@article {2365, title = {Blood progenitor redox homeostasis through olfaction-derived systemic GABA in hematopoietic growth control in Drosophila.}, journal = {Development}, volume = {149}, year = {2022}, month = {2022 Apr 15}, abstract = {

The role of reactive oxygen species (ROS) in myeloid development is well established. However, its aberrant generation alters hematopoiesis. Thus, a comprehensive understanding of events controlling ROS homeostasis forms the central focus of this study. We show that, in homeostasis, myeloid-like blood progenitor cells of the Drosophila larvae, which reside in a specialized hematopoietic organ termed the lymph gland, use TCA to generate ROS. However, excessive ROS production leads to lymph gland growth retardation. Therefore, to moderate blood progenitor ROS, Drosophila larvae rely on olfaction and its downstream systemic GABA. GABA internalization and its breakdown into succinate by progenitor cells activates pyruvate dehydrogenase kinase (PDK), which controls inhibitory phosphorylation of pyruvate dehydrogenase (PDH). PDH is the rate-limiting enzyme that connects pyruvate to the TCA cycle and to oxidative phosphorylation. Thus, GABA metabolism via PDK activation maintains TCA activity and blood progenitor ROS homeostasis, and supports normal lymph gland growth. Consequently, animals that fail to smell also fail to sustain TCA activity and ROS homeostasis, which leads to lymph gland growth retardation. Overall, this study describes the requirement of animal odor-sensing and GABA in myeloid ROS regulation and hematopoietic growth control.

}, issn = {1477-9129}, doi = {10.1242/dev.199550}, author = {Goyal, Manisha and Tomar, Ajay and Madhwal, Sukanya and Mukherjee, Tina} } @article {2503, title = {Dual control of dopamine in Drosophila myeloid-like progenitor cell proliferation and regulation of lymph gland growth.}, journal = {EMBO Rep}, year = {2022}, month = {2022 Apr 27}, pages = {e52951}, abstract = {

In Drosophila, definitive haematopoiesis takes place in a specialized organ termed "lymph gland". It harbours multi-potent stem-like blood progenitor cells whose development controls overall growth of this haematopoietic tissue and formation of mature blood cells. With respect to its development, neurotransmitters have emerged as potent regulators of blood-progenitor cell development and function. In this study, we extend our understanding of neurotransmitters and show that progenitors are self-sufficient with regard to synthesizing dopamine, a well-established neurotransmitter. These cells also have modules for dopamine sensing through the receptor and transporter. We found that modulating expression of these components in progenitor cells affected lymph gland growth, which suggested growth-promoting function of dopamine in blood-progenitor cells. Cell-cycle analysis of developing lymph glands revealed an unexpected requirement for intracellular dopamine in moderating the progression of early progenitor cells from S to G2 phase of the cell cycle, while activation of dopamine receptor signalling later in development regulated their progression from G2 and entry into mitosis. The dual capacity in which dopamine operated, first intracellularly to coordinate S/G2 transition and later extracellularly in G2/M transition, was critical for the growth of the lymph gland. Overall, the data presented highlight a novel non-canonical use of dopamine in the myeloid system that reveals an uncharacterized function of intracellular dopamine in cell-cycle phasing with outcomes on haematopoietic growth and immunity as well.

}, issn = {1469-3178}, doi = {10.15252/embr.202152951}, author = {Kapoor, Ankita and Padmavathi, Achalla and Madhwal, Sukanya and Mukherjee, Tina} } @article {2154, title = {Immune Control of Animal Growth in Homeostasis and Nutritional Stress in .}, journal = {Front Immunol}, volume = {11}, year = {2020}, month = {2020}, pages = {1528}, abstract = {

A large body of research implicates the brain and fat body (liver equivalent) as central players in coordinating growth and nutritional homeostasis in multicellular animals. In this regard, an underlying connection between immune cells and growth is also evident, although mechanistic understanding of this cross-talk is scarce. Here, we explore the importance of innate immune cells in animal growth during homeostasis and in conditions of nutrient stress. We report that larvae lacking blood cells eclose as small adults and show signs of insulin insensitivity. Moreover, when exposed to dietary stress of a high-sucrose diet (HSD), these animals are further growth retarded than normally seen in regular animals raised on HSD. In contrast, larvae carrying increased number of activated macrophage-like plasmatocytes show no defects in adult growth when raised on HSD and grow to sizes almost comparable with that seen with regular diet. These observations imply a central role for immune cell activity in growth control. Mechanistically, our findings reveal a surprising influence of immune cells on balancing fat body inflammation and insulin signaling under conditions of homeostasis and nutrient overload as a means to coordinate systemic metabolism and adult growth. This work integrates both the cellular and humoral arm of the innate immune system in organismal growth homeostasis, the implications of which may be broadly conserved across mammalian systems as well.

}, issn = {1664-3224}, doi = {10.3389/fimmu.2020.01528}, author = {P, Preethi and Tomar, Ajay and Madhwal, Sukanya and Mukherjee, Tina} } @article {2208, title = {Metabolic control of cellular immune-competency by odors in .}, journal = {Elife}, volume = {9}, year = {2020}, month = {2020 12 29}, abstract = {

Studies in different animal model systems have revealed the impact of odors on immune cells; however, any understanding on why and how odors control cellular immunity remained unclear. We find that employ an olfactory-immune cross-talk to tune a specific cell type, the lamellocytes, from hematopoietic-progenitor cells. We show that neuronally released GABA derived upon olfactory stimulation is utilized by blood-progenitor cells as a metabolite and through its catabolism, these cells stabilize Sima/HIFα protein. Sima capacitates blood-progenitor cells with the ability to initiate lamellocyte differentiation. This systemic axis becomes relevant for larvae dwelling in wasp-infested environments where chances of infection are high. By co-opting the olfactory route, the preconditioned animals elevate their systemic GABA levels leading to the upregulation of blood-progenitor cell Sima expression. This elevates their immune-potential and primes them to respond rapidly when infected with parasitic wasps. The present work highlights the importance of the olfaction in immunity and shows how odor detection during animal development is utilized to establish a long-range axis in the control of blood-progenitor competency and immune-priming.

}, issn = {2050-084X}, doi = {10.7554/eLife.60376}, author = {Madhwal, Sukanya and Shin, Mingyu and Kapoor, Ankita and Goyal, Manisha and Joshi, Manish K and Ur Rehman, Pirzada Mujeeb and Gor, Kavan and Shim, Jiwon and Mukherjee, Tina} }