-
Cell Reports Jun 2024Oligodendrocyte death is common in aging and neurodegenerative disease. In these conditions, dying oligodendrocytes must be efficiently removed to allow remyelination...
Oligodendrocyte death is common in aging and neurodegenerative disease. In these conditions, dying oligodendrocytes must be efficiently removed to allow remyelination and to prevent a feedforward degenerative cascade. Removal of this cellular debris is thought to primarily be carried out by resident microglia. To investigate the cellular dynamics underlying how microglia do this, we use a single-cell cortical demyelination model combined with longitudinal intravital imaging of dual-labeled transgenic mice. Following phagocytosis, single microglia clear the targeted oligodendrocyte and its myelin sheaths in one day via a precise, rapid, and stereotyped sequence. Deletion of the fractalkine receptor, CX3CR1, delays the microglial phagocytosis of the cell soma but has no effect on clearance of myelin sheaths. Unexpectedly, deletion of the phosphatidylserine receptor, MERTK, has no effect on oligodendrocyte or myelin sheath clearance. Thus, separate molecular signals are used to detect, engage, and clear distinct sub-compartments of dying oligodendrocytes to maintain tissue homeostasis.
PubMed: 38935500
DOI: 10.1016/j.celrep.2024.114385 -
Antioxidants (Basel, Switzerland) Jun 2024Oxidative stress (OS) and disrupted antioxidant defense mechanisms play a pivotal role in the etiology of male infertility. The alterations in reactive oxygen species...
Exogenous Oxidative Stress in Human Spermatozoa Induces Opening of the Mitochondrial Permeability Transition Pore: Effect on Mitochondrial Function, Sperm Motility and Induction of Cell Death.
Oxidative stress (OS) and disrupted antioxidant defense mechanisms play a pivotal role in the etiology of male infertility. The alterations in reactive oxygen species (ROS) production and calcium (Ca) homeostasis are the main activators for the mitochondrial permeability transition pore (mPTP) opening. The mPTP opening is one of the main mechanisms involved in mitochondrial dysfunction in spermatozoa. This alteration in mitochondrial function adversely affects energy supply, sperm motility, and fertilizing capacity and contributes to the development of male infertility. In human spermatozoa, the mPTP opening has been associated with ionomycin-induced endogenous oxidative stress and peroxynitrite-induced nitrosative stress; however, the effect of exogenous oxidative stress on mPTP opening in sperm has not been evaluated. The aim of this study was to determine the effect of exogenous oxidative stress induced by hydrogen peroxide (HO) on mPTP opening, mitochondrial function, motility, and cell death markers in human spermatozoa. Human spermatozoa were incubated with 3 mmol/L of HO for 60 min, and intracellular Ca concentration, mPTP opening, mitochondrial membrane potential (ΔΨm), ATP levels, mitochondrial reactive oxygen species (mROS) production, phosphatidylserine (PS) externalization, DNA fragmentation, viability, and sperm motility were evaluated. HO-induced exogenous oxidative stress caused increased intracellular Ca, leading to subsequent mPTP opening and alteration of mitochondrial function, characterized by ΔΨm dissipation, decreased ATP levels, increased mROS production, and the subsequent alteration of sperm motility. Furthermore, HO-induced opening of mPTP was associated with the expression of apoptotic cell death markers including PS externalization and DNA fragmentation. These results highlight the role of exogenous oxidative stress in causing mitochondrial dysfunction, deterioration of sperm motility, and an increase in apoptotic cell death markers, including PS externalization and DNA fragmentation, through the mPTP opening. This study yielded new knowledge regarding the effects of this type of stress on mitochondrial function and specifically on mPTP opening, factors that can contribute to the development of male infertility, considering that the role of mPTP in mitochondrial dysfunction in human sperm is not completely elucidated. Therefore, these findings are relevant to understanding male infertility and may provide an in vitro model for further research aimed at improving human sperm quality.
PubMed: 38929178
DOI: 10.3390/antiox13060739 -
Antioxidants (Basel, Switzerland) May 2024This study was conducted to investigate the effects of dietary phosphatidylserine (PS) supplementation on the growth performance, stress response, non-specific immunity...
This study was conducted to investigate the effects of dietary phosphatidylserine (PS) supplementation on the growth performance, stress response, non-specific immunity and antioxidant capacity of juvenile blunt snout bream () cultured under a high stocking density. A 2 × 2 two-factorial design was adopted, including two stocking densities (10 and 20 fish/m) and two dietary PS levels (0 and 50 mg/kg). After the 12-week feeding trial, the high stocking density significantly decreased the final weight; weight gain rate; specific growth rate; feed intake; nitrogen retention efficiency; plasma complement 3 (C3) level; albumin/globulin (ALB/GLB, A/G) ratio; activity of myeloperoxidase, lysozyme (LZM) and glutathione peroxidase (GPX); transcription; and abundance of sirtuin3 (Sirt3) and nuclear factor erythroid-2-related factor 2 (Nrf2). However, it significantly increased the plasma levels of cortisol, glucose (GLU), lactic acid (LD), total protein and GLB; hepatic malondialdehyde (MDA) content; and transcription. PS supplementation significantly increased the plasma ALB and C4 levels; the A/G ratio; the activity of LZM, CAT and GPX; the transcription of , , manganese-containing superoxide dismutase and catalase; and the Nrf2 abundance. However, it significantly decreased the plasma levels of cortisol, GLU and GLB, as well as the hepatic MDA content. In addition, there was a significant interaction between the stocking density and PS supplementation regarding the effects on the plasma LD, ALB, GLB and C3 levels; A/G ratio; hepatic CAT activity; and protein abundance of Sod2. In conclusion, PS supplementation can counteract the high stocking density-induced stress response, redox imbalance and immunosuppression in blunt snout bream.
PubMed: 38929083
DOI: 10.3390/antiox13060644 -
Frontiers in Molecular Biosciences 2024Numerous strategies have been proposed to minimize obesity-associated health effects, among which phytocannabinoids appear to be effective and safe compounds. In...
Numerous strategies have been proposed to minimize obesity-associated health effects, among which phytocannabinoids appear to be effective and safe compounds. In particular, cannabigerol (CBG) emerges as a potent modulator of the composition of membrane phospholipids (PLs), which plays a critical role in the development of insulin resistance. Therefore, here we consider the role of CBG treatment on the composition of PLs fraction with particular emphasis on phospholipid subclasses (e.g., phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS), and phosphatidylinositol (PI)) in the red gastrocnemius muscle of Wistar rats fed the standard or high-fat, high-sucrose (HFHS) diet. The intramuscular PLs content was determined by gas-liquid chromatography and based on the composition of individual FAs, we assessed the stearoyl-CoA desaturase 1 (SCD1) index as well as the activity of n-3 and n-6 polyunsaturated fatty acids (PUFAs) pathways. Expression of various proteins engaged in the inflammatory pathway, FAs elongation, and desaturation processes was measured using Western blotting. Our research has demonstrated the important association of obesity with alterations in the composition of muscular PLs, which was significantly improved by CBG supplementation, enriching the lipid pools in n-3 PUFAs and decreasing the content of arachidonic acid (AA), which in turn influenced the activity of PUFAs pathways in various PLs subclasses. CBG also inhibited the local inflammation development and profoundly reduced the SCD1 activity. Collectively, restoring the PLs homeostasis of the myocyte membrane by CBG indicates its new potential medical application in the treatment of obesity-related metabolic disorders.
PubMed: 38919749
DOI: 10.3389/fmolb.2024.1401558 -
The EMBO Journal Jun 2024Phosphatidylserine (PS) is an important anionic phospholipid that is synthesized within the endoplasmic reticulum (ER). While PS shows the highest enrichment and serves...
Phosphatidylserine (PS) is an important anionic phospholipid that is synthesized within the endoplasmic reticulum (ER). While PS shows the highest enrichment and serves important functional roles in the plasma membrane (PM) but its role in the nucleus is poorly explored. Using three orthogonal approaches, we found that PS is also uniquely enriched in the inner nuclear membrane (INM) and the nuclear reticulum (NR). Nuclear PS is critical for supporting the translocation of CCTα and Lipin1α, two key enzymes important for phosphatidylcholine (PC) biosynthesis, from the nuclear matrix to the INM and NR in response to oleic acid treatment. We identified the PS-interacting regions within the M-domain of CCTα and M-Lip domain of Lipin1α, and show that lipid droplet formation is altered by manipulations of nuclear PS availability. Our studies reveal an unrecognized regulatory role of nuclear PS levels in the regulation of key PC synthesizing enzymes within the nucleus.
PubMed: 38918635
DOI: 10.1038/s44318-024-00151-z -
BMC Genomics Jun 2024Global per capita meat consumption continues to rise, especially pork. Meat quality is influenced by the content of intramuscular fat (IMF) as a key factor. The...
BACKGROUND
Global per capita meat consumption continues to rise, especially pork. Meat quality is influenced by the content of intramuscular fat (IMF) as a key factor. The longissimus dorsi muscle of Dahe pigs (DHM, IMF: 7.98% ± 1.96%) and Dahe black pigs (DHBM, IMF: 3.30% ± 0.64%) was studied to explore cellular heterogeneity and differentially expressed genes (DEGs) associated with IMF deposition using single-nucleus RNA sequencing (snRNA-seq). The lipid composition was then analyzed using non-targeted lipidomics.
RESULTS
A total of seven cell subpopulations were identified, including myocytes, fibroblast/fibro/adipogenic progenitors (FAPs), satellite cells, endothelial cells, macrophages, pericytes, and adipocytes. Among them, FAPs and adipocytes were more focused because they could be associated with lipid deposition. 1623 DEGs in the FAPs subpopulation of DHBM were up-regulated compared with DHM, while 1535 were down-regulated. These DEGs enriched in the glycolysis/gluconeogenesis pathway. 109 DEGs were up-regulated and 806 were down-regulated in the adipocyte subpopulation of DHBM compared with DHM, which were mainly enriched in the PPAR signaling pathway and fatty acid (FA) biosynthesis. The expression level of PPARG, ABP4, LEP, and ACSL1 genes in DHM was higher than that in DHBM. Lipidomics reveals porcine lipid composition characteristics of muscle tissue. A total of 41 lipid classes and 2699 lipid species were identified in DHM and DHBM groups. The top ten relative peak areas of lipid classes in DHM and DHBM were triglyceride (TG), phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS), diglyceride (DG), cardiolipin (CL), ceramides (Cer), Simple Glc series (Hex1Cer), sphingomyelin (phSM), and phosphatidylinositol (PI). The relative peak areas of 35 lipid species in DHM were lower than DHBM, and 28 lipid species that were higher. There was a significant increase in the TG fatty acyl chains C6:0, C17:0, and C11:4, and a significant decrease in C16:0, C18:1, C18:2, and C22:4 in DHBM (p < 0.05).
CONCLUSIONS
C16:0 FA may downregulate the expression level of PPARG gene, which leads to the downregulation of fat metabolism-related genes such as ACSL, PLIN2, and FABP4 in DHBM compared with DHM. This may be the reason that the lipid deposition ability of Dahe pigs is stronger than that of Dahe black pigs, which need further investigation.
Topics: Animals; Swine; Muscle, Skeletal; Lipid Metabolism; Lipidomics; Sequence Analysis, RNA; Single-Cell Analysis; Lipids; Gene Expression Profiling
PubMed: 38902599
DOI: 10.1186/s12864-024-10488-8 -
Cancers May 2024This review delves into the enzymatic processes governing the initial stages of glycerophospholipid (phosphatidylcholine, phosphatidylethanolamine, and... (Review)
Review
This review delves into the enzymatic processes governing the initial stages of glycerophospholipid (phosphatidylcholine, phosphatidylethanolamine, and phosphatidylserine) and triacylglycerol synthesis. The key enzymes under scrutiny include GPAT and AGPAT. Additionally, as most AGPATs exhibit LPLAT activity, enzymes participating in the Lands cycle with similar functions are also covered. The review begins by discussing the properties of these enzymes, emphasizing their specificity in enzymatic reactions, notably the incorporation of polyunsaturated fatty acids (PUFAs) such as arachidonic acid and docosahexaenoic acid (DHA) into phospholipids. The paper sheds light on the intricate involvement of these enzymes in various diseases, including obesity, insulin resistance, and cancer. To underscore the relevance of these enzymes in cancer processes, a bioinformatics analysis was conducted. The expression levels of the described enzymes were correlated with the overall survival of patients across 33 different types of cancer using the GEPIA portal. This review further explores the potential therapeutic implications of inhibiting these enzymes in the treatment of metabolic diseases and cancer. By elucidating the intricate enzymatic pathways involved in lipid synthesis and their impact on various pathological conditions, this paper contributes to a comprehensive understanding of these processes and their potential as therapeutic targets.
PubMed: 38893234
DOI: 10.3390/cancers16112115 -
Heliyon Jun 2024Washed red blood cells (RBCs) can be used to treat immune-related diseases. However, whether the washing process changes the quality of RBCs and affects the curative...
Washed red blood cells (RBCs) can be used to treat immune-related diseases. However, whether the washing process changes the quality of RBCs and affects the curative effect of transfusion therapy remains unclear. We retrospectively analysed the clinical data of patients who received blood transfusion. The physiological and biochemical parameters of RBCs were tested on an automated haematology-biochemical analyser. CD47 and phosphatidylserine (PS) plasma membrane expression were analysed using flow cytometry. Morphological changes in RBCs were observed using scanning electron microscopy. The results showed that the curative effect on patients who received washed RBCs was weaker than that on those who received non-washed RBCs. Physiological and biochemical parameters of RBCs were not significantly different. RBC immune indices changed significantly after washing. The expression of "don't eat me" signals was weakened, whereas the intensity of "eat me" signals was enhanced. This study suggests that the current use of physiological and biochemical parameters as indicators to evaluate the quality of RBCs may not be comprehensive and that evaluation of the real status of RBCs requires other effective parameters. Immune molecules in RBCs are expected to become supplementary markers for evaluating RBC quality.
PubMed: 38882340
DOI: 10.1016/j.heliyon.2024.e32056 -
Biomedical Optics Express Jun 2024The activation of astrocytes derived from induced pluripotent stem cells (iPSCs) is of great significance in neuroscience research, and it is crucial to obtain both...
The activation of astrocytes derived from induced pluripotent stem cells (iPSCs) is of great significance in neuroscience research, and it is crucial to obtain both cellular morphology and biomolecular information non-destructively in situ, which is still complicated by the traditional optical microscopy and biochemical methods such as immunofluorescence and western blot. In this study, we combined digital holographic microscopy (DHM) and surface-enhanced Raman scattering (SERS) to investigate the activation characteristics of iPSCs-derived astrocytes. It was found that the projected area of activated astrocytes decreased by 67%, while the cell dry mass increased by 23%, and the cells changed from a flat polygonal shape to an elongated star-shaped morphology. SERS analysis further revealed an increase in the intensities of protein spectral peaks (phenylalanine 1001 cm, proline 1043 cm, etc.) and lipid-related peaks (phosphatidylserine 524 cm, triglycerides 1264 cm, etc.) decreased in intensity. Principal component analysis-linear discriminant analysis (PCA-LDA) modeling based on spectral data distinguished resting and reactive astrocytes with a high accuracy of 96.5%. The increase in dry mass correlated with the increase in protein content, while the decrease in projected area indicated the adjustment of lipid composition and cell membrane remodeling. Importantly, the results not only reveal the cellular morphology and molecular changes during iPSCs-derived astrocytes activation but also reflect their mapping relationship, thereby providing new insights into diagnosing and treating neurodegenerative diseases.
PubMed: 38867782
DOI: 10.1364/BOE.524356 -
Biological & Pharmaceutical Bulletin 2024Ceramide (Cer) is synthesized de novo in the bilayer of the endoplasmic reticulum and transported to the cytosolic leaflet of the trans-Golgi apparatus for sphingomyelin...
Ceramide (Cer) is synthesized de novo in the bilayer of the endoplasmic reticulum and transported to the cytosolic leaflet of the trans-Golgi apparatus for sphingomyelin (SM) synthesis. As the active site of SM synthase (SMS) is located on the luminal side of the Golgi membrane, Cer translocates to the lumen via transbilayer movement for SM synthesis. However, the mechanism of transbilayer movement is not fully understood. As the Cer-related translocases seem to localize near the SMS, the protein was identified using proximity-dependent biotin identification proteomics. Phospholipid scramblase 1 (PLSCR1), which is thought to act as a scramblase for phosphatidylserine and phosphatidylethanolamine, was identified as a protein proximal to the SMS isoforms SMS1 and SMS2. Although five isoforms of PLSCR have been reported in humans, only PLSCR1, PLSCR3, and PLSCR4 are expressed in HEK293T cells. Confocal microscopic analysis showed that PLSCR1 and PLSCR4 partially co-localized with p230, a trans-Golgi network marker, where SMS isoforms are localized. We established CRISPR/Cas9-mediated PLSCR1, PLSCR3, and PLSCR4 single-knockout cells and PLSCR1, 3, 4 triple knockout HEK293T cells. Liquid chromatography-tandem mass spectrometry revealed that the levels of species with distinct acyl chains in Cer and SM were not significantly different in single knockout cells or in the triple knockout cells compared to the wild-type cells. Our findings suggest that PLSCR1 is localized in the vicinity of SMS isoforms, however is not involved in the transbilayer movement of Cer for SM synthesis.
Topics: Humans; Phospholipid Transfer Proteins; Transferases (Other Substituted Phosphate Groups); HEK293 Cells; Sphingomyelins; Membrane Proteins; Isoenzymes; Golgi Apparatus
PubMed: 38866522
DOI: 10.1248/bpb.b24-00177