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Brain Research Jul 2024Multiple system atrophy (MSA) is a rare, neurodegenerative disorder with rapid motor and non-motor symptom progression. MSA is characterized by protein aggregations of...
Multiple system atrophy (MSA) is a rare, neurodegenerative disorder with rapid motor and non-motor symptom progression. MSA is characterized by protein aggregations of α-synuclein found in the cytoplasm of oligodendrocytes. Despite this pathological hallmark, there is still little known about the cause of this disease, resulting in poor treatment options and quality of life post-diagnosis. In this study, we investigated differentially expressed genes (DEGs) via RNA-sequencing of brain samples from a validated PLP-α-synuclein transgenic mouse model, identifying a total of 40 DEGs in the PLP group compared to wild-type (WT), with top detected genes being Gm15446, Mcm6, Aldh7a1 and Gm3435. We observed a significant enrichment of immune pathways and endothelial cell genes among the upregulated genes, whereas downregulated genes were significantly enriched for oligodendrocyte and neuronal genes. We then calculated possible overlap of these DEGs with previously profiled human MSA RNA, resulting in the identification of significant downregulation of the Tsr2 gene. Identifying key gene expression profiles specific to MSA patients is crucial to further understanding the cause, and possible prevention, of this rapidly progressive neurodegenerative disorder.
Topics: Animals; Humans; Mice; alpha-Synuclein; Brain; Disease Models, Animal; Mice, Inbred C57BL; Mice, Transgenic; Multiple System Atrophy; Myelin Proteolipid Protein; Oligodendroglia; Transcriptome; Male; Female
PubMed: 38575106
DOI: 10.1016/j.brainres.2024.148912 -
JCI Insight Apr 2024Duchenne muscular dystrophy (DMD) is a progressive muscle-wasting disease associated with cardiomyopathy. DMD cardiomyopathy is characterized by abnormal intracellular...
Duchenne muscular dystrophy (DMD) is a progressive muscle-wasting disease associated with cardiomyopathy. DMD cardiomyopathy is characterized by abnormal intracellular Ca2+ homeostasis and mitochondrial dysfunction. We used dystrophin and utrophin double-knockout (mdx:utrn-/-) mice in a sarcolipin (SLN) heterozygous-knockout (sln+/-) background to examine the effect of SLN reduction on mitochondrial function in the dystrophic myocardium. Germline reduction of SLN expression in mdx:utrn-/- mice improved cardiac sarco/endoplasmic reticulum (SR) Ca2+ cycling, reduced cardiac fibrosis, and improved cardiac function. At the cellular level, reducing SLN expression prevented mitochondrial Ca2+ overload, reduced mitochondrial membrane potential loss, and improved mitochondrial function. Transmission electron microscopy of myocardial tissues and proteomic analysis of mitochondria-associated membranes showed that reducing SLN expression improved mitochondrial structure and SR-mitochondria interactions in dystrophic cardiomyocytes. These findings indicate that SLN upregulation plays a substantial role in the pathogenesis of cardiomyopathy and that reducing SLN expression has clinical implications in the treatment of DMD cardiomyopathy.
Topics: Animals; Male; Mice; Calcium; Cardiomyopathies; Disease Models, Animal; Dystrophin; Mice, Inbred mdx; Mice, Knockout; Mitochondria, Heart; Muscle Proteins; Muscular Dystrophy, Duchenne; Myocardium; Myocytes, Cardiac; Proteolipids; Utrophin
PubMed: 38564291
DOI: 10.1172/jci.insight.170185 -
Journal of Ethnopharmacology Jun 2024The repairment of myelin sheaths is crucial for mitigating neurological impairments of intracerebral hemorrhage (ICH). However, the current research on remyelination...
ETHNOPHARMACOLOGICAL RELEVANCE
The repairment of myelin sheaths is crucial for mitigating neurological impairments of intracerebral hemorrhage (ICH). However, the current research on remyelination processes in ICH remains limited. A representative traditional Chinese medicine, Buyang Huanwu decoction (BYHWD), shows a promising therapeutic strategy for ICH treatment.
AIM OF THE STUDY
To investigate the pro-remyelination effects of BYHWD on ICH and explore the underlying mechanisms.
MATERIALS AND METHODS
The collagenase-induced mice ICH model was created for investigation. BYHWD's protective effects were assessed by behavioral tests and histological staining. Transmission electron microscopy was used for displaying the structure of myelin sheaths. The remyelination and oligodendrocyte differentiation were evaluated by the expressions of myelin proteolipid protein (PLP), myelin basic protein (MBP), MBP/TAU, Olig2/CC1, and PDGFRα/proliferating cell nuclear antigen (PCNA) through RT-qPCR and immunofluorescence. Transcriptomics integrated with disease database analysis and experiments in vivo and in vitro revealed the microRNA-related underlying mechanisms.
RESULTS
Here, we reported that BYHWD promoted the neurological function of ICH mice and improved remyelination by increasing PLP, MBP, and TAU, as well as restoring myelin structure. Besides, we showed that BYHWD promoted remyelination by boosting the differentiation of PDGFRα oligodendrocyte precursor cells into olig2/CC1 oligodendrocytes. Additionally, we demonstrated that the remyelination effects of BYHWD worked by inhibiting G protein-coupled receptor 17 (GPR17). miRNA sequencing integrated with miRNA database prediction screened potential miRNAs targeting GPR17. By applying immunofluorescence, RNA in situ hybridization and dual luciferase reporter gene assay, we confirmed that BYHWD suppressed GPR17 and improved remyelination by increasing miR-760-3p.
CONCLUSIONS
BYHWD improves remyelination and neurological function in ICH mice by targeting miR-760-3p to inhibit GPR17. This study may shed light on the orchestration of remyelination mechanisms after ICH, thus providing novel insights for developing innovative prescriptions with brain-protective properties.
Topics: Mice; Animals; Remyelination; Receptor, Platelet-Derived Growth Factor alpha; Drugs, Chinese Herbal; Cerebral Hemorrhage; Receptors, G-Protein-Coupled; MicroRNAs; Nerve Tissue Proteins
PubMed: 38556140
DOI: 10.1016/j.jep.2024.118126 -
Biomolecules Mar 2024Phosphatase and tensin homolog (Pten) is a key regulator of cell proliferation and a potential target to stimulate postnatal enteric neuro- and/or gliogenesis. To...
Phosphatase and tensin homolog (Pten) is a key regulator of cell proliferation and a potential target to stimulate postnatal enteric neuro- and/or gliogenesis. To investigate this, we generated two tamoxifen-inducible Cre recombinase murine models in which was conditionally ablated, (1) in glia (-expressing cells) and (2) in neurons (-expressing cells). Tamoxifen-treated adult (7-12 weeks of age; = 4-15) mice were given DSS to induce colitis, EdU to monitor cell proliferation, and were evaluated at two timepoints: (1) early (3-4 days post-DSS) and (2) late (3-4 weeks post-DSS). We investigated gut motility and evaluated the enteric nervous system. inhibition in -expressing cells elicited gliogenesis at baseline and post-DSS (early and late) in the colon, and neurogenesis post-DSS late in the proximal colon. They also exhibited an increased frequency of colonic migrating motor complexes (CMMC) and slower whole gut transit times. inhibition in -expressing cells did not induce enteric neuro- or gliogenesis, and no alterations were detected in CMMC or whole gut transit times when compared to the control at baseline or post-DSS (early and late). Our results merit further research into modulation where increased glia and/or slower intestinal transit times are desired (e.g., short-bowel syndrome and rapid-transit disorders).
Topics: Animals; Mice; Enteric Nervous System; Neurogenesis; Proteolipids; Tamoxifen; Tensins
PubMed: 38540765
DOI: 10.3390/biom14030346 -
Methods in Molecular Biology (Clifton,... 2024β-barrel membrane proteins populate the outer membrane of Gram-negative bacteria, mitochondria, and chloroplasts, playing significant roles in multiple key cellular...
β-barrel membrane proteins populate the outer membrane of Gram-negative bacteria, mitochondria, and chloroplasts, playing significant roles in multiple key cellular pathways. Characterizing the functions of these membrane proteins in vivo is often challenging due to the complex protein network in the periplasm of Gram-negative bacteria (or intermembrane space in mitochondria and chloroplasts) and the presence of other outer membrane proteins. In vitro reconstitution into lipid-bilayer-like environments such as nanodiscs or proteoliposomes provides an excellent method for examining the specific function and mechanism of these membrane proteins in an isolated system. Here, we describe the methodologies employed to investigate Slam, a 14-stranded β-barrel membrane protein also known as the type XI secretion system that is responsible for translocating proteins across the outer membrane of many bacterial species.
Topics: Bacterial Outer Membrane Proteins; Proteolipids; Mitochondria; Protein Transport; Gram-Negative Bacteria
PubMed: 38478273
DOI: 10.1007/978-1-0716-3734-0_6 -
Expression and functional analysis of a recombinant aquaporin Z from Antarctic Pseudomonas sp. AMS3.Proteins Jul 2024Aquaporin (AQP) is a water channel protein from the family of transmembrane proteins which facilitates the movement of water across the cell membrane. It is ubiquitous...
Aquaporin (AQP) is a water channel protein from the family of transmembrane proteins which facilitates the movement of water across the cell membrane. It is ubiquitous in nature, however the understanding of the water transport mechanism, especially for AQPs in microbes adapted to low temperatures, remains limited. AQP also has been recognized for its ability to be used for water filtration, but knowledge of the biochemical features necessary for its potential applications in industrial processes has been lacking. Therefore, this research was conducted to express, extract, solubilize, purify, and study the functional adaptations of the aquaporin Z family from Pseudomonas sp. AMS3 via molecular approaches. In this study, AqpZ1 AMS3 was successfully subcloned and expressed in E. coli BL21 (DE3) as a recombinant protein. The AqpZ1 AMS3 gene was expressed under optimized conditions and the best optimized condition for the AQP was in 0.5 mM IPTG incubated at 25°C for 20 h induction time. A zwitterionic mild detergent [(3-cholamidopropyl) dimethylammonio]-1-propanesulfonate was the suitable surfactant for the protein solubilization. The protein was then purified via affinity chromatography. Liposome and proteoliposome was reconstituted to determine the particle size using dynamic light scattering. This information obtained from this psychrophilic AQP identified provides new insights into the structural adaptation of this protein at low temperatures and could be useful for low temperature application and molecular engineering purposes in the future.
Topics: Pseudomonas; Recombinant Proteins; Escherichia coli; Aquaporins; Cloning, Molecular; Bacterial Proteins; Gene Expression; Proteolipids; Antarctic Regions; Liposomes; Water; Solubility; Amino Acid Sequence
PubMed: 38477414
DOI: 10.1002/prot.26680 -
Clinical Epigenetics Mar 2024MAL (T-lymphocyte maturation-associated protein) is highly downregulated in most cancers, including cervical cancer (CaCx), attributable to promoter hypermethylation....
MAL expression downregulation through suppressive H3K27me3 marks at the promoter in HPV16-related cervical cancers is prognostically relevant and manifested by the interplay of novel MAL antisense long noncoding RNA AC103563.8, E7 oncoprotein and EZH2.
BACKGROUND
MAL (T-lymphocyte maturation-associated protein) is highly downregulated in most cancers, including cervical cancer (CaCx), attributable to promoter hypermethylation. Long noncoding RNA genes (lncGs) play pivotal roles in CaCx pathogenesis, by interacting with human papillomavirus (HPV)-encoded oncoproteins, and epigenetically regulating coding gene expression. Hence, we attempted to decipher the impact and underlying mechanisms of MAL downregulation in HPV16-related CaCx pathogenesis, by interrogating the interactive roles of MAL antisense lncRNA AC103563.8, E7 oncoprotein and PRC2 complex protein, EZH2.
RESULTS
Employing strand-specific RNA-sequencing, we confirmed the downregulated expression of MAL in association with poor overall survival of CaCx patients bearing HPV16, along with its antisense long noncoding RNA (lncRNA) AC103563.8. The strength of positive correlation between MAL and AC103563.8 was significantly high among patients compared to normal individuals. While downregulated expression of MAL was significantly associated with poor overall survival of CaCx patients bearing HPV16, AC103563.8 did not reveal any such association. We confirmed the enrichment of chromatin suppressive mark, H3K27me3 at MAL promoter, using ChIP-qPCR in HPV16-positive SiHa cells. Subsequent E7 knockdown in such cells significantly increased MAL expression, concomitant with decreased EZH2 expression and H3K27me3 marks at MAL promoter. In silico analysis revealed that both E7 and EZH2 bear the potential of interacting with AC103563.8, at the same binding domain. RNA immunoprecipitation with anti-EZH2 and anti-E7 antibodies, respectively, and subsequent quantitative PCR analysis in E7-silenced and unperturbed SiHa cells confirmed the interaction of AC103563.8 with EZH2 and E7, respectively. Apparently, AC103563.8 seems to preclude EZH2 and bind with E7, failing to block EZH2 function in patients. Thereby, enhanced EZH2 expression in the presence of E7 could potentially inactivate the MAL promoter through H3K27me3 marks, corroborating our previous results of MAL expression downregulation in patients.
CONCLUSION
AC103563.8-E7-EZH2 axis, therefore, appears to crucially regulate the expression of MAL, through chromatin inactivation in HPV16-CaCx pathogenesis, warranting therapeutic strategy development.
Topics: Female; Humans; Chromatin; DNA Methylation; Down-Regulation; Enhancer of Zeste Homolog 2 Protein; Histones; Human papillomavirus 16; Oncogene Proteins, Viral; Papillomavirus E7 Proteins; RNA, Long Noncoding; Uterine Cervical Neoplasms; Myelin and Lymphocyte-Associated Proteolipid Proteins
PubMed: 38461243
DOI: 10.1186/s13148-024-01651-9 -
BMC Biology Feb 2024Membranes are protein and lipid structures that surround cells and other biological compartments. We present a conceptual model wherein all membranes are organized into...
Membranes are protein and lipid structures that surround cells and other biological compartments. We present a conceptual model wherein all membranes are organized into structural and functional zones. The assembly of zones such as receptor clusters, protein-coated pits, lamellipodia, cell junctions, and membrane fusion sites is explained to occur through a protein-lipid code. This challenges the theory that lipids sort proteins after forming stable membrane subregions independently of proteins.
Topics: Proteolipids; Membranes; Carrier Proteins; Cell Membrane
PubMed: 38414038
DOI: 10.1186/s12915-024-01849-6 -
Biochimica Et Biophysica Acta.... Apr 2024The proteolipid code determines how cytosolic proteins find and remodel membrane surfaces. Here, we investigate how this process works with sorting nexins Snx1 and Snx3.... (Review)
Review
The proteolipid code determines how cytosolic proteins find and remodel membrane surfaces. Here, we investigate how this process works with sorting nexins Snx1 and Snx3. Both proteins form sorting machines by recognizing membrane zones enriched in phosphatidylinositol 3-phosphate (PI3P), phosphatidylserine (PS) and cholesterol. This co-localized combination forms a unique "lipid codon" or lipidon that we propose is responsible for endosomal targeting, as revealed by structures and interactions of their PX domain-based readers. We outline a membrane recognition and remodeling mechanism for Snx1 and Snx3 involving this code element alongside transmembrane pH gradients, dipole moment-guided docking and specific protein-protein interactions. This generates an initial membrane-protein assembly (memtein) that then recruits retromer and additional PX proteins to recruit cell surface receptors for sorting to the trans-Golgi network (TGN), lysosome and plasma membranes. Post-translational modification (PTM) networks appear to regulate how the sorting machines form and operate at each level. The commonalities and differences between these sorting nexins show how the proteolipid code orchestrates parallel flows of molecular information from ribosome emergence to organelle genesis, and illuminates a universally applicable model of the membrane.
Topics: Carrier Proteins; Vesicular Transport Proteins; Sorting Nexins; Protein Transport; Proteolipids
PubMed: 38408696
DOI: 10.1016/j.bbamem.2024.184305 -
International Journal of Molecular... Feb 2024Aquaporins (AQPs), membrane proteins responsible for facilitating water transport, found in plant membrane vesicles (MV), have been related to the functionality and...
Aquaporins (AQPs), membrane proteins responsible for facilitating water transport, found in plant membrane vesicles (MV), have been related to the functionality and stability of MV. We focused on AQPs obtained from broccoli, as they show potential for biotechnological applications. To gain further insight into the role of AQPs in MV, we describe the heterologous overexpression of two broccoli AQPs ( and ) in , resulting in their purification with high yield (0.14 and 0.99 mg per gram cells for BoPIP1;2 and BoPIP2;2). We reconstituted AQPs in liposomes to study their functionality, and the size of proteoliposomes did not change concerning liposomes. BoPIP2;2 facilitated water transport, which was preserved for seven days at 4 °C and at room temperature but not at 37 °C. BoPIP2;2 was incorporated into liposomes to encapsulate a resveratrol extract, resulting in increased entrapment efficiency (EE) compared to conventional liposomes. Molecular docking was utilized to identify binding sites in PIP2s for resveratrol, highlighting the role of aquaporins in the improved EE. Moreover, interactions between plant AQP and human integrin were shown, which may increase internalization by the human target cells. Our results suggest AQP-based alternative encapsulation systems can be used in specifically targeted biotechnological applications.
Topics: Humans; Liposomes; Resveratrol; Molecular Docking Simulation; Aquaporins; Brassica; Water; Proteolipids
PubMed: 38396666
DOI: 10.3390/ijms25041987