Oxytocin Signaling Regulates the Homeostatic Response to Cold Stress in Poikilothermic Vertebrates

When exposed to low temperature, homeothermic vertebrates maintain internal body temperature by activating thermogenesis and by altered metabolism, synchronized by neuroendocrine responses. Although such physiological responses also occur in poikilothermic vertebrates, the prevailing notion is that their reactions are passive. Here, we explored molecular hypothalamic and physiological responses to cold stress in the tropical poikilotherm Nile tilapia (Oreochromis niloticus). We show that cold exposed tilapia exhibit complex homeostatic responses, including increased hypothalamic oxytocin, plasma glucose and cortisol concomitant with reduced plasma lactate and metabolic rate. Pharmacological or genetic blockage of oxytocin signaling further affected metabolic rate in two cold-exposed poikilothermic models. This indicates that oxytocin, a known thermoregulator in homeotherms, actively regulates temperature-related homeostasis in poikilotherms. Overall, our findings show that the brain of poikilotherms actively responds to cold temperature by regulating metabolic physiology. Moreover, we identify oxytocin signaling as an adaptive and evolutionarily conserved metabolic regulator of temperature-related homeostasis.

Neutrophil Profiles of Pediatric COVID-19 and Multisystem Inflammatory Syndrome in Children

Multisystem Inflammatory Syndrome in Children (MIS-C) is a delayed-onset, COVID-19-related hyperinflammatory systemic illness characterized by SARS-CoV-2 antigenemia, cytokine storm and immune dysregulation; however, the role of the neutrophil has yet to be defined. In adults with severe COVID-19, neutrophil activation has been shown to be central to overactive inflammatory responses and complications. Thus, we sought to define neutrophil activation in children with MIS-C and acute COVID-19. We collected samples from 141 children: 31 cases of MIS-C, 43 cases of acute pediatric COVID-19, and 67 pediatric controls. We found that MIS-C neutrophils display a granulocytic myeloid-derived suppressor cell (G-MDSC) signature with highly altered metabolism, which is markedly different than the neutrophil interferon-stimulated gene (ISG) response observed in pediatric patients during acute SARS-CoV-2 infection. Moreover, we identified signatures of neutrophil activation and degranulation with high levels of spontaneous neutrophil extracellular trap (NET) formation in neutrophils isolated from fresh whole blood of MIS-C patients. Mechanistically, we determined that SARS-CoV-2 immune complexes are sufficient to trigger NETosis. Overall, our findings suggest that the hyperinflammatory presentation of MIS-C could be mechanistically linked to persistent SARS-CoV-2 antigenemia through uncontrolled neutrophil activation and NET release in the vasculature.

A comparative meta-analysis of membraneless organelle associated proteins with age related proteome of C. elegans

Proteome imbalance can lead to protein misfolding and aggregation which is associated with pathologies. Protein aggregation can also be an active, organized process and can be exploited by cells as a survival strategy. In adverse conditions, it is beneficial to deposit the proteins in a condensate rather degrading and resynthesizing. Membrane less organelles (MLOs) are biological condensates formed through liquid liquid phase separation (LLPS), involving cellular components such as nucleic acids and proteins. LLPS is a regulated process, which when perturbed, can undergo a transition from a physiological liquid condensate to pathological solid-like protein aggregates. To understand how the MLO-associated proteins (MLO-APs) behave during aging, we performed a comparative meta analysis with age related proteome of C. elegans. We found that the MLO-APs are highly abundant throughout the lifespan. Interestingly, they are aggregating more in long-lived mutant worms compared to the age matched wildtype worms. GO term analysis revealed that the cell cycle and embryonic development are among the top enriched processes in addition to RNA metabolism RNP components. Considering antagonistic pleotropic nature of these developmental genes and post mitotic status of C. elegans, we assume that these proteins phase transit during post development. As the organism ages, these MLO-APs either mature to become more insoluble or dissolve in uncontrolled manner. However, in the long-lived daf-2 mutant worms, the MLOs may attain protective states due to enhanced proteostasis components and altered metabolism that eventually make these worms more protected.

Amyotrophic Lateral Sclerosis: A Diet Review

Amyotrophic lateral sclerosis (ALS) is a fatal disease related to upper and lower motor neurons degeneration. Although the environmental and genetic causes of this disease are still unclear, some factors involved in ALS onset such as oxidative stress may be influenced by diet. A higher risk of ALS has been correlated with a high fat and glutamate intake and β-methylamino-L-alanine. On the contrary, a diet based on antioxidant and anti-inflammatory compounds, such as curcumin, creatine, coenzyme Q10, vitamin E, vitamin A, vitamin C, and phytochemicals could reduce the risk of ALS. However, data are controversial as there is a discrepancy among different studies due to a limited number of samples and the many variables that are involved. In addition, an improper diet could lead to an altered microbiota and consequently to an altered metabolism that could predispose to the ALS onset. In this review we summarized some research that involve aspects related to ALS such as the epidemiology, the diet, the eating behaviour, the microbiota, and the metabolic diseases. Further research is needed to better comprehend the role of diet and the metabolic diseases in the mechanisms leading to ALS onset and progression.

Polymorphonuclear Cells Show Features of Dysfunctional Activation During Fatal Sepsis

Sepsis and septic shock remain leading causes of morbidity and mortality for patients in the intensive care unit. During the early phase, immune cells produce various cytokines leading to prompt activation of the immune system. Polymorphonuclear leukocytes (PMNs) respond to different signals producing inflammatory factors and executing their antimicrobial mechanisms, resulting in the engulfment and elimination of invading pathogens. However, excessive activation caused by various inflammatory signals produced during sepsis progression can lead to the alteration of PMN signaling and subsequent defects in their functionality. Here, we analyzed samples from 34 patients in septic shock, focusing on PMNs gene expression and proteome changes associated with septic shock. We revealed that, compared to those patients who survived longer than five days, PMNs from patients who had fulminant sepsis were characterized by a dysfunctional hyper-activation, show altered metabolism, and recent exit from the cell cycle and signs of cellular lifespan. We believe that this multi-omics approach, although limited, pinpoints the alterations in PMNs’ functionality, which may be rescued by targeted treatments.

Sex disparate gut microbiome and metabolome perturbations precede disease progression in a mouse model of Rett syndrome

Rett syndrome (RTT) is a regressive neurodevelopmental disorder in girls, characterized by multisystem complications including gut dysbiosis and altered metabolism. While RTT is known to be caused by mutations in the X-linked gene MECP2, the intermediate molecular pathways of progressive disease phenotypes are unknown. Mecp2 deficient rodents used to model RTT pathophysiology in most prior studies have been male. Thus, we utilized a patient-relevant mouse model of RTT to longitudinally profile the gut microbiome and metabolome across disease progression in both sexes. Fecal metabolites were altered in Mecp2e1 mutant females before onset of neuromotor phenotypes and correlated with lipid deficiencies in brain, results not observed in males. Females also displayed altered gut microbial communities and an inflammatory profile that were more consistent with RTT patients than males. These findings identify new molecular pathways of RTT disease progression and demonstrate the relevance of further study in female Mecp2 animal models.

Archaic introgression and variation in pharmacogenes and implications for local adaptation

Modern humans carry Neanderthal and Denisovan (archaic) genome elements which may have been a result of environmental adaptation. These effects may be particularly evident in pharmacogenes - genes responsible for the processing of exogenous substances such as food, pollutants, and medications. However, the health implications and contribution of archaic ancestry in pharmacogenes of modern humans remains understudied. We characterize eleven key cytochrome P450 (CYP450) genes involved in drug metabolizing reactions in three Neanderthal and one Denisovan individuals and examine archaic introgression in modern human populations. We infer the metabolizing efficiency of these eleven genes in archaic individuals and show important genetic differences relative to modern human variants. We identify archaic-specific SNVs in each CYP450 gene, including some that are potentially damaging, which may result in altered metabolism in modern human people carrying these variants. We highlight four genes which display interesting patterns of archaic variation: CYP2B6 - we find a large number of unique variants in the Vindija Neanderthal, some of which are shared with a small subset of African modern humans; CYP2C9 - containing multiple variants that are shared between Europeans and Neanderthals; CYP2A6*12 - a variant defined by a hybridization event that was found in humans and Neanderthals, suggesting the recombination event predates both species; and CYP2J2 - in which we hypothesize a Neanderthal variant was re-introduced in non-African populations by archaic admixture. The genetic variation identified in archaic individuals imply environmental pressures that may have driven CYP450 gene evolution.

Comparative Proteomics Demonstrates Altered Metabolism Pathways in Cotrimoxazole- Resistant and Amikacin-Resistant Klebsiella pneumoniae Isolates

Antibiotic resistance (AMR) has always been a hot topic all over the world and its mechanisms are varied and complicated. Previous evidence revealed the metabolic slowdown in resistant bacteria, suggesting the important role of metabolism in antibiotic resistance. However, the molecular mechanism of reduced metabolism remains poorly understood, which inspires us to explore the global proteome change during antibiotic resistance. Here, the sensitive, cotrimoxazole-resistant, amikacin-resistant, and amikacin/cotrimoxazole -both-resistant KPN clinical isolates were collected and subjected to proteome analysis through liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS). A deep coverage of 2,266 proteins were successfully identified and quantified in total, representing the most comprehensive protein quantification data by now. Further bioinformatic analysis showed down-regulation of tricarboxylic acid cycle (TCA) pathway and up-regulation of alcohol metabolic or glutathione metabolism processes, which may contribute to ROS clearance and cell survival, in drug-resistant isolates. These results indicated that metabolic pathway alteration was directly correlated with antibiotic resistance, which could promote the development of antibacterial drugs from “target” to “network.” Moreover, combined with minimum inhibitory concentration (MIC) of cotrimoxazole and amikacin on different KPN isolates, we identified nine proteins, including garK, uxaC, exuT, hpaB, fhuA, KPN_01492, fumA, hisC, and aroE, which might contribute mostly to the survival of KPN under drug pressure. In sum, our findings provided novel, non-antibiotic-based therapeutics against resistant KPN.

Metabolic Changes in Venetoclax Resistance Are Determined By Differentiation State in T-Cell Acute Lymphoblastic Leukemia

T-cell acute lymphoblastic leukaemia (T-ALL) is an aggressive hematologic malignancy arising from the transformation of immune T-cell lymphocytes. Early T-cell progenitor (ETP-ALL) is a subgroup particularly associated with chemoresistance and a high risk for relapse. Recently, it was shown that ETP-ALL is dependent on the expression of the anti-apoptotic protein BCL-2, and is sensitive to inhibition with ABT-199, a BCL-2 specific BH3 mimetic 1,2. However, one issue with a targeted agent, such as ABT-199, is the development of acquired resistance. Interestingly, there have been numerous high impact papers connecting ABT-199 resistance to altered oxidative phosphorylation (OXPHOS) 3,4. While there are relatively few studies into T-ALL metabolism, there is evidence that aerobic glycolysis, the conversion of glucose to lactate, is greater in proliferating T-cells than in T-ALL and that NOTCH signalling can drive mitochondrial OXPHOS 5. A recent study showed that the transcription factor RUNX2 altered T-ALL metabolism, increasing both glycolysis and OXPHOS and enhancing leukemic cell migration 6. However, there has been relatively little research into the metabolic profile of T-ALL at distinct stages of differentiation. The aim of this study was to determine the role of ABT-199 resistance in altering metabolism and determine if that was due to the differentiation state of the T-ALL. ABT-199 R LOUCY cells were generated by chronic exposure to increasing concentrations of ABT-199 administered every two days. The EZH2 KO Jurkat cell lines were previously generated through CRISPR-Cas9 engineering 7. In order to assess the metabolic profile, cells were attached to a 96 well plate using CellTak and the extracellular acidification rate (ECAR) and oxidative phosphorylation (OXPHOS) was measured on a Seahorse Bioscience XF96 Extracellular Flux Analyzer. Anti-apoptotic dependence was measured using BH3 profiling and cell death by Annexin V/propidium iodide staining. The mitochondrial structure was visualized using transmission electron microscopy. Previously, we generated ABT-199 resistant ETP-ALL LOUCY cells (ABT-199 R) following continuous exposure to ABT-199 over a prolonged period of several months 8. The ABT-199 R cells showed dependence on BCL-XL for survival and sensitivity to the BCL-XL inhibitor WEHI 539. The ABT-199 R cells showed evidence of differentiation to a more mature T-cell. The ABT-199 R cells had increased surface CD3 (sCD3) expression and CD1A expression, along with increased expression of TAL1 and LMO2 genes compared to parental LOUCY cells. Interestingly, the ABT-199 R cells showed enhanced basal respiration, ATP production and max respiration compared to the parental cells. Indeed, analysis of the expression of OXPHOS complexes showed increased expression of complexes I-IV in the ABT-199 R cells, compared to the parental controls. Indeed, the parental LOUCY cells appeared to have reduced cristae number and length compared to the ABT-199R cells. Next, we assessed if inhibiting OXPHOS with a series of inhibitors (oligomycin, rotenone, antimycin) could sensitize the ABT-199 R LOUCY cells to ABT-199. However, we did not detect any changes to sensitivity of ABT-199. This led us to hypothesize that perhaps the changes in OXPHOS were due differentiation state of the LOUCY cells. We confirmed that more typical T-ALL cell lines (JURKAT and CEM-CCRF) had higher OXPHOS than the ETP-ALL cell line LOUCY and had higher expression of the OXPHOS complexes I-IV by Western blotting. To assess if de-differentiation of a more typical T-ALL cell line would cause a reduction in OXPHOS we turned to the EZH2 knockout (K/O) Jurkat cells 7. We found that EZH2 KO2 showed a reduction in the differentiation markers CD1A and CD3 on the cell surface and TAL1 gene expression, compared to WT control Jurkats. Next, we assessed the OXPHOS and found that the de-differentiated EZH2 cells had reduced OXPHOS compared to the parental controls, with altered mitochondrial structure. Suggesting, that de-differentiation of typical T-ALL cell line reduces OXPHOS. In this study we show that metabolic phenotype is linked to the maturation stage of T-ALL. We believe that the altered metabolism identified in ABT-199 resistance is linked to the selection of a more mature cell type. Highlighting, that altered metabolism may not be a driver of resistance to ABT-199 but a consequence of the maturation stage of the resistant cell. Disclosures Di Grande: Novartis: Current Employment. Leon: BenevolentAI: Current Employment. Mansour: Astellas: Consultancy, Honoraria; Janssen: Consultancy. Bond: Haematology Association of Ireland Award funded by Novartis: Research Funding. Ni Chonghaile: AbbVie: Research Funding.

Use of ATP, GTP, ADP and AMP as an Index of Energy Utilization and Storage in HIV Infected Individuals at NAUTH, Nigeria: A Longitudinal, Prospective, Case-Controlled Study

Human immunodeficiency virus (HIV) is associated with altered metabolism and increased energy expenditure, this energy requirement increases significantly as the HIV disease progresses. This study aimed on the use of Adenosine triphosphate (ATP), Guanosine triphosphate (GTP), Adenosine diphosphate (ADP) and Adenosine monophosphate (AMP) as an index of energy utilization, storage and energy balance in HIV infected individuals. This is a longitudinal, prospective, case-controlled study involving seventy seven (77) HIV Sero-positive individuals newly diagnosed attending retroviral disease treatment centre of Nnamdi Azikiwe University University Teaching Hospital (NAUTH) aged 18-60 years both male and female not on highly active antiretroviral therapy (HAART), were enrolled in the study as test subjects and thirty six (36) apparently healthy HIV Sero-negative individuals both male and female as control subjects. ATP, GTP, ADP and AMP were estimated by enzyme linked immunosorbent assay (ELISA), while, total Energy Balance was determined by calculation. The data obtained were subjected to statistical analysis using SPSS software application (version 21.0) and the results expressed as mean ± standard deviation. The plasma ATP and GTP were significantly lower (P<0.05) in both HIV pre-treatment and post-treatment group compared with control group. Meanwhile, the plasma level of ADP and AMP were significantly lower (P<0.05) in HIV post-treatment group compared with HIV pre-treatment and control group. There was also a significant difference (P<0.05) in ATP, ADP, AMP and GTP level between HIV pre-treatment and post-treatment group. Meanwhile, the energy balance was lower (P<0.05) in HIV groups compared with control group. However, the energy balance in HIV post-treatment group was significantly lower (P<0.05) compared to HIV pre- treatment group. In conclusion, the significant changes in the biochemical parameters measured suggest altered metabolism, increased energy expenditure and energy deficit/negative energy balance in HIV subjects resulting from increased energy expenditure. Hence, High energy molecules such ATP, ADP, GTP and AMP can be used to predict early energy deficit and manage energy imbalance in HIV infected individuals.