@article {9105, title = {Macrophage metabolic reprogramming during dietary stress influences adult body size in Drosophila [Central Imaging and Flow Cytometry Facility (INT)]}, journal = {EMBO Rep}, year = {2025}, month = {2025 Sep 09}, abstract = {

Immune cells are increasingly recognized as nutrient sensors; however, their developmental role in regulating growth under homeostasis or dietary stress remains elusive. Here, we show that Drosophila larval macrophages, in response to excessive dietary sugar (HSD), reprogram their metabolic state by activating glycolysis, thereby enhancing TCA-cycle flux, and increasing lipogenesis-while concurrently maintaining a lipolytic state. Although this immune-metabolic configuration correlates with growth retardation under HSD, our genetic analyses reveal that enhanced lipogenesis supports growth, whereas glycolysis and lipolysis are growth-inhibitory. Notably, promoting immune-driven lipogenesis offsets early growth inhibition in imaginal discs caused by glycolytic and lipolytic immune-metabolic states. Our findings reveal a model of immune-metabolic imbalance, where growth-suppressive states (glycolysis, lipolysis) dominate over a growth-supportive lipogenic state, thereby impairing early organ size control and ultimately affecting adult size. Overall, this study provides important insights into dietary stress-induced immune-metabolic reprogramming and its link to organ size regulation and early developmental plasticity.

}, issn = {1469-3178}, doi = {10.1038/s44319-025-00574-7}, author = {Mahanta, Anusree and Najar, Sajad Ahmad and Hariharan, Nivedita and Bhowmick, Ajit and Rizvi, Syed Iqra and Goyal, Manisha and Parupalli, Preethi and Subramanian, Ramaswamy and Giangrande, Angela and Palakodeti, Dasaradhi and Mukherjee, Tina} } @article {9118, title = {Metabolic coupling of ROS generation and antioxidant synthesis by the GABA shunt pathway in myeloid-like blood progenitor cells of Drosophila. [CIFF \& Metabolomics Facility]}, journal = {PLoS Genet}, volume = {21}, year = {2025}, month = {2025 Sep}, pages = {e1011602}, abstract = {

Redox balance is crucial for normal development of stem and progenitor cells that reside in oxidative environments. In this study, we explore the mechanisms of redox homeostasis in such niches and show that myeloid-like blood progenitor cells of the Drosophila larval lymph gland, that generate reactive oxygen species (ROS), moderate it developmentally by de novo synthesizing glutathione (GSH) to ensure redox balance. During lymph gland development, as the blood-progenitor cells oxidize pyruvate via the TCA cycle leading to the generation of ROS, GABA-shunt restricts pyruvate dehydrogenase (PDH) activity and consequently TCA cycle flux. This moderation enables a metabolic rerouting of TCA-derived oxaloacetate (OAA) to pyruvate via gluconeogenesis, which is necessary to sustain serine levels, the rate-limiting precursor for de novo GSH synthesis. Disruption of GABA metabolism causes metabolic imbalance, marked by excessive PDH activity and heightened TCA cycle flux. This results in reduced OAA availability, impaired gluconeogenic capacity, and insufficient serine/GSH production, ultimately leading to ROS dysregulation. Overall, this study identifies a unique metabolic framework in blood progenitor cells, where the GABA shunt, by restraining PDH and TCA cycle activity, maintains ROS at developmental levels. By coupling TCA-derived metabolites to GSH production, this state enables the TCA cycle to support both ROS generation and ROS scavenging, ensuring the developmental roles of ROS while preserving progenitor homeostasis.

}, keywords = {Animals, Antioxidants, Citric Acid Cycle, Drosophila, Drosophila melanogaster, Drosophila Proteins, gamma-Aminobutyric Acid, Gluconeogenesis, Glutathione, Hematopoietic Stem Cells, Larva, Myeloid Cells, Oxidation-Reduction, Oxidative Stress, Pyruvic Acid, Reactive Oxygen Species}, issn = {1553-7404}, doi = {10.1371/journal.pgen.1011602}, author = {Goyal, Manisha and Tiwari, Sakshi and Arora, Jagriti and Cooper, Bruce and Subramanian, Ramaswamy and Mukherjee, Tina} } @article {8462, title = {A curated list of targeted optimized promiscuous ketoreductases (TOP-K). [Bugworks Research Pvt. Ltd., a C-CAMP Startup]}, journal = {Biochem J}, volume = {480}, year = {2023}, month = {2023 Jul 12}, pages = {975-997}, abstract = {

Enzymes are either specific or promiscuous catalysts in nature. The latter is portrayed by protein families like CYP450Es, Aldo-ketoreductases and short/medium-chain dehydrogenases which participate in detoxification or secondary metabolite production. However, enzymes are evolutionarily {\textquoteright}blind{\textquoteright} to an ever-increasing synthetic substrate library. Industries and laboratories have circumvented this by high-throughput screening or site-specific engineering to synthesize the product of interest. However, this paradigm entails cost and time-intensive one-enzyme, one-substrate catalysis model. One of the superfamilies regularly used for chiral alcohol synthesis are short-chain dehydrogenases/reductases (SDRs). Our objective is to determine a superset of promiscuous SDRs that can catalyze multiple ketones. They are typically classified into shorter {\textquoteright}Classical{\textquoteright} and longer {\textquoteright}Extended{\textquoteright} type ketoreductases. However, current analysis of modelled SDRs reveals a length-independent conserved N-terminus Rossmann-fold and a variable substrate-binding C-terminus substrate-binding region for both categories. The latter is recognized to influence the enzyme{\textquoteright}s flexibility and substrate promiscuity and we hypothesize these properties are directly linked with each other. We tested this by catalyzing ketone intermediates with the essential and specific enzyme: FabG_E, as well as non-essential SDRs such as UcpA and IdnO. The experimental results confirmed this biochemical-biophysical association, making it an interesting filter for ascertaining promiscuous enzymes. Hence, we created a dataset of physicochemical properties derived from the protein sequences and employed machine learning algorithms to examine potential candidates. This resulted in 24 targeted optimized ketoreductases (TOP-K) from 81 014 members. The experimental validation of select TOP-Ks demonstrated the correlation between the C-terminal lid-loop structure, enzyme flexibility and turnover rate on pro-pharmaceutical substrates.

}, keywords = {ketoreductases, machine learning, medium-chain dehydrogenases, short-chain dehydrogenases}, issn = {1470-8728}, doi = {10.1042/BCJ20230051}, url = {https://pubmed.ncbi.nlm.nih.gov/37335080/}, author = {Shanbhag, Anirudh P and Rajagopal, Sreenath and Ghatak, Arindam and Katagihallimath, Nainesh and Subramanian, Ramaswamy and Datta, Santanu} } @article {1860, title = {Glycomic and glycotranscriptomic profiling of mucin-type O-glycans in planarian Schmidtea mediterranea [Mass Spectrometry - Glycomics]}, journal = {Glycobiology}, year = {2021}, month = {09/2021}, type = {Journal Article}, abstract = {

O-Glycans on cell surfaces play important roles in cell-cell, cell-matrix, and receptor-ligand interaction. Therefore, glycan-based interactions are important for tissue regeneration and homeostasis. Free-living flatworm Schmidtea mediterranea, because of its robust regenerative potential, is of great interest in the field of stem cell biology and tissue regeneration. Nevertheless, information on the composition and structure of O-glycans in planaria is unknown. Using mass spectrometry and in silico approaches, we characterized the glycome and the related transcriptome of mucin-type O-glycans of planarian S. mediterranea. Mucin-type O-glycans were composed of multiple isomeric, methylated, and unusually extended mono- and di-substituted O-GalNAc structures. Extensions made of hexoses and 3-O methyl hexoses were the glycoforms observed. From glycotranscriptomic analysis, sixty genes belonging to five distinct enzyme classes were identified to be involved in mucin-type O-glycan biosynthesis. These genes shared homology with those in other invertebrate systems. While a majority of the genes involved in mucin-type O-glycan biosynthesis was highly expressed during organogenesis and in differentiated cells, a few select genes in each enzyme class were specifically enriched during early embryogenesis. Our results indicate a unique temporal and spatial role for mucin-type O-glycans during embryogenesis and organogenesis and in adulthood. In summary, this is the first report on O-glycans in planaria. This study expands the structural and biosynthetic possibilities in cellular glycosylation in the invertebrate glycome and provides a framework towards understanding the biological role of mucin-type O-glycans in tissue regeneration using planarians.

}, keywords = {Flatworm, GC-MS, Invertebrates, MALDI-TOF mass spectrometry, ScRNAseq}, doi = {https://doi.org/10.1093/glycob/cwab097}, url = {https://academic.oup.com/glycob/advance-article-abstract/doi/10.1093/glycob/cwab097/6361079}, author = {Subramanian, Sabarinath Peruvemba and Lakshmanan, Vairavan and Palakodeti, Dasaradhi and Subramanian, Ramaswamy} } @article {1178, title = {Serotonin is essential for eye regeneration in planaria Schmidtea~mediterranea [Mass Spectrometry (Metabolomics) and Central Imaging \& Flow Cytometry Facilities (INT)]}, journal = {FEBS Lett}, year = {2019}, month = {2019 Sep 17}, abstract = {

Planaria is an ideal system to study factors involved in regeneration and tissue homeostasis. Little is known about the role of metabolites and small molecules in stem cell maintenance and lineage specification in planarians. Using liquid chromatography and mass spectrometry (LC-MS)-based quantitative metabolomics, we determined the relative levels of metabolites in stem cells, progenitors, and differentiated cells of the planarian Schmidtea\ mediterranea. Tryptophan and its metabolic product serotonin are significantly enriched in stem cells and progenitor population. Serotonin biosynthesis in these cells is brought about by a noncanonical enzyme, phenylalanine hydroxylase. Knockdown of Smed-pah leads to complete disappearance of eyes in regenerating planaria, while exogenous supply of serotonin and its precursor rescues the eyeless phenotype. Our results demonstrate a key role for serotonin in eye regeneration.

}, issn = {1873-3468}, doi = {10.1002/1873-3468.13607}, author = {Sarkar, Arunabha and Mukundan, Namita and Sowndarya, Sai and Dubey, Vinay Kumar and Babu, Rosana and Lakshmanan, Vairavan and Rangiah, Kannan and Panicker, Mitradas M and Palakodeti, Dasaradhi and Subramanian, Sabarinath Peruvemba and Subramanian, Ramaswamy} } @article {765, title = {Identification of multiple isomeric core chitobiose-modified high-mannose and paucimannose -glycans in the planarian. [Mass Spectrometry Facility - Glycomics (INT)]}, journal = {J Biol Chem}, volume = {293}, year = {2018}, month = {2018 May 04}, pages = {6707-6720}, abstract = {

Cell surface-associated glycans mediate many cellular processes, including adhesion, migration, signaling, and extracellular matrix organization. The galactosylation of core fucose (GalFuc epitope) in paucimannose and complex-type -glycans is characteristic of protostome organisms, including flatworms (planarians). Although uninvestigated, the structures of these glycans may play a role in planarian regeneration. Whole-organism MALDI-MS analysis of -linked oligosaccharides from the planarian revealed the presence of multiple isomeric high-mannose and paucimannose structures with unusual mono-, di-, and polygalactosylated ( = 3-5) core fucose structures; the latter structures have not been reported in other systems. Di- and trigalactosylated core fucoses were the most dominant glycomers. -Glycans showed extensive, yet selective, methylation patterns, ranging from non-methylated to polymethylated glycoforms. Although the majority of glycoforms were polymethylated, a small fraction also consisted of non-methylated glycans. Remarkably, monogalactosylated core fucose remained unmethylated, whereas its polygalactosylated forms were methylated, indicating structurally selective methylation. Using database searches, we identified two potential homologs of the GalĪ²1-4Fuc-synthesizing enzyme from nematodes (GALT-1) that were expressed in the prepharyngeal, pharyngeal, and mesenchymal regions in The presence of two GALT-1 homologs suggests different requirements for mono- and polygalactosylation of core fucose for the formation of multiple isomers. Furthermore, we observed variations in core fucose glycosylation patterns in different planarian strains, suggesting evolutionary adaptation in fucose glycosylation. The various core chitobiose modifications and methylations create \>60 different glycoforms in These results contribute greatly to our understanding of -glycan biosynthesis and suggest the presence of a GlcNAc-independent biosynthetic pathway in

}, issn = {1083-351X}, doi = {10.1074/jbc.RA117.000782}, author = {Subramanian, Sabarinath Peruvemba and Babu, Ponnusamy and Palakodeti, Dasaradhi and Subramanian, Ramaswamy} }