Sex Determining Region Y-box Research Articles

Longitudinal effects of ketamine on cell proliferation and death in the CNS of zebrafish

Zebrafish is known for its widespread neurogenesis and regenerative capacity, as well as several biological advantages, which turned it into a relevant animal model in several areas of research, namely in toxicological studies. Ketamine is a well-known anesthetic used both in human as well as veterinary medicine, due to its safety, short duration and unique mode of action. However, ketamine administration is associated with neurotoxic effects and neuronal death, which renders its use on pediatric medicine problematic. Thus, the evaluation of ketamine effects administration at early stages of neurogenesis is of pivotal importance. The 1‐41–4 somites stage of zebrafish embryo development corresponds to the beginning of segmentation and formation of neural tube. In this species, as well as in other vertebrates, longitudinal studies are scarce, and the evaluation of ketamine long-term effects in adults is poorly understood. This study aimed to assess the effects of ketamine administration at the 1–4 somites stage, both in subanesthetic and anesthetic concentrations, in brain cellular proliferation, pluripotency and death mechanisms in place during early and adult neurogenesis. For that purpose, embryos at the 1–4 somites stage (10.5 h post fertilization - hpf) were distributed into study groups and exposed for 20 min to ketamine concentrations at 0.2/0.8 mg/mL. Animals were grown until defined check points, namely 50 hpf, 144 hpf and 7 months adults. The assessment of the expression and distribution patterns of proliferating cell nuclear antigen (PCNA), of sex-determining region Y-box 2 (Sox 2), apoptosis-inducing factor (AIF) and microtubule-associated protein 1 light chain 3 (LC3) was performed by Western-blot and immunohistochemistry. The results evidenced the main alterations in 144 hpf larvae, namely in autophagy and in cellular proliferation at the highest concentration of ketamine (0.8 mg/mL). Nonetheless, in adults no significant alterations were seen, pointing to a return to a homeostatic stage. This study allowed clarifying some of the aspects pertaining the longitudinal effects of ketamine administration regarding the CNS capacity to proliferate and activate the appropriate cell death and repair mechanisms leading to homeostasis in zebrafish. Moreover, the results indicate that ketamine administration at 1–4 somites stage in the subanesthetic and anesthetic concentrations despite some transitory detrimental effects at 144 hpf, is long-term safe for CNS, which are newly and promising results in this research field.

SOX2 expression in prostate cancer drives resistance to nuclear hormone receptor signaling inhibition through the WEE1/CDK1 signaling axis

The development of androgen receptor signaling inhibitor (ARSI) drug resistance in prostate cancer (PC) remains therapeutically challenging. Our group has described the role of sex determining region Y-box 2 (SOX2) overexpression in ARSI-resistant PC. Continuing this work, we report that NR3C1, the gene encoding glucocorticoid receptor (GR), is a novel SOX2 target in PC, positively regulating its expression. Similar to ARSI treatment, SOX2-positive PC cells are insensitive to GR signaling inhibition using a GR modulating therapy. To understand SOX2-mediated nuclear hormone receptor signaling inhibitor (NHRSI) insensitivity, we performed RNA-seq in SOX2-positive and -negative PC cells following NHRSI treatment. RNA-seq prioritized differentially regulated genes mediating the cell cycle, including G2 checkpoint WEE1 Kinase (WEE1) and cyclin-dependent kinase 1 (CDK1). Additionally, WEE1 and CDK1 were differentially expressed in PC patient tumors dichotomized by high vs low SOX2 gene expression. Importantly, pharmacological targeting of WEE1 (WEE1i) in combination with an ARSI or GR modulator re-sensitizes SOX2-positive PC cells to nuclear hormone receptor signaling inhibition in vitro, and WEE1i combined with ARSI significantly slowed tumor growth in vivo. Collectively, our data suggest SOX2 predicts NHRSI resistance, and simultaneously indicates the addition of WEE1i to improve therapeutic efficacy of NHRSIs in SOX2-positive PC.

Characterization of Schistosome Sox Genes and Identification of a Flatworm Class of Sox Regulators.

Schistosome helminths infect over 200 million people across 78 countries and are responsible for nearly 300,000 deaths annually. However, our understanding of basic genetic pathways crucial for schistosome development is limited. The sex determining region Y-box 2 (Sox2) protein is a Sox B type transcriptional activator that is expressed prior to blastulation in mammals and is necessary for embryogenesis. Sox expression is associated with pluripotency and stem cells, neuronal differentiation, gut development, and cancer. Schistosomes express a Sox-like gene expressed in the schistosomula after infecting a mammalian host when schistosomes have about 900 cells. Here, we characterized and named this Sox-like gene SmSOXS1. SmSoxS1 protein is a developmentally regulated activator that localizes to the anterior and posterior ends of the schistosomula and binds to Sox-specific DNA elements. In addition to SmSoxS1, we have also identified an additional six Sox genes in schistosomes, two Sox B, one SoxC, and three Sox genes that may establish a flatworm-specific class of Sox genes with planarians. These data identify novel Sox genes in schistosomes to expand the potential functional roles for Sox2 and may provide interesting insights into early multicellular development of flatworms.

Reprogramming efficiency and pluripotency of mule iPSCs over its parents†.

The mule is the interspecific hybrid of horse and donkey and has hybrid vigour in muscular endurance, disease resistance and longevity over its parents. Here, we examined adult fibroblasts of mule (MAFs) compared with the cells from their parents (DAFs and HAFs) (each species have repeated three independent individuals) in proliferation, apoptosis and glycolysis and found significant differences. We subsequently derived mule, donkey and horse induced pluripotent stem cells (miPSCs, diPSCs and hiPSCs) from three independent individuals of each species and found the reprogramming efficiency of MAFs were significantly higher than that of cells of donkey and horse. miPSCs, diPSCs and hiPSCs all expressed high levels of crucial endogenous pluripotency genes such as POU class 5 homeobox 1 (POU5F1, OCT4), SRY-box 2 (SOX2) and Nanog homeobox (NANOG) and propagated robustly in single cell passaging. miPSCs exhibited faster proliferation and higher pluripotency and differentiation than diPSCs and hiPSCs, which were reflected in co-cultures and separate-cultures, teratoma formation and chimera contribution. The establishment of miPSCs provide unique research material for investigation of "heterosis" and perhaps is more significant to study hybrid gamete formation.

SOX1 Functions as a Tumor Suppressor by Repressing HES1 in Lung Cancer.

The development of lung cancer is a complex process that involves many genetic and epigenetic changes. Sex-determining region Y (SRY)-box (SOX) genes encode a family of proteins that are involved in the regulation of embryonic development and cell fate determination. SOX1 is hypermethylated in human cancers. However, the role of SOX1 in the development of lung cancer is unclear. We used quantitative methylation-specific polymerase chain reaction (MSP), quantitative reverse transcription polymerase chain reaction (RT-PCR) analysis, and web tools to confirm the frequent epigenetic silencing of SOX1 in lung cancer. Stable overexpression of SOX1 repressed cell proliferation, anchorage-independent growth, and invasion in vitro as well as cancer growth and metastasis in a xenograft mouse model. Knockdown of SOX1 by the withdrawal of doxycycline partly restored the malignant phenotype of inducible SOX1-expressing NSCLC cells. Next, we discovered the potential downstream pathways of SOX1 using RNA-seq analysis and identified HES1 as a direct target of SOX1 using chromatin immunoprecipitation (ChIP)-PCR. Furthermore, we performed phenotypic rescue experiments to prove that overexpression of HES1-FLAG in SOX1-expressing H1299 cells partly reversed the tumor-suppressive effect. Taken together, these data demonstrated that SOX1 acts as a tumor suppressor by directly inhibiting HES1 during the development of NSCLC.

ASO silencing of a glycosyltransferase, Poglut1 , improves the liver phenotypes in mouse models of Alagille syndrome.

Paucity of intrahepatic bile ducts (BDs) is caused by various etiologies and often leads to cholestatic liver disease. For example, in patients with Alagille syndrome (ALGS), which is a genetic disease primarily caused by mutations in jagged 1 ( JAG1) , BD paucity often results in severe cholestasis and liver damage. However, no mechanism-based therapy exists to restore the biliary system in ALGS or other diseases associated with BD paucity. Based on previous genetic observations, we investigated whether postnatal knockdown of the glycosyltransferase gene protein O -glucosyltransferase 1 ( Poglut1) can improve the ALGS liver phenotypes in several mouse models generated by removing one copy of Jag1 in the germline with or without reducing the gene dosage of sex-determining region Y-box 9 in the liver. Using an ASO established in this study, we show that reducing Poglut1 levels in postnatal livers of ALGS mouse models with moderate to profound biliary abnormalities can significantly improve BD development and biliary tree formation. Importantly, ASO injections prevent liver damage in these models without adverse effects. Furthermore, ASO-mediated Poglut1 knockdown improves biliary tree formation in a different mouse model with no Jag1 mutations. Cell-based signaling assays indicate that reducing POGLUT1 levels or mutating POGLUT1 modification sites on JAG1 increases JAG1 protein level and JAG1-mediated signaling, suggesting a likely mechanism for the observed in vivo rescue. Our preclinical studies establish ASO-mediated POGLUT1 knockdown as a potential therapeutic strategy for ALGS liver disease and possibly other diseases associated with BD paucity.

Noninvasive Assessment of Renal Fibrosis of Chronic Kidney Disease in Rats by [68Ga]Ga-FAPI-04 Small Animal PET/CT and Biomarkers

Renal fibrosis is the most common pathological feature and common pathway of progression in chronic kidney disease (CKD). We evaluated [68Ga]Ga-FAPI-04 small animal positron emission tomography/computed tomography (PET/CT) and biomarkers as noninvasive assessments of renal fibrosis (RF) in CKD rats to generate new ideas for clinical diagnosis. A rat model of renal fibrosis was administered adenine by gavage (n = 28), and the control group was given 0.9% NaCl by gavage (n = 20). At different time points (weeks 1, 2, 4, and 6), five rats were randomly selected from the two groups for [68Ga]Ga-FAPI-04 small animal PET/CT imaging. At the same time, the expression of Fibroblast activation protein (FAP) in renal tissue and the expression levels of type III procollagen N-terminal peptide (PIIINP), transforming growth factor (TGF-β1), Klotho, and sex-determining region Y-box protein 9 (SOX9) in blood and urine were determined. FAP was highly expressed in the renal tissue of rats in the CKD group and expression increased with the progression of renal fibrosis. [68Ga]Ga-FAPI-04 small animal PET/CT examination showed that the uptake of radioactive tracers in the CKD group was higher than that in the control group, and SUVmax (r = 0.9405) and target-to-background ratio (TBR) (r = 0.9392) were positively correlated with renal fibrosis. The serum levels of PIIINP, TGF-β1, and SOX9 in CKD rats were significantly higher than those in the control group and were positively correlated with RF (r = 0.8234, r = 0.7733, and r = 0.7135, respectively) and SUVmax (r = 0.8412, r = 0.7763, and r = 0.6814, respectively). Compared with the control group, the level of serum Klotho decreased and was negatively correlated with RF (r = -0.6925) and SUVmax (r = -0.6322). Compared with the control group, the levels of PIIINP and TGF-β1 in urine were positively correlated with RF (r = 0.8127 and r = 0.8077, respectively) and SUVmax (r = 0.8400 and r = 0.8177, respectively). Urine Klotho decreased compared with the control group and was negatively correlated with RF (r = -0.5919) and SUVmax (r = -0.5995). The change in urine SOX9 was not statistically significant. In conclusion, compared with renal biopsy, [68Ga]Ga-FAPI-04 small animal PET/CT shows renal fibrosis quickly and noninvasively. PIIINP, TGF-β1, and Klotho in serum and urine may be used as biomarkers of RF, and serum SOX9 is expected to become a new diagnostic biomarker of RF.

Establishment of neural stem cells from fetal monkey brain for neurotoxicity testing.

Neurotoxicity assessments are generally performed using laboratory animals. However, as in vitro neurotoxicity models are continuously refined to reach adequate predicative concordance with in vivo responses, they are increasingly used for some endpoints of neurotoxicity. In this study, gestational day 80 fetal rhesus monkey brain tissue was obtained for neural stem cells (NSCs) isolation. Cells from the entire hippocampus were harvested, mechanically dissociated, and cultured for proliferation and differentiation. Immunocytochemical staining and biological assays demonstrated that the harvested hippocampal cells exhibited typical NSC phenotypes in vitro: (1) cells proliferated vigorously and expressed NSC markers nestin and sex-determining region Y-box 2 (SOX2) and (2) cells differentiated into neurons, astrocytes, and oligodendrocytes, as confirmed by positive staining with class III β-tubulin, glial fibrillary acidic protein, and galactocerebroside, respectively. The NSC produced detectable responses following neurotoxicant exposures (e.g. trimethyltin and 3-nitropropionic acid). Our results indicated that non-human primate NSCs may be a practical tool to study the biology of neural cells and to evaluate the neurotoxicity of chemicals in vitro, thereby providing data that are translatable to humans and may also reduce the number of animals needed for developmental neurotoxicological studies.

Clinicopathological Significance of Cancer Stem Cell Markers (OCT-3/4 and SOX-2) in Oral Submucous Fibrosis and Oral Squamous Cell Carcinoma

Oral submucous fibrosis (OSMF) is highly prevalent in South East Asia with higher rates of malignant transformation in Indian subcontinent. Numerous biomarkers are now being studied to predict disease prognosis and detect malignant alterations at an early stage. Patients with clinically and biopsy-proven oral submucous fibrosis and oral squamous cell carcinoma were included in the study as the experimental group, while patients without a tobacco or betel nut habit who had their third molars surgically removed were included as the healthy control group. For the immunohistochemistry (IHC) investigation, 5-μm slices from formalin-fixed, paraffin-embedded tissue blocks (FFPE) were obtained. Fresh tissues (n = 45) from all three groups were collected and gene expression was studied using relative quantitation-based qPCR. The protein expression of octamer-binding transcription factor 3/4 (OCT 3/4) and sex-determining region Y-box 2 (SOX 2) was evaluated in the experimental group and compared with healthy controls. The IHC results showed a significant correlation with the expression of OCT 3/4 (p value = 0.000; χ2 = 20.244) and SOX 2 (p value = 0.006; χ2 = 10.101) among OSCC and OSMF patients in comparison to healthy controls. Both OCT 3/4 and SOX 2 showed overexpression of four-fold and three-fold in OSMF when compared to OSCC and healthy controls, respectively. This study shows the significant importance of cancer stem cell markers OCT 3/4 and SOX 2 to assess the disease prognosis in OSMF.

Photocrosslinkable, Injectable Locust Bean Gum Hydrogel Induces Chondrogenic Differentiation of Stem Cells for Cartilage Regeneration.

Due to the limited therapeutic efficacy of current treatments, articular cartilage regeneration is still challenging work. Scaffold-based tissue engineering provides a promising strategy for cartilage regeneration, but most scaffolds are limited by poor mechanical properties or unfavorable biocompatibility. Here, a novel photocrosslinkable, injectable locust bean gum (LBG)-methacrylate (MA) hydrogel is reported as a biomimetic extracellular matrix (ECM) for cartilage repair with minimal invasive operation. LBG-MA hydrogels show controllable degradation rate and improve mechanical properties and excellent biocompatibility. More importantly, LBG-MA hydrogel significantly induces bone mesenchymal stem cells to chondrogenic differentiation in vitro, as evidenced by high accumulation of cartilage-specific ECM components glycosaminoglycan and upregulated expression of key chondrogenic genes (collagen type II, aggrecan, and sex determining region Y-box9). Besides, the hydrogel is injectable, which can be in situ crosslinked via UV irradiation. Further, the photocrosslinkable hydrogels accelerate cartilage healing in vivo after 8 weeks of therapy. A strategy is provided here for photocrosslinkable, injectable, biodegradable scaffold fabrication based on native polysaccharide polymer for minimal invasive cartilage repair.

The Adipokine Visfatin Modulates Cancer Stem Cell Properties in Triple-Negative Breast Cancer

Obesity is a cancer progression risk factor; excessive adipocytes increase adipokine secretion. Visfatin, a novel adipokine highly expressed in cancer patients, is related to breast cancer risk. The modulation of nicotinamide adenine dinucleotide (NAD+) metabolism and the induction of a tumorigenic environment plays a vital role in cancer progression. Among cancer cell types, cancer stem-like cells (CSCs) with self-renewal and chemotherapy-resistance abilities could modulate tumor progression and cancer recurrence ability. In this study, we focused on visfatin's modulation effect on stemness-related properties using the high-malignancy breast cancer cell line MDA-MB-231 in in vitro and in vivo studies. Visfatin treatment significantly increased both the sphere number and sphere diameter and increased the protein expression of NANOG homeobox (NANOG), sex-determining region Y-box 2 (SOX2), and octamer-binding transcription factor 4 (OCT4), as well as SIRT1 protein levels. The serum angiogenesis marker VEGF and extracellular nicotinamide phosphoribosyl transferase (NAMPT, visfatin) were induced after visfatin treatment, increasing the stemness and angiogenesis environment, which were significantly reduced by the visfatin inhibitor FK866. Our results demonstrate that the visfatin-activated SIRT-SOX2 axis promotes triple-negative breast cancer stemness and enriches the tumorigenic microenvironment.

Expression and Clinical Significance of Ki67 and SOX2 in Colorectal Cancer.

The purpose of the paper is to explore the expression levels and clinical significance of Ki67 and sex-determining region Y-box 2 (SOX2) in colorectal cancer. From January 2013 to December 2016, 176 patients with colorectal cancer who were pathologically diagnosed after surgery in the Department of General Surgery in Xiamen Chinese Medical Hospital are included in this study. The pathological parameters, including gender, age, pathological stage, depth of tumor invasion, lymph node metastasis, and distant metastasis, are recorded. Immunohistochemistry is used to detect the correlation between Ki67 and Sox2 protein expression and clinicopathological parameters in colorectal cancer. Immunohistochemistry shows that in each stage of colorectal cancer, the positive rate of SOX2 is higher than that of Ki67, and the sensitivity of SOX2 is relatively high. Moreover, the levels of Ki67 and SOX2 in the cancerous tissues are not related to gender, age, lymph node metastasis and distant metastasis (p > 0.05).

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.

Biocomposites composed of cartilage and natural rubber latex

We have successfully fabricated the cartilage/natural rubber latex (NRL) biocomposites via human mesenchymal stem cells (hMSCs) spheroid under hypoxic condition. It was revealed that NRL nanoparticles acted as the main component, providing surface heterogeneity for the spheroids and resulting in a mechanically stable structure with a modulus two times higher compared to controls. The formation of the cartilage/NRL nanoparticles biocomposite results in having a stiff property was demonstrated. The gene expression levels of SRY-box 9 (SOX9), aggrecan and type II collagen (Col-II), and formation of glycosaminoglycan’s were higher in spheroids under hypoxic conditions, and administration of NRL nanoparticles enhanced chondrogenic differentiation is successfully induced. The promise of NRL nanoparticles for well-controlled chondrogenic differentiation and mechanically stable cartilage tissue was demonstrated.

Type IV Collagen and SOX9 Are Molecular Targets of BET Inhibition in Experimental Glomerulosclerosis.

Progressive glomerulonephritis (GN) is characterized by an excessive accumulation of extracellular (ECM) proteins, mainly type IV collagen (COLIV), in the glomerulus leading to glomerulosclerosis. The current therapeutic approach to GN is suboptimal. Epigenetic drugs could be novel therapeutic options for human disease. Among these drugs, bromodomain and extra-terminal domain (BET) inhibitors (iBETs) have shown beneficial effects in experimental kidney disease and fibrotic disorders. Sex-determining region Y-box 9 (SOX9) is a transcription factor involved in regulating proliferation, migration, and regeneration, but its role in kidney fibrosis is still unclear. We investigated whether iBETs could regulate ECM accumulation in experimental GN and evaluated the role of SOX9 in this process. For this purpose, we tested the iBET JQ1 in mice with anti-glomerular basement membrane nephritis induced by nephrotoxic serum (NTS). In NTS-injected mice, JQ1 treatment reduced glomerular ECM deposition, mainly by inhibiting glomerular COLIV accumulation and Col4a3 gene overexpression. Moreover, chromatin immunoprecipitation assays demonstrated that JQ1 inhibited the recruitment and binding of BRD4 to the Col4a3 promoter and reduced its transcription. Active SOX9 was found in the nuclei of glomerular cells of NTS-injured kidneys, mainly in COLIV-stained regions. JQ1 treatment blocked SOX9 nuclear translocation in injured kidneys. Moreover, in vitro JQ1 blocked TGF-β1-induced SOX9 activation and ECM production in cultured mesangial cells. Additionally, SOX9 gene silencing inhibited ECM production, including COLIV production. Our results demonstrated that JQ1 inhibited SOX9/COLIV, to reduce experimental glomerulosclerosis, supporting further research of iBET as a potential therapeutic option in progressive glomerulosclerosis.

SENP1 induced protein deSUMO modification increased the chemotherapy sensitivity of endometrial cancer side population cells

Objective: To inhibit the stemness maintenance potential of endometrial cancer and increase the sensitivity of endometrial cancer side population cells to chemotherapy drugs by inducing extensive deSUMOylation modification of proteins. Methods: Flow cytometry was used to sort and culture CD133(+) CD44(+) KLE endometrial cancer cell clone spheres. Protein expression level of small ubiquitin-related modifier 1 (SUMO1) and two stemness maintenance genes of tumor side population cells, octamer binding transcription factor-4 (Oct4) and sex determining region Y-box2 (Sox2), were detected by western blotting method. Lentivirus-mediated Sentrin/SUMO-specific proteases 1 (SENP1) gene was stably transfected into KLE side population cells. Western blotting was used to detect the protein expressions of SENP1, SUMO1, Oct4 and Sox2. The clone formation rate was compared between KLE side population cells with or without SENP1 overexpression. Flow cytometry was applied to detect cell cycle changes. 3-(4, 5-Dimethylthiazole-2)-2, 5-diphenyl-tetrazolium bromide (MTT) experiment and flow cytometry apoptosis method were used to detect the chemosensitivity of the side population of endometrial cancer cells to cisplatin. Tumor-bearing mouse models of endometrial cancer were established to detect the effect of SENP1 overexpression on the chemotherapy sensitivity of cisplatin. Results: Compared with CD133(-)CD44(-) KLE cells, CD133(+) CD44(+) KLE side population cells could form clonal spheres and express higher levels of SUMO1, Oct4 and Sox2 proteins (P<0.05). Compared with KLE side population cells that were not transfected with SENP1 gene, the expression level of SENP1 protein in KLE side population cells overexpressing SUMO1、Oct4 and Sox2 were lower. The clonal sphere formation rate was reduced from (25.67±5.44)% to (7.46±1.42)%, and cell cycle shifted from G(0)/G(1) phase to G(2) phase. IC(50) of cisplatin decreased from (55.46±6.14) μg/ml to (11.55±3.12) μg/ml, and cell apoptosis rate increased from (9.76±2.09)% to (16.79±3.44)%. Overexpression of SENP1 could reduce the tumorigenesis rate of KLE side population cells in vivo and increase their chemotherapy sensitivity to cisplatin (P<0.05). Conclusion: Overexpression of SENP1 can induce protein deSUMOylation modification, inhibit the stemness maintenance potential of endometrial cancer side population cells, and enhance their chemotherapy sensitivity, which provides a new reference for gene therapy of endometrial cancer.

Loss of SOX18/CLAUDIN5 disrupts the pulmonary endothelial barrier in ventilator-induced lung injury.

Mechanical strain contributes to ventilator-induced lung injury (VILI) through multi-factorial and complex mechanisms that remain unresolved. Prevailing evidence suggests that the loss of pulmonary endothelial tight junctions (TJs) plays a critical role. TJs are dynamically regulated by physiologic and hemodynamic forces to stabilize the endothelial barrier. The transcription factor sex-determining region Y-box (SOX)-18 is important in regulating blood vessel development and vascular permeability through its ability to regulate the transcription of Claudin-5, an endothelial TJ protein. Previously, we demonstrated that SOX18 expression is increased by shear stress in the pulmonary endothelium. Therefore, in this study, we investigated how mechanical strain mediated through cyclic stretch affects the SOX18/Claudin-5 regulatory axis. Our data demonstrate that SOX18 and Claudin-5 are downregulated in human lung microvascular endothelial cells (HLMVEC) exposed to cyclic stretch and the mouse lung exposed to high tidal mechanical ventilation. Overexpression of SOX18 reduced the loss of Claudin-5 expression in HLMVEC with cyclic stretch and preserved endothelial barrier function. Additionally, overexpression of Claudin-5 in HLMVEC ameliorated barrier dysfunction in HLMVEC exposed to cyclic stretch, although SOX18 expression was not enhanced. Finally, we found that the targeted overexpression of SOX18 in the pulmonary vasculature preserved Claudin-5 expression in the lungs of mice exposed to HTV. This, in turn reduced lung vascular leak, attenuated inflammatory lung injury, and preserved lung function. Together, these data suggest that enhancing SOX18 expression may prove a useful therapy to treat patients with ventilator-induced lung injury.

An Injectable Enzymatically Crosslinked and Mechanically Tunable Silk Fibroin/Chondroitin Sulfate Chondro‐Inductive Hydrogel

AbstractAn injectable hybrid hydrogel is synthesized, comprising silk fibroin (SF) and chondroitin sulfate (CS) through di‐tyrosine formation bond of SF chains. CS and SF are reported with excellent biocompatibility as tissue engineering scaffolds. Nonetheless, the rapid degradation rate of pure CS scaffolds presents a challenge to effectively recreate articular cartilage. As CS is one of the cartilage extracellular matrix (ECM) components, it has the potential to enhance the biological activity of SF‐based hydrogel in terms of cartilage repair. Therefore, altering the CS concentrations (i.e., 0 wt%, 0.25 wt%, 0.5 wt%, 1 wt%, and 2 wt%), which are interpenetrated between SF β‐sheets and chains, can potentially adjust the physical, chemical, and mechanical features of these hybrid hydrogels. The formation of β‐sheets by 30 days of immersion in de‐ionized (DI) water can improve the compression strength of the SF/CS hybrid hydrogels in comparison with the same SF/CS hybrid hydrogels in the dried state. Biological investigation and observation depicts proper cell attachment, proliferation and cell viability for C28/I2 cells. Gene expression of sex‐determining region YBox 9 (SOX9), Collagen II α1, and Aggrecan (AGG) exhibits positive C3H10T1/2 growth and expression of cartilage‐specific genes in the 0.25 wt% and 0.5 wt% SF/CS hydrogels.

Diesel exhaust particles inhibit lung branching morphogenesis via the YAP/TAZ pathway

Prenatal exposure to air pollution may associated with inhibition of lung development in the child, however the possible mechanism is unclear. We investigated the effects of traffic-related diesel exhaust particle (DEP) exposure on fetal lung branching morphogenesis and elucidate the possible mechanism. Ex vivo fetal lungs collected from ICR mice at an age of 11.5 embryonic (E) days were exposed to DEPs at 0 (control), 10, and 50 μg/mL and branching morphogenesis was measured for 3 days. Normal IMR-90 human fetal lung fibroblast cells were exposed to DEPs at 0 (control), 10, and 50 μg/mL for 24 h. We observed that DEP exposure significantly inhibited lung branching morphogenesis with reduced lung branching ratios and surface areas on day 3. RNA sequencing (RNA-Seq) showed that DEP increased the inflammatory response and impaired lung development-related gene expressions. DEPs significantly decreased Yes-associated protein (YAP), phosphorylated (p)-YAP, transcriptional coactivator with a PDZ-binding motif (TAZ), and p-TAZ in IMR-90 cells at 10 and 50 μg/mL. Treatment of fetal lungs with the YAP inhibitor, PFI-2, also demonstrated restricted lung branching development similar to that of DEP exposure, with a significantly decreased lung branching ratio on day 3. DEP exposure significantly decreased the lung branching modulators fibroblast growth factor receptor 2 (FGFR2), sex-determining region Y-box 2 (SOX2), and SOX9 in IMR-90 cells at 10 and 50 μg/mL. Fetal lung immunofluorescence staining showed that DEP decreased SOX2 expression in fibronectin+ fibroblasts. DEP exposure decreased the cellular senescence regulator, p-sirtuin 1 (SIRT1)/SIRT1 in IMR-90 cells, with RNA-Seq showing impaired telomere maintenance. DEP exposure impaired fetal lung growth during the pseudoglandular stage through dysregulating the Hippo signaling pathway, causing fibroblast lung branching restriction and early senescence. Prenatal exposure to traffic-related air pollution has adverse effects on fetal lung development.

The injury-induced transcription factor SOX9 alters the expression of LBR, HMGA2, and HIPK3 in the human kidney.

Induction of SRY box transcription factor 9 (SOX9) has been shown to occur in response to kidney injury in rodents, where SOX9-positive cells proliferate and regenerate the proximal tubules of injured kidneys. Additionally, SOX9-positive cells demonstrate a capacity to differentiate toward other nephron segments. Here, we characterized the role of SOX9 in normal and injured human kidneys. SOX9 expression was found to colocalize with a proportion of so-called scattered tubular cells in the uninjured kidney, a cell population previously shown to be involved in kidney injury and regeneration. Following injury and in areas adjacent to inflammatory cell infiltrates, SOX9-positive cells were increased in number. With the use of primary tubular epithelial cells (PTECs) obtained from human kidney tissue, SOX9 expression was spontaneously induced in culture and further increased by transforming growth factor-β1, whereas it was suppressed by interferon-γ. siRNA-mediated knockdown of SOX9 in PTECs followed by analysis of differential gene expression, immunohistochemical expression, and luciferase promoter assays suggested lamin B receptor (LBR), high mobility group AT-hook 2 (HMGA2), and homeodomain interacting protein kinase 3 (HIPK3) as possible target genes of SOX9. Moreover, a kidney explant model was used to demonstrate that only SOX9-positive cells survive the massive injury associated with kidney ischemia and that the surviving SOX9-positive cells spread and repopulate the tubules. Using a wound healing assay, we also showed that SOX9 positively regulated the migratory capacity of PTECs. These findings shed light on the functional and regulatory aspects of SOX9 activation in the human kidney during injury and regeneration.NEW & NOTEWORTHY Recent studies using murine models have shown that SRY box transcription factor 9 (SOX9) is activated during repair of renal tubular cells. In this study, we showed that SOX9-positive cells represent a proportion of scattered tubular cells found in the uninjured human kidney. Furthermore, we suggest that expression of LBR, HMGA2, and HIPK3 is altered by SOX9 in the kidney tubular epithelium, suggesting the involvement of these gene products in kidney injury and regeneration.