scholarly journals MicroRNA-135a is involved in podocyte injury in a transient receptor potential channel 1-dependent manner

2017 ◽  
Vol 40 (5) ◽  
pp. 1511-1519 ◽  
Author(s):  
Xianggui Yang ◽  
Dongming Wu ◽  
Hongfei Du ◽  
Fang Nie ◽  
Xueli Pang ◽  
...  
Keyword(s):  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Transient Receptor Potential Channel ◽  
Dependent Manner ◽  
Podocyte Injury ◽  
Transient Receptor

scholarly journals Potentiation of TRPC5 by Protons

2007 ◽  
Vol 282 (46) ◽  
pp. 33868-33878 ◽  
Author(s):  
Marcus Semtner ◽  
Michael Schaefer ◽  
Olaf Pinkenburg ◽  
Tim D. Plant
Keyword(s):  
Phospholipase C ◽  
Transient Receptor Potential ◽  
Single Channel ◽  
Receptor Potential ◽  
High Sensitivity ◽  
Transient Receptor Potential Channel ◽  
Extracellular Ph ◽  
Dependent Manner ◽  
Open Probability ◽  
Transient Receptor

Mammalian members of the classical transient receptor potential channel subfamily (TRPC) are Ca2+-permeable cation channels involved in receptor-mediated increases in intracellular Ca2+. TRPC4 and TRPC5 form a group within the TRPC subfamily and are activated in a phospholipase C-dependent manner by an unidentified messenger. Unlike most other Ca2+-permeable channels, TRPC4 and -5 are potentiated by micromolar concentrations of La3+ and Gd3+. This effect results from an action of the cations at two glutamate residues accessible from the extracellular solution. Here, we show that TRPC4 and -5 respond to changes in extracellular pH. Lowering the pH increased both G protein-activated and spontaneous TRPC5 currents. Both effects were already observed with small reductions in pH (from 7.4 to 7.0) and increased up to pH 6.5. TRPC4 was also potentiated by decreases in pH, whereas TRPC6 was only inhibited, with a pIC50 of 5.7. Mutation of the glutamate residues responsible for lanthanoid sensitivity of TRPC5 (E543Q and E595Q) modified the potentiation of TRPC5 by acid. Further evidence for a similarity in the actions of lanthanoids and H+ on TRPC5 is the reduction in single channel conductance and dramatic increase in channel open probability in the presence of either H+ or Gd3+ that leads to larger integral currents. In conclusion, the high sensitivity of TRPC5 to H+ indicates that, in addition to regulation by phospholipase C and other factors, the channel may act as a sensor of pH that links decreases in extracellular pH to Ca2+ entry and depolarization.

scholarly journals The Calcium-Dependent Protease Calpain-1 Links TRPC6 Activity to Podocyte Injury

2018 ◽  
Vol 29 (8) ◽  
pp. 2099-2109 ◽  
Author(s):  
Kim A.T. Verheijden ◽  
Ramon Sonneveld ◽  
Marinka Bakker-van Bebber ◽  
Jack F.M. Wetzels ◽  
Johan van der Vlag ◽  
...  
Keyword(s):  
Transient Receptor Potential ◽  
Calcium Influx ◽  
Receptor Potential ◽  
Transient Receptor Potential Channel ◽  
Slit Diaphragm ◽  
Calpain Inhibitor ◽  
Podocyte Injury ◽  
Calcium Dependent ◽  
Transient Receptor ◽  
Calcineurin Activity

BackgroundThe hallmark of podocytopathies, such as FSGS, is podocyte injury resulting in proteinuria. Transient receptor potential channel C6 (TRPC6) is a calcium-conducting ion channel expressed at the slit diaphragm. TRPC6 gain-of-function mutations and glomerular TRPC6 overexpression are associated with proteinuria. However, the pathways linking TRPC6 to podocyte injury, which is characterized by loss of the slit diaphragm protein nephrin, activation of several intracellular pathways (including calcineurin-NFAT signaling), and cytoskeletal rearrangement, remain elusive.MethodsWe tested whether the calcium-dependent protease calpain-1 mediates TRPC6-dependent podocyte injury in human and experimental FSGS and cultured podocytes.ResultsCompared with kidneys of healthy controls, kidneys of patients with FSGS had increased TRPC6 expression, increased calpain and calcineurin activity, and reduced expression of the calpain target Talin-1, which links the actin cytoskeleton to integrins and is critical for podocyte cytoskeletal stability. In a rat model of human FSGS, increased glomerular and urinary calpain activity associated with reduced Talin-1 abundance, enhanced calcineurin activity, and increased proteinuria. Treatment with the calpain inhibitor calpeptin prevented these effects. In cultured podocytes, pharmacologic stimulation of TRPC6-dependent calcium influx increased calpain-1 and calcineurin activity and reduced Talin-1 expression, and knockdown of TRPC6 or calpain-1 prevented these effects.ConclusionsWe elucidated a novel mechanism that links TRPC6 activity to calpain-1 activation and through Talin-1 loss and possibly, calcineurin activation, the podocyte injury characterizing FSGS. Therefore, calpain-1 and/or TRPC6 inhibition could be future therapeutic options to treat patients with FSGS or other podocytopathies.

scholarly journals Mahogunin Ring Finger 1 regulates pigmentation by controlling the pH of melanosomes in melanocytes and melanoma cells

2021 ◽  
Author(s):  
Julia Sirés-Campos ◽  
Ana Lambertos ◽  
Cédric Delevoye ◽  
Graça Raposo ◽  
Dorothy C. Bennett ◽  
...  
Keyword(s):  
Transient Receptor Potential ◽  
Specific Activity ◽  
Ring Finger ◽  
Receptor Potential ◽  
Transient Receptor Potential Channel ◽  
Melanoma Cells ◽  
Live Cells ◽  
Dependent Manner ◽  
Transient Receptor ◽  
Acidic Organelles

AbstractMahogunin Ring Finger 1 (MGRN1) is an E3-ubiquitin ligase absent in dark-furred mahoganoid mice. We investigated the mechanisms of hyperpigmentation in Mgrn1-null melan-md1 melanocytes, Mgrn1-KO cells obtained by CRISPR-Cas9-mediated knockdown of Mgrn1 in melan-a6 melanocytes, and melan-a6 cells depleted of MGRN1 by siRNA treatment. Mgrn1-deficient melanocytes showed higher melanin content associated with increased melanosome abundance and higher fraction of melanosomes in highly melanized maturation stages III–IV. Expression, post-translational processing and enzymatic activity of the rate-limiting melanogenic enzyme tyrosinase measured in cell-free extracts were comparable in control and MGRN1-depleted cells. However, tyrosinase activity measured in situ in live cells and expression of genes associated with regulation of pH increased upon MGRN1 repression. Using pH-sensitive fluorescent probes, we found that downregulation of MGRN1 expression in melanocytes and melanoma cells increased the pH of acidic organelles, including melanosomes, strongly suggesting a previously unknown role of MGRN1 in the regulation of melanosomal pH. Among the pH regulatory genes upregulated by Mgrn1 knockdown, we identified those encoding several subunits of the vacuolar adenosine triphosphatase V-ATPase (mostly Atp6v0d2) and a calcium channel of the transient receptor potential channel family, Mucolipin 3 (Mcoln3). Manipulation of expression of the Mcoln3 gene showed that overexpression of Mcoln3 played a significant role in neutralization of the pH of acidic organelles and activation of tyrosinase in MGRN1-depleted cells. Therefore, lack of MGRN1 led to cell-autonomous stimulation of pigment production in melanocytes mostly by increasing tyrosinase specific activity through neutralization of the melanosomal pH in a MCOLN3-dependent manner.

scholarly journals Evaluation of podocyte Rac-1 induced kidney disease by modulation of TRPC5

2021 ◽  
Author(s):  
Jochen Reiser ◽  
Onur K Polat ◽  
Elena Isaeva ◽  
Ke Zhu ◽  
Manuel Noben ◽  
...  
Keyword(s):  
Transgenic Mouse ◽  
Transient Receptor Potential ◽  
Kidney Diseases ◽  
Receptor Potential ◽  
Transient Receptor Potential Channel ◽  
Dominant Negative ◽  
Podocyte Injury ◽  
Chronic Kidney Diseases ◽  
Double Transgenic Mouse ◽  
Transient Receptor

Background Transient receptor potential channel 5 (TRPC5) is a non-selective cationic ion channel expressed in brain, kidney and other organs where its activation underlies podocyte injury in chronic kidney diseases. Specifically, it has been suggested that a podocyte TRPC5 plasma membrane relocation and channel activation following injury results from activation of Rac-1, propagating podocyte dysfunction and proteinuria. However, previous TRPC5 transgenic mouse studies had questioned a pathogenic role for TRPC5 in podocytes. This investigation was designed to specifically evaluate podocyte Rac-1 activation in the context of functional TRPC5 or a TRPC5 pore mutant to assess effects on proteinuria. Materials and Methods We employed single cell patch-clamp studies of cultured podocytes and studied proteinuria in transgenic mouse models to characterize the effects of TRPC5 following podocyte Rac-1 activation. Results Inhibition of TRPC5 by small molecules reportedly ameliorated proteinuria in murine models of proteinuric kidney diseases. In order to directly examine TRPC5 function following Rac-1-induced podocyte injury, we analyzed TRPC5 inhibition in podocyte specific Rac-1 (active) transgenic mice. In addition, we generated a double-transgenic mouse constitutively overexpressing either TRPC5 (TRPC5WT) or a TRPC5 dominant-negative pore mutant (TRPC5DN) in concert with podocyte specific and inducible activation of active Rac-1 (Rac-1Dtg). In electrophysiological experiments, active TRPC5 was detected in primary podocytes overexpressing TRPC5 but not in podocytes with endogenous TRPC5 expression, nor with Rac-1 overexpressing podocytes. TRPC5 inhibition did not change proteinuria in mice with active podocyte Rac-1, nor did an increase or loss of TRPC5 activity affected podocyte injury in Rac-1Dtg animals. Administration of TRPC5 inhibitors, ML204 and AC1903, did not alleviate podocyte Rac-1 induced proteinuria. Conclusion TRPC5 inhibition did not modify podocyte Rac-1 induced proteinuria in mice.

scholarly journals Function of the Porcine TRPC1 Gene in Myogenesis and Muscle Growth

Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 147
Author(s):  
Yu Fu ◽  
Peng Shang ◽  
Bo Zhang ◽  
Xiaolong Tian ◽  
Ruixue Nie ◽  
...  
Keyword(s):  
Transient Receptor Potential ◽  
Growth Traits ◽  
Expression Profiles ◽  
Muscle Growth ◽  
Receptor Potential ◽  
Transient Receptor Potential Channel ◽  
Nucleotide Polymorphisms ◽  
Pig Breeds ◽  
Muscle Tissues ◽  
Transient Receptor

In animals, muscle growth is a quantitative trait controlled by multiple genes. Previously, we showed that the transient receptor potential channel 1 (TRPC1) gene was differentially expressed in muscle tissues between pig breeds with divergent growth traits base on RNA-seq. Here, we characterized TRPC1 expression profiles in different tissues and pig breeds and showed that TRPC1 was highly expressed in the muscle. We found two single nucleotide polymorphisms (SNPs) (C-1763T and C-1604T) in TRPC1 that could affect the promoter region activity and regulate pig growth rate. Functionally, we used RNAi and overexpression to illustrate that TRPC1 promotes myoblast proliferation, migration, differentiation, fusion, and muscle hypertrophy while inhibiting muscle degradation. These processes may be mediated by the activation of Wnt signaling pathways. Altogether, our results revealed that TRPC1 might promote muscle growth and development and plays a key role in Wnt-mediated myogenesis.

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