HS-Prdx4 axis mitigates Golgi stress to bolster tumor-reactive T cell immunotherapeutic response.

The role of tumor microenvironment (TME)-associated inadequate protein modification and trafficking due to insufficiency in Golgi function, leading to Golgi stress, in the regulation of T cell function is largely unknown. Here, we show that disruption of Golgi architecture under TME stress, identified by the decreased expression of GM130, was reverted upon treatment with hydrogen sulfide (HS) donor GYY4137 or overexpressing cystathionine β-synthase (CBS), an enzyme involved in the biosynthesis of endogenous HS, which also promoted stemness, antioxidant capacity, and increased protein translation, mediated in part by endoplasmic reticulum-Golgi shuttling of Peroxiredoxin-4. In in vivo models of melanoma and lymphoma, antitumor T cells conditioned ex vivo with exogenous HS or overexpressing CBS demonstrated superior tumor control upon adoptive transfer.

Mitochondrial Dysfunction and Metabolic Disturbances Induced by Viral Infections.

Viruses are intracellular parasites that utilize organelles, signaling pathways, and the bioenergetics machinery of the cell to replicate the genome and synthesize proteins to build up new viral particles. Mitochondria are key to supporting the virus life cycle by sustaining energy production, metabolism, and synthesis of macromolecules. Mitochondria also contribute to the antiviral innate immune response.

Synergism of small molecules targeting VDAC with sorafenib, regorafenib or lenvatinib on hepatocarcinoma cell proliferation and survival.

Voltage dependent anion channels (VDAC) in the outer mitochondrial membrane regulate the influx of metabolites that sustain mitochondrial metabolism and the efflux of ATP to the cytosol. Free tubulin and NADH close VDAC. The VDAC-binding small molecules X1 and SC18 modulate mitochondrial metabolism.

Fluorescence microscopy imaging of mitochondrial metabolism in cancer cells.

Mitochondrial metabolism is an important contributor to cancer cell survival and proliferation that coexists with enhanced glycolytic activity. Measuring mitochondrial activity is useful to characterize cancer metabolism patterns, to identify metabolic vulnerabilities and to identify new drug targets. Optical imaging, especially fluorescent microscopy, is one of the most valuable tools for studying mitochondrial bioenergetics because it provides semiquantitative and quantitative readouts as well as spatiotemporal resolution of mitochondrial metabolism.

Fast Determination of Mitochondrial Metabolism and Respiratory Complex Activity in Permeabilized and Intact Cells.

Assessment of mitochondrial metabolism is multidimensional and time consuming, usually requiring specific training. Respiration, NADH generation, and mitochondrial membrane potential (ΔΨm) are dynamic readouts of the metabolism and bioenergetics of mitochondria. Methodologies available to determine functional parameters in isolated mitochondria and permeabilized cells are sometimes of limited use or inapplicable to studies in live cells.

Small molecules targeting the NADH-binding pocket of VDAC modulate mitochondrial metabolism in hepatocarcinoma cells.

Voltage dependent anion channels (VDAC) control the flux of most anionic respiratory substrates, ATP, ADP, and small cations, crossing the outer mitochondrial membrane. VDAC closure contributes to the partial suppression of mitochondrial metabolism that favors the Warburg phenotype of cancer cells. Recently, it has been shown that NADH binds to a specific pocket in the inner surface of VDAC1, also conserved in VDAC2 and 3, closing the channel.

Carbon Monoxide Activates PERK-Regulated Autophagy to Induce Immunometabolic Reprogramming and Boost Antitumor T-cell Function.

Unlabelled: Mitochondria and endoplasmic reticulum (ER) share structural and functional networks and activate well-orchestrated signaling processes to shape cells' fate and function. While persistent ER stress (ERS) response leads to mitochondrial collapse, moderate ERS promotes mitochondrial function. Strategies to boost antitumor T-cell function by targeting ER-mitochondria cross-talk have not yet been exploited.

Mitochondrial depolarization after acute ethanol treatment drives mitophagy in living mice.

Ethanol increases hepatic mitophagy driven by unknown mechanisms. Type 1 mitophagy sequesters polarized mitochondria for nutrient recovery and cytoplasmic remodeling. In Type 2, mitochondrial depolarization (mtDepo) initiates mitophagy to remove the damaged organelles.

Non-enzymatic glycoxidation linked with nutrition enhances the tumorigenic capacity of prostate cancer epithelia through AGE mediated activation of RAGE in cancer associated fibroblasts.

The molecular implications of food consumption on cancer etiology are poorly defined. The rate of nutrition associated non-enzymatic glycoxidation, a reaction that occurs between reactive carbonyl groups on linear sugars and nucleophilic amino, lysyl and arginyl groups on fats and proteins, is rapidly increased by food cooking and manufacturing processes. In this study, we assign nutrition-associated glycoxidation with significant oncogenic potential, promoting prostate tumor growth, progression, and metastasis in vivo.

Flavin Adenine Dinucleotide Depletion Caused by Haploinsufficiency Leads to Hepatic Steatosis and Injury in Zebrafish.

The electron transfer flavoprotein (ETF) complex, made up of the ETF alpha subunit (ETFA), ETF beta subunit (ETFB), and ETF dehydrogenase (ETFDH), regulates fatty acid β-oxidation activity while scavenging leaked electrons through flavin adenine dinucleotide (FAD)/reduced form FAD (FADH) redox reactions in mitochondria. Here, we hypothesized that ETF dysfunction-mediated FAD deficiency may result in increased mitochondrial oxidative stress and steatosis and subsequent liver injury. We report that haploinsufficiency caused hyperlipidemia, hypercholesterolemia, and hepatic steatosis and injury in adult zebrafish.

Neuropilin-2b facilitates resistance to tyrosine kinase inhibitors in non-small cell lung cancer.

Objective: Innate and acquired resistance is the principle factor limiting the efficacy of tyrosine kinase inhibitors in lung cancer. We have observed a dramatic upregulation of the cell surface co-receptor neuropilin-2b in lung cancers clinically treated with tyrosine kinase inhibitors correlating with acquired resistance. We hypothesize that neuropilin-2b plays a functional role in acquired tyrosine kinase inhibitor resistance.

Role of mitochondrial depolarization and disrupted mitochondrial homeostasis in non-alcoholic steatohepatitis and fibrosis in mice.

The pathogenesis of non-alcoholic steatohepatitis (NASH) is poorly understood. Here, relationships between mitochondrial depolarization (mtDepo) and mitochondrial homeostasis were studied in a mouse model of NASH. C57BL/6 mice were fed a Western diet (high fat, fructose and cholesterol) for 2 weeks, 2 months and 6 months, and livers were harvested for histology and biochemical analysis.

JNK activation and translocation to mitochondria mediates mitochondrial dysfunction and cell death induced by VDAC opening and sorafenib in hepatocarcinoma cells.

The multikinase inhibitor sorafenib, and opening of voltage dependent anion channels (VDAC) by the erastin-like compound X1 promotes oxidative stress and mitochondrial dysfunction in hepatocarcinoma cells. Here, we hypothesized that X1 and sorafenib induce mitochondrial dysfunction by increasing reactive oxygen species (ROS) formation and activating c-Jun N-terminal kinases (JNKs), leading to translocation of activated JNK to mitochondria. Both X1 and sorafenib increased production of ROS and activated JNK.

Mitochondrial protein import is regulated by p17/PERMIT to mediate lipid metabolism and cellular stress.

How lipid metabolism is regulated at the outer mitochondrial membrane (OMM) for transducing stress signaling remains largely unknown. We show here that this process is controlled by trafficking of ceramide synthase 1 (CerS1) from the endoplasmic reticulum (ER) to the OMM by a previously uncharacterized p17, which is now renamed protein that mediates ER-mitochondria trafficking (PERMIT). Data revealed that p17/PERMIT associates with newly translated CerS1 on the ER surface to mediate its trafficking to the OMM.

Effects of vagus nerve stimulation are mediated in part by TrkB in a parkinson's disease model.

Vagus nerve stimulation (VNS) is being explored as a potential therapeutic for Parkinson's disease (PD). VNS is less invasive than other surgical treatments and has beneficial effects on behavior and brain pathology. It has been suggested that VNS exerts these effects by increasing brain-derived neurotrophic factor (BDNF) to enhance pro-survival mechanisms of its receptor, tropomyosin receptor kinase-B (TrkB).

Nkx2-5 Second Heart Field Target Gene Ccdc117 Regulates DNA Metabolism and Proliferation.

The cardiac transcription factor Nkx2-5 is essential for normal outflow tract (OFT) and right ventricle (RV) development. Nkx2-5 null mouse embryos display severe OFT and RV hypoplasia and a single ventricle phenotype due to decreased proliferation of Second Heart Field (SHF) cells, a pool of cardiac progenitors present in anterior pharyngeal arch mesoderm at mid-gestation. However, definition of the precise role of Nkx2-5 in facilitating SHF expansion is incomplete.

Acid sphingomyelinase promotes mitochondrial dysfunction due to glutamate-induced regulated necrosis.

Inhibiting the glutamate/cystine antiporter system x, a key antioxidant defense machinery in the CNS, could trigger a novel form of regulated necrotic cell death, ferroptosis. The underlying mechanisms of system x-dependent cell demise were elucidated using primary oligodendrocytes (OLs) treated with glutamate to block system x function. Pharmacological analysis revealed ferroptosis as a major contributing factor to glutamate-initiated OL death.

Vagus nerve stimulation improves locomotion and neuronal populations in a model of Parkinson's disease.

Background: Parkinson's disease (PD) is a progressive, neurodegenerative disorder with no disease-modifying therapies, and symptomatic treatments are often limited by debilitating side effects. In PD, locus coeruleus noradrenergic (LC-NE) neurons degenerate prior to substantia nigra dopaminergic (SN-DA) neurons. Vagus nerve stimulation (VNS) activates LC neurons, and decreases pro-inflammatory markers, allowing improvement of LC targets, making it a potential PD therapeutic.

Nitration and Glycation Turn Mature NGF into a Toxic Factor for Motor Neurons: A Role for p75 and RAGE Signaling in ALS.

Introduction: Glycating stress can occur together with oxidative stress during neurodegeneration and contribute to the pathogenic mechanism. Nerve growth factor (NGF) accumulates in several neurodegenerative diseases. Besides promoting survival, NGF can paradoxically induce cell death by signaling through the p75 neurotrophin receptor (p75).

Role of Adipose Tissue Endothelial ADAM17 in Age-Related Coronary Microvascular Dysfunction.

Objective: A disintegrin and metalloproteinase ADAM17 (tumor necrosis factor-α [TNF]-converting enzyme) regulates soluble TNF levels. We tested the hypothesis that aging-induced activation in adipose tissue (AT)-expressed ADAM17 contributes to the development of remote coronary microvascular dysfunction in obesity.

Approach And Results: Coronary arterioles (CAs, ≈90 µm) from right atrial appendages and mediastinal AT were examined in patients (aged: 69±11 years, BMI: 30.

Transforming growth factor β1 (TGFβ1)-induced CD44V6-NOX4 signaling in pathogenesis of idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a progressive clinical syndrome of fatal outcome. The lack of information about the signaling pathways that sustain fibrosis and the myofibroblast phenotype has prevented the development of targeted therapies for IPF. Our previous study showed that isolated fibrogenic lung fibroblasts have high endogenous levels of the hyaluronan receptor, CD44V6 (CD44 variant containing exon 6), which enhances the TGFβ1 autocrine signaling and induces fibroblasts to transdifferentiate into myofibroblasts.