición de la expresión de miR-15b-5p, las células RCC tuvieron una proliferación atenuada, un aumento de la apoptosis y una migración e invasión atenuadas. has-miR-15b-5p-WEE1, has- miR-15b-5p-EIF4E, has-miR-15b-5p-PPP2R1B pueden ser tres posibles vías reguladoras en ccRCC. miR-15b-5p se expresa altamente en tejidos cancerosos de pacientes con ccRCC. Puede promover la proliferación, inhibir la apoptosis y mejorar la migración celular y la invasión de células RCC. has-miR-15b-5p-WEE1, has- miR-15b-5p-EIF4E y has-miR-15b-5p-PPP2R1B pueden ser tres posibles vías reguladoras en ccRCC.

Partial versus radical nephrectomy for the treatment of pT3aN0M0 renal cell carcinoma: A propensity score analysis.

BACKGROUND: The survival benefit of partial nephrectomy (PN) in pT3a RCC patients is controversial. Here we aimed to explore the potential benefit of PN for pT3aN0M0 renal cell carcinoma (RCC). MATERIAL AND METHODS: Data of patients with pT3aN0M0 RCC who were diagnosed between 2010 and 2012 in the National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) database were retrospectively collected. Overall survival (OS) and cancer specific survival (CSS) were compared using a Cox proportional hazards model between PN and radical nephrectomy (RN) in pT3aN0M0 RCC. Propensity score (-adjusted, -stratified, -weighted, and -matched) analyses were performed to control for imbalances in individual risk factors. RESULTS: A total of 1277 patients with pT3aN0M0 RCC were identified, of whom 200 patients were treated with PN and 1077 patients were RN. PN showed favorable OS and CSS in 0-4 cm pT3aN0M0 RCC (P < 0.05), and similar OS and CSS in 4-7 cm pT3aN0M0 RCC, compared with RN using un-adjusted analyses. The Propensity score analyses further demonstrated the survival benefit of PN compared with the RN in 0-4 cm pT3aN0M0 RCC (P < 0.05). CONCLUSIONS: In this retrospective study, PN was associated with improved survival compared with RN in 0-4 cm pT3aN0M0 RCC. Moreover, survival was comparable between PN and RN in 4-7 cm pT3aN0M0 RCC. These data provided evidence that PN could be an alternative choice for T3aN0M0 RCC less than 7 cm. Particularly, patients with 0-4 cm pT3aN0M0 RCC might benefit from PN.

Characteristics of reflux and gastric electrical activity in gastroesophageal reflux disease with ineffective esophageal motility.

OBJECTIVES: The impact of ineffective esophageal motility (IEM) on gastroesophageal reflux disease (GERD) remains unknown, and abnormal esophageal motility often coexists with abnormal gastric motility. We aimed to investigate the role of IEM in GERD and its relationship with gastric electrical activity. METHODS: Patients diagnosed as GERD based on GERD-questionnaire score ≥8 in our hospital from January 2020 to June 2022 were included. All patients underwent 24-h multichannel intraluminal impedance-pH monitoring, high-resolution manometry, and electrogastrogram and were categorized into the normal esophageal motility (NEM) and IEM groups, respectively. Reflux characteristics and gastric electric activity were compared between the two groups, and the correlation between gastric electric activity and reflux was analyzed. RESULTS: Acid exposure time, total reflux episodes, and DeMeester score in the IEM group were higher than those in the NEM group. Distal mean nocturnal baseline impedance was significantly lower in the IEM group. Compared with the NEM group, the power ratio (PR) of fundus, antrum and pylorus and premeal and postmeal normal wave ratio of antrum were significantly lower in IEM. The total reflux episodes were negatively correlated with the PR of fundus and pylorus, and the DeMeester score was negatively correlated with the PR of corpus and pylorus. CONCLUSIONS: IEM may lead to increased reflux, resulting in esophageal mucosal damage. There may be consistency between abnormal esophageal motility and gastric motility.

Correlation between methylenetetrahydrofolate reductase gene-specific methylation and recurrent spontaneous abortion.

OBJECTIVE: To investigate the correlation between methylenetetrahydrofolate reductase (MTHFR) gene-specific methylation and recurrent spontaneous abortion (RSA). METHODS: A total of 50 RSA patients who visited our hospital were recruited in the study group; 50 multiparous women who underwent physical examinations during the same period were enrolled in the control group. The levels of homocysteine, folic acid, and vitamin B12 and their MTHFR gene polymorphism and specific methylation were measured in both groups. The Logistic regression equation was used to analyze the correlation between MTHFR gene-specific methylation and RSA. RESULTS: The methylated allele MM was not found in the control group, and the frequency in the study group was 1.19%. The frequency of the MU genotype in the study group 32.93% was higher than that in the control group 12.45%. The frequency of methylated alleles of CC and CT genotypes carrying MTHFR C677T polymorphism in the study group was higher than that in the control group (P < 0.05). There was no significant difference in the TT genotype between the two groups (P > 0.05). Multivariate Logistic regression analysis exhibited that patients with methylated alleles of CC genotype had a risk of RSA increased by 1.167 times, and the risk increased by 2.500 times in patients with methylated alleles of CT genotype (P < 0.05). 83.33% of RSA patients carrying methylated alleles affected hyperhomocysteinemia. In patients with elevated homocysteine levels, the risk of RSA caused by methylated allele was significantly increased by 7.321 times. CONCLUSION: MTHFR gene-specific methylation can significantly increase the risk of RSA.

Rad regulation of CaV1.2 channels controls cardiac fight-or-flight response.

Fight-or-flight responses involve ß-adrenergic-induced increases in heart rate and contractile force. In the present study, we uncover the primary mechanism underlying the heart's innate contractile reserve. We show that four protein kinase A (PKA)-phosphorylated residues in Rad, a calcium channel inhibitor, are crucial for controlling basal calcium current and essential for ß-adrenergic augmentation of calcium influx in cardiomyocytes. Even with intact PKA signaling to other proteins modulating calcium handling, preventing adrenergic activation of calcium channels in Rad-phosphosite-mutant mice (4SA-Rad) has profound physiological effects: reduced heart rate with increased pauses, reduced basal contractility, near-complete attenuation of ß-adrenergic contractile response and diminished exercise capacity. Conversely, expression of mutant calcium-channel ß-subunits that cannot bind 4SA-Rad is sufficient to enhance basal calcium influx and contractility to adrenergically augmented levels of wild-type mice, rescuing the failing heart phenotype of 4SA-Rad mice. Hence, disruption of interactions between Rad and calcium channels constitutes the foundation toward next-generation therapeutics specifically enhancing cardiac contractility.

Multi Spherical Wave Imaging Method Based on Ultrasonic Array.

The imaging range of traditional plane wave imaging is usually limited by the directivity of the plane wave. In this paper, a multi spherical wave imaging method based on an ultrasonic array is proposed, which radiates both compression and shear waves in a solid medium to form the multi spherical wave. Firstly, excitation characteristics of the multi spherical wave are analyzed theoretically and the calculation method of echo delay of multi spherical wave imaging is derived. Multi spherical wave imaging is compared with conventional ultrasonic plane wave imaging by designing experiments. Compared with ultrasonic plane wave imaging, multi spherical wave imaging is not limited to the size of the transducer and can greatly improve the detection range. In addition, compared with the multi plane wave imaging method, the multi spherical wave imaging algorithm is relatively simple, fast, and has high application value.

Pien Tze Huang Inhibits Migration and Invasion of Hepatocellular Carcinoma Cells by Repressing PDGFRB/YAP/CCN2 Axis Activity.

OBJECTIVE: To investigate the effects of Pien Tze Huang (PZH) on the migration and invasion of HCC cells and underlying molecular mechanism. METHODS: Cell counting kit-8 (CCK-8) was applied to evaluate the cell viabilities of SMMC-7721, SK-Hep-1, C3A and HL-7702 (6 × 103 cells/well) co-incubated with different concentrations of PZH (0, 0.2, 0.4, 0.6, 0.8 mg/mL) for 24 h. Transwell, wound healing assay, CCK-8 and Annexin V-FITC/PI staining were conducted to investigate the effects of PZH on the migration, invasion, proliferation and apoptosis of SK-Hep-1 and SMMC-7721 cells (650 µ g/mL for SK-Hep-1 cells and 330 µ g/mL for SMMC-7721 cells), respectively. In vivo, lung metastasis mouse model constructed by tail vein injection of HCC cells was used for evaluating the anti-metastasis function of PZH. SK-Hep-1 cells (106 cells/200 µ L per mice) were injected into B-NDG mice via tail vein. Totally 8 mice were randomly divided into PZH and control groups, 4 mice in each group. After 2-d inoculation, mice in the PZH group were administered with PZH (250 mg/kg, daily) and mice in the control group received only vehicle (PBS) from the 2nd day after xenograft to day 17. Transcriptome analysis based on RNA-seq was subsequently used for deciphering anti-tumor mechanism of PZH. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were applied to verify RNA-seq results. Luciferase reporter assay was performed to examine the transcriptional activity of yes-associated protein (YAP). RESULTS: PZH treatment significantly inhibited the migration, invasion, proliferation and promoted the apoptosis of HCC cells in vitro and in vivo (P<0.01). Transcriptome analysis indicated that Hippo signaling pathway was associated with anti-metastasis function of PZH. Mechanical study showed PZH significantly inhibited the expressions of platelet derived growth factor receptor beta (PDGFRB), YAP, connective tissue growth factor (CCN2), N-cadherin, vimentin and matrix metallopeptidase 2 (MMP2, P<0.01). Meanwhile, the phosphorylation of YAP was also enhanced by PZH treatment in vitro and in vivo. Furthermore, PZH played roles in inhibiting the transcriptional activity of YAP. CONCLUSION: PZH restrained migration, invasion and epithelial-mesenchymal transition of HCC cells through repressing PDGFRB/YAP/CCN2 axis.

Fibroblast growth factor homologous factors serve as a molecular rheostat in tuning arrhythmogenic cardiac late sodium current.

Voltage-gated sodium (Nav1.5) channels support the genesis and brisk spatial propagation of action potentials in the heart. Disruption of NaV1.5 inactivation results in a small persistent Na influx known as late Na current (I Na,L), which has emerged as a common pathogenic mechanism in both congenital and acquired cardiac arrhythmogenic syndromes. Here, using low-noise multi-channel recordings in heterologous systems, LQTS3 patient-derived iPSCs cardiomyocytes, and mouse ventricular myocytes, we demonstrate that the intracellular fibroblast growth factor homologous factors (FHF1-4) tune pathogenic I Na,L in an isoform-specific manner. This scheme suggests a complex orchestration of I Na,L in cardiomyocytes that may contribute to variable disease expressivity of NaV1.5 channelopathies. We further leverage these observations to engineer a peptide-inhibitor of I Na,L with a higher efficacy as compared to a well-established small-molecule inhibitor. Overall, these findings lend insights into molecular mechanisms underlying FHF regulation of I Na,L in pathophysiology and outline potential therapeutic avenues.

Analysis of flavonoids and phenylethanoid glycosides in the Tibetan herb Lagotis brevituba Maxim based on UHPLC-LTQ-orbitrap-MS / 药学学报

Ultra high performance liquid chromatography tandem linear ion trap orbitrap mass spectrometry (UHPLC-LTQ-orbitrap-MS) was applied to analyze and identify flavonoids and phenylethanoid glycosides in the Tibetan herb Lagotis brevituba Maxim. A method of data-dependent scan coupling with dynamic exclusion was developed for analyzing flavonoids and phenylethanoid glycosides under positive and negative ion mode of electrospray ionization (ESI). The compounds of Lagotis brevituba Maxim. were systematically identified through exact molecular mass, fragmentation patterns, retention time and reported references. A total of 167 compounds were detected, of which 84 were flavonoids and 83 were phenylethanoid glycosides, which greatly enriched the number and types of flavonoids and phenylethanol glycosides in Lagotis genus medicinal plants. Baohuoside Ⅰ, 4 disaccharide O-glycoside flavonoids (composed of deoxyhexose and glucuronic acid), 9 C-glycoside flavonoids, 15 tetrasaccharide phenylethanoid glycosides and 5 phenylethanoid glycosides with substituents on the β-position of the phenylethyl group were identified in Lagotis genus medicinal plants for the first time. This study provides scientific support for elucidating the material basis and improving the quality control of Lagotis brevituba Maxim.

Attenuating persistent sodium current-induced atrial myopathy and fibrillation by preventing mitochondrial oxidative stress.

Mechanistically driven therapies for atrial fibrillation (AF), the most common cardiac arrhythmia, are urgently needed, the development of which requires improved understanding of the cellular signaling pathways that facilitate the structural and electrophysiological remodeling that occurs in the atria. Similar to humans, increased persistent Na+ current leads to the development of an atrial myopathy and spontaneous and long-lasting episodes of AF in mice. How increased persistent Na+ current causes both structural and electrophysiological remodeling in the atria is unknown. We crossbred mice expressing human F1759A-NaV1.5 channels with mice expressing human mitochondrial catalase (mCAT). Increased expression of mCAT attenuated mitochondrial and cellular reactive oxygen species (ROS) and the structural remodeling that was induced by persistent F1759A-Na+ current. Despite the heterogeneously prolonged atrial action potential, which was unaffected by the reduction in ROS, the incidences of spontaneous AF, pacing-induced after-depolarizations, and AF were substantially reduced. Expression of mCAT markedly reduced persistent Na+ current-induced ryanodine receptor oxidation and dysfunction. In summary, increased persistent Na+ current in atrial cardiomyocytes, which is observed in patients with AF, induced atrial enlargement, fibrosis, mitochondrial dysmorphology, early after-depolarizations, and AF, all of which can be attenuated by resolving mitochondrial oxidative stress.

Temporal-spatial variation and the affecting factors of protected areas in Guizhou, China.

The establishment of protected areas is the bottom line of ecological security for promoting the construction of ecological civilization and supporting economic and social development, which is an important strategy to realize sustainable development and maintain ecological security. In order to reveal the large spatial process of protected areas and its influencing factors, we used the methods of nearest neighbor index, kernel density, and standard deviational ellipse to analyze the temporal-spatial variation characteristics of the protected areas in Guizhou Province from 2002 to 2017, as well as the influencing factors combined with geo-detectors. The results showed that, during the study period, the number, area, and types of protected areas in Guizhou Province showed a diversified and rapid development, forming a protected area system with nature reserves, forest parks and scenic spots as the main body and wetland parks, geoparks and natural heritage sites as the supplement. The spatial cohesion of protected areas was strengthened, the scope of spatial distribution was expanding, and the speed of spatial movement was declining, forming a spatial pattern dominated by the northeast-southwest direction and gradually stable. The coalescence process in protected areas was strongly influenced by topography and vegetation distribution. The protected areas tended to cluster in gentle terrain around rivers and mountains and in areas of concentrated vegetation. The spatial differentiation of protected areas was jointly affected by multiple factors at different levels. The explanatory power of different factors to the spatial differentiation of protected areas was different. Among them, the normalized difference vegetation index, areas of forest and highway mileage were the common main factors affecting the spatial differentiation of the number and area of protected areas, and the explanatory power of different factors was significantly consolidated after interaction, characterized as nonlinear or bi-factor enhancement.

Analysis of Studies in Tinnitus-Related Gene Research.

OBJECTIVE: Summarize and analyze the current research results of tinnitus-related genes, explore the potential links between the results of each study, and provide reference for subsequent studies. METHODS: Collect and sort out the research literature related to tinnitus genes included in PubMed, Web of Science, China National Knowledge Infrastructure, and Wanfang Data Knowledge Service Platform before December 31, 2019. Then the relevant contents of the literature were sorted out and summarized. RESULTS: Fifty-one articles were finally selected for analysis: 31 articles (60.8%) were classified as researches on animal models of tinnitus, and 20 (39.2%) as researches on tinnitus patients. Existing studies have shown that genes related to oxidative stress, inflammatory response, nerve excitation/inhibition, and nerve growth are differentially expressed in tinnitus patients or animal models, and have presented the potential links between genes or proteins in the occurrence and development of tinnitus. CONCLUSION: The research on tinnitus-related genes is still in the exploratory stage, and further high-quality research evidence is needed.

Adrenergic CaV1.2 Activation via Rad Phosphorylation Converges at α1C I-II Loop.

RATIONALE: Changing activity of cardiac CaV1.2 channels under basal conditions, during sympathetic activation, and in heart failure is a major determinant of cardiac physiology and pathophysiology. Although cardiac CaV1.2 channels are prominently upregulated via activation of PKA (protein kinase A), essential molecular details remained stubbornly enigmatic. OBJECTIVE: The primary goal of this study was to determine how various factors converging at the CaV1.2 I-II loop interact to regulate channel activity under basal conditions, during ß-adrenergic stimulation, and in heart failure. METHODS AND RESULTS: We generated transgenic mice with expression of CaV1.2 α1C subunits with (1) mutations ablating interaction between α1C and ß-subunits, (2) flexibility-inducing polyglycine substitutions in the I-II loop (GGG-α1C), or (3) introduction of the alternatively spliced 25-amino acid exon 9* mimicking a splice variant of α1C upregulated in the hypertrophied heart. Introducing 3 glycine residues that disrupt a rigid IS6-α-interaction domain helix markedly reduced basal open probability despite intact binding of CaVß to α1C I-II loop and eliminated ß-adrenergic agonist stimulation of CaV1.2 current. In contrast, introduction of the exon 9* splice variant in the α1C I-II loop, which is increased in ventricles of patients with end-stage heart failure, increased basal open probability but did not attenuate stimulatory response to ß-adrenergic agonists when reconstituted heterologously with ß2B and Rad or transgenically expressed in cardiomyocytes. CONCLUSIONS: Ca2+ channel activity is dynamically modulated under basal conditions, during ß-adrenergic stimulation, and in heart failure by mechanisms converging at the α1C I-II loop. CaVß binding to α1C stabilizes an increased channel open probability gating mode by a mechanism that requires an intact rigid linker between the ß-subunit binding site in the I-II loop and the channel pore. Release of Rad-mediated inhibition of Ca2+ channel activity by ß-adrenergic agonists/PKA also requires this rigid linker and ß-binding to α1C.