Background and Aims: There is accumulating evidence that sympathetic nervous hyperactivity contributes to the pathogenesis of glomerular sclerosis independent of blood pressure effects. A previous study showed that α₁-adrenoceptor (α₁-AR) antagonists inhibit mesangial cell (MC) proliferation. However, the underlying mechanism remains unclear. Methods and Results: We found that α₁-AR is expressed in a human mesangial cell line. The α₁-AR agonist phenylephrine (PE) induced Ca²⁺ influx as well as release from intracellular Ca²⁺ stores. Blockade of TRPC6 with siRNA, anti-TRPC6 antibodies and a TRPC blocker attenuated the PE-induced [Ca²⁺]_i increase. Additionally, the PE-induced [Ca²⁺]_i increase was phospholipase C dependent. Furthermore, PE induced a [Ca²⁺]_i increase even when the intracellular Ca²⁺ stores were already depleted. This effect was mimicked by an analog of diacylglycerol. These results suggested that, upon α₁-AR stimulation, TRPC6 mediates Ca²⁺ influx via a receptor-operated Ca²⁺ entry mechanism. Finally, TRPC6 contributes to the PE-induced MC proliferation. The mechanisms are associated with the extracellular signal-regulated kinase (ERK) signaling pathway because blockade of TRPC6 and chelation of extracellular Ca²⁺ abrogated PE-induced ERK1/2 abrogated PE-induced ERK1/2 phosphorylation. Conclusion: TRPC6 channels are involved in α₁-AR activation-induced Ca²⁺ entry, which mediates proliferation via ERK signaling in human MCs

Background/Aims: Recent studies provided compelling evidence that stimulation of the calcium sensing receptor (CaSR) exerts direct renoprotective action at the glomerular podocyte level. This protective action may be attributed to the RhoA-dependent stabilization of the actin cytoskeleton. However, the underlying mechanisms remain unclear. Methods: In the present study, an immortalized human podocyte cell line was used. Fluo-3 fluorescence was utilized to determine intracellular Ca²⁺ concentration ([Ca²⁺]_i), and western blotting was used to measure canonical transient receptor potential 6 (TRPC6) protein expression and RhoA activity. Stress fibers were detected by FITC-phalloidin. Results: Activating CaSR with a high extracellular Ca²⁺ concentration ([Ca²⁺]_o) or R-568 (a type II CaSR agonist) induces an increase in the [Ca²⁺]_i in a dose-dependent manner. This increase in [Ca²⁺]_i is phospholipase C (PLC)-dependent and is smaller in the absence of extracellular Ca²⁺ than in the presence of 0.5 mM [Ca²⁺]_o. The CaSR activation-induced [Ca²⁺]_i increase is attenuated by the pharmacological blockage of TRPC6 channels or siRNA targeting TRPC6. These data suggest that TRPC6 is involved in CaSR activation-induced Ca²⁺ influx. Consistent with a previous study, CaSR stimulation results in an increase in RhoA activity. However, the knockdown of TRPC6 significantly abolished the RhoA activity increase induced by CaSR stimulation, suggesting that TRPC6-dependent Ca²⁺ entry is required for RhoA activation. The activated RhoA is involved in the formation of stress fibers and focal adhesions in response to CaSR stimulation because siRNA targeting RhoA attenuated the increase in the stress fiber mediated by CaSR stimulation. Moreover, this effect of CaSR activation on the formation of stress fibers is also abolished by the knockdown of TRPC6. Conclusion: TRPC6 is involved in the regulation of stress fiber formation and focal adhesions via the RhoA pathway in response to CaSR activation. This may explain the direct protective action of CaSR agonists.

<b><i>Introduction:</i></b> Telemedicine (TM) has shown to provide potential benefits on clinical outcomes in patients with chronic kidney disease but limited evidences published in the peritoneal dialysis (PD) population. This study aimed to explore the long-term effects of TM on the mortality and technique failure. <b><i>Methods:</i></b> The Peritoneal Dialysis Telemedicine-assisted Platform Cohort Study (PDTAP Study) was conducted prospectively in 27 hospitals in China since 2016. Patient and practice data were collected through the doctor-end of the TM app (Manburs) for all participants. TM including self-monitoring records, on-line education materials, and real-time physician-patient contact was only performed for the patient-end users of the Manburs. The primary outcome was all-cause mortality. The secondary outcomes were cause-specific mortality and all-cause and cause-specific permanent transfer to hemodialysis. <b><i>Results:</i></b> A total of 7,539 PD patients were enrolled between June 2016 and April 2019, with follow-up till December 2020. Patients were divided into two cohorts: TM group (39.1%) and non-TM group (60.9%). A propensity score was used to create 2,160 matched pairs in which the baseline covariates were well-balanced. There were significantly lower risks of all-cause mortality (HR 0.59 [0.51, 0.67], <i>p</i> &#x3c; 0.001), CVD mortality (HR 0.59 [0.49, 0.70], <i>p</i> &#x3c; 0.001), all-cause transfer to hemodialysis (0.57 [0.48, 0.67], <i>p</i> &#x3c; 0.001), transfer to hemodialysis from PD-related infection (0.67 [0.51, 0.88], <i>p</i> = 0.003), severe fluid overload (0.40 [0.30, 0.55], <i>p</i> &#x3c; 0.001), inadequate solute clearance (0.49 [0.26, 0.92], <i>p</i> = 0.026), and catheter-related noninfectious complications (0.41 [0.17, 0.97], <i>p</i> = 0.041) in the TM group compared with the non-TM group. <b><i>Conclusion:</i></b> This study indicated real-world associations between TM usage and reduction in patient survival and technique survival through a multicenter prospective cohort.

Although extended pluripotent stem cells (EPSCs) have the potential to form both embryonic and extraembryonic lineages, how their transcriptional regulatory mechanism differs from that of embryonic stem cells (ESCs) remains unclear. Here, we discovered that YY1 binds to specific open chromatin regions in EPSCs. Yy1 depletion in EPSCs leads to a gene expression pattern more similar to that of ESCs than control EPSCs. Moreover, Yy1 depletion triggers a series of epigenetic crosstalk activities, including changes in DNA methylation, histone modifications and high-order chromatin structures. Yy1 depletion in EPSCs disrupts the enhancer-promoter (EP) interactions of EPSC-specific genes, including Dnmt3l. Yy1 loss results in DNA hypomethylation and dramatically reduces the enrichment of H3K4me3 and H3K27ac on the promoters of EPSC-specific genes by upregulating the expression of Kdm5c and Hdac6 through facilitating the formation of CCCTC-binding factor (CTCF)-mediated EP interactions surrounding their loci. Furthermore, single-cell RNA sequencing (scRNA-seq) experiments revealed that YY1 is required for the derivation of extraembryonic endoderm (XEN)-like cells from EPSCs in vitro. Together, this study reveals that YY1 functions as a key regulator of multidimensional epigenetic crosstalk associated with extended pluripotency.