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1.
Invest Ophthalmol Vis Sci ; 65(6): 2, 2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38829670

ABSTRACT

Purpose: The purpose of this study was to investigate the involvement of the TLR4/NF-κB/NLRP3 signaling pathway and its underlying mechanism in diabetic dry eye. Methods: Two models of diabetic dry eye were established in high glucose-induced human corneal epithelial (HCE-T) cells and streptozotocin (STZ)-induced C57BL/6 mice, and the TLR4 inhibitor fosfenopril (FOS) was utilized to suppress the TLR4/NF-κB/NLRP3 signaling pathway. The expression changes in TLR4, NF-κB, NLRP3, and IL-1ß, and other factors were detected by Western blot and RT‒qPCR, the wound healing rate was evaluated by cell scratch assay, and the symptoms of diabetic mice were evaluated by corneal sodium fluorescein staining and tear secretion assay. Results: In the diabetic dry eye model, the transcript levels of TLR4, NF-κB, NLRP3, and IL-1ß were raised, and further application of FOS, a TLR4 inhibitor, downregulated the levels of these pathway factors. In addition, FOS was found to be effective in increasing the wound healing rate of high glucose-induced HCE-T cells, increasing tear production, and decreasing corneal fluorescence staining scores in diabetic mice, as measured by cell scratch assay, corneal sodium fluorescein staining assay, and tear production. Conclusions: The current study found that the TLR4/NF-κB/NLRP3 signaling pathway regulates diabetic dry eye in an in vitro and in vivo model, and that FOS reduces the signs of dry eye in diabetic mice, providing a new treatment option for diabetic dry eye.


Subject(s)
Diabetes Mellitus, Experimental , Dry Eye Syndromes , Mice, Inbred C57BL , NF-kappa B , NLR Family, Pyrin Domain-Containing 3 Protein , Signal Transduction , Toll-Like Receptor 4 , Animals , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/antagonists & inhibitors , Toll-Like Receptor 4/metabolism , Toll-Like Receptor 4/antagonists & inhibitors , Mice , Diabetes Mellitus, Experimental/drug therapy , Diabetes Mellitus, Experimental/metabolism , NF-kappa B/metabolism , NF-kappa B/antagonists & inhibitors , Dry Eye Syndromes/drug therapy , Dry Eye Syndromes/metabolism , Epithelium, Corneal/drug effects , Epithelium, Corneal/metabolism , Humans , Male , Blotting, Western , Disease Models, Animal , Cells, Cultured , Tears/metabolism , Real-Time Polymerase Chain Reaction
2.
PeerJ ; 12: e17498, 2024.
Article in English | MEDLINE | ID: mdl-38827305

ABSTRACT

Background: The method currently available to diagnose shigellosis is insensitive and has many limitations. Thus, this study was designed to identify specific antigenic protein(s) among the cell surface associated proteins (SAPs) of Shigella that would be valuable in the development of an alternative diagnostic assay for shigellosis, particularly one that could be run using a stool sample rather than serum. Methods: The SAPs of clinical isolates of S. dysenteriae, S. boydii, Shigella flexneri, and S. sonnei were extracted from an overnight culture grown at 37 °C using acidified-glycine extraction methods. Protein profiles were observed by SDS-PAGE. To determine if antibodies specific to certain Shigella SAPs were present in both sera and stool suspensions, Western blot analysis was used to detect the presence of IgA, IgG, and IgM. Results: Immunoblot analysis revealed that sera from patients infected with S. flexneri recognized 31 proteins. These SAP antigens are recognized by the host humoral response during Shigella infection. Specific antibodies against these antigens were also observed in intestinal secretions of shigellosis patients. Of these 31 S. flexneri proteins, the 35 kDa protein specifically reacted against IgA present in patients' stool suspensions. Further study illustrated the immunoreactivity of this protein in S. dysenteriae, S. boydii, and S. sonnei. This is the first report that demonstrates the presence of immunoreactive Shigella SAPs in stool suspensions. The SAPSs could be very useful in developing a simple and rapid serodiagnostic assay for shigellosis directly from stool specimens.


Subject(s)
Bacterial Proteins , Dysentery, Bacillary , Feces , Shigella flexneri , Humans , Feces/microbiology , Feces/chemistry , Dysentery, Bacillary/diagnosis , Dysentery, Bacillary/immunology , Dysentery, Bacillary/microbiology , Shigella flexneri/immunology , Shigella flexneri/isolation & purification , Bacterial Proteins/immunology , Bacterial Proteins/analysis , Antibodies, Bacterial/blood , Antibodies, Bacterial/immunology , Antigens, Bacterial/immunology , Antigens, Bacterial/analysis , Blotting, Western , Electrophoresis, Polyacrylamide Gel , Immunoglobulin A/immunology , Immunoglobulin A/blood , Immunoglobulin A/analysis
3.
Invest Ophthalmol Vis Sci ; 65(6): 1, 2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38829671

ABSTRACT

Purpose: Loss of function of the lacrimal gland (LG), which produces the aqueous tear film, is implicated in age-related dry eye. To better understand this deterioration, we evaluated changes in lipid metabolism and inflammation in LGs from an aging model. Methods: LG sections from female C57BL/6J mice of different ages (young, 2-3 months; intermediate, 10-14 months; old,  ≥24 months) were stained with Oil Red-O or Toluidine blue to detect lipids. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis and western blotting of LG lysates determined differences in the expression of genes and proteins related to lipid metabolism. A photobleaching protocol to quench age-related autofluorescence was used in LG sections to evaluate changes in immunofluorescence associated with NPC1, NPC2, CTSL, and macrophages (F4/80, CD11b) with age using confocal fluorescence microscopy. Results: Old LGs showed increased lipids prominent in basal aggregates in acinar cells and in extra-acinar sites. LG gene expression of Npc1, Npc2, Lipa, and Mcoln2, encoding proteins involved in lipid metabolism, was increased with age. NPC1 was also significantly increased in old LGs by western blotting. In photobleached LG sections, confocal fluorescence microscopy imaging of NPC1, NPC2, and CTSL immunofluorescence showed age-associated enrichment in macrophages labeled to detect F4/80. Although mononuclear macrophages were detectable in LG at all ages, this novel multinucleate macrophage population containing NPC1, NPC2, and CTSL and enriched in F4/80 and some CD11b was increased with age at extra-acinar sites. Conclusions: Lipid-metabolizing proteins enriched in F4/80-positive multinucleated macrophages are increased in old LGs adjacent to sites of lipid deposition in acini.


Subject(s)
Aging , Blotting, Western , Lacrimal Apparatus , Lipid Metabolism , Macrophages , Mice, Inbred C57BL , Real-Time Polymerase Chain Reaction , Animals , Female , Aging/physiology , Mice , Lipid Metabolism/physiology , Macrophages/metabolism , Lacrimal Apparatus/metabolism , Microscopy, Confocal , Disease Models, Animal , Dry Eye Syndromes/metabolism , Dry Eye Syndromes/pathology
4.
Arch Oral Biol ; 163: 105980, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38692246

ABSTRACT

OBJECTIVE: To determine the effect of hyaluronic acid (HA) degradation by hyaluronidase (HYAL) in inhibiting collagen fiber production by rat periodontal ligament cells (rPDLCs). DESIGN: Primary rPDLCs were isolated from the euthanized rats and used for in vitro experiments. The appropriate HYAL concentration was determined through CCK-8 testing for cytotoxicity detection and Alizarin red staining for mineralization detection. RT-qPCR and western blot assays were conducted to assess the effect of HYAL, with or without TGF-ß, on generation of collagen fiber constituents and expression of actin alpha 2, smooth muscle (ACTA2) of rPDLCs. RESULTS: Neither cell proliferation nor mineralization were significantly affected by treatment with 4 U/mL HYAL. HYAL (4 U/mL) alone downregulated type I collagen fiber (Col1a1 and Col1a2) and Acta2 mRNA expression; however, ACTA2 and COL1 protein levels were only downregulated by HYAL treatment after TGF-ß induction. CONCLUSIONS: Treatment of rPDLCs with HYAL can inhibit TGF-ß-induced collagen matrix formation and myofibroblast transformation.


Subject(s)
Cell Proliferation , Collagen , Fibroblasts , Hyaluronoglucosaminidase , Myofibroblasts , Periodontal Ligament , Transforming Growth Factor beta , Animals , Periodontal Ligament/cytology , Periodontal Ligament/drug effects , Periodontal Ligament/metabolism , Hyaluronoglucosaminidase/pharmacology , Rats , Myofibroblasts/drug effects , Myofibroblasts/metabolism , Transforming Growth Factor beta/metabolism , Collagen/metabolism , Cell Proliferation/drug effects , Fibroblasts/drug effects , Fibroblasts/metabolism , Hyaluronic Acid/pharmacology , Cells, Cultured , Rats, Sprague-Dawley , Actins/metabolism , Blotting, Western , In Vitro Techniques , Collagen Type I/metabolism , Biomarkers/metabolism , Real-Time Polymerase Chain Reaction , Male , RNA, Messenger/metabolism
5.
Int J Oral Sci ; 16(1): 35, 2024 May 08.
Article in English | MEDLINE | ID: mdl-38719825

ABSTRACT

The efficient clinical treatment of oral squamous cell carcinoma (OSCC) is still a challenge that demands the development of effective new drugs. Phenformin has been shown to produce more potent anti-tumor activities than metformin on different tumors, however, not much is known about the influence of phenformin on OSCC cells. We found that phenformin suppresses OSCC cell proliferation, and promotes OSCC cell autophagy and apoptosis to significantly inhibit OSCC cell growth both in vivo and in vitro. RNA-seq analysis revealed that autophagy pathways were the main targets of phenformin and identified two new targets DDIT4 (DNA damage inducible transcript 4) and NIBAN1 (niban apoptosis regulator 1). We found that phenformin significantly induces the expression of both DDIT4 and NIBAN1 to promote OSCC autophagy. Further, the enhanced expression of DDIT4 and NIBAN1 elicited by phenformin was not blocked by the knockdown of AMPK but was suppressed by the knockdown of transcription factor ATF4 (activation transcription factor 4), which was induced by phenformin treatment in OSCC cells. Mechanistically, these results revealed that phenformin triggers endoplasmic reticulum (ER) stress to activate PERK (protein kinase R-like ER kinase), which phosphorylates the transitional initial factor eIF2, and the increased phosphorylation of eIF2 leads to the increased translation of ATF4. In summary, we discovered that phenformin induces its new targets DDIT4 and especially NIBAN1 to promote autophagic and apoptotic cell death to suppress OSCC cell growth. Our study supports the potential clinical utility of phenformin for OSCC treatment in the future.


Subject(s)
Autophagy , Carcinoma, Squamous Cell , Cell Proliferation , Endoplasmic Reticulum Stress , Mouth Neoplasms , Phenformin , Transcription Factors , Phenformin/pharmacology , Endoplasmic Reticulum Stress/drug effects , Humans , Mouth Neoplasms/drug therapy , Autophagy/drug effects , Carcinoma, Squamous Cell/drug therapy , Cell Proliferation/drug effects , Cell Line, Tumor , Transcription Factors/metabolism , Transcription Factors/drug effects , Mice , Apoptosis Regulatory Proteins/drug effects , Apoptosis Regulatory Proteins/metabolism , Apoptosis/drug effects , AMP-Activated Protein Kinases/metabolism , Animals , Blotting, Western
6.
Invest Ophthalmol Vis Sci ; 65(5): 8, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38700874

ABSTRACT

Purpose: In the present study, we aim to elucidate the underlying molecular mechanism of endoplasmic reticulum (ER) stress induced delayed corneal epithelial wound healing and nerve regeneration. Methods: Human limbal epithelial cells (HLECs) were treated with thapsigargin to induce excessive ER stress and then RNA sequencing was performed. Immunofluorescence, qPCR, Western blot, and ELISA were used to detect the expression changes of SLIT3 and its receptors ROBO1-4. The role of recombinant SLIT3 protein in corneal epithelial proliferation and migration were assessed by CCK8 and cell scratch assay, respectively. Thapsigargin, exogenous SLIT3 protein, SLIT3-specific siRNA, and ROBO4-specific siRNA was injected subconjunctivally to evaluate the effects of different intervention on corneal epithelial and nerve regeneration. In addition, Ki67 staining was performed to evaluate the proliferation ability of epithelial cells. Results: Thapsigargin suppressed normal corneal epithelial and nerve regeneration significantly. RNA sequencing genes related to development and regeneration revealed that thapsigargin induced ER stress significantly upregulated the expression of SLIT3 and ROBO4 in corneal epithelial cells. Exogenous SLIT3 inhibited normal corneal epithelial injury repair and nerve regeneration, and significantly suppressed the proliferation and migration ability of cultured mouse corneal epithelial cells. SLIT3 siRNA inhibited ROBO4 expression and promoted epithelial wound healing under thapsigargin treatment. ROBO4 siRNA significantly attenuated the delayed corneal epithelial injury repair and nerve regeneration induced by SLIT3 treatment or thapsigargin treatment. Conclusions: ER stress inhibits corneal epithelial injury repair and nerve regeneration may be related with the upregulation of SLIT3-ROBO4 pathway.


Subject(s)
Cell Proliferation , Endoplasmic Reticulum Stress , Epithelium, Corneal , Nerve Regeneration , Receptors, Immunologic , Roundabout Proteins , Signal Transduction , Wound Healing , Animals , Humans , Mice , Blotting, Western , Cell Movement/physiology , Cells, Cultured , Endoplasmic Reticulum Stress/physiology , Enzyme-Linked Immunosorbent Assay , Epithelium, Corneal/metabolism , Limbus Corneae/cytology , Nerve Regeneration/physiology , Nerve Tissue Proteins/genetics , Nerve Tissue Proteins/metabolism , Receptors, Cell Surface/metabolism , Receptors, Cell Surface/genetics , Receptors, Immunologic/genetics , Receptors, Immunologic/metabolism , Signal Transduction/physiology , Wound Healing/physiology
7.
Int J Oral Sci ; 16(1): 38, 2024 May 11.
Article in English | MEDLINE | ID: mdl-38734708

ABSTRACT

Periodontitis is a chronic inflammatory and immune reactive disease induced by the subgingival biofilm. The therapeutic effect for susceptible patients is often unsatisfactory due to excessive inflammatory response and oxidative stress. Sinensetin (Sin) is a nature polymethoxylated flavonoid with anti-inflammatory and antioxidant activities. Our study aimed to explore the beneficial effect of Sin on periodontitis and the specific molecular mechanisms. We found that Sin attenuated oxidative stress and inflammatory levels of periodontal ligament cells (PDLCs) under inflammatory conditions. Administered Sin to rats with ligation-induced periodontitis models exhibited a protective effect against periodontitis in vivo. By molecular docking, we identified Bach1 as a strong binding target of Sin, and this binding was further verified by cellular thermal displacement assay and immunofluorescence assays. Chromatin immunoprecipitation-quantitative polymerase chain reaction results also revealed that Sin obstructed the binding of Bach1 to the HMOX1 promoter, subsequently upregulating the expression of the key antioxidant factor HO-1. Further functional experiments with Bach1 knocked down and overexpressed verified Bach1 as a key target for Sin to exert its antioxidant effects. Additionally, we demonstrated that Sin prompted the reduction of Bach1 by potentiating the ubiquitination degradation of Bach1, thereby inducing HO-1 expression and inhibiting oxidative stress. Overall, Sin could be a promising drug candidate for the treatment of periodontitis by targeting binding to Bach1.


Subject(s)
Basic-Leucine Zipper Transcription Factors , Oxidative Stress , Periodontitis , Ubiquitination , Oxidative Stress/drug effects , Periodontitis/drug therapy , Periodontitis/prevention & control , Periodontitis/metabolism , Animals , Basic-Leucine Zipper Transcription Factors/metabolism , Ubiquitination/drug effects , Rats , Male , Disease Models, Animal , Antioxidants/pharmacology , Rats, Sprague-Dawley , Humans , Chromatin Immunoprecipitation , Blotting, Western , Real-Time Polymerase Chain Reaction , Molecular Docking Simulation , Periodontal Ligament/drug effects , Periodontal Ligament/metabolism , Periodontal Ligament/cytology
8.
Bratisl Lek Listy ; 125(6): 360-364, 2024.
Article in English | MEDLINE | ID: mdl-38757592

ABSTRACT

Lyme disease. Our second goal was to identify bacterial and viral co-infections occurring concurrently with Lyme disease. Furthermore, it was our intention to also analyze the correlation of laboratory testing with the occurrence of erythema migrans (EM). BACKGROUND: The accuracy in diagnostic testing for Lyme disease in the early stages of infection is an important factor necessary for delivering proper treatment to patients. METHODS: A total of 173 individuals with confirmed Lyme disease or with laboratory testing underway participated in the quantitative survey. RESULTS: ELISA was the first test conducted in 51% of the respondents, 28% of whom yielded positive findings of both IgM and IgG antibody classes. The positivity of ELISA test findings was confirmed by Western blot in 100% of results. Negative results of ELISA were consistent with Western blot only in less than half of the patients. More than half of the respondents had not been tested for any bacterial or viral co-infections. The results of serological testing were not consistent with clinical findings in all cases, including those with clinically discernible skin manifestation of erythema migrans. CONCLUSION: The comparison of results obtained by ELISA and Western blot revealed significant discrepancies. Simultaneous infections by vectors with several pathogens were detected (Tab. 3, Fig. 2, Ref. 15).


Subject(s)
Blotting, Western , Enzyme-Linked Immunosorbent Assay , Lyme Disease , Humans , Lyme Disease/diagnosis , Female , Male , Adult , Middle Aged , Immunoglobulin M/blood , Coinfection/diagnosis , Surveys and Questionnaires , Antibodies, Bacterial/blood , Immunoglobulin G/blood , Adolescent , Young Adult , Aged , Child , Erythema Chronicum Migrans/diagnosis
9.
Methods Mol Biol ; 2807: 153-161, 2024.
Article in English | MEDLINE | ID: mdl-38743227

ABSTRACT

Recent evidence has shown that uncoating and reverse transcription precede nuclear import. These recent breakthroughs have been made possible through the development of innovative biochemical and imaging techniques. This method outlines the biochemical assay used for detecting the presence of the HIV-1 core in the nuclear compartment. In this procedure, human cells are infected with HIV-1NL4-3, with or without the inclusion of PF74, a small molecule that inhibits core entry into the nuclear compartment. Subsequently, cells are separated into cytosolic and nuclear fractions. To assess whether the capsid protein has reached the nuclear compartment, cytosolic and nuclear fractions are subjected to Western blot analysis, utilizing antibodies specific to the HIV-1 capsid protein p24. To validate the true origin of these fractions, Western blot analysis employing antibodies against cytosolic and nuclear markers are also performed. In summary, this assay provides a reliable and efficient means to detect the presence of the HIV-1 capsid protein in the nucleus during infection under various conditions.


Subject(s)
Capsid , Cell Nucleus , HIV Infections , HIV-1 , Humans , Cell Nucleus/metabolism , HIV Infections/virology , HIV Infections/metabolism , Capsid/metabolism , HIV Core Protein p24/metabolism , HIV Core Protein p24/analysis , Capsid Proteins/metabolism , Blotting, Western/methods , Phenylalanine/metabolism , Phenylalanine/analogs & derivatives , Cell Line
10.
Clin Oral Investig ; 28(6): 312, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38748326

ABSTRACT

OBJECTIVES: Material chemistry and workflow variables associated with the fabrication of dental devices may affect the biocompatibility of the dental devices. The purpose of this study was to compare digital and conventional workflow procedures in the manufacturing of acrylic-based occlusal devices by assessing the cytotoxic potential of leakage products. METHODS: Specimens were manufactured by 3D printing (stereolithography and digital light processing), milling, and autopolymerization. Print specimens were also subjected to different post-curing methods. To assess biocompatibility, a human tongue epithelial cell line was exposed to material-based extracts. Cell viability was measured by MTT assay while Western blot assessed the expression level of selected cytoprotective proteins. RESULTS: Extracts from the Splint 2.0 material printed with DLP technology and post-cured with the Asiga Flash showed the clearest loss of cell viability. The milled and autopolymerized materials also showed a significant reduction in cell viability. However, by storing the autopolymerized material in dH2O for 12 h, no significant viability loss was observed. Increased levels of cytoprotective proteins were seen in cells exposed to extracts from the print materials and the autopolymerized material. Similarly to the effect on viability loss, storing the autopolymerized material in dH2O for 12 h reduced this effect. CONCLUSIONS/CLINICAL RELEVANCE: Based on the biocompatibility assessments, clinical outcomes of acrylic-based occlusal device materials may be affected by the choice of manufacturing technique and workflow procedures.


Subject(s)
Biocompatible Materials , Cell Survival , Materials Testing , Printing, Three-Dimensional , Humans , Biocompatible Materials/chemistry , In Vitro Techniques , Acrylic Resins/chemistry , Cell Line , Blotting, Western
11.
Vet Res ; 55(1): 62, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38750594

ABSTRACT

The first case of CWD in a Norwegian red deer was detected by a routine ELISA test and confirmed by western blotting and immunohistochemistry in the brain stem of the animal. Two different western blotting tests were conducted independently in two different laboratories, showing that the red deer glycoprofile was different from the Norwegian CWD reindeer and CWD moose and from North American CWD. The isolate showed nevertheless features similar to the classical BSE (BSE-C) strain. Furthermore, BSE-C could not be excluded based on the PrPSc immunohistochemistry staining in the brainstem and the absence of detectable PrPSc in the lymphoid tissues. Because of the known ability of BSE-C to cross species barriers as well as its zoonotic potential, the CWD red deer isolate was submitted to the EURL Strain Typing Expert Group (STEG) as a BSE-C suspect for further investigation. In addition, different strain typing in vivo and in vitro strategies aiming at identifying the BSE-C strain in the red deer isolate were performed independently in three research groups and BSE-C was not found in it. These results suggest that the Norwegian CWD red deer case was infected with a previously unknown CWD type and further investigation is needed to determine the characteristics of this potential new CWD strain.


Subject(s)
Deer , Encephalopathy, Bovine Spongiform , Wasting Disease, Chronic , Animals , Norway , Blotting, Western/veterinary , Enzyme-Linked Immunosorbent Assay/veterinary , Prions/metabolism , Cattle , Immunohistochemistry/veterinary , PrPSc Proteins/metabolism
12.
Curr Protoc ; 4(5): e1042, 2024 May.
Article in English | MEDLINE | ID: mdl-38767195

ABSTRACT

Biochemical fractionation is a technique used to isolate and separate distinct cellular compartments, critical for dissecting cellular mechanisms and molecular pathways. Herein we outline a biochemical fraction methodology for isolation of ultra-pure nuclei and cytoplasm. This protocol utilizes hypotonic lysis buffer to suspend cells, coupled with a calibrated centrifugation strategy, for enhanced separation of cytoplasm from the nuclear fraction. Subsequent purification steps ensure the integrity of the isolated nuclear fraction. Overall, this method facilitates accurate protein localization, essential for functional studies, demonstrating its efficacy in separating cellular compartments. © 2024 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol: Biochemical fractionation Support Protocol 1: Protein quantification using Bradford assay Support Protocol 2: SDS/PAGE and Western blotting.


Subject(s)
Cell Fractionation , Cell Nucleus , Cytoplasm , Cytoplasm/metabolism , Cytoplasm/chemistry , Cell Nucleus/metabolism , Cell Nucleus/chemistry , Cell Fractionation/methods , Humans , Electrophoresis, Polyacrylamide Gel , Blotting, Western
13.
Acta Neuropathol ; 147(1): 87, 2024 May 18.
Article in English | MEDLINE | ID: mdl-38761203

ABSTRACT

Antibodies are essential research tools whose performance directly impacts research conclusions and reproducibility. Owing to its central role in Alzheimer's disease and other dementias, hundreds of distinct antibody clones have been developed against the microtubule-associated protein Tau and its multiple proteoforms. Despite this breadth of offer, limited understanding of their performance and poor antibody selectivity have hindered research progress. Here, we validate a large panel of Tau antibodies by Western blot (79 reagents) and immunohistochemistry (35 reagents). We address the reagents' ability to detect the target proteoform, selectivity, the impact of protein phosphorylation on antibody binding and performance in human brain samples. While most antibodies detected Tau at high levels, many failed to detect it at lower, endogenous levels. By WB, non-selective binding to other proteins affected over half of the antibodies tested, with several cross-reacting with the related MAP2 protein, whereas the "oligomeric Tau" T22 antibody reacted with monomeric Tau by WB, thus calling into question its specificity to Tau oligomers. Despite the presumption that "total" Tau antibodies are agnostic to post-translational modifications, we found that phosphorylation partially inhibits binding for many such antibodies, including the popular Tau-5 clone. We further combine high-sensitivity reagents, mass-spectrometry proteomics and cDNA sequencing to demonstrate that presumptive Tau "knockout" human cells continue to express residual protein arising through exon skipping, providing evidence of previously unappreciated gene plasticity. Finally, probing of human brain samples with a large panel of antibodies revealed the presence of C-term-truncated versions of all main Tau brain isoforms in both control and tauopathy donors. Ultimately, we identify a validated panel of Tau antibodies that can be employed in Western blotting and/or immunohistochemistry to reliably detect even low levels of Tau expression with high selectivity. This work represents an extensive resource that will enable the re-interpretation of published data, improve reproducibility in Tau research, and overall accelerate scientific progress.


Subject(s)
Antibodies , Blotting, Western , Brain , Immunohistochemistry , tau Proteins , tau Proteins/metabolism , tau Proteins/immunology , Humans , Immunohistochemistry/methods , Antibodies/immunology , Brain/metabolism , Brain/pathology , Phosphorylation , Alzheimer Disease/diagnosis , Alzheimer Disease/metabolism , Alzheimer Disease/immunology , Reproducibility of Results
14.
Braz J Med Biol Res ; 57: e13299, 2024.
Article in English | MEDLINE | ID: mdl-38716981

ABSTRACT

25-hydroxycholesterol (25-HC) plays a role in the regulation of cell survival and immunity. However, the effect of 25-HC on myocardial ischemia/reperfusion (MI/R) injury remains unknown. Our present study aimed to investigate whether 25-HC aggravated MI/R injury through NLRP3 inflammasome-mediated pyroptosis. The overlapping differentially expressed genes (DEGs) in MI/R were identified from the GSE775, GSE45818, GSE58486, and GSE46395 datasets in Gene Expression Omnibus (GEO) database. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were conducted using the database of Annotation, Visualization and Integration Discovery (DAVID). The protein-protein interaction (PPI) network of the overlapping DEGs was established using the Search Tool for the Retrieval of Interacting Genes (STRING) database. These bioinformatics analyses indicated that cholesterol 25-hydroxylase (CH25H) was one of the crucial genes in MI/R injury. The oxygen-glucose deprivation/reoxygenation (OGD/R) cell model was established to simulate MI/R injury. Western blot and RT-qPCR analysis demonstrated that CH25H was significantly upregulated in OGD/R-stimulated H9C2 cardiomyocytes. Moreover, knockdown of CH25H inhibited the OGD/R-induced pyroptosis and nod-like receptor protein 3 (NLRP3) inflammasome activation, as demonstrated by cell counting kit-8 (CCK8), lactate dehydrogenase (LDH), RT-qPCR, and western blotting assays. Conversely, 25-HC, which is synthesized by CH25H, promoted activation of NLRP3 inflammasome in OGD/R-stimulated H9C2 cardiomyocytes. In addition, the NLRP3 inhibitor BAY11-7082 attenuated 25-HC-induced H9C2 cell injury and pyroptosis under OGD/R condition. In conclusion, 25-HC could aggravate OGD/R-induced pyroptosis through promoting activation of NLRP3 inflammasome in H9C2 cells.


Subject(s)
Glucose , Hydroxycholesterols , Inflammasomes , Myocardial Reperfusion Injury , Myocytes, Cardiac , NLR Family, Pyrin Domain-Containing 3 Protein , Pyroptosis , Animals , Rats , Blotting, Western , Glucose/metabolism , Hydroxycholesterols/metabolism , Hydroxycholesterols/pharmacology , Inflammasomes/metabolism , Myocardial Reperfusion Injury/metabolism , Myocytes, Cardiac/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Oxygen/metabolism , Pyroptosis/physiology
15.
Biol Res ; 57(1): 34, 2024 May 29.
Article in English | MEDLINE | ID: mdl-38812057

ABSTRACT

Studies have suggested that endoplasmic reticulum stress (ERS) is involved in neurological dysfunction and that electroacupuncture (EA) attenuates neuropathic pain (NP) via undefined pathways. However, the role of ERS in the anterior cingulate cortex (ACC) in NP and the effect of EA on ERS in the ACC have not yet been investigated. In this study, an NP model was established by chronic constriction injury (CCI) of the left sciatic nerve in rats, and mechanical and cold tests were used to evaluate behavioral hyperalgesia. The protein expression and distribution were evaluated using western blotting and immunofluorescence. The results showed that glucose-regulated protein 78 (BIP) and inositol-requiring enzyme 1α (IRE-1α) were co-localized in neurons in the ACC. After CCI, BIP, IRE-1α, and phosphorylation of IRE-1α were upregulated in the ACC. Intra-ACC administration of 4-PBA and Kira-6 attenuated pain hypersensitivity and downregulated phosphorylation of IRE-1α, while intraperitoneal injection of 4-PBA attenuated hyperalgesia and inhibited the activation of P38 and JNK in ACC. In contrast, ERS activation by intraperitoneal injection of tunicamycin induced behavioral hyperalgesia in naive rats. Furthermore, EA attenuated pain hypersensitivity and inhibited the CCI-induced overexpression of BIP and pIRE-1α. Taken together, these results demonstrate that EA attenuates NP by suppressing BIP- and IRE-1α-mediated ERS in the ACC. Our study presents novel evidence that ERS in the ACC is implicated in the development of NP and provides insights into the molecular mechanisms involved in the analgesic effect of EA.


Subject(s)
Disease Models, Animal , Electroacupuncture , Endoplasmic Reticulum Stress , Gyrus Cinguli , Neuralgia , Rats, Sprague-Dawley , Animals , Electroacupuncture/methods , Gyrus Cinguli/metabolism , Neuralgia/therapy , Male , Endoplasmic Reticulum Stress/physiology , Rats , Blotting, Western , Heat-Shock Proteins/metabolism , Protein Serine-Threonine Kinases/metabolism , Hyperalgesia/therapy , Endoplasmic Reticulum Chaperone BiP
16.
Int J Oral Sci ; 16(1): 42, 2024 May 23.
Article in English | MEDLINE | ID: mdl-38782892

ABSTRACT

Bisphosphonate-related osteonecrosis of jaw (BRONJ) is characterized by impaired osteogenic differentiation of orofacial bone marrow stromal cells (BMSCs). Corin has recently been demonstrated to act as a key regulator in bone development and orthopedic disorders. However, the role of corin in BRONJ-related BMSCs dysfunction remains unclarified. A m6A epitranscriptomic microarray study from our group shows that the CORIN gene is significantly upregulated and m6A hypermethylated during orofacial BMSCs osteogenic differentiation. Corin knockdown inhibits BMSCs osteogenic differentiation, whereas corin overexpression or soluble corin (sCorin) exerts a promotion effect. Furthermore, corin expression is negatively regulated by bisphosphonates (BPs). Corin overexpression or sCorin reverses BPs-impaired BMSCs differentiation ability. Mechanistically, we find altered expression of phos-ERK in corin knockdown/overexpression BMSCs and BMSCs under sCorin stimulation. PD98059 (a selective ERK inhibitor) blocks the corin-mediated promotion effect. With regard to the high methylation level of corin during osteogenic differentiation, we apply a non-selective m6A methylase inhibitor, Cycloleucine, which also blocks the corin-mediated promotion effect. Furthermore, we demonstrate that METTL7A modulates corin m6A modification and reverses BPs-impaired BMSCs function, indicating that METTL7A regulates corin expression and thus contributes to orofacial BMSCs differentiation ability. To conclude, our study reveals that corin reverses BPs-induced BMSCs dysfunction, and METTL7A-mediated corin m6A modification underlies corin promotion of osteogenic differentiation via the ERK pathway. We hope this brings new insights into future clinical treatments for BRONJ.


Subject(s)
Cell Differentiation , Mesenchymal Stem Cells , Osteogenesis , Cell Differentiation/drug effects , Osteogenesis/drug effects , Mesenchymal Stem Cells/drug effects , Mesenchymal Stem Cells/metabolism , Diphosphonates/pharmacology , Humans , Methyltransferases/metabolism , Bisphosphonate-Associated Osteonecrosis of the Jaw , Animals , Up-Regulation , Blotting, Western , Cells, Cultured
17.
Int J Oral Sci ; 16(1): 43, 2024 May 27.
Article in English | MEDLINE | ID: mdl-38802345

ABSTRACT

Ferroptosis is implicated in the pathogenesis of numerous chronic-inflammatory diseases, yet its association with progressive periodontitis remains unexplored. To investigate the involvement and significance of ferroptosis in periodontitis progression, we assessed sixteen periodontitis-diagnosed patients. Disease progression was clinically monitored over twelve weeks via weekly clinical evaluations and gingival crevicular fluid (GCF) collection was performed for further analyses. Clinical metrics, proteomic data, in silico methods, and bioinformatics tools were combined to identify protein profiles linked to periodontitis progression and to explore their potential connection with ferroptosis. Subsequent western blot analyses validated key findings. Finally, a single-cell RNA sequencing (scRNA-seq) dataset (GSE164241) for gingival tissues was analyzed to elucidate cellular dynamics during periodontitis progression. Periodontitis progression was identified as occurring at a faster rate than traditionally thought. GCF samples from progressing and non-progressing periodontal sites showed quantitative and qualitatively distinct proteomic profiles. In addition, specific biological processes and molecular functions during progressive periodontitis were revealed and a set of hub proteins, including SNCA, CA1, HBB, SLC4A1, and ANK1 was strongly associated with the clinical progression status of periodontitis. Moreover, we found specific proteins - drivers or suppressors - associated with ferroptosis (SNCA, FTH1, HSPB1, CD44, and GCLC), revealing the co-occurrence of this specific type of regulated cell death during the clinical progression of periodontitis. Additionally, the integration of quantitative proteomic data with scRNA-seq analysis suggested the susceptibility of fibroblasts to ferroptosis. Our analyses reveal proteins and processes linked to ferroptosis for the first time in periodontal patients, which offer new insights into the molecular mechanisms of progressive periodontal disease. These findings may lead to novel diagnostic and therapeutic strategies.


Subject(s)
Disease Progression , Ferroptosis , Gingival Crevicular Fluid , Periodontitis , Humans , Gingival Crevicular Fluid/chemistry , Periodontitis/metabolism , Periodontitis/pathology , Female , Male , Proteomics , Cell Death , Adult , Middle Aged , Blotting, Western
18.
Clinics (Sao Paulo) ; 79: 100363, 2024.
Article in English | MEDLINE | ID: mdl-38692008

ABSTRACT

OBJECTIVE: This study aimed to investigate the effect of Esketamine (ESK) on the Hypoxia/Reoxygenation (H/R) injury of cardiomyocytes by regulating TRPV1 and inhibiting the concentration of intracellular Ca2+. METHODS: The H/R injury model of H9c2 cardiomyocytes was established after 4h hypoxia and 6h reoxygenation. H9c2 cells were treated with different concentrations of ESK or TRPV1 agonist capsaicin (10 µM) or TRPV1 inhibitor capsazepine (1 µM). Cell viability was detected by CCK-8 method, and apoptosis by flow cytometry. Intracellular Ca2+ concentration was evaluated by Fluo-4 AM. LDH, MDA, SOD, and GSH-Px were detected with corresponding commercial kits. TRPV1 and p-TRPV1 proteins were detected by Western blot. RESULTS: After H/R, H9c2 cell viability decreased, apoptosis increased, intracellular Ca2+ concentration increased, LDH and MDA levels increased, SOD and GSH-Px levels decreased, and p-TRPV1 expression increased. ESK treatment rescued these changes induced by H/R. After up-regulating TRPV1, the protective effect of ESK on H/R injury of H9c2 cells was weakened, while down-regulating TRPV1 could further protect against H/R injury. CONCLUSION: ESK alleviates H/R injury of cardiomyocytes by regulating TRPV1 expression and inhibiting intracellular Ca2+ concentration.


Subject(s)
Apoptosis , Calcium , Capsaicin/analogs & derivatives , Cell Survival , Ketamine , Myocytes, Cardiac , TRPV Cation Channels , TRPV Cation Channels/metabolism , TRPV Cation Channels/drug effects , Myocytes, Cardiac/drug effects , Myocytes, Cardiac/metabolism , Calcium/metabolism , Cell Survival/drug effects , Apoptosis/drug effects , Animals , Ketamine/pharmacology , Myocardial Reperfusion Injury/metabolism , Myocardial Reperfusion Injury/drug therapy , Rats , Capsaicin/pharmacology , Cell Hypoxia/drug effects , Cell Line , Flow Cytometry , Oxidative Stress/drug effects , Blotting, Western
19.
Braz J Med Biol Res ; 57: e13379, 2024.
Article in English | MEDLINE | ID: mdl-38808888

ABSTRACT

Ulcerative colitis (UC) is a difficult intestinal disease characterized by inflammation, and its mechanism is complex and diverse. Angiopoietin-like protein 2 (ANGPT2) plays an important regulatory role in inflammatory diseases. However, the role of ANGPT2 in UC has not been reported so far. After exploring the expression level of ANGPT2 in serum of UC patients, the reaction mechanism of ANGPT2 was investigated in dextran sodium sulfate (DSS)-induced UC mice. After ANGPT2 expression was suppressed, the clinical symptoms and pathological changes of UC mice were detected. Colonic infiltration, oxidative stress, and colonic mucosal barrier in UC mice were evaluated utilizing immunohistochemistry, immunofluorescence, and related kits. Finally, western blot was applied for the estimation of mTOR signaling pathway and NLRP3 inflammasome-related proteins. ANGPT2 silencing improved clinical symptoms and pathological changes, alleviated colonic inflammatory infiltration and oxidative stress, and maintained the colonic mucosal barrier in DSS-induced UC mice. The regulatory effect of ANGPT2 on UC disease might occur by regulating the mTOR signaling pathway and thus affecting autophagy-mediated NLRP3 inflammasome inactivation. ANGPT2 silencing alleviated UC by regulating autophagy-mediated NLRP3 inflammasome inactivation via the mTOR signaling pathway.


Subject(s)
Autophagy , Colitis, Ulcerative , Disease Models, Animal , Inflammasomes , NLR Family, Pyrin Domain-Containing 3 Protein , Signal Transduction , TOR Serine-Threonine Kinases , Colitis, Ulcerative/chemically induced , Colitis, Ulcerative/pathology , Colitis, Ulcerative/metabolism , Animals , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Autophagy/physiology , TOR Serine-Threonine Kinases/metabolism , Mice , Inflammasomes/metabolism , Humans , Male , Angiopoietin-Like Protein 2 , Mice, Inbred C57BL , Female , Angiopoietin-2/metabolism , Dextran Sulfate , Oxidative Stress , Immunohistochemistry , Blotting, Western
20.
Braz J Med Biol Res ; 57: e13437, 2024.
Article in English | MEDLINE | ID: mdl-38808889

ABSTRACT

Clinical studies have found that neonatal sevoflurane exposure can increase the risk of cognitive dysfunction. However, recent studies have found that it can exhibit neuroprotective effects in some situations. In this study, we aimed to explore the effects of sevoflurane neonatal exposure in rats. A total of 144 rat pups (72 males and 72 females) were assigned to six groups and separately according to sevoflurane exposure of different times on the seventh day after birth. Blood gas analysis and western blot detection in the hippocampus were conducted after exposure. The Morris water maze test was conducted on the 32nd to 38th days after birth. The expression of PSD95 and synaptophysin in the hippocampus was detected after the Morris water maze test. We found that neonatal exposure to sevoflurane promoted apoptosis in the hippocampus, and Bax and caspase-3 were increased in a dose-dependent manner. The 2-h exposure had the greatest effects on cognitive dysfunction. However, with the extension of exposure time to 6 h, the effects on cognitive function were partly compensated. In addition, sevoflurane exposure decreased synaptogenesis in the hippocampus. However, as the exposure time was extended, the suppression of synaptogenesis was attenuated. In conclusion, neonatal sevoflurane exposure exhibited duration-dependent effects on cognitive function via Bax-caspase-3-dependent apoptosis and bidirectional effects on synaptogenesis in rats.


Subject(s)
Animals, Newborn , Cognition , Hippocampus , Sevoflurane , Sevoflurane/pharmacology , Animals , Female , Male , Hippocampus/drug effects , Hippocampus/metabolism , Rats , Cognition/drug effects , Time Factors , Maze Learning/drug effects , Anesthetics, Inhalation/pharmacology , Anesthetics, Inhalation/adverse effects , Apoptosis/drug effects , Sex Factors , Rats, Sprague-Dawley , Methyl Ethers/pharmacology , Blotting, Western , Blood Gas Analysis , Cognitive Dysfunction/chemically induced
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