Ethylmalonic encephalopathy ETHE1 p. D165H mutation alters the mitochondrial function in human skeletal muscle proteome

Targeting ETHE1 inhibits tumorigenesis in vitro and in vivo by preventing aerobic glycolysis in gastric adenocarcinoma cells

Gastric adenocarcinoma (GAC) is a prevalent form of cancer that frequently displays abnormal metabolism characterized by increased aerobic glycolysis. Therefore, inhibition of glycolysis may exhibit therapeutic potential for the management of advanced or recurrent gastric cancer. Analysis of ethylmalonic encephalopathy protein 1 (ETHE1) expression levels in 30 pairs of cancerous and paracancerous tissues, and 50 tumor tissue sections collected from patients with GAC revealed that ETHE1 expression was upregulated in cancerous tissues compared with in paracancerous tissues. Advanced tumor stage, lymph node metastasis and Tumor-Node-Metastasis stage were associated with high ETHE1 expression. Knockdown of ETHE1 expression in GAC cells resulted in a significant inhibition of cell proliferation and in cell cycle arrest, accompanied by downregulated levels of cyclin D1 and cyclin-dependent kinase 4. ETHE1 knockdown also resulted in increased apoptosis of GAC cells, and increased caspase-3 and caspase-9 activity. Additionally, the expression levels of proteins associated with aerobic glycolysis were downregulated following ETHE1 knockdown, which may reduce glucose consumption, lactic acid production and ATP levels. In the in vivo experiments, suppressed tumor growth and increased tumor cell apoptosis were observed in the xenograft tumor model in animals injected with ETHE1-knockdown GAC cells. In summary, knockdown of ETHE1 inhibited aerobic glycolysis, promoted apoptosis and inhibited tumor cell proliferation in GAC cells. These results highlight ETHE1 as a promising molecular target for the treatment of GAC potentially using an adjuvant to target it, offering a novel approach in the exploration of targeted therapeutic drugs for GAC.

Review: Utility of mass spectrometry in rare disease research and diagnosis

Individuals affected by a rare disease often experience a long and arduous diagnostic odyssey. Delivery of genetic answers in a timely manner is critical to affected individuals and their families. Multi-omics, a term which usually encompasses genomics, transcriptomics, proteomics, metabolomics and lipidomics, has gained increasing popularity in rare disease research and diagnosis over the past decade. Mass spectrometry (MS) is a technique allowing the study of proteins, metabolites and lipids and their fragments at scale, enabling researchers to effectively determine the presence and abundance of thousands of molecules in a single test, accurately quantify their specific levels, identify potential therapeutic biomarkers, detect differentially expressed proteins in patients with rare diseases, and monitor disease progression and treatment response. In this review, we focus on mass spectrometry (MS)-based omics and survey the literature describing the utility of different MS-based omics and how they have transformed rare disease research and diagnosis.

Mitochondria in biology and medicine - 2023

Mitochondria are an indispensable part of the cell that plays a crucial role in regulating various signaling pathways, energy metabolism, cell differentiation, proliferation, and cell death. Since mitochondria have their own genetic material, they differ from their nuclear counterparts, and dysregulation is responsible for a broad spectrum of diseases. Mitochondrial dysfunction is associated with several disorders, including neuro-muscular disorders, cancer, and premature aging, among others. The intricacy of the field is due to the cross-talk between nuclear and mitochondrial genes, which has also improved our knowledge of mitochondrial functions and their pathogenesis. Therefore, interdisciplinary research and communication are crucial for mitochondrial biology and medicine due to the challenges they pose for diagnosis and treatment. The ninth annual conference of the Society for Mitochondria Research and Medicine (SMRM)- India, titled "Mitochondria in Biology and Medicine" was organized at the Centre for DNA Fingerprinting and Diagnostics (CDFD), Hyderabad, India, on June 21-23, 2023. The latest advancements in the field of mitochondrial biology and medicine were discussed at the conference. In this article, we summarize the entire event for the benefit of researchers working in the field of mitochondrial biology and medicine.

Mitochondrial phosphoproteomes are functionally specialized across tissues

Mitochondria are essential organelles whose dysfunction causes human pathologies that often manifest in a tissue-specific manner. Accordingly, mitochondrial fitness depends on versatile proteomes specialized to meet diverse tissue-specific requirements. Increasing evidence suggests that phosphorylation may play an important role in regulating tissue-specific mitochondrial functions and pathophysiology. Building on recent advances in mass spectrometry (MS)-based proteomics, we here quantitatively profile mitochondrial tissue proteomes along with their matching phosphoproteomes. We isolated mitochondria from mouse heart, skeletal muscle, brown adipose tissue, kidney, liver, brain, and spleen by differential centrifugation followed by separation on Percoll gradients and performed high-resolution MS analysis of the proteomes and phosphoproteomes. This in-depth map substantially quantifies known and predicted mitochondrial proteins and provides a resource of core and tissue-specific mitochondrial proteins (mitophos.de). Predicting kinase substrate associations for different mitochondrial compartments indicates tissue-specific regulation at the phosphoproteome level. Illustrating the functional value of our resource, we reproduce mitochondrial phosphorylation events on dynamin-related protein 1 responsible for its mitochondrial recruitment and fission initiation and describe phosphorylation clusters on MIGA2 linked to mitochondrial fusion.

Diagnosis of primary mitochondrial disorders -Emphasis on myopathological aspects

Mitochondrial disorders are one of the most common neurometabolic disorders affecting all age groups. The phenotype-genotype heterogeneity in these disorders can be attributed to the dual genetic control on mitochondrial functions, posing a challenge for diagnosis. Though the advancement in the high-throughput sequencing and other omics platforms resulted in a "genetics-first" approach, the muscle biopsy remains the benchmark in most of the mitochondrial disorders. This review focuses on the myopathological aspects of primary mitochondrial disorders. The utility of muscle biopsy is not limited to analyse the structural abnormalities; rather it also proves to be a potential tool to understand the deranged sub-cellular functions.