@article {43952, title = {CHO Cells Adapted to Inorganic Phosphate Limitation Show Higher Growth and Higher Pyruvate Carboxylase Flux in Phosphate Replete Conditions}, journal = {Biotechnology progress}, volume = {33}, year = {2017}, month = {MAY}, pages = {749-758}, type = {Article}, abstract = {Inorganic phosphate (P-i) is an essential ion involved in diverse cellular processes including metabolism. Changes in cellular metabolism upon long term adaptation to P-i limitation have been reported in E. coli. Given the essential role of P-i, adaptation to P-i limitation may also result in metabolic changes in animal cells. In this study, we have adapted CHO cells producing recombinant IgG to limiting P-i conditions for 75 days. Not surprisingly, adapted cells showed better survival under P-i limitation. Here, we report the finding that such cells also showed better growth characteristics compared to control in batch culture replete with P-i ( higher peak density and integral viable cell density), accompanied by a lower specific oxygen uptake rate and cytochrome oxidase activity towards the end of exponential phase. Surprisingly, the adapted cells grew to a lower peak density under glucose limitation. This suggests long term P-i limitation may lead to selection for an altered metabolism with higher dependence on glucose availability for biomass assimilation compared to control. Steady state U-C-13 glucose labeling experiments suggest that adapted cells have a higher pyruvate carboxylase flux. Consistent with this observation, supplementation with aspartate abolished the peak density difference whereas supplementation with serine did not abolish the difference. This supports the hypothesis that cell growth in the adapted culture might be higher due to a higher pyruvate carboxylase flux. Decreased fitness under carbon limitation and mutations in the sucABCD operon has been previously reported in E. coli upon long term adaptation to P-i limitation, suggestive of a similarity in cellular response among such diverse species. (C) 2017 American Institute of Chemical Engineers}, doi = {10.1002/btpr.2450}, author = {Maralingannavar, Vishwanathgouda; and Parmar, Dharmeshkumar and Pant, Tejal and Gadgil, Chetan and Panchagnula, Venkateswarlu and Gadgil, Mugdha} } @article {43934, title = {Scalable metabolite supplementation strategy against antibiotic resistant pathogen Chromobacterium violaceum induced by NAD(+)/NADH(+) imbalanceA scalable metabolite supplementation strategy against antibiotic resistant pathogen Chromobacterium violaceu}, journal = {BMC Syst Biol. }, volume = {11}, year = {2017}, month = {APR}, abstract = {

BACKGROUND: The leading edge of the global problem of antibiotic resistance necessitates novel therapeutic strategies. This study develops a novel systems biology driven approach for killing antibiotic resistant pathogens using benign metabolites. RESULTS: Controlled laboratory evolutions established chloramphenicol and streptomycin resistant pathogens of Chromobacterium. These resistant pathogens showed higher growth rates and required higher lethal doses of antibiotic. Growth and viability testing identified malate, maleate, succinate, pyruvate and oxoadipate as resensitising agents for antibiotic therapy. Resistant genes were catalogued through whole genome sequencing. Intracellular metabolomic profiling identified violacein as a potential biomarker for resistance. The temporal variance of metabolites captured the linearized dynamics around the steady state and correlated to growth rate. A constraints-based flux balance model of the core metabolism was used to predict the metabolic basis of antibiotic susceptibility and resistance. CONCLUSIONS: The model predicts electron imbalance and skewed NAD/NADH ratios as a result of antibiotics - chloramphenicol and streptomycin. The resistant pathogen rewired its metabolic networks to compensate for disruption of redox homeostasis. We foresee the utility of such scalable workflows in identifying metabolites for clinical isolates as inevitable solutions to mitigate antibiotic resistance.

}, keywords = {Antibiotic resistance; Flux balance analysis; Flux variability analysis; Metabolism; Metabolomic; NAD; NADH; Redox homeostasis}, doi = {10.1186/s12918-017-0427-z}, author = {Banerjee, Deepanwita and Parmar, Dharmeshkumar and Bhattacharya, Nivedita and Ghanate, Avinash D. and Panchagnula, Venkateswarlu and Raghunathan, Anu} } @conference {44600, title = {Differential responses of CHO cells adapted to limitation of inorganic phosphate, glucose or glutamine}, booktitle = {255th National Meeting and Exposition of the American-Chemical-Society (ACS) - Nexus of Food, Energy, and Water}, year = {2018}, month = {MAR }, publisher = {American-Chemical-Society, 1155 16TH ST, NW, Washington, DC 20036 USA}, organization = {American-Chemical-Society, 1155 16TH ST, NW, Washington, DC 20036 USA}, address = {New Orleans, LA}, author = {Maralingannavar, Vishwanathgouda and Parmar, Dharmeshkumar and Pant, Tejal and Gadgil, Chetan and Panchagnula, Venkateswarlu and Gadgil, Mugdha} } @article {46354, title = {Superfluous glutamine synthetase activity in Chinese Hamster Ovary cells selected under glutamine limitation is growth limiting in glutamine-replete conditions and can be inhibited by serine}, journal = {Biotechnology Progress}, volume = {35}, year = {2019}, month = {SEP-OCT}, pages = {UNSP e2856}, type = {Article}, abstract = {

Passaging and expansion of animal cells in lean maintenance medium could result in periods of limitation of some nutrients. Over time, such stresses could possibly result in selection of cells with metabolic changes and contribute to heterogeneity. Here, we investigate whether selection of Chinese Hamster Ovary (CHO) cells under glutamine limitation results in changes in growth under glutamine-replete conditions. In glutamine-limiting medium, compared to control cells passaged in glutamine-rich medium, the selected cells showed higher glutamine synthetase (GS) activity and attained a higher peak viable cell density (PVCD). Surprisingly, in glutamine-replete conditions, selected cells still showed a higher GS activity but a lower PVCD. We show that in glutamine-replete medium, PVCD of selected cells was restored on (a) inhibition of GS activity with methionine sulfoximine, (b) supplementation of aspartate-without affecting GS activity, and (c) supplementation of serine, which is reported to inhibit GS in vitro. Consistent with the reported effect of serine, inhibition of GS activity was observed upon serine supplementation along with reduced growth of cells under glutamine-limiting conditions. The latter observation is important for the design of glutamine-free culture medium and feed used for GS-CHO and GS-NS0. In summary, we show that CHO cells selected under glutamine limitation have superfluous GS activity in glutamine-replete medium, which negatively affects their PVCD. This may be due to its effect on availability of aspartate which was the limiting nutrient for the growth of selected cells in glutamine-replete conditions.

}, keywords = {C-13 tracer analysis, CHO cells, glutamine limitation, Glutamine synthetase, GS-CHO, GS-NS0, selection under nutrient limitation, serine}, issn = {8756-7938}, doi = {10.1002/btpr.2856}, author = {Maralingannavar, Vishwanathgouda and Parmar, Dharmeshkumar and Panchagnula, Venkateswarlu and Gadgil, Mugdha} } @article {46955, title = {Plausible diagnostic value of urinary isomeric dimethylarginine ratio for diabetic nephropathy}, journal = {Scientific Reports}, volume = {10}, year = {2020}, month = {FEB}, pages = {2970}, type = {Article}, abstract = {

Altered circulatory asymmetric and symmetric dimethylarginines have been independently reported in patients with end-stage renal failure suggesting their potential role as mediators and early biomarkers of nephropathy. These alterations can also be reflected in urine. Herein, we aimed to evaluate urinary asymmetric to symmetric dimethylarginine ratio (ASR) for early prediction of diabetic nephropathy (DN). In this cross-sectional study, individuals with impaired glucose tolerance (IGT), newly diagnosed diabetes (NDD), diabetic microalbuminuria (MIC), macroalbuminuria (MAC), and normal glucose tolerance (NGT) were recruited from Dr. Mohans{\textquoteright} Diabetes Specialties centre, India. Urinary ASR was measured using a validated high-throughput MALDI-MS/MS method. Significantly lower ASR was observed in MIC (0.909) and MAC (0.741) in comparison to the NGT and NDD groups. On regression models, ASR was associated with MIC [OR: 0.256; 95\% CI: 0.158-0.491] and MAC [OR 0.146; 95\% CI: 0.071-0.292] controlled for all the available confounding factors. ROC analysis revealed ASR cut-point of 0.95 had C-statistic of 0.691 (95\% CI: 0.627-0.755) to discriminate MIC from NDD with 72\% sensitivity. Whereas, an ASR cut-point of 0.82 had C-statistic of 0.846 (95\% CI: 0.800 - 0.893) had 91\% sensitivity for identifying MAC. Our results suggest ASR as a potential early diagnostic biomarker for DN among the Asian Indians.

}, issn = {2045-2322}, doi = {10.1038/s41598-020-59897-1}, author = {Parmar, Dharmeshkumar and Bhattacharya, Nivedita and Kannan, Shanthini and Vadivel, Sangeetha and Pandey, Gautam Kumar and Ghanate, Avinash and Ragi, Nagarjuna Chary and Prabu, Paramasivam and Pramodkumar, Thyparambil Aravindakshan and Manickam, Nagaraj and Mohan, Viswanathan and Sripadi, Prabhakar and Kuppan, Gokulakrishnan and Panchagnula, Venkateswarlu} } @article {49215, title = {Circulatory levels of lysophosphatidylcholine species in obese adolescents: Findings from cross-sectional and prospective lipidomics analyses}, journal = {NUTRITION METABOLISM AND CARDIOVASCULAR DISEASES}, volume = {34}, year = {2024}, month = {JUL}, pages = {1807-1816}, type = {Journal Article}, keywords = {Adolescent obesity, Asian Indians, biomarker, Lipidomics, Lysophosphatidyl- choline}, issn = {0939-4753}, doi = {10.1016/j.numecd.2024.02.009}, author = {Sharma, Sapna and Subrahmanyam, Yalamanchili Venkata and Ranjani, Harish and Sidra, Sidra and Parmar, Dharmeshkumar and Vadivel, Sangeetha and Kannan, Shanthini and Grallert, Harald and Usharani, Dandamudi and Anjana, Ranjit Mohan and Balasubramanyam, Muthuswamy and Mohan, Viswanathan and Jerzy, Adamski and Panchagnula, Venkateswarlu and Gokulakrishnan, Kuppan} }