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The Journal of Cell Biology Dec 2023Peroxisomes are organelles involved in many metabolic processes including lipid metabolism, reactive oxygen species (ROS) turnover, and antimicrobial immune responses....
Peroxisomes are organelles involved in many metabolic processes including lipid metabolism, reactive oxygen species (ROS) turnover, and antimicrobial immune responses. However, the cellular mechanisms by which peroxisomes contribute to bacterial elimination in macrophages remain elusive. Here, we investigated peroxisome function in iPSC-derived human macrophages (iPSDM) during infection with Mycobacterium tuberculosis (Mtb). We discovered that Mtb-triggered peroxisome biogenesis requires the ESX-1 type 7 secretion system, critical for cytosolic access. iPSDM lacking peroxisomes were permissive to Mtb wild-type (WT) replication but were able to restrict an Mtb mutant missing functional ESX-1, suggesting a role for peroxisomes in the control of cytosolic but not phagosomal Mtb. Using genetically encoded localization-dependent ROS probes, we found peroxisomes increased ROS levels during Mtb WT infection. Thus, human macrophages respond to the infection by increasing peroxisomes that generate ROS primarily to restrict cytosolic Mtb. Our data uncover a peroxisome-controlled, ROS-mediated mechanism that contributes to the restriction of cytosolic bacteria.
Topics: Humans; Cytosol; Macrophages; Mycobacterium tuberculosis; Peroxisomes; Reactive Oxygen Species; Type VII Secretion Systems
PubMed: 37737955
DOI: 10.1083/jcb.202303066 -
Nature Communications Sep 2023Cellular metabolism relies on just a few redox cofactors. Selective compartmentalization may prevent competition between metabolic reactions requiring the same cofactor....
Cellular metabolism relies on just a few redox cofactors. Selective compartmentalization may prevent competition between metabolic reactions requiring the same cofactor. Is such compartmentalization necessary for optimal cell function? Is there an optimal compartment size? Here we probe these fundamental questions using peroxisomal compartmentalization of the last steps of lysine and histidine biosynthesis in the fission yeast Schizosaccharomyces japonicus. We show that compartmentalization of these NAD dependent reactions together with a dedicated NADH/NAD recycling enzyme supports optimal growth when an increased demand for anabolic reactions taxes cellular redox balance. In turn, compartmentalization constrains the size of individual organelles, with larger peroxisomes accumulating all the required enzymes but unable to support both biosynthetic reactions at the same time. Our reengineering and physiological experiments indicate that compartmentalized biosynthetic reactions are sensitive to the size of the compartment, likely due to scaling-dependent changes within the system, such as enzyme packing density.
Topics: NAD; Bandages; Lysine; Paclitaxel; Peroxisomes
PubMed: 37684233
DOI: 10.1038/s41467-023-41347-x -
The Journal of Clinical Investigation Oct 2023Melanomas reprogram their metabolism to rapidly adapt to therapy-induced stress conditions, allowing them to persist and ultimately develop resistance. We report that a...
Melanomas reprogram their metabolism to rapidly adapt to therapy-induced stress conditions, allowing them to persist and ultimately develop resistance. We report that a subpopulation of melanoma cells tolerate MAPK pathway inhibitors (MAPKis) through a concerted metabolic reprogramming mediated by peroxisomes and UDP-glucose ceramide glycosyltransferase (UGCG). Compromising peroxisome biogenesis, by repressing PEX3 expression, potentiated the proapoptotic effects of MAPKis via an induction of ceramides, an effect limited by UGCG-mediated ceramide metabolism. Cotargeting PEX3 and UGCG selectively eliminated a subset of metabolically active, drug-tolerant CD36+ melanoma persister cells, thereby sensitizing melanoma to MAPKis and delaying resistance. Increased levels of peroxisomal genes and UGCG were found in patient-derived MAPKi-relapsed melanomas, and simultaneously inhibiting PEX3 and UGCG restored MAPKi sensitivity in multiple models of therapy resistance. Finally, combination therapy consisting of a newly identified inhibitor of the PEX3-PEX19 interaction, a UGCG inhibitor, and MAPKis demonstrated potent antitumor activity in preclinical melanoma models, thus representing a promising approach for melanoma treatment.
Topics: Humans; Peroxisomes; Lipid Metabolism; Melanoma; Ceramides
PubMed: 37616051
DOI: 10.1172/JCI166644 -
Redox Biology Oct 2023Peroxisomes are metabolically active organelles that are known for exerting oxidative metabolism, but the precise mechanism remains unclear in diabetic nephropathy (DN)....
Peroxisomes are metabolically active organelles that are known for exerting oxidative metabolism, but the precise mechanism remains unclear in diabetic nephropathy (DN). Here, we used proteomics to uncover a correlation between the antioxidant protein disulfide-bond A oxidoreductase-like protein (DsbA-L) and peroxisomal function. In vivo, renal tubular injury, oxidative stress, and cell apoptosis in high-fat diet plus streptozotocin (STZ)-induced diabetic mice were significantly increased, and these changes were accompanied by a "ghost" peroxisomal phenotype, which was further aggravated in DsbA-L-deficient diabetic mice. In vitro, the overexpression of DsbA-L in peroxisomes could improve peroxisomal phenotype and function, reduce oxidative stress and cell apoptosis induced by high glucose (HG, 30 mM) and palmitic acid (PA, 250 μM), but this effect was reversed by 3-Amino-1,2,4-triazole (3-AT, a catalase inhibitor). Mechanistically, DsbA-L regulated the activity of catalase by binding to it, thereby reducing peroxisomal leakage and proteasomal degradation of peroxisomal matrix proteins induced by HG and PA. Additionally, the expression of DsbA-L in renal tubules of patients with DN significantly decreased and was positively correlated with peroxisomal function. Taken together, these results highlight an important role of DsbA-L in ameliorating tubular injury in DN by improving peroxisomal function.
Topics: Animals; Mice; Catalase; Diabetic Nephropathies; Peroxisomes; Diabetes Mellitus, Experimental; Oxidative Stress
PubMed: 37597421
DOI: 10.1016/j.redox.2023.102855 -
International Journal of Molecular... Jul 2023Mitochondria (MITO) and peroxisomes (PEXO) are the major organelles involved in the oxidative metabolism of cells, but detailed examination of their dynamics and...
Mitochondria (MITO) and peroxisomes (PEXO) are the major organelles involved in the oxidative metabolism of cells, but detailed examination of their dynamics and functional adaptations during skeletal muscle (SKM) development (myogenesis) is still lacking. In this study, we found that during myogenesis, MITO DNA, ROS level, and redox ratio increased in myotubes, but the membrane potential (Δψm) and ATP content reduced, implying that the MITO efficiency might reduce during myogenesis. The PEXO number and density both increased during myogenesis, which probably resulted from the accumulation and increased biogenesis of PEXO. The expression of PEXO biogenesis factors was induced during myogenesis in vitro and in utero, and their promoters were also activated by MyoD. Knockdown of the biogenesis factors repressed not only the PEXO density and functions but also the levels of MITO genes and functions, suggesting a close coupling between PEXO biogenesis and MITO functions. Surprisingly, knockdown by the CRISPRi system repressed myogenic differentiation, indicating critical involvement of PEXO biogenesis in myogenesis. Taken together, these observations suggest that the dynamics and functions of both MITO and PEXO are coupled with each other and with the metabolic changes that occur during myogenesis, and these metabolic couplings are critical to myogenesis.
Topics: Peroxisomes; Cell Differentiation; Muscle Fibers, Skeletal; Mitochondria; Muscle Development; Muscle, Skeletal
PubMed: 37569637
DOI: 10.3390/ijms241512262 -
Biology Open Aug 2023Low colostrum intake relates to poorer health and infertility in swine. We previously connected vaginal lipid profiles at weaning to fertility of sows. We hypothesized...
Low colostrum intake relates to poorer health and infertility in swine. We previously connected vaginal lipid profiles at weaning to fertility of sows. We hypothesized vaginal lipidome varied with colostrum intake. Our objective was to determine whether indicators of colostrum intake, immunocrit (IM) and weight gain 24 h postnatal (PN), related to vaginal lipids at d21 PN. Gilts (n=60) were weighed and blood sampled to measure IM. On d21 PN vaginal swabs were taken and lipids measured using multiple reaction monitoring. Abundance of multiple lipids differed (P<0.05) between gilts categorized as high versus low IM and high versus low 24 h gain. The abundance of multiple lipids correlated with IM and 24 h gain. Phosphatidylcholine PC(36:3), PC(36:2), and arachidonic acid (C20:4) positively (P<0.05) correlated with IM. The ether lipid PCo(38:6) and multiple cholesteryl esters negatively (P<0.05) correlated with IM. ROC analysis indicated arachidonic acid and docosanoic acid (C22:0) may serve as excellent biomarkers that distinguish between high and low IM. Similar to gilts found to be infertile, lipid profiles of low colostrum intake animals had greater abundance of very long chain fatty acids, lipids with high levels of unsaturation, and cholesteryl esters, which are metabolized in peroxisomes indicating their potential dysfunction.
Topics: Pregnancy; Swine; Animals; Female; Colostrum; Cholesterol Esters; Peroxisomes; Diet; Arachidonic Acids
PubMed: 37566396
DOI: 10.1242/bio.060044 -
The Journal of Cell Biology Sep 2023Organelle division and segregation are important in cellular homeostasis. Peroxisomes (POs) and mitochondria share a core division machinery and mechanism of membrane...
Organelle division and segregation are important in cellular homeostasis. Peroxisomes (POs) and mitochondria share a core division machinery and mechanism of membrane scission. The division of each organelle is interdependent not only on the other but also on other organelles, reflecting the dynamic communication between subcellular compartments, even as they coordinate the exchange of metabolites and signals. We highlight common and unique mechanisms involved in the fission of these organelles under the premise that much can be gleaned regarding the division of one organelle based on information available for the other.
Topics: Peroxisomes; Mitochondria
PubMed: 37530713
DOI: 10.1083/jcb.202304076 -
Genetics in Medicine : Official Journal... Nov 2023Zellweger spectrum disorders (ZSDs) are known as autosomal recessive disorders caused by defective peroxisome biogenesis due to bi-allelic pathogenic variants in any of...
PURPOSE
Zellweger spectrum disorders (ZSDs) are known as autosomal recessive disorders caused by defective peroxisome biogenesis due to bi-allelic pathogenic variants in any of at least 13 different PEX genes. Here, we report 2 unrelated patients who present with an autosomal dominant ZSD.
METHODS
We performed biochemical and genetic studies in blood and skin fibroblasts of the patients and demonstrated the pathogenicity of the identified PEX14 variants by functional cell studies.
RESULTS
We identified 2 different single heterozygous de novo variants in the PEX14 genes of 2 patients diagnosed with ZSD. Both variants cause messenger RNA mis-splicing, leading to stable expression of similar C-terminally truncated PEX14 proteins. Functional studies indicated that the truncated PEX14 proteins lost their function in peroxisomal matrix protein import and cause increased degradation of peroxisomes, ie, pexophagy, thus exerting a dominant-negative effect on peroxisome functioning. Inhibition of pexophagy by different autophagy inhibitors or genetic knockdown of the peroxisomal autophagy receptor NBR1 resulted in restoration of peroxisomal functions in the patients' fibroblasts.
CONCLUSION
Our finding of an autosomal dominant ZSD expands the genetic repertoire of ZSDs. Our study underscores that single heterozygous variants should not be ignored as possible genetic cause of diseases with an established autosomal recessive mode of inheritance.
Topics: Humans; Alleles; Peroxisomes; Protein Transport; Proteins; Zellweger Syndrome
PubMed: 37493040
DOI: 10.1016/j.gim.2023.100944 -
The Journal of Cell Biology Aug 2023Tail-anchored proteins are tethered to membranes of the ER, mitochondria, and peroxisomes. In this issue, Pleiner and colleagues (2023. J. Cell...
Tail-anchored proteins are tethered to membranes of the ER, mitochondria, and peroxisomes. In this issue, Pleiner and colleagues (2023. J. Cell Biol.https://doi.org/10.1083/jcb.202212007) show that the ER membrane complex (EMC) uses an inbuilt charge-dependent selectivity filter to specifically insert ER tail-anchored proteins according to their topology signals and to prevent the misincorporation of mitochondrial proteins.
Topics: Endoplasmic Reticulum; Mitochondria; Peroxisomes; Membrane Proteins; Mitochondrial Proteins
PubMed: 37436711
DOI: 10.1083/jcb.202306035 -
MBio Aug 2023Peroxisomes are versatile eukaryotic organelles essential for many functions in fungi, including fatty acid metabolism, reactive oxygen species detoxification, and...
Peroxisomes are versatile eukaryotic organelles essential for many functions in fungi, including fatty acid metabolism, reactive oxygen species detoxification, and secondary metabolite biosynthesis. A suite of Pex proteins (peroxins) maintains peroxisomes, while peroxisomal matrix enzymes execute peroxisome functions. Insertional mutagenesis identified peroxin genes as essential components supporting the intraphagosomal growth of the fungal pathogen . Disruption of the peroxins Pex5, Pex10, or Pex33 in prevented peroxisome import of proteins targeted to the organelle via the PTS1 pathway. This loss of peroxisome protein import limited intracellular growth in macrophages and attenuated virulence in an acute histoplasmosis infection model. Interruption of the alternate PTS2 import pathway also attenuated virulence, although only at later time points of infection. The Sid1 and Sid3 siderophore biosynthesis proteins contain a PTS1 peroxisome import signal and localize to the peroxisome. Loss of either the PTS1 or PTS2 peroxisome import pathway impaired siderophore production and iron acquisition in , demonstrating compartmentalization of at least some biosynthetic steps for hydroxamate siderophore biosynthesis. However, the loss of PTS1-based peroxisome import caused earlier virulence attenuation than either the loss of PTS2-based protein import or the loss of siderophore biosynthesis, indicating additional PTS1-dependent peroxisomal functions are important for virulence. Furthermore, disruption of the Pex11 peroxin also attenuated virulence independently of peroxisomal protein import and siderophore biosynthesis. These findings demonstrate peroxisomes contribute to pathogenesis by facilitating siderophore biosynthesis and another unidentified role(s) for the organelle during fungal virulence. IMPORTANCE The fungal pathogen infects host phagocytes and establishes a replication-permissive niche within the cells. To do so, overcomes and subverts antifungal defense mechanisms which include the limitation of essential micronutrients. replication within host cells requires multiple distinct functions of the fungal peroxisome organelle. These peroxisomal functions contribute to pathogenesis at different times during infection and include peroxisome-dependent biosynthesis of iron-scavenging siderophores to enable fungal proliferation, particularly after activation of cell-mediated immunity. The multiple essential roles of fungal peroxisomes reveal this organelle as a potential but untapped target for the development of therapeutics.
Topics: Histoplasma; Virulence; Siderophores; Peroxins; Peroxisomes; Adaptation, Physiological
PubMed: 37432032
DOI: 10.1128/mbio.03284-22