Fragmentation and roles of junctophilin1 in muscle of patients with cytosolic leak of stored calcium

The mechanisms that link the primary increase in SR Ca2+ leak of MH susceptibility and related conditions to their disease phenotypes are not well understood. We found that abnormal Ca2+ homeostasis in MHS individuals induces proteolysis of junctophilin1 (JPh1), an essential structural protein of EC coupling (Perni, in 2017). Guo (in 2018) and Lahiri (in 2020) reported similar fragmentation of JPh2 in stressed hearts. Western blot of patients’ muscle with domain-specific antibodies showed a deficit of full-length JPh1 and excess of a 44-kD C-terminal fragment (JPh44) in MHS subjects. While JPh1 was located in T-SR junctions, JPh44 was found anywhere within the I band, and at high densities within nuclei—a location forbidden for JPh1. Expression and cleavage in mice of a JPh1 plasmid tagged at both ends showed that its N-terminal fragment remained in triads, and the C-terminal fragment, orthologue to JPh44, entered nuclei, which indicates that JPh44 is the C-terminal cleavage product. Endogenous calpain1 appeared in T-SR junctions, colocalized with JPh1. On muscle extracts and primary cultures, Ca2+-activated calpain1 cleaved a 44-kD JPh1 piece, consistent with the C-terminal fragment that starts at Ser241, the highest probability cleavage site found by calpain1 algorithms. Completing the identification of Ser241 as the likely start of JPh44, the tagged deletion plasmid GFP-JPh1_Δ1-240, expressed in mice, copied the location and migration of JPh44. Expression of GFP-JPh1_Δ1-240 in C2C12 myoblasts reduced by more than twofold the transcription of PI3K-Akt genes that inhibit muscle uptake and storage of glucose, including GSK3β, an inhibitor of glycogen synthase that is activated in MHS patients. In agreement with the genetic profile, GSK3β protein content decreased upon expression of GFP-JPh1_Δ1-240. In sum, the identified gene control roles of JPh44 oppose the deleterious effects of chronically elevated cytosolic [Ca2+], including late-onset hyperglycemia and type-2 diabetes (Tammineni, in 2020).

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Faculty Opinions recommendation of Risk of non-fatal cardiovascular diseases in early-onset versus late-onset type 2 diabetes in China: a cross-sectional study.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.726040074.793514750 ◽

2016 ◽

Author(s):

Carlos Aguilar-Salinas

Keyword(s):

Type 2 Diabetes ◽

Cardiovascular Diseases ◽

Early Onset ◽

Late Onset ◽

Cross Sectional Study ◽

Sectional Study ◽

Cross Sectional ◽

Onset Type

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Impaired Glycogen Synthase Activity and Mitochondrial Dysfunction in Skeletal Muscle: Markers or Mediators of Insulin Resistance in Type 2 Diabetes?

Current Diabetes Reviews ◽

10.2174/1573399810602040375 ◽

2006 ◽

Vol 2 (4) ◽

pp. 375-395 ◽

Cited By ~ 41

Author(s):

Bentham Science Publisher Bentham Science Publisher

Keyword(s):

Insulin Resistance ◽

Type 2 Diabetes ◽

Skeletal Muscle ◽

Mitochondrial Dysfunction ◽

Glycogen Synthase ◽

Glycogen Synthase Activity

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Prevalent ALMS1 Pathogenic Variants in Spanish Alström Patients

Genes ◽

10.3390/genes12020282 ◽

2021 ◽

Vol 12 (2) ◽

pp. 282

Author(s):

Brais Bea-Mascato ◽

Carlos Solarat ◽

Irene Perea-Romero ◽

Teresa Jaijo ◽

Fiona Blanco-Kelly ◽

...

Keyword(s):

High Frequency ◽

Haplotype Analysis ◽

Genetic Diagnosis ◽

Allelic Frequency ◽

Structural Protein ◽

Alström Syndrome ◽

Pathogenic Variants ◽

Novel Variants ◽

Alstrom Syndrome

Alström syndrome (ALMS) is an ultrarare disease with an estimated prevalence lower than 1 in 1,000,000. It is associated with disease-causing mutations in the Alström syndrome 1 (ALMS1) gene, which codifies for a structural protein of the basal body and centrosomes. The symptomatology involves nystagmus, type 2 diabetes mellitus (T2D), obesity, dilated cardiomyopathy (DCM), neurodegenerative disorders and multiorgan fibrosis. We refined the clinical and genetic diagnosis data of 12 patients from 11 families, all of them from Spain. We also studied the allelic frequency of the different variants present in this cohort and performed a haplotype analysis for the most prevalent allele. The genetic analysis revealed 2 novel homozygous variants located in the exon 8, p.(Glu929Ter) and p.(His1808GlufsTer20) in 2 unrelated patients. These 2 novel variants were classified as pathogenic after an in silico experiment (computer analysis). On the other hand, 2 alleles were detected at a high frequency in our cohort: p.(Tyr1714Ter) (25%) and p.(Ser3872TyrfsTer19) (16.7%). The segregation analysis showed that the pathogenic variant p.(Tyr1714Ter) in 3 families is linked to a rare missense polymorphism, p.(Asn1787Asp). In conclusion, 2 novel pathological mutations have been discovered in homozygosis, as well as a probable founder effect in 3 unrelated families.

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N-terminal fragment of probrain natriuretic peptide is associated with diabetes microvascular complications in type 2 diabetes

Vascular Health and Risk Management ◽

10.2147/vhrm.s67753 ◽

2014 ◽

pp. 585 ◽

Cited By ~ 9

Author(s):

Kumiko Hamano ◽

Jun Suzuki ◽

Ikue Nakadaira ◽

Megumi Gonai

Keyword(s):

Type 2 Diabetes ◽

Natriuretic Peptide ◽

Microvascular Complications ◽

Terminal Fragment

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Inherent differences in morphology, proliferation, and migration in saphenous vein smooth muscle cells cultured from nondiabetic and Type 2 diabetic patients

AJP Cell Physiology ◽

10.1152/ajpcell.00608.2008 ◽

2009 ◽

Vol 297 (5) ◽

pp. C1307-C1317 ◽

Cited By ~ 41

Author(s):

Haifa A. Madi ◽

Kirsten Riches ◽

Philip Warburton ◽

David J. O'Regan ◽

Neil A. Turner ◽

...

Keyword(s):

Smooth Muscle ◽

Saphenous Vein ◽

Glucose Concentration ◽

Cell Counting ◽

Diabetic Patients ◽

Graft Stenosis ◽

Increased Risk ◽

And Migration ◽

Proliferation And Migration

Individuals with Type 2 diabetes mellitus (T2DM) are at increased risk of saphenous vein (SV) graft stenosis following coronary artery bypass. Graft stenosis is caused by intimal hyperplasia, a pathology characterized by smooth muscle cell (SMC) proliferation and migration. We hypothesized that SV-SMC from T2DM patients were intrinsically more proliferative and migratory than those from nondiabetic individuals. SV-SMC were cultured from nondiabetic and T2DM patients. Cell morphology (light microscopy, immunocytochemistry), S100A4 expression (real-time RT-PCR, immunoblotting), proliferation (cell counting), migration (Boyden chamber assay), and cell signaling (immunoblotting with phosphorylation state-specific antibodies) were studied. SV-SMC from T2DM patients were morphologically distinct from nondiabetic patients and exhibited a predominantly rhomboid phenotype, accompanied by disrupted F-actin cytoskeleton, disorganized α-smooth muscle actin network, and increased focal adhesion formation. However, no differences were observed in expression of the calcium-binding protein S100A4, a marker of rhomboid SMC phenotype, between the two cell populations. T2DM cells were less proliferative in response to fetal calf serum than nondiabetic cells, but both populations had similar proliferative responses to insulin plus PDGF. Under high glucose concentration conditions in the presence of insulin, migration of diabetic SV-SMC was greater than nondiabetic cells. Glucose concentration did not affect SV-SMC proliferation. No differences in insulin or PDGF-induced phosphorylation of ERK-1/2 or components of the Akt pathway (Akt-Ser473, Akt-Thr308, and GSK-3β) were apparent between the two populations. In conclusion, SV-SMC from T2DM patients differ from nondiabetic SV-SMC in that they exhibit a rhomboid phenotype and are more migratory, but less proliferative, in response to serum.

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HNF-4α: from MODY to late-onset type 2 diabetes

Trends in Molecular Medicine ◽

10.1016/j.molmed.2004.09.004 ◽

2004 ◽

Vol 10 (11) ◽

pp. 521-524 ◽

Cited By ~ 58

Author(s):

Rana K. Gupta ◽

Klaus H. Kaestner

Keyword(s):

Type 2 Diabetes ◽

Late Onset ◽

Onset Type

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Erectile dysfunction as a marker of renal function deterioration in type 2 diabetes male patients with late onset hypogonadism

Journal of Men s Health ◽

10.1016/j.jomh.2011.08.073 ◽

2011 ◽

Vol 8 (3) ◽

pp. 231-231

Author(s):

V. Luchytskiy ◽

V. Rybalchenko ◽

E. Luchytskiy ◽

G. Zubkova ◽

Y. Zasieda

Keyword(s):

Type 2 Diabetes ◽

Renal Function ◽

Erectile Dysfunction ◽

Late Onset ◽

Renal Function Deterioration ◽

Male Patients ◽

Late Onset Hypogonadism

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Glycogen synthase kinase 3β promotes osteosarcoma invasion and migration via regulating PTEN and phosphorylation of focal adhesion kinase

Bioscience Reports ◽

10.1042/bsr20193514 ◽

2021 ◽

Author(s):

Wei Mai ◽

Lingyu Kong ◽

Hongwei Yu ◽

Junjie Bao ◽

Chunyu Song ◽

...

Keyword(s):

Focal Adhesion Kinase ◽

Western Blotting ◽

Focal Adhesion ◽

Glycogen Synthase ◽

Migration And Invasion ◽

Glycogen Synthase Kinase 3Β ◽

Sirna Transfection ◽

Invasion And Migration ◽

Human Osteosarcoma ◽

And Migration

Aim: Typical features of human osteosarcoma are highly invasive and migratory capacities. Our study aimed to investigate the roles of glycogen synthase kinase 3β (GSK3β) in human osteosarcoma metastasis. Methods: GSK3β expressions in clinical osteosarcoma tissues with or without metastasis were examined by immunohistochemical staining. The expressions of GSK3β, p-GSK3βSer9, and p-GSK3βTyr216 in human osteoblast cells (hFOB1.19) and human osteosarcoma cells (MG63, SaOS-2 and U2-OS) were detected by western blotting. The GSK3β activity was measured by non-radio isotopic in vitro kinase assay. Migration and invasion abilities of MG-63 cells treated with small-molecular GSK3β inhibitors were respectively examined by monolayer-based wound-healing assay and transwell assay. The mRNA expressions of GSK3β, matrix metalloproteinase-2 (MMP-2), MMP-9, phosphatase with tensin homology (PTEN), and focal adhesion kinase (FAK) were detected after siRNA transfection for 72 h. Meanwhile, protein expressions of GSK3β, FAK, p-FAKY397, PTEN, MMP-2, and MMP-9 were measured by western blotting. Results: Clinical osteosarcoma tissues with metastasis showed higher GSK3β expressions. MG63 and U2-OS cells which were easy to occur metastasis showed significantly higher expressions and activities of GSK3β than SaOS-2 cells. Inhibition of GSK3β with small-molecular GSK3β inhibitors in MG63 cells significantly attenuated cell migration and invasion. These effects were associated with reduced expressions of MMP-2 and MMP-9. Moreover, increased PTEN and decreased p-FAKY397 expressions were observed following GSK3b knock-down by siRNA transfection. Conclusion: GSK3β might promote osteosarcoma invasion and migration via pathways associated with PTEN and phosphorylation of FAK.

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