Browsing by Author "Nalini J. Gupta"

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Development and characterization of hematopoietic stem cells from human embryonic stem cells
(Nova Science Publishers, Inc., 2021) Nalini J. Gupta; Swarup K. Chakrabarti; Minal Trivedi; Gopal Pande; Ratna Chattopadhyay; Lalji Singh; Baidyanath Chakravarty
The hematopietic stem cells (HSCs) have the property of selfrenewal as well the ability to differentiate into all blood cell types (multilineage). The common sources of HSCs are bone marrow, peripheral blood and umbilical cord blood, but the quantity and compatibility of these HSCs is limited. HSCs obtained from human embryonic stem cells (hESCs) may provide better solution to the problems of quantity and compatibility. Generation of hematopoietic progenitors from hESCs need to be better understood and optimized in order to use them for fundamental research in the future. In the present study, differentiation of hESCs and colonies dissected from embryoid body (EB) into erythroid lineage was observed where the colonies were grown on human feeders and later transferred to feeder free media with high concentration of fibroblast growth factor (β-FGF). Moreover, in this study, hESCs from two blastocysts were spontaneously differentiated into hematopoietic cells. These colonies were characterized using immunophenotyping and karyotyping. Therefore, the fundamental knowledge of the biology of the cellular differentiation as described in this study will help us to better understand the reprogramming of induced pluripotent stem cells into hematopoietic stem cells for potential therapeutic use in the future. © 2021 Nova Science Publishers, Inc. All rights reserved.
Development and characterization of hematopoietic stem cells from human embryonic stem cells
(Nova Science Publishers, Inc., 2019) Nalini J. Gupta; Swarup K. Chakrabarti; Minal Trivedi; Gopal Pande; Ratna Chattopadhyay; Lalji Singh; Baidyanath Chakravarty
The hematopietic stem cells (HSCs) have the property of self-renewal as well the ability to differentiate into all blood cell types (multilineage). The common sources of HSCs are bone marrow, peripheral blood and umbilical cord blood, but the quantity and compatibility of these HSCs is limited. HSCs obtained from human embryonic stem cells (hESCs) may provide better solution to the problems of quantity and compatibility. Generation of hematopoietic progenitors from hESCs need to be better understood and optimized in order to use them for fundamental research in the future. In the present study, differentiation of hESCs and colonies dissected from embryoid body (EB) into erythroid lineage was observed where the colonies were grown on human feeders and later transferred to feeder free media with high concentration of β fibroblast growth factor (β-FGF). Moreover, in this study, hESCs from two blastocysts were spontaneously differentiated into hemato-poietic cells. These colonies were characterized using immunophenotyping and karyotyping. Therefore, the fundamental knowledge of the biology of the cellular differentiation as described in this study will help us to better understand the reprogramming of induced pluripotent stem cells into hematopoietic stem cells for potential therapeutic use in the future. © 2020 Nova Science Publishers, Inc.
High frequencies of Non Allelic Homologous Recombination (NAHR) events at the AZF loci and male infertility risk in Indian men
(Nature Publishing Group, 2019) Deepa Selvi Rani; Singh Rajender; Kadupu Pavani; Gyaneshwer Chaubey; Avinash A. Rasalkar; Nalini J. Gupta; Mamta Deendayal; Baidyanath Chakravarty; Kumarasamy Thangaraj
Deletions in the AZoospermia Factor (AZF) regions (spermatogenesis loci) on the human Y chromosome are reported as one of the most common causes of severe testiculopathy and spermatogenic defects leading to male infertility, yet not much data is available for Indian infertile men. Therefore, we screened for AZF region deletions in 973 infertile men consisting of 771 azoospermia, 105 oligozoospermia and 97 oligoteratozoospermia cases, along with 587 fertile normozoospermic men. The deletion screening was carried out using AZF-specific markers: STSs (Sequence Tagged Sites), SNVs (Single Nucleotide Variations), PCR-RFLP (Polymerase Chain Reaction - Restriction Fragment Length Polymorphism) analysis of STS amplicons, DNA sequencing and Southern hybridization techniques. Our study revealed deletion events in a total of 29.4% of infertile Indian men. Of these, non-allelic homologous recombination (NAHR) events accounted for 25.8%, which included 3.5% AZFb deletions, 2.3% AZFbc deletions, 6.9% complete AZFc deletions, and 13.1% partial AZFc deletions. We observed 3.2% AZFa deletions and a rare long AZFabc region deletion in 0.5% azoospermic men. This study illustrates how the ethnicity, endogamy and long-time geographical isolation of Indian populations might have played a major role in the high frequencies of deletion events. © 2019, The Author(s).
L712V mutation in the androgen receptor gene causes complete androgen insensitivity syndrome due to severe loss of androgen function
(2013) Singh Rajender; Nalini J. Gupta; Baidyanath Chakrabarty; Lalji Singh; Kumarasamy Thangaraj
Inability to respond to the circulating androgens is named as androgen insensitivity syndrome (AIS). Mutations in the androgen receptor (AR) gene are the most common cause of AIS. A cause and effect relationship between some of these mutations and the AIS phenotype has been proven by in vitro studies. Several other mutations have been identified, but need to be functionally validated for pathogenicity. Screening of the AR mutations upon presumptive diagnosis of AIS is recommended. We analyzed a case of complete androgen insensitivity syndrome (CAIS) for mutations in the AR gene. Sequencing of the entire coding region revealed C > G mutation (CTT-GTT) at codon 712 (position according to the NCBI database) in exon 4 of the gene, resulting in replacement of leucine with valine in the ligand-binding domain of the AR protein. No incidence of this mutation was observed in 230 normal male individuals analyzed for comparison. In vitro androgen binding and transactivation assays using mutant clone showed approximately 71% loss of ligand binding and about 76% loss of transactivation function. We conclude that CAIS in this individual was due to L712V substitution in the androgen receptor protein. © 2013 Elsevier Ltd. All rights reserved.
Mutation analysis of mthfr gene in Indian women with unexplained recurrent miscarriages; Folic acid supplementation improves pregnancy outcomes
(Nova Science Publishers, Inc., 2021) Nalini J. Gupta; Gaurav Gupta; Swarup K. Chakrabarti; Kumarasamy Thangaraj; Lalji Singh; Baidyanath Chakravarty
Recurrent pregnancy loss (RPL) is classically defined as the occurrence of two or more consecutive clinically recognized pregnancy losses that end prior to twenty weeks. The cause(s) of RPL are elusive, often idiopathic, and multifactorial that is frustrating for the couples and the physicians. Many RPL results from chromosomal or genetic abnormalities and are random events. Methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphisms have been shown to be associated with many cases of RPL. The activity of the MTHFR enzyme is markedly reduced in people with C677T gene polymorphisms that decreases the conversion of homocysteine into methionine resulting in homocysteine accumulation in the blood, a condition known as hyperhomocysteinemia that has been described as a risk factor for the idiopathic RPL or recurrent miscarriages, however its role has not been firmly established in RPL till date. Furthermore, plasma folic acid levels have been observed to be lower in individuals with (MTHFR) C677T genotype. In the present study, we investigated the role of MTHFR C677T polymorphism in hyperhomocysteinemia leading to RPL in Indian women. Moreover, the effect of folic acid supplementation on RPL in Indian women with MTHFR C677T polymorphism was also investigated. Indian female patients of various age groups (24-39 years) with unexplained recurrent miscarriages including PCOS were selected (case group) for this study. They were genotyped for MTHFR C677T polymorphisms and homocysteine levels in the plasma were also measured. A total of 302 Indian female patients with the history of recurrent miscarriage/RPL were studied along with 100 control patients. Female patients with no PCOS were selected as control group for this study. Written consents were taken from all the patients. Peripheral blood from the patients was collected and the plasma homocysteine levels were measured. MTHFR C677T polymorphism was measured using sequencer and Restriction Fragment Length Polymorphism (RFLP). 21% of cases were found to be heterozygous for the point mutation at 677 C > T in MTHFR gene. All of them had elevated homocysteine levels. Odds Ratio (OR) was found to be 2.2405 at 95% of confidence interval (CI) and the Risk ratio was observed to be 1.9476, thereby indicating a strong positive correlation between the mutation and the RPL as observed in this study. Thus, the detection of wild type, homozygous/heterozygous status of mutation 677 C > T in the patients could predict risk factors for miscarriages and subsequent fetal health foundation. Furthermore, the mutational analysis will also be helpful to identify possible correlation with other health complications and diseases through case studies. Moreover, in this study we observed beneficial effect of folic acid supplementation in lowering homocyteine levels in patients with RPL. However, large prospective randomized clinical trials are needed to further ascertain the beneficial role of folic acid supplementation in the precise management of RPL. © 2021 Nova Science Publishers, Inc. All rights reserved.