GREM1 Negatively Regulates Osteo-/Dentinogenic Differentiation of Dental Pulp Stem Cells via Association with YWHAH.

OBJECTIVE: To investigate the biological regulatory function of Gremlin1 (GREM1) and tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein eta (YWHAH) in dental pulp stem cells (DPSCs), and determine the underlying molecular mechanism involved. METHODS: Alkaline phosphatase (ALP) activity, alizarin red staining, scratch migration assays and in vitro and in vivo osteo-/dentinogenic marker detection of bone-like tissue generation in nude mice were used to assess osteo-/dentinogenic differentiation. Coimmunoprecipitation and polypeptide microarray assays were employed to detect the molecular mechanisms involved. RESULTS: The data revealed that knockdown of GREM1 promoted ALP activity, mineralisation in vitro and the expression of osteo-/dentinogenic differentiation markers and enhanced osteo-/ dentinogenesis of DPSCs in vivo. GREM1 bound to YWHAH in DPSCs, and the binding site was also identified. Knockdown of YWHAH suppressed the osteo-/dentinogenesis of DPSCs in vitro, and overexpression of YWHAH promoted the osteo-/dentinogenesis of DPSCs in vitro and in vivo. CONCLUSION: Taken together, the findings highlight the critical roles of GREM1-YWHAH in the osteo-/dentinogenesis of DPSCs.

The mechanism of 14-3-3η in thyroxine induced mitophagy in cardiomyocytes.

Hyperthyroidism is becoming increasingly important as an independent risk factor for cardiovascular disease, eventually resulting in cardiac hypertrophy and heart failure. The 14-3-3 protein family subtypes regulate many cellular processes in eukaryotes by interacting with a diverse array of client proteins. Considering that the 14-3-3η protein protects cardiomyocytes by affecting mitochondrial function, exploring the biological influence and molecular mechanisms by which 14-3-3η alleviates the cardiac hypertrophy of hyperthyroidism is imperative. In vivo and in vitro, RT-PCR, Western blot, and Mitochondrial tracking assay were performed to understand the molecular mechanism of thyroxine-induced cardiomyocyte hypertrophy. HE staining, transmission electron microscopy, and immunofluorescence were used to observe intuitively changes of hearts and cardiomyocytes. The in vivo and in vitro results indicated that overexpression of the 14-3-3η ameliorated thyroxine-induced cardiomyocyte hypertrophy, whereas knockdown of the 14-3-3η protein aggravated thyroxine-induced cardiomyocyte hypertrophy. Additionally, overexpression of the 14-3-3η protein reduces thyroxine-induced mitochondrial damage and mitophagy in cardiomyocytes. Overexpression of 14-3-3η protein improves excessive mitophagy in the myocardium caused by thyroxine and thus prevents cardiac hypertrophy.

Unveiling YWHAH: A potential therapeutic target for overcoming CD8+ T cell exhaustion in colorectal cancer.

Colorectal cancer (CRC) is a significant global health challenge, with increasing rates of incidence and mortality. Despite advancements in immunotherapy, resistance, particularly due to T cell exhaustion, remains a major hurdle. This study explores the role of YWHAH, mediated by N4-acetylcytidine (ac4C) modification, in CRC progression and its impact on CD8+ T cell exhaustion. Analysis of five paired CRC patient tissue samples using acetylated RNA immunoprecipitation and sequencing (acRIP-seq)identified ac4C-modified mRNAs. Functional assays, including cell culture, transfection, qRT-PCR, and immune assays, investigated the influence of YWHAH expression on CRC advancement. Bioinformatics analysis of TCGA data assessed the correlation between YWHAH and immune responses, as well as checkpoint inhibitors. Flow cytometry and Immunohistochemistry validated these findings, complemented by a co-culture experiment involving CD8+ T cells and CRC cell lines (LOVO and HCT116). acRIP-seq revealed YWHAH as a potential driver of CRC progression, exhibiting ac4C modification-mediated stability and upregulation. High YWHAH levels correlated with adverse outcomes and immune evasion in CRC patients, showing strong associations with immune checkpoint proteins and modest correlations with CD8+ T cell infiltration. Co-culture experiments demonstrated YWHAH-induced CD8+ T cell exhaustion, characterized by decreased proliferation and increased exhaustion markers. NAT10-mediated ac4C modification enhanced YWHAH stability in CRC. The involvement of YWHAH in CD8 + T cell exhaustion suggests its potential as a therapeutic target and prognostic marker in CRC immunotherapy, highlighting the intricate interplay between epitranscriptomic modifications, the tumor microenvironment, and immune responses in CRC progression.

Inhibiting miR-33b-5p Enhances Chemoresistance in Lung Adenocarcinoma by Targeting YWHAH to Regulate Epithelial-mesenchymal Transition.

BACKGROUND/AIM: Lung adenocarcinoma (LUAD) is the most malignant type of lung cancer, whose clinical treatment is seriously hindered by chemoresistance. Numerous reports have demonstrated that miR-33b-5p plays an essential role in alleviating the chemoresistance of multiple cancers, but there are currently no reports about the effects of miR-33b-5p on the chemoresistance in LUAD. Our study aimed to investigate the impacts of miR-33b-5p on the chemoresistance in LUAD and the underlying mechanism. MATERIALS AND METHODS: Bioinformatics analyses were employed to investigate the relation between miR-33b-5p and YWHAH. The MTT assay and flow cytometry were respectively adopted to determine cell viability and apoptosis. A transwell assay was employed to evaluate cellular invasion and migration. qRT-PCR and western blotting were respectively employed to detect the gene expression of miR-33b-5p and the protein expression of YWHAH, MMP2, Snail, and Zeb1. RESULTS: Three bioinformatics analysis approaches predicted that YWHAH was the underlying targeted gene of miR-33b-5p and revealed the associated mechanisms. The concentration of paclitaxel (TAX) and cisplatin (DDP) needed to induce chemoresistance of LUAD cells was determined as 100 µM. Migration and invasion, as well as protein expression of YWHAH, MMP2, MMP8, Snail and Zeb1 were increased, but the apoptosis and levels of miR-33b-5p were reduced in A549 cells with chemoresistance. Knockdown of miR-33b-5p exerted the same effects produced by chemoresistance, but additional knockdown of YWHAH reversed the effects generated by inhibiting miR-33b-5p. CONCLUSION: Our study confirmed that knockdown of miR-33b-5p aggravated chemoresistance in LUAD via targeting YWHAH to regulate EMT.

YWHAH activates the HMGA1/PI3K/AKT/mTOR signaling pathway by positively regulating Fra-1 to affect the proliferation of gastric cancer cells.

Fos-related antigen 1 (Fra-1) is a nuclear transcription factor that regulates cell growth, differentiation, and apoptosis. It is involved in the proliferation, invasion, apoptosis and epithelial mesenchymal transformation of malignant tumor cells. Fra-1 is highly expressed in gastric cancer (GC), affects the cycle distribution and apoptosis of GC cells, and participates in GC occurrence and development. However, the detailed mechanism of Fra-1 in GC is unclear, such as the identification of Fra-1-interacting proteins and their role in GC pathogenesis. In this study, we identified tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein eta (YWHAH) as a Fra-1-interacting protein in GC cells using co-immunoprecipitation combined with liquid chromatography-tandem mass spectrometry. Experiments showed that YWHAH positively regulated Fra-1 mRNA and protein expression, and affected GC cell proliferation. Whole proteome analysis showed that Fra-1 affected the activity of the high mobility group AT-hook 1 (HMGA1)/phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/protein kinase B (AKT)/mechanistic target of rapamycin (mTOR) signaling pathway in GC cells. Western blotting and flow cytometry confirmed that YWHAH activated HMGA1/PI3K/AKT/mTOR signaling pathway by positively regulating Fra-1 to affect GC cell proliferation. These results will help to discover new molecular targets for the early diagnosis, treatment, and prognosis prediction of GC.

LINC00943 regulates miR-1252-5p/YWHAH axis to promote tumor proliferation and metastasis in lung adenocarcinoma.

Lung cancer is the most common malignant tumor worldwide. In recent years, the incidence of lung adenocarcinoma (LAD) has increased significantly, with an unfavorable 5-year survival rate. Long non-coding RNAs (lncRNAs) have been shown to play a significant role in the emergence, growth, and metastasis of tumors. However, the functional role and mechanism of LINC00943 in LAD progression have not yet been investigated. Aberrant expressions of LINC00943, miR-1252-5p, and YWHAH were determined by RT-qPCR and Western blot analyses. The binding relationship between miR-1252-5p and LINC00943 or YWHAH was examined by Pearson's correlation analysis, RNA pull-down, and dual-luciferase reporter assays. MTT assay was conducted to measure cell viability and colony formation assay was performed to evaluate cell proliferation potential. Transwell assay was used to investigate cell migration and invasion and flow cytometry was applied to evaluate cell apoptosis. We found that LINC00943 was highly expressed in LAD tissue samples and cell lines and was a reliable biomarker with high sensitivity, and specificity (P < 0.0001; AUC: 0.8966) for LAD detection. LINC00943 was mainly localized in the cytoplasm. In vitro, LINC00943 promoted LAD cell proliferation, migration, and invasion; however, silencing LINC00943 inhibited LAD tumor metastasis. Mechanistically, LINC00943 was competitively bound with miR-1252-5p to enhance YWHAH expression. Moreover, LINC00943 silencing sponged miR-1252-5p to inhibit YWHAH, thereby retraining LAD cell malignant behaviors. In summary, LINC00943 facilitates LAD cell malignancy through sponging miR-1252-5p to upregulate YWHAH. LINC00943 is a novel lncRNA that serves as an oncogene and might be used as a prognostic biomarker for LAD.

Circ_0000144 acts as a miR-1178-3p decoy to promote cell malignancy and angiogenesis by increasing YWHAH expression in papillary thyroid cancer.

Papillary thyroid cancer (PTC) is the most common subtype of thyroid cancer. Circular RNA hsa_circ_0000144 (circ_0000144) is related to the progression of thyroid cancer. However, the mechanism by which circ_0000144 accelerates PTC progression is still unclear. Circ_0000144 and YWHAH were upregulated in PTC tissues and cells, while miR-1178-3p had an opposite result. Circ_0000144 silencing constrained PTC cell growth in vitro and in vivo and induced apoptosis and repressed migration, invasion, and angiogenesis of PTC cells in vitro. Circ_0000144 acted as a molecular sponge for miR-1178-3p, which targeted YWHAH. MiR-1178-3p inhibitor reversed circ_0000144 silencing-mediated influence on PTC cell malignancy and angiogenesis. Furthermore, YWHAH overexpression overturned miR-1178-3p mimic-mediated influence on malignant behaviors and angiogenesis of PTC cells. Notably, circ_0000144 regulated YWHAH expression by adsorbing miR-1178-3p. Circ_0000144 promoted cell malignancy and angiogenesis by regulating the miR-1178-3p/YWHAH axis in PTC, offering a novel mechanism for the malignancy and angiogenesis of PTC cells.

YWHAH Genetic Variants are Associated with Increased Hypoxia Inducible Factor-1α/Vascular Endothelial Growth Factor in Egyptian Rheumatoid Arthritis Patients.

The 14-3-3 Eta (14-3-3 η) biomarker platform is a relatively recent discovery with the potential to significantly address the diagnosis and prognosis of rheumatoid arthritis (RA) disease. Hypoxia-inducible factor (HIF)-1α and vascular endothelial growth factor (VEGF) have been implicated in inflammatory mechanisms in RA. We hypothesized a molecular association of the coding YWHAH gene and its expressed protein 14-3-3 η with hypoxia and angiogenesis in RA. One hundred healthy subjects and 100 RA patients were enrolled in the study. YWHAH gene expression was determined using quantitative PCR, and its gene polymorphism rs2858750 was assessed by Taqman genotyping assay. Serum levels of 14-3-3 η, HIF-1α, and VEGF were measured using the ELISA technique, and clinical parameters were routinely examined. In RA patients, significant positive correlations were found between 14-3-3 η, HIF-1α (r = 0.84), and VEGF (r = 0.85). YWHAH gene expression was upregulated 10.8 fold (CI 95% 10.1-11.5) in RA patients and significantly correlated with all disease activity parameters, ACPA, and levels of 14-3-3 η, HIF-1α, and VEGF. RA patients showed a higher frequency of YWHAH rs2858750 A allele than healthy subjects (p = 0.02). The risk A allele carriers showed higher disease activity parameters, ACPA, YWHAH gene expression, and increased serum levels of 14-3-3 η (p < 0.001), HIF-1α (p = 0.002), and VEGF (p = 0.001) than the G allele. Serum 14-3-3 η and its rs2858750 genetic variant are associated with increased hypoxia and angiogenesis in RA and activity, and severity of the disease.

Similarity of the non-amyloid-ß component and C-terminal tail of monomeric and tetrameric alpha-synuclein with 14-3-3 sigma.

Alpha-synuclein (αSyn) is often described as a predominantly disordered protein that has a propensity to self-assemble into toxic oligomers that are found in patients with Parkinson's and Alzheimer's diseases. αSyn's chaperone behavior and tetrameric structure are proposed to be protective against toxic oligomerization. In this paper, we extended the previously proposed similarity between αSyn and 14-3-3 proteins to the α-helical tetrameric species of αSyn in detail. 14-3-3 proteins are a family of well-folded proteins with seven human isoforms, and function in signal transduction and as molecular chaperones. We investigated protein homology, using sequence alignment, amyloid, and disorder prediction, as well as three-dimensional visualization and protein-interaction networks. Our results show sequence homology and structural similarity between the aggregation-prone non-amyloid-ß component (NAC) residues Val-52 to Gly-111 in αSyn and 14-3-3 sigma residues Leu-12 to Gly-78. We identified an additional region of sequence homology in the C-terminal region of αSyn (residues Ser-129 to Asp-135) and a C-terminal loop of 14-3-3 between helix αH and αI (residues Ser-209 to Asp-215). This data indicates αSyn shares conserved domain architecture with small heat shock proteins. We show predicted regions of high amyloidogenic propensity and intrinsic structural disorder in αSyn coincide with amyloidogenic and disordered predictions for 14-3-3 proteins. The homology in the NAC region aligns with residues involved in dimer- and tetramerization of the non-amyloidogenic 14-3-3 proteins. Because 14-3-3 proteins are generally not prone to misfolding, our results lend further support to the hypothesis that the NAC region is critical to the assembly of αSyn into the non-toxic tetrameric state.

Genomics Links Inflammation With Neurocognitive Impairment in Children Living With Human Immunodeficiency Virus Type-1.

BACKGROUND: We identified host single-nucleotide variants (SNVs) associated with neurocognitive impairment (NCI) in perinatally HIV-infected (PHIV) children. METHODS: Whole-exome sequencing (WES) was performed on 217 PHIV with cognitive score for age (CSA) < 70 and 247 CSA ≥ 70 (discovery cohort [DC]). SNVs identified in DC were evaluated in 2 validation cohorts (VC). Logistic regression was used to estimate adjusted odds ratios (ORs) for NCI. A human microglia NLRP3 inflammasome assay characterized the role of identified genes. RESULTS: Twenty-nine SNVs in 24 genes reaching P ≤ .002 and OR ≥ 1.5 comparing CSA < 70 to CSA ≥ 70 were identified in the DC, of which 3 SNVs were identified in VCs for further study. Combining the 3 cohorts, SNV in CCRL2 (rs3204849) was associated with decreased odds of NCI (P < .0001); RETREG1/FAM134B (rs61733811) and YWHAH (rs73884247) were associated with increased risk of NCI (P < .0001 and P < .001, respectively). Knockdown of CCRL2 led to decreased microglial release of IL-1ß following exposure to ssRNA40 while knockdown of RETREG1 and YWHAH resulted in increased IL-1ß release. CONCLUSIONS: Using WES and 2 VCs, and gene silencing of microglia we identified 3 genetic variants associated with NCI and inflammation in HIV-infected children.

YWHA (14-3-3) protein isoforms and their interactions with CDC25B phosphatase in mouse oogenesis and oocyte maturation.

BACKGROUND: Immature mammalian oocytes are held arrested at prophase I of meiosis by an inhibitory phosphorylation of cyclin-dependent kinase 1 (CDK1). Release from this meiotic arrest and germinal vesicle breakdown is dependent on dephosphorylation of CDK1 by the protein, cell cycle division 25B (CDC25B). Evidence suggests that phosphorylated CDC25B is bound to YWHA (14-3-3) proteins in the cytoplasm of immature oocytes and is thus maintained in an inactive form. The importance of YWHA in meiosis demands additional studies. RESULTS: Messenger RNA for multiple isoforms of the YWHA protein family was detected in mouse oocytes and eggs. All seven mammalian YWHA isoforms previously reported to be expressed in mouse oocytes, were found to interact with CDC25B as evidenced by in situ proximity ligation assays. Interaction of YWHAH with CDC25B was indicated by Förster Resonance Energy Transfer (FRET) microscopy. Intracytoplasmic microinjection of oocytes with R18, a known, synthetic, non-isoform-specific, YWHA-blocking peptide promoted germinal vesicle breakdown. This suggests that inhibiting the interactions between YWHA proteins and their binding partners releases the oocyte from meiotic arrest. Microinjection of isoform-specific, translation-blocking morpholino oligonucleotides to knockdown or downregulate YWHA protein synthesis in oocytes suggested a role for a specific YWHA isoform in maintaining the meiotic arrest. More definitively however, and in contrast to the knockdown experiments, oocyte-specific and global deletion of two isoforms of YWHA, YWHAH (14-3-3 eta) or YWHAE (14-3-3 epsilon) indicated that the complete absence of either or both isoforms does not alter oocyte development and release from the meiotic prophase I arrest. CONCLUSIONS: Multiple isoforms of the YWHA protein are expressed in mouse oocytes and eggs and interact with the cell cycle protein CDC25B, but YWHAH and YWHAE isoforms are not essential for normal mouse oocyte maturation, fertilization and early embryonic development.