CACNA1H downregulation induces skeletal muscle atrophy involving endoplasmic reticulum stress activation and autophagy flux blockade

Abstract

Multiple vaginal delivery (MVD) is an important factor for pelvic floor muscle (PFM) function decline and pelvic floor dysfunction (PFD). PFD is common in middle-aged and elderly women, but its pathogenesis is not clear. In this study, we found that the expression of CACNA1H was lower in the PFM of old mice after MVD compared with old or adult mice. In in-vitro studies, we found that treatment with the T-type Ca 2+ channel (T-channel) inhibitor NNC-55 or downregulation of the CACNA1H gene by siRNA intervention promoted myotube atrophy and apoptosis. Mechanistically, we revealed that NNC-55 increased the expression of GRP78 and DDIT3 in myotubes, indicating endoplasmic reticulum stress (ERS) activation, and that the IRE1 and PERK pathways might be involved in this effect. NNC-55 induced the formation of autophagosomes but inhibited autophagy flux. Moreover, rapamycin, an autophagy activator, did not rescue myotube atrophy or apoptosis induced by NNC-55, and the autophagy inhibitors 3-MA and HCQ accelerated this damage. Further studies showed that the ERS inhibitors 4-PBA and TUDAC relieved NNC-55-induced damage and autophagy flux blockade. Finally, we found multisite muscle atrophy and decreased muscle function in Cacna1h −/− (TH-null) mice, as well as increased autophagy inhibition and apoptotic signals in the PFM of old WT mice after MVD and TH-null mice. Taken together, our results suggest that MVD-associated PFD is partially attributed to CACNA1H downregulation-induced PFM atrophy and that ERS is a potential therapeutic target for this disease.

Associations between gut microbiota and hand grip strength: a polygenetic scoring analysis and genome-wide environmental interaction study

“…Previous study indicated compound heterozygous CACNA1H mutations might lead to severe congenital amyotrophy [61]. Another experimental analysis suggested reduced expression of CACNA1H related to multiple vaginal delivery is associated with muscular atrophy, indicating the key regulator role of CACNA1H in skeletal muscle function [62]. In our study, we found CACNA1H is interacted with G_Butyricicoccus and might affect HGS in UK Biobank samples.…”

Calcium channelopathies and intellectual disability: a systematic review

“…Mouse model of visceral hypersensitivity and in irritable bowel syndrome [ 272 ]. Mouse model of inflammatory and neuropathic pain [ 273 ] (2S)-6-prenylnaringenin can block Cav3.2 current [ 150 ] Apoptotic pathway in myocardial cells [ 155 ] Autophagy pathway [ 158 ] CACNA2D1 Calcium voltage-gated channel auxiliary subunit alpha2delta 1 Cav1.3 L-type None Conventional knockout mouse using a construct targeting exon 2 of alpha (2)/delta-1 [ 274 ]. α2 δ1 Tg model for neuropathic pain [ 275 , 276 ] None None CACNA2D2 Calcium voltage-gated channel auxiliary subunit alpha2delta 2 Cav1.3 L-type None The “ducky’ du (2 J) mouse model of ataxia and absence epilepsy [ 277 ].…”

“…Induced pluripotent stem cells (iPSCs) and HEK293T cells for spinocerebellar ataxia [ 302 ] Endostatin, zonisamide, clozapine, roscovitine, mibefradil, iron and zinc can block Cav3.1 channel [ 179 – 185 ] Dearomatized isoprenylated acylphloroglucinol and monoterpenoid, hypatone A could rescue pathological gating properties for spinocerebellar ataxia 42 [ 186 ] Autophagic pathway in melanoma cells [ 198 ] Apoptotic pathway in [ 193 – 195 ] Ras-ERK signaling pathway [ 200 , 201 ] CACNA1H Calcium voltage-gated channel subunit alpha1 H Cav3.2 T-type None TsA-201 cell for amyotrophic lateral sclerosis [ 303 ] KYS-05090S can block Cav3.2 current [ 187 ] Apoptotic pathway in myocardial cells [ 155 ]. Autophagy pathway [ 158 ] CACNA1I Calcium Voltage-Gated Channel Subunit Alpha1 I Cav 3.3 T-type HEK293T and mouse chromaffin cells for ID and epilepsy [ 74 ] None Zinc modulates Cav3.3 channel gating [ 181 ] None CACNA2D1 Calcium voltage-gated channel auxiliary subunit alpha2delta 1 Cav1.3 L-type None MKN74 cells (human gastric cancer cell line) [ 190 ] MicroRNA-107 can inhibit expression of Cav1.3 in cancer [ 188 , 189 ] Amlodipine can block Cav1.3 in cancer [ 190 ] CXCR3/ERK1/2 signaling pathway [ 203 ] Ras/Raf/MEK/ERK signaling pathway [ 202 ] …”

T‐type calcium channel blockade induces apoptosis in C2C12 myotubes and skeletal muscle via endoplasmic reticulum stress activation

“…ER proteostasis surveillance mediated by ERS also plays a crucial physiological role in the maintenance of skeletal muscle and is emerging as a possible driver of cell apoptosis. Our previous study uncovered that TCC inhibition induced C2C12 myotube atrophy through ERS activation and autophagy flux blockade [24]. ERS is upstream of autophagy blockade induced by NNC‐55, and mitochondrial dysfunction could also regulate autophagic process through ROS production and mitochondria‐specific proteins.…”

“…We previously identified that the expression of TH ( CACNA1H ) is higher than that of the other two types in mammalian skeletal muscle and myoblasts. TCC inhibition by NNC 55‐0396 hydrate (NNC‐55) promoted ERS activation and autophagosome formation but blocked distal autophagy and autophagy flux [24]. Given that ERS is upstream of autophagy blockade induced by NNC‐55 and mitochondrial dysfunction could regulate autophagic process through ROS production and mitochondria‐specific proteins [25], we explore the primary effects of TCC function loss on ERS activation and mitochondrial‐related apoptosis.…”