Biology subjects

Matulionis, N.

Publications and source records attributed to Matulionis, N..

3 recordsLinked to original sources

bioRxiv2023

Atlas of fetal metabolism during mid-to-late gestation and diabetic pregnancy

Mounting evidence supports an instructive role for metabolism in stem cell fate decisions. However, much is yet unknown about how fetal metabolism changes during mammalian development and how altered maternal metabolism shapes fetal metabolism. Here, we present a descriptive atlas of in vivo fetal murine metabolism during mid-to-late gestation in normal and diabetic pregnancy. Using 13C-glucose and LC-MS, we profiled the metabolism of fetal brains, hearts, livers, and placentas harvested from pregnant dams between embryonic days (E)10.5 and 18.5. Comparative analysis of our large metabolomics dataset revealed metabolic features specific to fetal tissues developed under a hyperglycemic environment as well as metabolic signatures that may denote developmental transitions during euglycemic development. We observed sorbitol accumulation in fetal tissues and altered neurotransmitter levels in fetal brains isolated from dams with maternal hyperglycemia. Tracing 13C-glucose revealed disparate nutrient sourcing in fetuses depending on maternal glycemic states. Regardless of glycemic state, histidine-derived metabolites accumulated during late development in fetal tissues and maternal plasma. Our rich dataset presents a comprehensive overview of in vivo fetal tissue metabolism and alterations occurring as a result of maternal hyperglycemia.

cell biology↗

bioRxiv2022

FH variant pathogenicity promotes purine salvage pathway dependence in kidney cancer

The tricarboxylic citric acid cycle enzyme fumarate hydratase (FH) is a tumor suppressor. When lost in cells, its substrate fumarate accumulates to mM levels and drives oncogenic signaling and transformation. Germline alterations lead to an autosomal dominant condition known as hereditary leiomyomatosis and renal cell cancer (HLRCC) where patients are predisposed to various benign tumors and an aggressive form of kidney cancer. FH alterations of unclear significance are frequently observed with germline testing; thus, there is an unmet need to classify FH variants by their cancer-associated risk, allowing for screening, early diagnosis and treatment. Here we quantify catalytic efficiency of 74 FH variants of uncertain significance. Over half were enzymatically inactive which is strong evidence of pathogenicity. We generated a panel of HLRCC cell lines expressing FH variants with a range of catalytic activities, then correlated fumarate levels with metabolic features. We found that fumarate accumulation blocks purine biosynthesis, rendering FH-deficient cells reliant on purine salvage to maintain purine nucleotide pools. Genetic or pharmacologic inhibition of the purine salvage pathway reduced HLRCC tumor growth in vivo. Together, these findings suggest pathogenicity of many patient-associated FH variants and reveal purine salvage as a targetable vulnerability in FH-deficient tumors. Statement of SignificanceThis study functionally characterizes patient-associated FH variants with unknown significance for pathogenicity. This study also reveals nucleotide salvage pathways as a targetable feature of FH-deficient cancers, which are shown to be sensitive to the purine salvage pathway inhibitor 6-mercaptopurine. This presents a new rapidly translatable treatment strategy for FH-deficient cancers.

cancer biology↗

bioRxiv2022

Androgen receptor inhibition induces metabolic reprogramming and increased reliance on oxidative mitochondrial metabolism in prostate cancer

Prostate cancer cells that survive clinical androgen receptor (AR) blockade mediate disease progression and lethality. Reprogrammed metabolic signaling is one mechanism by which tumor cells can survive treatment. However, how AR inhibition reprograms metabolism, and whether altered metabolism can be exploited to eradicate cells that survive AR blockade, remains unclear. Here, we comprehensively characterized the effect of AR blockade on prostate cancer metabolism using transcriptomics, metabolomics, and bioenergetics approaches. AR inhibition maintains oxidative mitochondrial metabolism and reduces glycolytic signaling, through hexokinase II downregulation and decreased MYC activity. Robust elongation of mitochondria via reduced DRP1 activity supports cell fitness after AR blockade. In addition, AR inhibition enhances sensitivity to complex I inhibitors in several models, suggesting that AR blockade increases reliance on oxidative mitochondrial metabolism. Our study provides an enhanced understanding of how AR inhibition alters metabolic signaling and highlights the potential of therapies that target metabolic vulnerabilities in AR-inhibited cells.

cancer biology↗