Unraveling the causal genes and transcriptomic determinants of human telomere length.

Telomere length (TL) shortening is a pivotal indicator of biological aging and is associated with many human diseases. The genetic determinates of human TL have been widely investigated, however, most existing studies were conducted based on adult tissues which are heavily influenced by lifetime exposure. Based on the analyses of terminal restriction fragment (TRF) length of telomere, individual genotypes, and gene expressions on 166 healthy placental tissues, we systematically interrogate TL-modulated genes and their potential functions. We discover that the TL in the placenta is comparatively longer than in other adult tissues, but exhibiting an intra-tissue homogeneity. Trans-ancestral TL genome-wide association studies (GWASs) on 644,553 individuals identify 20 newly discovered genetic associations and provide increased polygenic determination of human TL. Next, we integrate the powerful TL GWAS with placental expression quantitative trait locus (eQTL) mapping to prioritize 23 likely causal genes, among which 4 are functionally validated, including MMUT, RRM1, KIAA1429, and YWHAZ. Finally, modeling transcriptomic signatures and TRF-based TL improve the prediction performance of human TL. This study deepens our understanding of causal genes and transcriptomic determinants of human TL, promoting the mechanistic research on fine-grained TL regulation.

YAP-mediated trophoblast dysfunction: the common pathway underlying pregnancy complications.

Yes-associated protein (YAP) is a pivotal regulator in cellular proliferation, survival, differentiation, and migration, with significant roles in embryonic development, tissue repair, and tumorigenesis. At the maternal-fetal interface, emerging evidence underscores the importance of precisely regulated YAP activity in ensuring successful pregnancy initiation and progression. However, despite the established association between YAP dysregulation and adverse pregnancy outcomes, insights into the impact of aberrant YAP levels in fetal-derived, particularly trophoblast cells, and the ensuing dysfunction at the maternal-fetal interface remain limited. This review comprehensively examines YAP expression and its regulatory mechanisms in trophoblast cells throughout pregnancy. We emphasize its integral role in placental development and maternal-fetal interactions and delve into the correlations between YAP dysregulation and pregnancy complications. A nuanced understanding of YAP's functions during pregnancy could illuminate intricate molecular mechanisms and pave the way for innovative prevention and treatment strategies for pregnancy complications. Video Abstract.

The role of neutrophils in chorioamnionitis.

Chorioamnionitis, commonly referred to as intrauterine infection or inflammation, is pathologically defined by neutrophil infiltration and inflammation at the maternal-fetal interface. Chorioamnionitis is the common complication during late pregnancy, which lead to a series of serious consequences, such as preterm labor, preterm premature rupture of the fetal membranes, and fetal inflammatory response syndrome. During infection, a large number of neutrophils migrate to the chorio-decidua in response to chemokines. Although neutrophils, a crucial part of innate immune cells, have strong anti-inflammatory properties, over-activating them can harm the body while also eliminating pathogens. This review concentrated on the latest studies on chorioamnionitis-related consequences as well as the function and malfunction of neutrophils. The release of neutrophil extracellular traps, production of reactive oxygen species, and degranulation from neutrophils during intrauterine infection, as well as their pathological roles in complications related to chorioamnionitis, were discussed in detail, offering fresh perspectives on the treatment of chorioamnionitis.

M2 Macrophage-Derived sEV Regulate Pro-Inflammatory CCR2+ Macrophage Subpopulations to Favor Post-AMI Cardiac Repair.

Tissue-resident cardiac macrophage subsets mediate cardiac tissue inflammation and repair after acute myocardial infarction (AMI). CC chemokine receptor 2 (CCR2)-expressing macrophages have phenotypical similarities to M1-polarized macrophages, are pro-inflammatory, and recruit CCR2+ circulating monocytes to infarcted myocardium. Small extracellular vesicles (sEV) from CCR2̶ macrophages, which phenotypically resemble M2-polarized macrophages, promote anti-inflammatory activity and cardiac repair. Here, the authors harvested M2 macrophage-derived sEV (M2EV ) from M2-polarized bone-marrow-derived macrophages for intramyocardial injection and recapitulation of sEV-mediated anti-inflammatory activity in ischemic-reperfusion (I/R) injured hearts. Rats and pigs received sham surgery; I/R without treatment; or I/R with autologous M2EV treatment. M2EV rescued cardiac function and attenuated injury markers, infarct size, and scar size. M2EV inhibited CCR2+ macrophage numbers, reduced monocyte-derived CCR2+ macrophage recruitment to infarct sites, induced M1-to-M2 macrophage switching and promoted neovascularization. Analysis of M2EV microRNA content revealed abundant miR-181b-5p, which regulated macrophage glucose uptake, glycolysis, and mitigated mitochondrial reactive oxygen species generation. Functional blockade of miR-181b-5p is detrimental to beneficial M2EV actions and resulted in failure to inhibit CCR2+ macrophage numbers and infarct size. Taken together, this investigation showed that M2EV rescued myocardial function, improved myocardial repair, and regulated CCR2+ macrophages via miR-181b-5p-dependent mechanisms, indicating an option for cell-free therapy for AMI.

Serum estradiol to testosterone ratio as a novel predictor of severe preeclampsia in the first trimester.

Preeclampsia (PE) is the most common medical complication during pregnancy and the second leading cause of maternal death worldwide. However, a better predictive model of PE remains to be explored. A total of 15 severe preeclampsia (sPE) and 75 healthy control patients were included in this study. Patient data was obtained from September 2019 to September 2021. Nuchal translucency (NT) and crown-rump length (CRL) of the fetus were acquired by ultrasound. Maternal blood samples were collected at 11+0 to 13+6  weeks of gestation. Chemiluminescent immunoassays were used to detect serum testosterone (T) and estradiol (E2) levels. Time-resolved fluorescence analysis was used to examine the levels of serum pregnancy-associated plasma protein A (PAPPA) and ß-human chorionic gonadotrophin (ß-HCG) protein. The sPE group exhibited increased T levels, and decreased E2 levels and E2/T ratios from 11 to 14 weeks of gestation, compared with the control group. E2 and the E2/T ratio showed positive linear correlation with CRL in pregnant women. Body-mass-index (BMI), T, and E2 were determined to be the main factors that affected the occurrence of sPE at the 12-week gestation period time point. The receiver operating characteristic (ROC) curve revealed that the AUC of the E2/T ratio was .717. The imbalanced T and E2 levels in the patients had a specific intrinsic relevance with sPE, which suggests them as novel predictors of the sPE.

The ERα-NRF2 signalling axis promotes bicalutamide resistance in prostate cancer.

BACKGROUND: Bicalutamide is a nonsteroidal antiandrogen widely used as a first-line clinical treatment for advanced prostate cancer (PCa). Although patients initially show effective responses to bicalutamide treatment, resistance to bicalutamide frequently occurs and leads to the development of castration-resistant PCa (CRPC). This research investigated the roles of the oestrogen receptor α (ERα)-nuclear factor E2-related factor 2 (NRF2) signalling pathway in bicalutamide resistance in PCa cells. METHODS: We performed bioinformatic analysis and immunohistochemical staining on normal and cancerous prostate tissue to evaluate ERα and NRF2 expression and their correlation. Gene expression and localization in PCa cell lines were further investigated using real-time reverse transcription PCR/Western blotting and immunofluorescence staining. We treated PCa cells with the ER inhibitor tamoxifen and performed luciferase reporter assays and chromatin immunoprecipitation (ChIP) assays to understand ERα-dependent NRF2 expression. Overexpression and knockdown of ERα and NRF2 were used to explore the potential role of the ERα-NRF2 signalling axis in bicalutamide resistance in PCa cells. RESULTS: We found that the expression of ERα and NRF2 was positively correlated and was higher in human CRPC tissues than in primary PCa tissues. Treatment with oestrogen or bicalutamide increased the expression of ERα and NRF2 as well as NRF2 target genes in PCa cell lines. These effects were blocked by pretreatment with tamoxifen. ChIP assays demonstrated that ERα directly binds to the oestrogen response element (ERE) in the NRF2 promoter. This binding led to increased transcriptional activity of NRF2 in a luciferase reporter assay. Activation of the ERα-NRF2 signalling axis increased the expression of bicalutamide resistance-related genes. Inhibition of this signalling axis by knockdown of ERα or NRF2 downregulated the expression of bicalutamide resistance-related genes and inhibited the proliferation and migration of PCa cells. CONCLUSIONS: We demonstrated the transcriptional interaction between ERα and NRF2 in CRPC tissues and cell lines by showing the direct binding of ERα to the ERE in the NRF2 promoter under oestrogen treatment. Activation of the ERα-NRF2 signalling axis contributes to bicalutamide resistance in PCa cells, suggesting that the ERα-NRF2 signalling axis is a potential therapeutic target for CRPC. Video Abstract.

Silencing ATF3 Might Delay TBHP-Induced Intervertebral Disc Degeneration by Repressing NPC Ferroptosis, Apoptosis, and ECM Degradation.

Intervertebral disc degeneration (IDD), being the predominant root cause of lower back pain, has led to an enormous socioeconomic burden in the world. Ferroptosis is an iron-dependent nonapoptotic and nonpyroptotic programmed cell death associated with an increase in reactive oxygen species (ROS), which has been implicated in the pathogenesis of IDD. Activation transcription factor 3 (ATF3) is widely reported to promote ferroptosis and apoptosis in multiple diseases, but its roles and underlying regulatory mechanism in IDD have not been identified. FAoptosis is defined as a mixed cell death consisting of ferroptosis and apoptosis. The loss- and gain-of-function experiments demonstrated that ATF3 positively regulated tert-butyl hydroperoxide- (TBHP-) induced nucleus pulposus cell (NPC) FAoptosis, ROS production, inflammatory response, and extracellular matrix (ECM) degradation. Furthermore, silencing ATF3 ameliorated the progression of IDD in vivo, whereas its overexpression showed the opposite phenotype. Bioinformatics analysis and molecular experiments corroborated that ATF3 is a direct target of miR-874-3p, suggesting that the upregulation of ATF3 in IDD might be caused at least in part due to the downregulation of miR-874-3p in IDD, thereby relieving the inhibition of ATF3 by miR-874-3p. The findings revealed that ATF3 has the potential to be used as a promising therapeutic target against IDD.

CYP1B1-catalyzed 4-OHE2 promotes the castration resistance of prostate cancer stem cells by estrogen receptor α-mediated IL6 activation.

BACKGROUND: Resistance to androgen deprivation therapy remains a major challenge for the clinical treatment of patients with castration-resistant prostate cancer (CRPC). CYP1B1, a critical enzyme that catalyzes the conversion of estradiol to 4-Hydroxy-17ß-estradiol (4-OHE2), has been reported to promote the development and progression of hormone-related cancer, but its role in CRPC is unclear. METHODS: To explore the underlying mechanism which CYP1B1 promotes the prostate cancer stem cells (PCSCs) characteristics, bioinformatics analyses of human clinical prostate cancer (PCa) datasets were performed. CYP1B1, IL6, and estrogen receptor-α (ERα) expression levels were evaluated in PCa and CRPC tissues via immunohistochemistry. The high-performance liquid chromatography-mass spectrometry assay was carried out to examine intracellular 4-OHE2 levels. Serum-free suspension culture and flow cytometry assays were performed to evaluate PCSCs. Chromatin immunoprecipitation was used to validate that 4-OHE2 recruited ERα to the IL6 promoter. RESULTS: CYP1B1 expression was significantly increased in CRPC tissues and androgen-independent PCa cell lines. CYP1B1+ PCa cells were significantly enriched in bicalutamide-treated LNCaP cells, and CYP1B1 knockdown reduced the cell viability under bicalutamide treatment. In addition, CYP1B1 knockdown decreased the intracellular 4-OHE2 concentration, accompanied by reduced PCSC characteristics. In PCa cells, 4-OHE2 stimulated ERα transcriptional activity and upregulated the expression of IL6 and downstream genes of the IL6-STAT3 signaling. 4-OHE2 increased cell viability under bicalutamide treatment and promoted PCSC characteristics, while IL6 neutralizing antibody reversed these effects. Mechanistically, siERα and the ER antagonist ICI182780 significantly attenuated 4-OHE2-induced IL6 expression, and 4-OHE2 promoted the binding of ERα to the estrogen response element of the IL6 promoter. CONCLUSIONS: Our findings indicate that CYP1B1-catalyzed 4-OHE2 enhanced PCSC characteristics and attenuated bicalutamide sensitivity by ERα-mediated the IL6-STAT3 pathway activation. Our study further emphasizes the role of CYP1B1 in castration resistance and illustrates a novel mechanism of CRPC development. Video Abstract.

The sustained PGE2 release matrix improves neovascularization and skeletal muscle regeneration in a hindlimb ischemia model.

BACKGROUND: The promising therapeutic strategy for the treatment of peripheral artery disease (PAD) is to restore blood supply and promote regeneration of skeletal muscle regeneration. Increasing evidence revealed that prostaglandin E2 (PGE2), a lipid signaling molecule, has significant therapeutic potential for tissue repair and regeneration. Though PGE2 has been well reported in tissue regeneration, the application of PGE2 is hampered by its short half-life in vivo and the lack of a viable system for sustained release of PGE2. RESULTS: In this study, we designed and synthesized a new PGE2 release matrix by chemically bonding PGE2 to collagen. Our results revealed that the PGE2 matrix effectively extends the half-life of PGE2 in vitro and in vivo. Moreover, the PGE2 matrix markedly improved neovascularization by increasing angiogenesis, as confirmed by bioluminescence imaging (BLI). Furthermore, the PGE2 matrix exhibits superior therapeutic efficacy in the hindlimb ischemia model through the activation of MyoD1-mediated muscle stem cells, which is consistent with accelerated structural recovery of skeletal muscle, as evidenced by histological analysis. CONCLUSIONS: Our findings highlight the chemical bonding strategy of chemical bonding PGE2 to collagen for sustained release and may facilitate the development of PGE2-based therapies to significantly improve tissue regeneration.

Circ_0004354 might compete with circ_0040039 to induce NPCs death and inflammatory response by targeting miR-345-3p-FAF1/TP73 axis in intervertebral disc degeneration.

The abnormal function of nucleus pulposus cells (NPCs) plays a crucial role in the pathogenesis of intervertebral disc degeneration (IVDD). Recent studies have demonstrated that circular RNAs (circRNAs) are involved in the pathological process of IVDD by regulating NPCs' function. Nevertheless, the investigation on circRNA-circRNA interaction has not yet been reported. Here, we identified the top upregulated circ_0040039 and circ_0004354 in IVDD, derived from the syntrophin beta 2 gene but had different degrees of biological functions. Accumulating studies have reported PANoptosis is composed of apoptosis, pyroptosis, and necroptosis. Based on this, we think there should be a new pro-inflammatory cell death PAoptosis in the form of apoptosis and pyroptosis. Circ_0004354 might compete with circ_0040039 to induce the development of IVDD by modulating miR-345-3p-FAF1/TP73 axis-mediated PAoptosis, inflammatory response, growth inhibition, and ECM degradation of NPCs. Thus, these findings offer a novel insight into the circRNAs-mediated posttranscriptional regulatory network in IVDD, contributing to further clarification of the pathological mechanism of IVDD to develop a promising therapeutic target for IVDD diseases.

Delivery management of a complete hydatidiform mole and co-existing viable fetus: A meta-analysis and systematic review.

OBJECTIVE: A twin pregnancy with a complete hydatidiform mole and co-existing viable fetus (CHMCF) is an exceedingly rare obstetric complication with few data related to perinatal treatment. This study determined the optimal timing of pregnancy termination and mode of delivery in women with CHMCF and a viable fetus. METHODS: The articles published involving CHMCF and a viable fetus from 1967 to 31 December 2020 in the PubMed and EMBASE databases were systematically reviewed. Observational cohort studies with three or more cases identified and data on delivery management were selected. The articles were analyzed independently for full text and the data were integrated. The timing of pregnancy termination and mode of delivery were calculated using Review Manager 5.4.1. RESULTS: There were 192 reports involving CHMCF; 209 cases had a viable fetus. According to the inclusion criteria, there were 6 case series, including 72 cases that were eligible for the analysis. The average rate of live births was 34.4%. The average duration of pregnancy was 34 weeks, ranging from 25 to 41 weeks. From 2000-2017 the live birth rate was increased year-after-year. Specifically, the live birth rate was16.7% in 2000, 33.3% in 2012, and 50% in 2017. Fifty-two cases (72.2%) had cesarean sections and 20 cases (27.8%) had vaginal deliveries. The incidence of gestational trophoblastic neoplasia was not significantly different between the two modes of delivery. CONCLUSIONS: Ideally, a twin pregnancy with a complete hydatidiform mole co-existing with a viable fetus is managed by an obstetrician, pediatrician, and oncologist. Appropriate timing of pregnancy termination and mode of delivery are related to the pregnancy outcome.

GPR30 knockdown weakens the capacity of CAF in promoting prostate cancer cell invasion via reducing macrophage infiltration and M2 polarization.

Cancer-associated fibroblasts (CAFs) can promote the development and metastasis of prostate cancer partly by mediating tumor-associated inflammation. An increasing amount of studies have focused on the functional interactions between CAFs and immune cells in the tumor microenvironment (TME). We previously reported that G protein-coupled receptor 30 (GPR30) was highly expressed in prostate CAFs and plays a crucial role in prostate stromal cell activation. However, the effect and underlying mechanism of GPR30 expression in prostate CAFs affecting the interaction between CAFs and tumor-associated macrophages (TAMs) need further elucidation. Here, we found that, compared with CAF-shControl, CAF-shGPR30 inhibited macrophage migration through transwell migration assays, which should be attributed to the decreased expression of C-X-C motif chemokine ligand 12 (CXCL12). In addition, macrophages treated with a culture medium of CAF-shGPR30 exhibited attenuated M2 polarization with downregulated M2-like markers expression. Moreover, macrophages stimulated with a culture medium of CAF-shGPR30 were less efficient in promoting activation of fibroblast cells and invasion of PCa cells. Finally, cocultured CAF-shGPR30 and macrophages suppressed PCa cell invasion compared to cocultured CAF-shControl and macrophages by decreasing interleukin-6 (IL-6) secretion, and this effect could be abrogated with rescue expression of IL-6. Our results pinpoint the function of GPR30 in prostate CAFs on regulating the CAF-TAM interaction in the TME and provide new insights into PCa therapies via regulating TME.

Highly interconnected inverse opal extracellular matrix scaffolds enhance stem cell therapy in limb ischemia.

The therapeutic effectiveness of cell transplantation in treatment of diseases and injuries is often limited by low cell retention, survivability, and engraftment. Extracellular matrix (ECM)-derived scaffolds are capable of controlling cell responses, thereby offering potential solutions to current challenges associated with cell therapy. However, it remains a technical challenge to produce ECM scaffolds with highly interconnected porous structure specifically required for cell transplantation. Here, we developed inverse opal porous extracellular matrix (ioECM) scaffolds through subcutaneous implantation of sacrificial templates assembled from polymer microspheres, followed by removal of the microsphere template and cellular content. Such highly interconnected porous ioECM scaffolds supported the anchorage, survival, viability, anti-apoptotic and paracrine activities of rat bone marrow mesenchymal stem cells (BMSCs), which further promoted endothelial cell migration and tube formation and viability. Upon transplantation into nude mouse critical limb ischemic model, ioECM promoted the engraftment of laden BMSCs, facilitated interconnected vascular network formation with accelerated recovery of blood perfusion and inhibited muscle atrophy and fibrosis. Our study demonstrates a unique strategy to engineer highly porous yet well-interconnected ECM scaffolds specifically for cell transplantation with marked improvement of survivability and vascularization, which offers an essential step toward the success of cell therapy and regenerative medicine. STATEMENT OF SIGNIFICANCE: Cell-based therapy has a good developing foreground applied in a variety of tissue regeneration. Extracellular matrix (ECM) scaffolds is an optimal choice for cell delivery duo to its superior biocompatibility and favorable immune responses. However, the current ECM scaffolds lacking of the controllable pore structure restrict the cell delivery efficiency and therapeutic outcome. Here, we fabricated highly interconnected inverse opal extracellular matrix (ioECM) scaffolds, which can enhance the effect of stem cell therapy in limb ischemic model by improving the survival, viability, and paracrine activities of stem cells. Our study provides reference value for the design and fabrication of ECM based biomaterials for cell transplantation.

Aligned microfiber-induced macrophage polarization to guide schwann-cell-enabled peripheral nerve regeneration.

Mechanistic understanding of the topological cues delivered by biomaterials in promotion of oriented tissue regeneration (e.g., peripheral nerve regrowth) remains largely elusive. Here, we engineered nerve conduits composed of oriented microfiber-bundle cores and randomly organized nanofiber sheaths to particularly interrogate the regulatory mechanism of microfiber orientation on promoted peripheral nerve regeneration. With comprehensive yet systematic analyses, we were able to elucidate the intricate cascade of biological responses associated with conduit-assisted nerve regrowth, i.e., oriented microfibers facilitated macrophage recruitment and subsequent polarization toward a pro-healing phenotype, which in turn promoted Schwann cell (SC) migration, myelinization and axonal extension. Pronounced improvement of nerve regeneration in rat sciatic nerve injury was evidenced with enhanced electrophysiologic function, sciatic functional index and alleviated muscle atrophy 3 months post-implantation. The obtained results offer essential insights on the topological regulation of biomaterials in functional nerve tissue regeneration via immune modulation.

The HeyL-Aromatase Axis Promotes Cancer Stem Cell Properties by Endogenous Estrogen-Induced Autophagy in Castration-Resistant Prostate Cancer.

Treatment of patients with castration-resistant prostate cancer (CRPC) remains a major clinical challenge. We previously showed that estrogenic effects contribute to CRPC progression and are primarily caused by the increased endogenous estradiol produced via highly expressed aromatase. However, the mechanism of aromatase upregulation and its role in CRPC are poorly described. In this study, we report that HeyL is aberrantly upregulated in CRPC tissues, and its expression is positively correlated with aromatase levels. HeyL overexpression increased endogenous estradiol levels and estrogen receptor-α (ERα) transcriptional activity by upregulating CYP19A1 expression, which encodes aromatase, enhancing prostate cancer stem cell (PCSC) properties in PC3 cells. Mechanistically, HeyL bound to the CYP19A1 promoter and activated its transcription. HeyL overexpression significantly promoted bicalutamide resistance in LNCaP cells, which was reversed by the aromatase inhibitor letrozole. In PC3 cells, the HeyL-aromatase axis promoted the PCSC phenotype by upregulating autophagy-related genes, while the autophagy inhibitor chloroquine (CQ) suppressed the aromatase-induced PCSC phenotype. The activated HeyL-aromatase axis promoted PCSC autophagy via ERα-mediated estrogenic effects. Taken together, our results indicated that the HeyL-aromatase axis could increase endogenous estradiol levels and activate ERα to suppress PCSC apoptosis by promoting autophagy, which enhances the understanding of how endogenous estrogenic effects influence CRPC development.

Baicalin alleviates adriamycin-induced focal segmental glomerulosclerosis and proteinuria by inhibiting the Notch1-Snail axis mediated podocyte EMT.

Podocyte injury is an early event and core in the development of focal segmental glomerular sclerosis (FSGS) that induces poor prognosis. Epithelial-mesenchymal transition (EMT) as a response of podocyte to injury leads to podocyte depletion and proteinuria. The abnormally reactivated NOTCH pathway may be involved in podocyte EMT. Baicalin, as a natural flavonoid compound, had significant inhibitory activity on tissue fibrosis and tumor cell invasion. However, its potential role and molecular mechanisms to injured podocyte in FSGS are little known. Here we found that baicalin could inhibit podocyte EMT markers expression and cell migration induced by TGF-ß1, accompanied by the up-regulated expression of slit diaphragm (SD) proteins and cell-cell adhesion molecule. Further investigation revealed that EMT inhibition of baicalin on injured podocyte is mainly mediated by the reduction of notch1 activation and its downstream Snail expression. Using the adriamycin-induced FSGS model, we determined that baicalin suppresses the Notch1-Snail axis activation in podocytes, relieves glomerulus structural disruption and dysfunction, and reduces proteinuria. Altogether, these findings suggest that baicalin is a novel renoprotective agent against podocyte EMT in FSGS and indicate its underlying mechanism that involves in negative regulation of the Notch1-Snail axis.

Aromatase-induced endogenous estrogen promotes tumour metastasis through estrogen receptor-α/matrix metalloproteinase 12 axis activation in castration-resistant prostate cancer.

Castration-resistant prostate cancer (CRPC) following androgen deprivation therapy remains a major obstacle advanced prostate cancer management. Aromatase catalyzes estrogen from androgens, yet the role of aromatase-generated endogenous estrogen in CRPC is poorly understood. In this study, we assessed the expression and function of aromatase in CRPC. We found that aromatase expression was significantly increased in CRPC tissues and cell lines. In some prostate cancer cell lines, aromatase was predominantly expressed in CD44+ subsets. Bicalutamide treatment significantly increased aromatase expression, and CYP19A1 expression positively correlated with estrogen responses and epithelial-mesenchymal transition. Aromatase knockdown in PC3 cells reduced invasiveness and decreased metastasis-related gene expression. The aromatase inhibitor, letrozole, attenuated tumour metastasis in castrated PC3-xenograft mice. Mechanistically, aromatase-induced endogenous estrogen promoted estrogen receptor-α (ERα) binding to matrix metalloproteinase 12 (MMP12) promoter estrogen response element (ERE). MMP12 co-localized with CD44 on the cell membrane and MMP12 knockdown significantly reduced estradiol-induced PC3 invasion. Taken together, our findings indicated that increased endogenous estrogen, catalysed by elevated aromatase levels, enhanced MMP12 expression via ERα, participated in CRPC progression and promoted tumour metastasis. Thus, aromatase represents a potential novel therapeutic target for CRPC.

Estrogen receptor α-NOTCH1 axis enhances basal stem-like cells and epithelial-mesenchymal transition phenotypes in prostate cancer.

BACKGROUND: Prostate cancer (PCa) is the second leading cause of mortality and a leading cause of malignant tumors in males. Prostate cancer stem cells (PCSCs) are likely the responsible cell types for cancer initiation, clinical treatment failure, tumor relapse, and metastasis. Estrogen receptor alpha (ERα) is mainly expressed in the basal layer cells of the normal prostate gland and has key roles in coordinating stem cells to control prostate organ development. Here, we investigated the roles of the estrogen-ERα signaling pathway in regulating PCSCs. METHODS: Correlation of CD49f and ERα/NOTCH1 was analyzed in human clinical datasets and tissue samples. Flow cytometry was used to sort CD49fHi and CD49fLow cells. EZH2 recruitment by ERα and facilitation of ERα binding to the NOTCH1 promoter was validated by Co-IP and ChIP. Primary tumor growth, tumor metastasis and sensitivity to 17ß-estradiol (E2) inhibitor (tamoxifen) were evaluated in castrated mice. RESULTS: ERα expression was significantly higher in CD49fHi prostate cancer basal stem-like cells (PCBSLCs), which showed basal and EMT features with susceptibility to E2 treatment. ERα-induced estrogen effects were suggested to drive the NOTCH1 signaling pathway activity via binding to the NOTCH1 promoter. Moreover, EZH2 was recruited by ERα and acted as a cofactor to assist ERα-induced estrogen effects in regulating NOTCH1 in PCa. In vivo, E2 promoted tumor formation and metastasis, which were inhibited by tamoxifen. CONCLUSIONS: Our results implicated CD49f+/ERα + prostate cancer cells associated with basal stem-like and EMT features, named EMT-PCBSLCs, in heightened potential for promoting metastasis. NOTCH1 was regulated by E2 in CD49fHi EMT-PCBSLCs. These results contribute to insights into the metastatic mechanisms of EMT-PCBSLCs in PCa.

Prohibitin-2 negatively regulates AKT2 expression to promote prostate cancer cell migration.

Prostate cancer (PCa) is a leading cause of cancer­associated mortality in men; however, the factors that contribute to disease development have yet to be fully elucidated. Previous studies have suggested that prohibitin-2 (PHB2), which is a multifunctional protein that contributes to various cellular processes, is positively correlated with malignant progression of PCa; however, the molecular mechanisms underlying the effects of PHB2 on the enhancement of cell migration have not been identified. The present study induced overexpression and knockdown of PHB2 in PCa cell lines (PC3 and DU145) with the aim of examining the effects of PHB2 on PCa cell migration via wound healing assays. The results indicated that PHB2 overexpression promoted migration of both cell lines. AKT serine/threonine kinase 2 (AKT2), which interacts with PHB2, has been reported to participate in cell migration; therefore, the present study examined the effects PHB2 overexpression and knockdown on AKT2 in PCa cells. The present study demonstrated that overexpression of PHB2 reduced the expression of AKT2, whereas PHB2 knockdown increased AKT2 expression in both PCa cell lines. In addition, knockdown of PHB2 enhanced the protein stability of AKT2. Furthermore, AKT2 overexpression resulted in a significant decrease in migration, whereas AKT2 knockdown promoted migration of PC3 and DU145 PCa cells. The combined overexpression of PHB2 and AKT2 inhibited migration of both cell lines, thus suggesting that AKT2 overexpression abolished PHB2-induced migration. Mechanistically, the present study suggested that PHB2 may promote PCa cell migration by inhibiting the expression of AKT2. These results provide information regarding the role of PHB2 in PCa migration and malignancy.

Folic acid stimulates proliferation of transplanted neural stem cells after focal cerebral ischemia in rats.

Folic acid (FA) stimulates neural stem cell (NSC) proliferation in vitro and enhances hippocampal neurogenesis in rats after middle cerebral artery occlusion (MCAO). The effect of FA supplementation on exogenous NSCs transplanted in MCAO rats was observed to determine if FA can stimulate NSC replacement after focal cerebral ischemia. Rats were randomly assigned to 3 groups: MCAO; MCAO and exogenous NSC transplantation (MCAO+NSCs); and MCAO, NSC transplantation and FA (MCAO+NSCs+FA). FA (0.8 mg/kg) or vehicle was administered by gavage daily for 28 days before MCAO and 23 days afterward. NSCs were labeled with superparamagnetic iron oxide (SPIO) and bromodeoxyuridine (BrdU) prior to transplantation into the striatum, contralateral to the ischemic zone, at 2 days post-MCAO. Magnetic resonance imaging tracking and fluorescent immunohistochemistry, as well as measurement of serum folate concentration, were performed at intervals up to 21 days after transplantation. FA supplementation caused sustained increases of 400-600% in serum folate concentration. Magnetic resonance images indicated that SPIO-labeled NSCs were more abundant at the transplantation and ischemic brain sites in MCAO+NSCs+FA rats than in MCAO+NSCs rats. Similarly, immunohistochemistry showed that the numbers of Sox-2/BrdU double positive cells at the transplantation and ischemic sites were higher in the rats that received FA. In conclusion, after focal cerebral ischemia, FA supplementation stimulates transplanted NSCs to proliferate and migrate to ischemic sites.