Splicing factor YBX1 regulates bone marrow stromal cell fate during aging.

Senescence and altered differentiation potential of bone marrow stromal cells (BMSCs) lead to age-related bone loss. As an important posttranscriptional regulatory pathway, alternative splicing (AS) regulates the diversity of gene expression and has been linked to induction of cellular senescence. However, the role of splicing factors in BMSCs during aging remains poorly defined. Herein, we found that the expression of the splicing factor Y-box binding protein 1 (YBX1) in BMSCs decreased with aging in mice and humans. YBX1 deficiency resulted in mis-splicing in genes linked to BMSC osteogenic differentiation and senescence, such as Fn1, Nrp2, Sirt2, Sp7, and Spp1, thus contributing to BMSC senescence and differentiation shift during aging. Deletion of Ybx1 in BMSCs accelerated bone loss in mice, while its overexpression stimulated bone formation. Finally, we identified a small compound, sciadopitysin, which attenuated the degradation of YBX1 and bone loss in old mice. Our study demonstrated that YBX1 governs cell fate of BMSCs via fine control of RNA splicing and provides a potential therapeutic target for age-related osteoporosis.

RBM10 regulates the tumorigenic potential of human cancer cells by modulating PPM1B and YBX1 activities.

RNA binding protein RBM10 participates in various RNA metabolism, and its decreased expression or loss of function by mutation has been identified in many human cancers. However, how its dysregulation contributes to human cancer pathogenesis remains to be determined. Here, we found that RBM10 expression was decreased in breast tumors, and breast cancer patients with low RBM10 expression presented poorer survival rates. RBM10 depletion in breast cancer cells significantly promotes the cellular proliferation and migration. We further demonstrated that RBM10 forms a triple complex with YBX1 and phosphatase 1B (PPM1B), in which PPM1B serves as the phosphatase of YBX1. RBM10 knock-down markedly attenuated association between YBX1 and PPM1B, leading to elevated levels of YBX1 phosphorylation and its nuclear translocation. Furthermore, cancer cells with RBM10 depletion had a significantly accelerated tumor growth in nude mice. Importantly, these enhanced tumorigenic phenotypes can be reversed by overexpression of PPM1B. Our findings provide the mechanistic bases for functional loss of RBM10 in promoting tumorigenicity, and are potentially useful in the development of combined therapeutic strategies for cancer patients with defective RBM10.

Transcriptional factors targeting in cancer stem cells for tumor modulation.

Cancer Stem Cells (CSCs) are now considered the primary "seeds" for the onset, development, metastasis, and recurrence of tumors. Despite therapeutic breakthroughs, cancer remains the leading cause of death worldwide. This is because the tumor microenvironment contains a key population of cells known as CSCs, which promote tumor aggression. CSCs are self-renewing cells that aid tumor recurrence by promoting tumor growth and persisting in patients after many traditional cancer treatments. According to reports, numerous transcription factors (TF) play a key role in maintaining CSC pluripotency and its self-renewal property. The understanding of the functions, structures, and interactional dynamics of these transcription factors with DNA has modified the hypothesis, paving the way for novel transcription factor-targeted therapies. These TFs, which are crucial and are required by cancer cells, play a vital function in the etiology of human cancer. Such CSC TFs will help with gene expression profiling, which provides crucial data for predicting the prognosis of patients. To overcome anti-cancer medication resistance and completely eradicate cancer, a potent therapy combining TFs-based CSC targets with traditional chemotherapy may be developed. In order to develop therapies that could eliminate CSCs, we here concentrated on the effect of TFs and other components of signalling pathways on cancer stemness.

Molecular Pathways and Animal Models of Tricuspid Atresia and Univentricular Heart.

The process of valve formation is a complex process that involves intricate interplay between various pathways at precise times. Although we have not completely elucidated the molecular pathways that lead to normal valve formation, we have identified a few major players in this process. We are now able to implicate TGF-ß, BMP, and NOTCH as suspects in tricuspid atresia (TA), as well as their downstream targets: NKX2-5, TBX5, NFATC1, GATA4, and SOX9. We know that the TGF-ß and the BMP pathways converge on the SMAD4 molecule, and we believe that this molecule plays a very important role to tie both pathways to TA. Similarly, we look at the NOTCH pathway and identify the HEY2 as a potential link between this pathway and TA. Another transcription factor that has been implicated in TA is NFATC1. While several mouse models exist that include part of the TA abnormality as their phenotype, no true mouse model can be said to represent TA. Bridging this gap will surely shed light on this complex molecular pathway and allow for better understanding of the disease process.

Targeting LINC070974 inhibits lung adenocarcinoma cell proliferation and progression by interacting with Y-box binding protein 1.

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related mortality worldwide. Increasing evidence suggests that long noncoding RNAs play crucial roles in lung cancer pathogenesis. We previously identified a novel lncRNA, LINC070974, which is associated with tumor cell proliferation. In the present study, we find that knockdown of LINC070974 inhibits cell proliferation, migration and invasion as well as tumor formation both in vitro and in nude mice. LINC070974 silencing also improves cisplatin efficacy in A549/DDP cells. The function of LINC070974 may depend on its interaction with YBX1. Knockdown of LINC070974 reduces the recruitment of YBX1 to the CCND1 promoter and delays tumor progression through its coregulatory genes, which are mainly involved in the p53 signaling pathway. We utilize nebulized inhalation to deliver siRNAs targeting LINC070974 and find that LINC070974 significantly prevents tumor metastasis and growth in lung tissues. These findings reveal the role of LINC070974 in lung cancer and suggest a promising therapeutic approach involving siRNA inhalation.

Y-Box Binding Protein 1: Unraveling the Multifaceted Role in Cancer Development and Therapeutic Potential.

Y-box binding protein 1 (YBX1), a member of the Cold Shock Domain protein family, is overexpressed in various human cancers and is recognized as an oncogenic gene associated with poor prognosis. YBX1's functional diversity arises from its capacity to interact with a broad range of DNA and RNA molecules, implicating its involvement in diverse cellular processes. Independent investigations have unveiled specific facets of YBX1's contribution to cancer development. This comprehensive review elucidates YBX1's multifaceted role in cancer across cancer hallmarks, both in cancer cell itself and the tumor microenvironment. Based on this, we proposed YBX1 as a potential target for cancer treatment. Notably, ongoing clinical trials addressing YBX1 as a target in breast cancer and lung cancer have showcased its promise for cancer therapy. The ramp up in in vitro research on targeting YBX1 compounds also underscores its growing appeal. Moreover, the emerging role of YBX1 as a neural input is also proposed where the high level of YBX1 was strongly associated with nerve cancer and neurodegenerative diseases. This review also summarized the up-to-date advanced research on the involvement of YBX1 in pancreatic cancer.

Blastocyst-like Structures in the Peripheral Retina of Young Adult Beagles.

In this immunohistological study on the peripheral retina of 3-year-old beagle dogs, excised retina specimens were immunostained with antibodies against nestin, Oct4, Nanog, Sox2, CDX2, cytokeratin 18 (CK 18), RPE65, and YAP1, as well as hematoxylin and DAPI, two nuclear stains. Our findings revealed solitary cysts of various sizes in the inner retina. Intriguingly, a mass of small round cells with scant cytoplasms was observed in the cavity of small cysts, while many disorganized cells partially occupied the cavity of the large cysts. The small cysts were strongly positive for nestin, Oct4, Nanog, Sox2, CDX2, CK18, and YAP1. RPE65-positive cells were exclusively observed in the tissue surrounding the cysts. Since RPE65 is a specific marker of retinal pigment epithelial (RPE) cells, the surrounding cells of the peripheral cysts were presumably derived from RPE cells that migrated intraretinally. In the small cysts, intense positive staining for nestin, a marker of retinal stem cells, seemed to indicate that they were derived from retinal stem cells. The morphology and positive staining for markers of blastocyst and RPE cells indicated that the small cysts may have formed structures resembling the blastocyst, possibly caused by the interaction between retinal stem cells and migrated RPE cells.

ERK/RSK-mediated phosphorylation of Y-box binding protein-1 aggravates diabetic cardiomyopathy by suppressing its interaction with deubiquitinase OTUB1.

Diabetic cardiomyopathy (DCM) is a major complication of diabetes, but its underlying mechanisms still remain unclear. The multifunctional protein Y-box binding protein-1 (YB-1) plays an important role in cardiac pathogenesis by regulating cardiac apoptosis, cardiac fibrosis, and pathological remodeling, whereas its role in chronic DCM requires further investigation. Here, we report that the phosphorylation of YB-1 at serine102 (S102) was markedly elevated in streptozotocin-induced diabetic mouse hearts and in high glucose-treated cardiomyocytes, whereas total YB-1 protein levels were significantly reduced. Coimmunoprecipitation experiments showed that YB-1 interacts with the deubiquitinase otubain-1, but hyperglycemia-induced phosphorylation of YB-1 at S102 diminished this homeostatic interaction, resulting in ubiquitination and degradation of YB-1. Mechanistically, the high glucose-induced phosphorylation of YB-1 at S102 is dependent on the upstream extracellular signal-regulated kinase (ERK)/Ras/mitogen-activated protein kinase (p90 ribosomal S6 kinase [RSK]) signaling pathway. Accordingly, pharmacological inhibition of the ERK pathway using the upstream kinase inhibitor U0126 ameliorated features of DCM compared with vehicle-treated diabetic mice. We demonstrate that ERK inhibition with U0126 also suppressed the phosphorylation of the downstream RSK and YB-1 (S102), which stabilized the interaction between YB-1 and otubain-1 and thereby preserved YB-1 protein expression in diabetic hearts. Taken together, we propose that targeting the ERK/RSK/YB-1 pathway could be a potential therapeutic approach for treating DCM.

DNA binding protein YB-1 is a part of the neutrophil extracellular trap mediation of kidney damage and cross-organ effects.

Open-heart surgery is associated with high morbidity, with acute kidney injury (AKI) being one of the most commonly observed postoperative complications. Following open-heart surgery, in an observational study we found significantly higher numbers of blood neutrophils in a group of 13 patients with AKI compared to 25 patients without AKI (AKI: 12.9±5.4 ×109 cells/L; non-AKI: 10.1±2. 9 ×109 cells/L). Elevated serum levels of neutrophil extracellular trap (NETs) components, such as dsDNA, histone 3, and DNA binding protein Y-box protein (YB)-1, were found within the first 24 hours in patients who later developed AKI. We could demonstrate that NET formation and hypoxia triggered the release of YB-1, which was subsequently shown to act as a mediator of kidney tubular damage. Experimentally, in two models of AKI mimicking kidney hypoperfusion during cardiac surgery (bilateral ischemia/reperfusion (I/R) and systemic lipopolysaccharide (LPS) administration), a neutralizing YB-1 antibody was administered to mice. In both models, prophylactic YB-1 antibody administration significantly reduced the tubular damage (damage score range 1-4, the LPS model: non-specific IgG control, 0.92±0.23; anti-YB-1 0.65±0.18; and in the I/R model: non-specific IgG control 2.42±0.23; anti-YB-1 1.86±0.44). Even in a therapeutic, delayed treatment model, antagonism of YB-1 ameliorated AKI (damage score, non-specific IgG control 3.03±0.31; anti-YB-1 2.58±0.18). Thus, blocking extracellular YB-1 reduced the effects induced by hypoxia and NET formation in the kidney and significantly limited AKI, suggesting that YB-1 is part of the NET formation process and an integral mediator of cross-organ effects.

YB-1 activating cascades as potential targets in KRAS-mutated tumors.

Y­box binding protein­1 (YB-1) is a multifunctional protein that is highly expressed in human solid tumors of various entities. Several cellular processes, e.g. cell cycle progression, cancer stemness and DNA damage signaling that are involved in the response to chemoradiotherapy (CRT) are tightly governed by YB­1. KRAS gene with about 30% mutations in all cancers, is considered the most commonly mutated oncogene in human cancers. Accumulating evidence indicates that oncogenic KRAS mediates CRT resistance. AKT and p90 ribosomal S6 kinase are downstream of KRAS and are the major kinases that stimulate YB­1 phosphorylation. Thus, there is a close link between the KRAS mutation status and YB­1 activity. In this review paper, we highlight the importance of the KRAS/YB­1 cascade in the response of KRAS-mutated solid tumors to CRT. Likewise, the opportunities to interfere with this pathway to improve CRT outcome are discussed in light of the current literature.

Fluctuation of CD9/SOX2-positive cell populations during the turnover of GH- and TSH-producing cells in the adult anterior pituitary gland.

The adenohypophysis is comprised of the anterior and intermediate lobes (AL and IL, respectively). Cluster of differentiation 9 (CD9)- and sex-determining region Y-box 2 (SOX2)-positive cells are stem/progenitor hormone-producing cells in the AL. They are located in the marginal cell layer (MCL) facing Rathke's cleft between the AL and IL (primary niche) and the parenchyma of the AL (secondary niche). We previously showed that, in rats, CD9/SOX2-positive cells in the IL side of the MCL (IL-side MCL) migrate to the AL side (AL-side MCL) and differentiate into prolactin-producing cells (PRL cells) in the AL parenchyma during pregnancy, lactation, and diethylstilbestrol treatment, all of which increase PRL cell turnover. This study examined the changes in CD9/SOX2-positive stem/progenitor cell niches and their proportions by manipulating the turnover of growth hormone (GH)- and thyroid-stimulating hormone (TSH)-producing cells (GH and TSH cells, respectively), which are Pit1 lineage cells, as well as PRL cells. After induction, the isolated CD9/SOX2-positive cells from the IL-side MCL formed spheres and differentiated into GH and TSH cells. We also observed an increased GH cell proportion upon treatment with GH-releasing hormone and recovery from continuous stress and an increased TSH cell proportion upon propylthiouracil treatment, concomitant with alterations in the proportion of CD9/SOX2-positive cells in the primary and secondary niches. These findings suggest that CD9/SOX2-positive cells have the potential to supply GH and TSH when an increase in GH and TSH cell populations is required in the adult pituitary gland.

YB-1 Is a Novel Target for the Inhibition of α-Adrenergic-Induced Hypertrophy.

Cardiac hypertrophy resulting from sympathetic nervous system activation triggers the development of heart failure. The transcription factor Y-box binding protein 1 (YB-1) can interact with transcription factors involved in cardiac hypertrophy and may thereby interfere with the hypertrophy growth process. Therefore, the question arises as to whether YB-1 influences cardiomyocyte hypertrophy and might thereby influence the development of heart failure. YB-1 expression is downregulated in human heart biopsies of patients with ischemic cardiomyopathy (n = 8), leading to heart failure. To study the impact of reduced YB-1 in cardiac cells, we performed small interfering RNA (siRNA) experiments in H9C2 cells as well as in adult cardiomyocytes (CMs) of rats. The specificity of YB-1 siRNA was analyzed by a miRNA-like off-target prediction assay identifying potential genes. Testing three high-scoring genes by transfecting cardiac cells with YB-1 siRNA did not result in downregulation of these genes in contrast to YB-1, whose downregulation increased hypertrophic growth. Hypertrophic growth was mediated by PI3K under PE stimulation, as well by downregulation with YB-1 siRNA. On the other hand, overexpression of YB-1 in CMs, caused by infection with an adenovirus encoding YB-1 (AdYB-1), prevented hypertrophic growth under α-adrenergic stimulation with phenylephrine (PE), but not under stimulation with growth differentiation factor 15 (GDF15; n = 10-16). An adenovirus encoding the green fluorescent protein (AdGFP) served as the control. YB-1 overexpression enhanced the mRNA expression of the Gq inhibitor regulator of G-protein signaling 2 (RGS2) under PE stimulation (n = 6), potentially explaining its inhibitory effect on PE-induced hypertrophic growth. This study shows that YB-1 protects cardiomyocytes against PE-induced hypertrophic growth. Like in human end-stage heart failure, YB-1 downregulation may cause the heart to lose its protection against hypertrophic stimuli and progress to heart failure. Therefore, the transcription factor YB-1 is a pivotal signaling molecule, providing perspectives for therapeutic approaches.

[Y-box-binding protein 1 mediates sorafenib resistance via the extracellular signal regulated-protein kinase pathway in hepatoma cells].

Objective: To investigate the effect and possible mechanism of Y-box-binding protein 1 (YB-1) on sorafenib resistance in hepatoma cells. Methods: Lentiviral vectors with YB-1 overexpression and knockdown were constructed, respectively, to stimulate human hepatoma cell lines (HepG2 and Huh7) alone or in combination with sorafenib.The overexpression part of the experiment was divided into four groups: overexpression control group (Lv-NC), YB-1 overexpression group (Lv-YB-1), overexpression control combined with sorafenib resistance group (Lv-NC+sorafenib), YB-1 overexpression combined with sorafenib resistance group (Lv-YB-1 + sorafenib). The knockdown part of the experiment was also divided into four groups: knockdown control group (Lv-shNC), YB-1 knockdown group (Lv-shYB-1), knockdown control combined with sorafenib resistance group (Lv-shNC + sorafenib), YB-1 knockdown combined with sorafenib resistance group (Lv-shYB-1 + sorafenib). The occurrence of cell apoptosis was detected by TUNEL. The protein expression levels of phosphorylated (p)-ERK and ERK, key proteins in the extracellular regulatory protein kinase (ERK) signaling pathway, were detected by Western blot and quantified by ImageJ software. Subcutaneous tumorigenesis experiments were performed in nude mice. The effect of YB-1 on the efficacy of sorafenib was verified in vivo. The comparison between the two sets of data was carried out by an independent sample t-test. One-way ANOVA was used for comparisons between the three groups of data above. Results: Sorafenib had accelerated the occurrence of apoptosis in hepatoma cells, while YB-1 overexpression had inhibited cell apoptosis, and at the same time also inhibited the apoptosis-accelerating impact of sorafenib. On the contrary, YB-1 knockdown accelerated cell apoptosis and amplified the induction effect of sorafenib on apoptosis. Furthermore, sorafenib resistance had down-regulated p-ERK levels (HepG2: Lv-NC 0.685 ± 0.143, Lv-NC + sorafenib 0.315 ± 0.168, P < 0.05; Huh7: Lv-NC 0.576 ± 0.078, Lv-NC + sorafenib 0.150 ± 0.131, P < 0.01), whereas YB-1 overexpression had inhibited sorafenib resistance p-ERK reduction (HepG2: Lv-NC + sorafenib 0.315 ± 0.168, Lv-YB-1 + sorafenib 0.688 ± 0.042, P < 0.05; Huh7: Lv-NC + sorafenib 0.150 ± 0.131, Lv-YB-1 + sorafenib 0.553 ± 0.041, P < 0.05). YB-1 knockdown further increased sorafenib-induced p-ERK downregulation (HepG2: Lv-shNC + sorafenib 0.911 ± 0.252, Lv-shYB-1 + sorafenib 0.500 ± 0.201, P < 0.05; Huh7: Lv-shNC + sorafenib 0.577 ± 0.082, Lv-shYB-1 + sorafenib 0.350 ± 0.143, P < 0.05), which was further verified in naked mice (Lv-shNC + sorafenib 0.812 ± 0.279, Lv-shYB-1 + sorafenib 0.352 ± 0.109, P < 0.05). Conclusion: YB-1 mediates the occurrence of sorafenib resistance via the ERK signaling pathway in hepatoma cells.

[Research progress of SOX9 in the evolution of prostate cancer].

Sex-determining region Y-box transcription factor 9（SOX9）is essential for prostate development. The dysregulation of SOX9 not only affects the occurrence of Prostate cancer (PCa), but also plays a key role in castration-resistant prostate cancer (CRPC). However, the mechanism of SOX9 affecting the evolution of PCa is still unclear. This paper mainly reviews the molecular mechanism and signal pathway related to the occurrence and development of SOX9 and PCa. SOX9 gene may be an important new biomarker in the development of PCa,providing new ideas for clinical diagnosis and treatment.

N(6)-methyladenosine RNA methyltransferase like 3 inhibits extracellular matrix synthesis of endplate chondrocytes by downregulating sex-determining region Y-Box transcription factor 9 expression under tension.

OBJECTIVE: Tension stimulation is an important inducer of endplate cartilage degeneration, but the specific regulatory mechanism remains unclear. This study was the first to reveal the mechanism by which methyltransferase-like 3 (METTL3)-mediated N(6)-methyladenosine (m6A) modification affected the extracellular matrix anabolism by tension-induced endplate chondrocytes. METHOD: We examined the differences in METTL3 expression and m6A methylation levels in human endplate chondrocytes and human cartilage endplate tissues under in vitro tension. The effect on endplate cartilage degeneration was evaluated by manipulating m6A methylation mediated by METTL3 in vivo and in vitro. The effect of METTL3-mediated m6A methylation on the stability of sex-determining region Y-box transcription factor 9 (SOX9) gene expression was determined experimentally. RESULTS: METTL3 expression and m6A methylation levels were significantly increased in degenerative human endplate cartilage tissue. Similarly, tension stimulation inhibited the ability of human endplate chondrocytes to synthesize extracellular matrix, which was accompanied by an increase in METTL3-mediated m6A methylation. The ability of endplate chondrocytes to resist tension was significantly enhanced by inhibiting METTL3 expression and subsequently downregulating m6A methylation in vitro and in vivo, thereby reducing intervertebral disc degeneration. Furthermore, METTL3 mediated SOX9 RNA methylation and disrupted SOX9 mRNA stability, thereby inhibiting the gene expression of the downstream collagen type II alpha 1 chain. CONCLUSION: Tension stimulation downregulated SOX9 expression through METTL3-mediated m6A methylation, thereby inhibiting the synthesis of extracellular matrix in endplate chondrocytes.

Role of Y-Box Binding Proteins in Ontogenesis.

Y-box binding proteins (YB proteins) are multifunctional DNA/RNA-binding proteins capable of regulating gene expression at multiple levels. At present, the most studied function of these proteins is the regulation of protein synthesis. Special attention in this review has been paid to the role of YB proteins in the control of mRNA translation and stability at the earliest stages of organism formation, from fertilization to gastrulation. Furthermore, the functions of YB proteins in the formation of germ cells, in which they accumulate in large amounts, are summarized. The review then discusses the contribution of YB proteins to the regulation of gene expression during the differentiation of various types of somatic cells. Finally, future directions in the study of YB proteins and their role in ontogenesis are considered.

Role of YB-1 in Regulation of Poly(ADP-Ribosylation) Catalyzed by Poly(ADP-Ribose) Polymerases.

Poly(ADP-ribosyl)ation is a post-translational modification of proteins that performs an essential regulatory function in the cellular response to DNA damage. The key enzyme synthesizing poly(ADP-ribose) (PAR) in the cells is poly(ADP-ribose) polymerase 1 (PARP1). Understanding the mechanisms of the PARP1 activity regulation within the cells is necessary for development of the PARP1-targeted antitumor therapy. This review is devoted to the studies of the role of the RNA-binding protein YB-1 in the PARP1-catalyzed PARylation. The mechanisms of PARP1 activity stimulation by YB-1 protein can possibly be extended to other RNA-binding proteins involved in the maintenance of the genome stability.

MiR-133b regulates the proliferation, colony formation, and invasion of bladder cancer cells via inhibiting SOX4. / MiR-133b通过抑制SOX4è°ƒèŠ‚è†€èƒ±ç™Œç»†èƒžçš„å¢žæ®–ã€å ‹éš†å½¢æˆå’Œä¾µè¢­èƒ½åŠ›.

OBJECTIVES: Bladder cancer is one of the most common urothelial tumors with high incidence and mortality rates. Although it has been reported that microRNA (miR)-133b can regulate tumorigenesis of bladder cancer, the mechanism remains unclear. Sex-determining region Y-box transcription factor 4 (SOX4) exhibits an important role in tumorigenesis, but it is unclear whether SOX4 and miR-133b are associated with regulation of pathogenesis of bladder cancer. This study aims to determine the expressions of SOX4 and miR-133b in bladder cancer tissues and cells, investigate their effects on the proliferation, colony formation, and invasion of bladder cancer cells, and to explore the association between miR-133b and SOX4 in regulating biological featurss of bladder cancer cells. METHODS: The bladder cancer and adjacent tissue samples of 10 patients who underwent surgical resection in the Second Xiangya Hospital of Central South Universty from Januray to June 2015 were obtained. The levels of miR-133b were tested by real-time PCR, and the protein levels of SOX4 were evaluated using Western blotting in bladder cancer tissues, matched adjacent tissues, and cell lines. The correlation between miR-133b expression and SOX4 expression in bladder cancer tissues was analyzed. Using the online database TargetScan, the relationship between SOX4 and miR-133b was predicted. MiR-133b mimics, miR-133b inhibitor, and short hairpin RNA (shRNA)-SOX4 were transfected into T24 cells by Lipofectamine 2000. The relationship between miR-133b and SOX4 was also verified by a dual-luciferase reporter assay. The proliferation of T24 cells cultured for 0, 12, 48, 72, and 96 h was evaluated by cell counting kit-8 (CCK-8) assay. The colony formation capacity of bladder cancer cells was tested after 14-day culture, and cell invasion capacity was evaluated with Transwell invasion assay. RESULTS: Bladder cancer tissue and bladder cancer cells had low level of miR-133b but high level of SOX4, compared with matched adjacent tissues and normal bladder epithelial cells. A negative correlation between miR-133b mRNA and SOX4 protein levels in bladder cancer tissues was also found (r=-0.84). The results of online database TargetScan showed that miR-133b targets at SOX4, and overexpression of miR-133b significantly attenuated the expression of SOX4 in T24 cells. Both overexpression of miR-133b and knockdown of SOX4 significantly inhibited the proliferation, colony formation, and invasion capacity of bladder cancer cells in vitro. SOX4 down-regulation restored the effects of miR-133b inhibitor on the proliferation, colony formation, and invasion capacity of T24 cells. CONCLUSIONS: The up-regulation of SOX4 contributes to the progression of bladder cancer, and miR-133b can regulate the proliferation, colony formation, and invasion of bladder cancer cells via inhibiting SOX4.

The transcription factor PITX1 drives astrocyte differentiation by regulating the SOX9 gene.

Astrocytes perform multiple essential functions in the developing and mature brain, including regulation of synapse formation, control of neurotransmitter release and uptake, and maintenance of extracellular ion balance. As a result, astrocytes have been implicated in the progression of neurodegenerative disorders such as Alzheimer's disease, Huntington's disease, and Parkinson's disease. Despite these critical functions, the study of human astrocytes can be difficult because standard differentiation protocols are time-consuming and technically challenging, but a differentiation protocol recently developed in our laboratory enables the efficient derivation of astrocytes from human embryonic stem cells. We used this protocol along with microarrays, luciferase assays, electrophoretic mobility shift assays, and ChIP assays to explore the genes involved in astrocyte differentiation. We demonstrate that paired-like homeodomain transcription factor 1 (PITX1) is critical for astrocyte differentiation. PITX1 overexpression induced early differentiation of astrocytes, and its knockdown blocked astrocyte differentiation. PITX1 overexpression also increased and PITX1 knockdown decreased expression of sex-determining region Y box 9 (SOX9), known initiator of gliogenesis, during early astrocyte differentiation. Moreover, we determined that PITX1 activates the SOX9 promoter through a unique binding motif. Taken together, these findings indicate that PITX1 drives astrocyte differentiation by sustaining activation of the SOX9 promoter.

Depleting SOX2 improves ischemic stroke via lncRNA PVT1/microRNA-24-3p/STAT3 axis.

OBJECTIVES: Studies have widely explored in the filed of ischemic stroke (IS) with their focus on transcription factors. However, few studies have pivoted on sex determining region Y-box 2 (SOX2) in IS. Thus, this study is launched to figure out the mechanisms of SOX2 in IS. METHODS: Rat middle cerebral artery occlusion (MCAO) was established as a stroke model. MCAO rats were injected with depleted SOX2 or long non-coding RNA plasmacytoma variant translocation 1 (PVT1) to explore their roles in neurological deficits, cerebral water content, neuron survival, apoptosis and oxidative stress. The relationship among SOX2, PVT1, microRNA (miR)-24-3p and signal transducer and activator of transcription 3 (STAT3) was verified by a series of experiments. RESULTS: SOX2, PVT1 and STAT3 were highly expressed while miR-24-3p was poorly expressed in cerebral cortex tissues of MCAO rats. Depleted SOX2 or PVT1 alleviated brain injury in MCAO rats as reflected by neuronal apoptosis and oxidative stress restriction, brain water content reduction, and neurological deficit and neuron survival improvements. Overexpression of PVT1 functioned oppositely. Restored miR-24-3p abolished PVT1 overexpression-induced brain injury in MCAO rats. SOX2 directly promoted PVT1 expression and further increased STAT3 by sponging miR-24-3p. CONCLUSION: This study presents that depleting SOX2 improves IS via PVT1/miR-24-3p/STAT3 axis which may broaden our knowledge about the mechanisms of SOX2/PVT1/miR-24-3p/STAT3 axis and provide a reference of therapy for IS.