Biology subjects

K, R.

Publications and source records attributed to K, R..

4 recordsLinked to original sources

bioRxiv2024

Stress-free Bioprinting of Human Primary and iPSC-derived Islets with Retained Functionality

Currently, Type 1 diabetes (T1D) can be treated through implantation of allogenic islets, which replenish the beta cell population, however this method requires an extensive post-implantation immunosuppressant regimen. Personalized cellular therapy can address this through implantation of an autologous cell population, induced pluripotent stem cells (iPSCs). Cellular therapy, however, requires an encapsulation device for implantation, and so to achieve this uniformly with cells in a clinical setting, bioprinting is a useful option. Bioprinting is dependent on having a bioink that is printable, retains structural fidelity after printing, and is supportive of cell type and function. While bioprinting of pancreatic islets has been demonstrated previously, success in maintaining islet function post-printing has been varied. The objective of this study is to investigate the feasibility of printing functional islets by determining the appropriate combination of bioink, printing parameters, and cell configuration. Here, we detail the successful bioprinting of both primary human islets and iPSC-derived islets embedded in an alginate/methylcellulose bioink, with functionality sustained within the construct for both cell lineages. Sc-RNAseq analysis also revealed that printing did not adversely affect the genetic expression and metabolic functionality of the iPSC-derived islets. Importantly, the iPSC-derived islets displayed comparable functionality to the primary islets, indicating the potential to act as a cell source alternative for T1D implantation.

bioengineering↗

bioRxiv2024

A metabolic-dysfunction associated steatotic liver acinus biomimetic induces pancreatic islet dysfunction in a coupled microphysiology system

Preclinical and clinical studies suggest that lipid-induced hepatic insulin resistance is a primary defect that predisposes to dysfunction in pancreatic islets, implicating a perturbed liver-pancreas axis underlying the comorbidity of T2DM and MASLD. To investigate this hypothesis, we developed a human biomimetic microphysiological system (MPS) coupling our vascularized liver acinus MPS (vLAMPS) with primary islets on a chip (PANIS) enabling MASLD progression and islet dysfunction to be quantitatively assessed. The modular design of this system (vLAMPS-PANIS) allows intra-organ and inter-organ dysregulation to be deconvoluted. When compared to normal fasting (NF) conditions, under early metabolic syndrome (EMS) conditions, the standalone vLAMPS exhibited characteristics of early stage MASLD, while no significant differences were observed in the standalone PANIS. In contrast, with EMS, the coupled vLAMPS-PANIS exhibited a perturbed islet-specific secretome and a significantly dysregulated glucose stimulated insulin secretion (GSIS) response implicating direct signaling from the dysregulated liver acinus to the islets. Correlations between several pairs of a vLAMPS-derived and a PANIS-derived secreted factors were significantly altered under EMS, as compared to NF conditions, mechanistically connecting MASLD and T2DM associated hepatic factors with islet-derived GLP-1 synthesis and regulation. Since vLAMPS-PANIS is compatible with patient-specific iPSCs, this platform represents an important step towards addressing patient heterogeneity, identifying complex disease mechanisms, and advancing precision medicine.

bioengineering↗

bioRxiv2024

Exploring the potential of Celtis aetnensis compounds through Molecular Docking for Hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) accounts for 1% of the liver malignances; HCC progresses in hepatocytes primarily as a result of inflammation, oxidative stress, and primary liver disease. Thanks to the in-silico methods that help in the identification of the targets and the drugs/potential drugs that can inhibit these proteins that cater to the growth of the cancer cells. Plant actives have been long considered as potential sources of anticancer drugs. In this regard, we studied the actives from Celtis tournefortii Lam (Celtis aetnensis) using GCMS analysis. The protein structures of three receptors--NF-B P50 homodimer, FGF receptor 4, and vascular endothelial growth factor receptor 2 (VEGFR2)--were then subjected to docking studies using phytocompounds from Celtis aetnensis. Three receptor proteins were used in the docking analysis against 7 ligands. In this study, the PDB was used to obtain the structures of 3 cancer-related receptor proteins. The proteins were produced by eliminating water molecules, ligands using PyMol, and were then exposed to docking experiments. Docking studies revealed that the compounds with a binding energy ranging from -1.83 kcal/mol to -6.12 kcal/mol. The docking results revealed that eicosatetraenoic acid has a binding energy of-6.12 kcal/mol against the FGFR4 receptor. Sulfadoxines binding energy to the VEGFR2 receptor protein was-4.9 kcal/mol. Promethazine sulfoxide docks with an energy of -5.36 kcal/mol against NFKB P50. By attaching to the protein, these substances demonstrated good inhibitory activity. The results are supportive that these compounds may be used to treat HCC.

cancer biology↗

bioRxiv2019

Computational prediction and analysis of very high risk single nucleotide polymorphisms in human cytochrome P450 oxidoreductase gene

Cytochrome P450 oxidoreductase (POR) is a highly polymorphic gene which is involved in metabolism of drugs and steroids through transfer of electron from NADPH to all CYP enzymes. In this study, we attempt to identify the very high risk single nucleotide polymorphisms in POR gene that would affect phenotype of the enzyme. The genetic variants in POR gene were retrieved from databases and analyzed with appropriate online computation tools. Very high risk non-synonymous SNPs were identified with 12 different sequence and structure homology based tools and evolutionary conservation tool (Consurf). Further the phenotype effect of the variant was assessed with MutPred2 and LigPlot. The very high risk non-coding variants were predicted with HaploReg V4 and RegulomeDB tools. The very high risk SNPs that may affect miRNA target sites were screened using PolymiRTs v3.0, miRNA SNP v2.0 and MirSNP. Among 4,601 variants in POR gene, 58 missense variants, 8 non-coding variants and three SNPs in miRNA target sites were found to be very high risk. These very high risk variants may regulate the expression and activity of cytochrome P450 oxidoreductase enzyme leading to differential drug and steroid metabolism by CYP enzymes.

genomics↗