Ranjeet Kumar - Academia.edu (original) (raw)

Papers by Ranjeet Kumar

Research paper thumbnail of MicroRNA 17-5p regulates autophagy in Mycobacterium tuberculosis-infected macrophages by targeting Mcl-1 and STAT3

Cellular microbiology, Jan 29, 2015

Autophagy plays a crucial role in the control of bacterial burden during Mycobacterium tuberculos... more Autophagy plays a crucial role in the control of bacterial burden during Mycobacterium tuberculosis infection. MicroRNAs (miRNAs) are small non-coding RNAs which regulate immune signaling and inflammation in response to challenge by pathogens. Appreciating the potential of host-directed therapies designed to control autophagy during mycobacterial infection, we focused on the role of miRNAs in regulating M. tuberculosis-induced autophagy in macrophages. Here we demonstrate that M. tuberculosis infection leads to downregulation of miR-17 and concomitant upregulation of its targets Mcl-1 and STAT3, a transcriptional activator of Mcl-1. Forced expression of miR-17 reduces expression of Mcl-1 and STAT3, and also the interaction between Mcl-1 and Beclin-1. This is directly linked to enhanced autophagy, since Mcl-1 overexpression attenuates the effects of miR-17. At the same time, transfection with a kinase-inactive mutant of protein kinase C δ (PKCδ) (an activator of STAT3), augments M. t...

Research paper thumbnail of MicroRNA let-7 Modulates the Immune Response to Mycobacterium tuberculosis Infection via Control of A20, an Inhibitor of the NF-κB Pathway

Cell Host & Microbe, 2015

Highlights d M. tuberculosis macrophage infection causes ESAT-6dependent miRNA let-7f downregulat... more Highlights d M. tuberculosis macrophage infection causes ESAT-6dependent miRNA let-7f downregulation d Let-7f targets A20 (TNFAIP3) to modulate NF-kB activity during M. tuberculosis infection d A20-deleted macrophages show enhanced immune markers and attenuated bacterial survival d Macrophage expression of a let-7f mimic reduces M. tuberculosis survival

Research paper thumbnail of Miltefosine: An oral drug for visceral leishmaniasis

The Indian Journal of Pediatrics, 2004

Miltefosine,a phosphocholine analogue originally developed as antimalignant drug, has been found ... more Miltefosine,a phosphocholine analogue originally developed as antimalignant drug, has been found to be highly active against leishmania in vitro and animal model. 1,2 Based on these experiences this drug was tried against human visceral leishmaniasis and found to be highly effective and achieved 97% and 94% cure in phase 2 and phase 3 trial in children.

Research paper thumbnail of Identification of a novel role of ESAT-6-dependent miR-155 induction during infection of macrophages withMycobacterium tuberculosis

Cellular Microbiology, 2012

Research paper thumbnail of Management of diarrhoea in practice

The Indian Journal of Pediatrics, 2002

Diarrhoea, a major cause of morbidity and mortality can be produced by a variety of etiological f... more Diarrhoea, a major cause of morbidity and mortality can be produced by a variety of etiological factors. Management protocol includes assessment of the child, physical examination, lab-evaluation, assessment of severity of dehydration and rehydration therapy using either of the following-WHO-ORS, Home available fluids (HAF), sugar salt solution (SSS), improve WHO-ORS, Amino acid fortified ORS, rice based ORS, low osmolarity ORS. Intravenous fluids are required if patients can't accept orally. Commonly observed electrolyte disturbances are hypernatremia, hyponatremia and hypokalemia. Conculsion is a common problem and can result due to electrolyte imbalance, cavemous sinus thrombosis, associated meningitis, shigella eccephalopathy and hypoglycemia in undernourished children. Treatment includes I.V. diazepam and I.V. glucose and correction of electrolyte imbalance. Additional treatment interventions include antimicrobial drugs including antibiotics, antimotility drugs, absorbents, nutritional and micro and macro nutrient supplementation.

Research paper thumbnail of Mechanism of action of hydrogen peroxide in wheat thermotolerance - interaction between antioxidant isoenzymes, proline and cell membrane

AFRICAN JOURNAL OF BIOTECHNOLOGY, 2012

Terminal heat stress causes an array of physiological, biochemical and morphological changes in p... more Terminal heat stress causes an array of physiological, biochemical and morphological changes in plants, which affect plant growth and development. It has very severe effect on the pollen viability and seed setting in wheat. In the present investigation, an altered expression of H 2 O 2 (0.9 µg/g in C-306 and 0.75 µg/g in HD2329) was observed with the highest accumulation at seed hardening stage and against heat shock (HS) of 42°C for 2 h. With the increase in H 2 O 2 accumulation, an increase in the number of isoenzymes of superoxide dismutase and catalase were observed with high activities under differential heat shock. A decrease in the proline accumulation was observed under differential heat shock. Exogenous application of H 2 O 2 (10 mmole/L) leads to increase in the accumulation of intracellular H 2 O 2 and further an increase in the number of isoenzymes of superoxide dismutase (SOD) and catalase (CAT) was observed. The tolerant cultivar was more responsive to exogenous application of H 2 O 2 compared to susceptible cultivar. The percentage decrease in cell membrane stability under differential heat shock was low in H 2 O 2 treated plants compared to non-treated. The results from this study suggest a potential role for H 2 O 2 in regulating the activity of antioxidant enzymes and accumulation of proline inside cells and in turn influence the cell membrane stability under heat stress. All the defense associated genes were observed to be very responsive to intracellular H 2 O 2 , which gives inference that H 2 O 2 has regulatory role to play in controlling the expression and activities of these proteins under abiotic stresses.

Research paper thumbnail of MicroRNA 17-5p regulates autophagy in Mycobacterium tuberculosis-infected macrophages by targeting Mcl-1 and STAT3

Cellular microbiology, Jan 29, 2015

Autophagy plays a crucial role in the control of bacterial burden during Mycobacterium tuberculos... more Autophagy plays a crucial role in the control of bacterial burden during Mycobacterium tuberculosis infection. MicroRNAs (miRNAs) are small non-coding RNAs which regulate immune signaling and inflammation in response to challenge by pathogens. Appreciating the potential of host-directed therapies designed to control autophagy during mycobacterial infection, we focused on the role of miRNAs in regulating M. tuberculosis-induced autophagy in macrophages. Here we demonstrate that M. tuberculosis infection leads to downregulation of miR-17 and concomitant upregulation of its targets Mcl-1 and STAT3, a transcriptional activator of Mcl-1. Forced expression of miR-17 reduces expression of Mcl-1 and STAT3, and also the interaction between Mcl-1 and Beclin-1. This is directly linked to enhanced autophagy, since Mcl-1 overexpression attenuates the effects of miR-17. At the same time, transfection with a kinase-inactive mutant of protein kinase C δ (PKCδ) (an activator of STAT3), augments M. t...

Research paper thumbnail of MicroRNA let-7 Modulates the Immune Response to Mycobacterium tuberculosis Infection via Control of A20, an Inhibitor of the NF-κB Pathway

Cell Host & Microbe, 2015

Highlights d M. tuberculosis macrophage infection causes ESAT-6dependent miRNA let-7f downregulat... more Highlights d M. tuberculosis macrophage infection causes ESAT-6dependent miRNA let-7f downregulation d Let-7f targets A20 (TNFAIP3) to modulate NF-kB activity during M. tuberculosis infection d A20-deleted macrophages show enhanced immune markers and attenuated bacterial survival d Macrophage expression of a let-7f mimic reduces M. tuberculosis survival

Research paper thumbnail of Miltefosine: An oral drug for visceral leishmaniasis

The Indian Journal of Pediatrics, 2004

Miltefosine,a phosphocholine analogue originally developed as antimalignant drug, has been found ... more Miltefosine,a phosphocholine analogue originally developed as antimalignant drug, has been found to be highly active against leishmania in vitro and animal model. 1,2 Based on these experiences this drug was tried against human visceral leishmaniasis and found to be highly effective and achieved 97% and 94% cure in phase 2 and phase 3 trial in children.

Research paper thumbnail of Identification of a novel role of ESAT-6-dependent miR-155 induction during infection of macrophages withMycobacterium tuberculosis

Cellular Microbiology, 2012

Research paper thumbnail of Management of diarrhoea in practice

The Indian Journal of Pediatrics, 2002

Diarrhoea, a major cause of morbidity and mortality can be produced by a variety of etiological f... more Diarrhoea, a major cause of morbidity and mortality can be produced by a variety of etiological factors. Management protocol includes assessment of the child, physical examination, lab-evaluation, assessment of severity of dehydration and rehydration therapy using either of the following-WHO-ORS, Home available fluids (HAF), sugar salt solution (SSS), improve WHO-ORS, Amino acid fortified ORS, rice based ORS, low osmolarity ORS. Intravenous fluids are required if patients can't accept orally. Commonly observed electrolyte disturbances are hypernatremia, hyponatremia and hypokalemia. Conculsion is a common problem and can result due to electrolyte imbalance, cavemous sinus thrombosis, associated meningitis, shigella eccephalopathy and hypoglycemia in undernourished children. Treatment includes I.V. diazepam and I.V. glucose and correction of electrolyte imbalance. Additional treatment interventions include antimicrobial drugs including antibiotics, antimotility drugs, absorbents, nutritional and micro and macro nutrient supplementation.

Research paper thumbnail of Mechanism of action of hydrogen peroxide in wheat thermotolerance - interaction between antioxidant isoenzymes, proline and cell membrane

AFRICAN JOURNAL OF BIOTECHNOLOGY, 2012

Terminal heat stress causes an array of physiological, biochemical and morphological changes in p... more Terminal heat stress causes an array of physiological, biochemical and morphological changes in plants, which affect plant growth and development. It has very severe effect on the pollen viability and seed setting in wheat. In the present investigation, an altered expression of H 2 O 2 (0.9 µg/g in C-306 and 0.75 µg/g in HD2329) was observed with the highest accumulation at seed hardening stage and against heat shock (HS) of 42°C for 2 h. With the increase in H 2 O 2 accumulation, an increase in the number of isoenzymes of superoxide dismutase and catalase were observed with high activities under differential heat shock. A decrease in the proline accumulation was observed under differential heat shock. Exogenous application of H 2 O 2 (10 mmole/L) leads to increase in the accumulation of intracellular H 2 O 2 and further an increase in the number of isoenzymes of superoxide dismutase (SOD) and catalase (CAT) was observed. The tolerant cultivar was more responsive to exogenous application of H 2 O 2 compared to susceptible cultivar. The percentage decrease in cell membrane stability under differential heat shock was low in H 2 O 2 treated plants compared to non-treated. The results from this study suggest a potential role for H 2 O 2 in regulating the activity of antioxidant enzymes and accumulation of proline inside cells and in turn influence the cell membrane stability under heat stress. All the defense associated genes were observed to be very responsive to intracellular H 2 O 2 , which gives inference that H 2 O 2 has regulatory role to play in controlling the expression and activities of these proteins under abiotic stresses.