Mitochondrial DNA copy number in adults with and without Type 1 diabetes.

AIMS: Mitochondrial damage is implicated in diabetes pathogenesis and complications. Mitochondrial DNA copy number (mtDNA-cn) in human Type 1 diabetes (T1D) studies are lacking. We related mtDNA-cn in T1D and non-diabetic adults (CON) with diabetes complications and risk factors. METHODS: Cross-sectional study: 178 T1D, 132 non-diabetic controls. Associations of whole blood mtDNA-cn (qPCR) with complications, inflammation, and C-peptide. RESULTS: mtDNA-cn (median (LQ, UQ)) was lower in: T1D vs. CON (271 (189, 348) vs. 320 (264, 410); p < 0.0001); T1D with vs. without kidney disease (238 (180, 309) vs. 294 (198, 364); p = 0.02); and insulin injection vs. pump-users (251 (180, 340) vs. 322 (263, 406); p = 0.008). Significant univariate correlates of mtDNA-cn: T1D: (positive) HDL-C; (negative) fasting glucose, white cell count (WCC), sVCAM-1, sICAM-1; CON: (negative) WHR (waist-hip-ratio). Detectable C-peptide in T1D increased with lowest-highest mtDNA-cn tertiles (54%, 69%, 79%, p = 0.02). Independent determinants of mtDNA-cn: T1D: (positive) HDL-C; (negative) age, sICAM-1; AUROC 0.71; CON: WCC (negative), never smoking, (positive) female, pulse pressure; AUROC 0.74. CONCLUSIONS: mtDNA-cn is lower in T1D vs. CON, and in T1D kidney disease. In T1D, mtDNA-cn correlates inversely with age and inflammation, and positively with HDL-C, detectable C-peptide and pump use. Further clinical and basic science studies are merited.

Cell Cycle Deficits in Neurodegenerative Disorders: Uncovering Molecular Mechanisms to Drive Innovative Therapeutic Development.

Cell cycle dysregulation has been implicated in the pathogenesis of neurodegenerative disorders. Specialised function obligates neuronal cells to subsist in a quiescent state of cell cycle once differentiated and therefore the circumstances and mechanisms underlying aberrant cell cycle activation in post-mitotic neurons in physiological and disease conditions remains an intriguing area of research. There is a strict requirement of concurrence to cell cycle regulation for neurons to ensure intracellular biochemical conformity as well as interrelationship with other cells within neural tissues. This review deliberates on various mechanisms underlying cell cycle regulation in neuronal cells and underscores potential implications of their non-compliance in neural pathology. Recent research suggests that successful duplication of genetic material without subsequent induction of mitosis induces inherent molecular flaws that eventually assert as apoptotic changes. The consequences of anomalous cell cycle activation and subsequent apoptosis are demonstrated by the increased presence of molecular stress response and apoptotic markers. This review delineates cell cycle events under normal physiological conditions and deficits amalgamated by alterations in protein levels and signalling pathways associated with cell-division are analysed. Cell cycle regulators essentially, cyclins, CDKs, cip/kip family of inhibitors, caspases, bax and p53 have been identified to be involved in impaired cell cycle regulation and associated with neural pathology. The pharmacological modulators of cell cycle that are shown to impart protection in various animal models of neurological deficits are summarised. Greater understanding of the molecular mechanisms that are indispensable to cell cycle regulation in neurons in health and disease conditions will facilitate targeted drug development for neuroprotection.

Serum exosomal miRNA as biomarkers for Retinoblastoma.

Retinoblastoma (RB) is a childhood eye tumor, caused by RB1 mutation. Though diagnosing RB is easier, prognosticating RB is limited to examining the patient under anesthesia and imaging technique. The aim of the study is to find exosomal miRNA biomarkers to prognosticate RB. Exosomes were isolated from one control - MIO-M1 and two RB cell lines - WERI-Rb-1 and NCC-RbC-51. Small RNA sequencing was performed on exosomal miRNA isolated from the three cell lines. miRNAs specific to each cell line were shortlisted. A total of 243, 606 and 400 miRNAs were identified in MIO-M1, WERI-Rb-1 and NCC-RbC-51 cell lines respectively. Nine miRNAs were shortlisted based on adjusted p value and literature, MIO-M1 specific (n = 1), WERI-RB-1 specific (n = 2), NCC-RbC-51 specific (n = 2) and miRNAs common to both RB cell lines (n = 4) were chosen. Validation was done using specific Taqman miRNA assays.miRNA validation was carried out on cell lines, cell line derived exosomes, primary RB tissues and exosomes isolated from serum of the RB patients. Validation of the miRNAs in cell lines and exosomes derived from the cell lines, confirmed the sequencing data. However, only 2 miRNAs - hsa-miR-301b-3p and hsa-miR-216b-5p were upregulated in the primary RB tissues. None of the miRNAs had significant expression in the serum exosomes of RB patients. Therefore, serum exosomal miRNA may not be ideal for prognosticating RB.Further research on other body fluids like CSF and vitreous could serve as potential source for biomarkers for prognosticating RB.

Characterization of NCC-RbC-51, an RB cell line isolated from a metastatic site.

Retinoblastoma (RB) is a childhood eye tumor, caused by the RB1 gene mutation. Since RB is a rapidly proliferating tumor, the patient presents with a Group-D/E tumor at the time of diagnosis. Enucleation is preferred in most unilateral cases to prevent metastasis. Various cell lines have been established to study the tumor's growth pattern and target the cancer cells. The commonly used cell lines are WERI-Rb-1 and Y79, both isolated from the primary tumor of RB. Cell lines established from the metastatic site of RB have not been characterized before. In this study, we have characterized NCC-RbC-51, derived from RB tumor to cervical lymph node site and investigated its potential to represent a highly aggressive and metastatic tumor. We compared the proliferative and invasive properties of NCC-RbC-51 with a cell line isolated from the primary site, WERI-Rb-1. NCC-RbC-51 had higher rates of proliferation and apoptosis and had better invasive ability. Copy number variation analysis and the pathways predicted from these show that the pathways altered in NCC-RbC-51 could contribute to its metastatic nature. In all, the results suggest that NCC-RbC-51, a cell line isolated from metastatic site, could be a potential model to study aggressive/invasive RB.

An Atypical System for Studying Epithelial-Mesenchymal Transition in Hepatocellular Carcinoma.

Intrahepatic and extrahepatic metastases are frequently detected in hepatocellular carcinoma (HCC). Epithelial-mesenchymal transition (EMT) is believed to drive metastasis. There are not many well-established model systems to study EMT in HCC. Here we identified an atypical EMT while characterizing a population of mesenchymal cells in Huh7.5 hepatoma cell cultures. Cells with distinct morphology appeared during geneticin treatment of Huh7.5 cultures. Molecular characterization of geneticin resistant Huh7.5M cells confirmed EMT. Huh7.5M cells expressed cancer stem cell markers. p38MAPK and ERK1/2 were substantially activated in Huh7.5M cells. Their Inhibition elevated E-Cadherin expression with concerted suppression of Vimentin and anchorage independent growth in Huh7.5M cells. TGFß could not induce EMT in Huh7.5 cultures, but enriched mesenchymal populations, similar to geneticin. Huh7.5M cells formed more aggressive solid tumors, primarily comprising cells with epithelial morphology, in nude mice. Canonical EMT-TFs did not participate in this atypical EMT, indicating that the established canonical EMT-TFs do not drive every EMT and there is a dire need to identify additional factors. The system that we characterized is a unique model to study EMT, MET and biphasic TGFß signaling in HCC and offers considerable potential to facilitate more insightful studies on deeper questions in tumor metastasis.