Biology subjects

Thamodaran, V.

Publications and source records attributed to Thamodaran, V..

4 recordsLinked to original sources

bioRxiv2026

Establishment of a healthy control iPSC line from an Eastern Indian donor as a population specific resource for disease modelling

BackgroundiPSCs generated from healthy individuals constitute an important control resource for disease modelling applications but existing biobanks are highly skewed towards populations of European ancestry while well characterized control lines from Indian populations remain limited. Given the extensive genetic diversity of the Indian subcontinent, the availability of ethnically relevant healthy control lines is important for developing accurate disease models and reducing population specific confounding effects. MethodologyWe used peripheral blood mononuclear cells (PBMNCs) of a healthy female donor of Eastern Indian origin for the generation a wild type iPSC line using non-integrating episomal reprogramming vectors. Established colonies were expanded and characterized through morphological assessment, expression of pluripotency and trilineage markers, episomal vector clearance analysis, and chromosomal stability evaluation and mycoplasma contamination analysis. ResultsThe line generated exhibited characteristic pluripotent stem cell morphology and also showed strong expression of pluripotency markers, was free from any contamination and free from the reprogramming vectors confirming an integration free system. The cells maintained a normal diploidy number during characterization. Expression of lineage specific markers associated with ectoderm, mesoderm and endoderm confirmed the developed iPSCs functional capacity to undergo trilineage differentiation. ConclusionWe have developed and validated an iPSC line from an underrepresented Indian population. This well characterized, ethnicity specific iPSC line provides a valuable cell line for establishing a high quality, well characterized control baseline, which is a major missing element in South Asian stem cell repositories and thus will provide a solid foundation for future disease specific modelling and screening.

cell biology↗

bioRxiv2025

Development of a Stable Human iPSC Line from Peripheral Blood: A Control Resource for Disease Modeling

IntroductionTraditional disease modeling approaches have primarily utilized animal models and immortalized cell lines to investigate disease mechanisms and develop therapeutic strategies. However, previous research indicates that only about 5% of therapeutic interventions tested in animal models eventually receive regulatory approval for human use, highlighting limitations. The discovery of human-induced pluripotent stem cells (iPSCs) by Yamanakas team in 2007 has revolutionized the field with remarkable possibilities for modeling human diseases, drug testing, and regenerative medicine. Differentiated cells derived from iPSCs in two-dimensional (2D) monolayers offer a relatively straightforward system to study disease pathogenesis and underlying molecular mechanisms. ObjectiveThe present study aimed to generate and characterize an induced pluripotent stem cell (iPSC) line from peripheral blood mono-nuclear cells (PBMCs) of a healthy individual intending to serve as an age and gender-matched control for future disease modeling and regenerative medicine research. Materials and MethodsPBMCs were isolated from a healthy 31-year-old male volunteer. Somatic reprogramming was performed using episomal vectors expressing OCT3/4, SOX2, KLF4, and L-MYC. The resulting colonies were cultured and characterized for pluripotency markers by immunocytochemistry demonstrating the ability to differentiate into three germ layers. Karyotype analysis was performed to check the chromosomal abnormalities. InferencesThe resulting iPSC line exhibited pluripotency markers with the differentiation ability into three germ layers. Karyotyping analysis confirmed a normal chromosomal profile in both the donor and the reprogrammed iPSC line. This iPSC line could be a valuable resource as a healthy control for disease modeling and will contribute to advancing stem cell research with potential for regenerative medicine applications.

molecular biology↗

bioRxiv2025

An iPSC-based iMSC Model for Osteogenesis Imperfecta: A Platform for Disease Modeling and Drug Screening

IntroductionOsteogenesis Imperfecta (OI) is a rare genetic disorder of connective tissue, primarily caused by mutations in the COL1A1 or COL1A2 genes. Research is hampered by the limitations of primary patient-derived cells, which are obtained through invasive methods and have finite proliferative capacity and high variability. While induced pluripotent stem cell (iPSC) models exist, direct differentiation to osteoblasts is often inefficient and may not fully replicate disease characteristics. Our study aimed to develop and characterize a robust iPSC-derived mesenchymal stem cell (iMSC) model of OI using a simple two-step differentiation protocol to serve as a platform for disease modeling and drug screening. MethodsBone marrow MSCs (BMMSCs) were isolated from two OI patients with heterozygous missense mutations, in COL1A1 (c.2299G >A) and COL1A2 (c.982G>A). The patient BMMSCs were reprogrammed into iPSCs using an integration-free Sendai virus. The resulting OI-iPSCs were characterized for pluripotency via immunofluorescence and RT-PCR, trilineage differentiation potential, and karyotype analysis. A two-step protocol was used to differentiate the OI-iPSCs into OI-iMSCs via mesodermal lineage. The OI-iMSCs were then characterized for morphology, immunophenotype by flow cytometry, and trilineage differentiation capacity. Functional osteogenic differentiation was assessed by Alizarin Red S staining and RT-PCR analysis of key osteogenic genes. Sanger sequencing confirmed the retention of patient-specific mutations in the OI-iMSCs. ResultsPatient-derived BMMSCs were successfully differentiated into adipocytes and chondrocytes but showed impaired osteogenic potential. The reprogramming process successfully generated stable OI-iPSC lines that expressed key pluripotency markers, demonstrated trilineage potential, and maintained a normal karyotype. Critically, while direct osteogenic differentiation of these iPSCs failed to recapitulate the primary cell phenotype, the two-step differentiation protocol successfully produced a homogeneous population of iMSCs. These OI-iMSCs displayed characteristics of MSC surface markers (CD73+, CD90+, CD105+) and recapitulated the disease phenotype seen in the original patient BMMSCs. Specifically, COL1A1-iMSCs exhibited cellular rolling and detachment, while COL1A2-iMSCs showed poor mineralization during osteogenic differentiation. Both OI-iMSC lines showed significantly decreased calcium deposition and downregulation of key osteogenic genes (RUNX2, ALP, COL1) compared to controls. ConclusionOur study successfully established an iMSC-based cellular model of OI that recapitulates patient-specific disease phenotypes, including impaired osteogenic differentiation. The two-stage differentiation of iPSCs to iMSCs proved more reliable than direct osteogenic differentiation for modeling the disease. iMSC model circumvents the limitations of primary cells by providing a scalable and homogeneous source of patient-specific cells. Our platform offers a valuable and robust tool for investigating OI pathophysiology and for high-throughput screening of potential therapeutic molecules, advancing efforts toward personalized therapies

genetics↗

bioRxiv2019

p38-mitogen activated kinases mediate a developmental regulatory response to amino acid depletion and associated oxidative stress in mouse blastocyst embryos

Maternal starvation coincident with preimplantation development has profound consequences for placental-foetal development, with various identified pathologies persisting/manifest in adulthood; the Developmental Origin of Health and Disease (DOHaD) hypothesis/model. Despite evidence describing DOHaD-related incidence, supporting mechanistic and molecular data relating to preimplantation embryos themselves are comparatively meagre. We recently identified the classically recognised stress-related p38-mitogen activated kinases (p38-MAPK) as regulating formation of the extraembryonic primitive endoderm (PrE) lineage within mouse blastocyst inner cell mass (ICM). Thus, we wanted to assay if PrE differentiation is sensitive to amino acid availability, in a manner regulated by p38-MAPK. Although blastocysts appropriately mature, without developmental/morphological or cell fate defects, irrespective of amino acid supplementation status, we found the extent of p38-MAPK inhibition induced phenotypes was more severe in the absence of amino acid supplementation. Specifically, both PrE and epiblast (EPI) ICM progenitor populations remained unspecified and there were fewer cells and smaller blastocyst cavities. Such phenotypes could be ameliorated, to resemble those observed in groups supplemented with amino acids, by addition of the anti-oxidant NAC (N-acetyl-cysteine), although PrE differentiation deficits remained. Therefore, p38-MAPK performs a hitherto unrecognised homeostatic early developmental regulatory role (in addition to direct specification of PrE), by buffering blastocyst cell number and ICM cell lineage specification (relating to EPI) in response to amino acid availability, partly by counteracting induced oxidative stress; with clear implications for the DOHaD model.

developmental biology↗