Partial male-to-female reprogramming of mouse fetal testis by Sertoli cell ablation.

Temporal transcription profiles of fetal testes with Sertoli cell ablation were examined in 4-day culture using a diphtheria toxin (DT)-dependent cell knockout system in AMH-TRECK transgenic (Tg) mice. RNA analysis revealed that ovarian-specific genes, including Foxl2, were ectopically expressed in DT-treated Tg testis explants initiated at embryonic days 12.5-13.5. FOXL2-positive cells were ectopically observed in two testicular regions: near the testicular surface epithelia and around its adjacent mesonephros. The surface FOXL2-positive cells, together with ectopic expression of Lgr5 and Gng13 (markers of ovarian cords), were derived from the testis epithelia/subepithelia, whereas another FOXL2-positive population was the 3ßHSD-negative stroma near the mesonephros. In addition to high expression of Fgfr1/Fgfr2 and heparan sulfate proteoglycan (a reservoir for FGF ligand) in these two sites, exogenous FGF9 additives repressed DT-dependent Foxl2 upregulation in Tg testes. These findings imply retention of Foxl2 inducibility in the surface epithelia and peri-mesonephric stroma of the testicular parenchyma, in which certain paracrine signals, including FGF9 derived from fetal Sertoli cells, repress feminization in these two sites of the early fetal testis.

Modeling the structure and DAP5-binding site of the FGF-9 5'-UTR RNA utilized in cap-independent translation.

Cap-independent or eukaryotic initiation factor (eIF) 4E-independent, translation initiation in eukaryotes requires scaffolding protein eIF4G or its homolog, death-associated protein 5 (DAP5). eIF4G associates with the 40S ribosomal subunit, recruiting the ribosome to the RNA transcript. A subset of RNA transcripts, such as fibroblast growth factor 9 (FGF-9), contain 5' untranslated regions (5' UTRs) that directly bind DAP5 or eIF4GI. For viral mRNA, eIF recruitment usually utilizes RNA structure, such as a pseudoknot or stem-loops, and the RNA-helicase eIF4A is required for DAP5- or 4G-mediated translation, suggesting these 5' UTRs are structured. However, for cellular IRES-like translation, no consensus RNA structures or sequences have yet been identified for eIF binding. However, the DAP5-binding site within the FGF-9 5' UTR is unknown. Moreover, DAP5 binds to other, dissimilar 5' UTRs, some of which require an unpaired, accessible 5' end to stimulate cap-independent translation. Using SHAPE-seq, we modeled the 186 nt FGF-9 5'-UTR RNA's complex secondary structure in vitro. Further, DAP5 footprinting, toeprinting, and UV cross-linking experiments identify DAP5-RNA interactions. Modeling of FGF-9 5'-UTR tertiary structure aligns DAP5-interacting nucleotides on one face of the predicted structure. We propose that RNA structure involving tertiary folding, rather than a conserved sequence or secondary structure, acts as a DAP5-binding site. DAP5 appears to contact nucleotides near the start codon. Our findings offer a new perspective in the hunt for cap-independent translational enhancers. Structural, rather than sequence-specific, eIF-binding sites may act as attractive chemotherapeutic targets or as dosage tools for mRNA-based therapies.

Inefficient Sox9 upregulation and absence of Rspo1 repression lead to sex reversal in the B6.XYTIR mouse gonad†.

Sry on the Y-chromosome upregulates Sox9, which in turn upregulates a set of genes such as Fgf9 to initiate testicular differentiation in the XY gonad. In the absence of Sry expression, genes such as Rspo1, Foxl2, and Runx1 support ovarian differentiation in the XX gonad. These two pathways antagonize each other to ensure the development of only one gonadal sex in normal development. In the B6.YTIR mouse, carrying the YTIR-chromosome on the B6 genetic background, Sry is expressed in a comparable manner with that in the B6.XY mouse, yet, only ovaries or ovotestes develop. We asked how testicular and ovarian differentiation pathways interact to determine the gonadal sex in the B6.YTIR mouse. Our results showed that (1) transcript levels of Sox9 were much lower than in B6.XY gonads while those of Rspo1 and Runx1 were as high as B6.XX gonads at 11.5 and 12.5 days postcoitum. (2) FOXL2-positive cells appeared in mosaic with SOX9-positive cells at 12.5 days postcoitum. (3) SOX9-positive cells formed testis cords in the central area while those disappeared to leave only FOXL2-positive cells in the poles or the entire area at 13.5 days postcoitum. (4) No difference was found at transcript levels of all genes between the left and right gonads up to 12.5 days postcoitum, although ovotestes developed much more frequently on the left than the right at 13.5 days postcoitum. These results suggest that inefficient Sox9 upregulation and the absence of Rspo1 repression prevent testicular differentiation in the B6.YTIR gonad.

Co-exposure to fluoride and sulfur dioxide induces abnormal enamel mineralization in rats via the FGF9-mediated MAPK signaling pathway.

Fluoride (F) and sulfur dioxide (SO2) contamination is recognized as a public health concern worldwide. Our previous research has shown that Co-exposure to F and SO2 can cause abnormal enamel mineralization. Ameloblastin (AMBN) plays a crucial role in the process of enamel mineralization. However, the process by which simultaneous exposure to F and SO2 influences enamel formation by regulating AMBN expression still needs to be understood. This study aimed to establish in vivo and in vitro models of F-SO2 Co-exposure and investigate the relationship between AMBN and abnormal enamel mineralization. By overexpressing/knocking out the Fibroblast Growth Factor 9 (FGF9) gene, we investigated the impact of FGF9-mediated Mitogen-Activated Protein Kinase (MAPK) signaling on AMBN synthesis to elucidate the mechanism underlying the induction of abnormal enamel mineralization by F-SO2 Co-exposure in rats. The results showed that F-SO2 exposure damaged the structure of rat enamel and ameloblasts. When exposed to F or SO2, gradual increases in the protein expression of FGF9 and phosphorylated p38 mitogen-activated protein kinase (p-P38) were observed. Conversely, the protein levels of AMBN, phosphorylated extracellular signal-regulated kinase (p-ERK), and phosphorylated c-Jun N-terminal kinase (p-JNK) were decreased. AMBN expression was significantly correlated with FGF9, p-ERK, and p-JNK expression in ameloblasts. Interestingly, FGF9 overexpression reduced the levels of p-ERK and p-JNK, worsening the inhibitory effect of F-SO2 on AMBN. Conversely, FGF9 knockout increased the phosphorylation of ERK and JNK, partially reversing the F-SO2-induced downregulation of AMBN. Taken together, these findings strongly demonstrate that FGF9 plays a critical role in F-SO2-induced abnormal enamel mineralization by regulating AMBN synthesis through the JNK and ERK pathways.

FGF-independent MEK1/2 signalling in the developing foetal testis is essential for male germline differentiation in mice.

BACKGROUND: Disrupted germline differentiation or compromised testis development can lead to subfertility or infertility and are strongly associated with testis cancer in humans. In mice, SRY and SOX9 induce expression of Fgf9, which promotes Sertoli cell differentiation and testis development. FGF9 is also thought to promote male germline differentiation but the mechanism is unknown. FGFs typically signal through mitogen-activated protein kinases (MAPKs) to phosphorylate ERK1/2 (pERK1/2). We explored whether FGF9 regulates male germline development through MAPK by inhibiting either FGF or MEK1/2 signalling in the foetal testis immediately after gonadal sex determination and testis cord formation, but prior to male germline commitment. RESULTS: pERK1/2 was detected in Sertoli cells and inhibition of MEK1/2 reduced Sertoli cell proliferation and organisation and resulted in some germ cells localised outside of the testis cords. While pERK1/2 was not detected in germ cells, inhibition of MEK1/2 after somatic sex determination profoundly disrupted germ cell mitotic arrest, dysregulated a broad range of male germline development genes and prevented the upregulation of key male germline markers, DPPA4 and DNMT3L. In contrast, while FGF inhibition reduced Sertoli cell proliferation, expression of male germline markers was unaffected and germ cells entered mitotic arrest normally. While male germline differentiation was not disrupted by FGF inhibition, a range of stem cell and cancer-associated genes were commonly altered after 24 h of FGF or MEK1/2 inhibition, including genes involved in the maintenance of germline stem cells, Nodal signalling, proliferation, and germline cancer. CONCLUSIONS: Together, these data demonstrate a novel role for MEK1/2 signalling during testis development that is essential for male germline differentiation, but indicate a more limited role for FGF signalling. Our data indicate that additional ligands are likely to act through MEK1/2 to promote male germline differentiation and highlight a need for further mechanistic understanding of male germline development.

Upregulation of FGF9 and NOVA1 in cancer-associated fibroblasts promotes cell proliferation, invasion and migration of triple negative breast cancer.

Cancer-associated fibroblasts (CAFs) play a pivotal role in cancer progression. This study aimed to explore the roles of CAFs-derived Fibroblast growth factor 9 (FGF9) and Neuro-oncological ventral antigen 1 (NOVA1) in triple negative breast cancer (TNBC) progression. MDA-MB-231 and BT-549 cells were cocultured with CAF conditioned-medium (CAF-CM) or normal fibroblasts conditioned-medium (NF-CM). MTT, EdU, colony formation, wound healing, transwell migration, and invasion assays were employed to determine cell proliferation, migration and invasion, respectively. Western blot and RT-qPCR were carried out to examine the protein and mRNA expression of FGF9 and NOVA1. Xenograft tumor experiments were conducted to evaluate the effects of CAFs, FGF9, and NOVA1 on tumor growth in vivo. Our results showed that CAFs significantly promoted the proliferation, invasion, and migration of TNBC cells. FGF9 and NOVA1 were significantly upregulated in TNBC CAFs, tissues and cells. CAF-CM also could increase the expression of FGF9 and NOVA1 in TNBC cells. Knockdown of FGF9 or NOVA1 could hamper cell proliferation, invasion, migration, and EMT of TNBC cells. Moreover, CAFs with FGF9/NOVA1 knockdown also could inhibit TNBC progression. Besides, CAFs significantly accelerated tumor growth in vivo, which was blocked by FGF9/NOVA1 knockdown in nude mice. In conclusion, our results indicated the tumor-promoting role of CAFs in TNBC progression. FGF9 and NOVA1 upregulation in CAFs induced cell proliferation, migration and invasion in vitro, and facilitated tumor growth in vivo in TNBC development.

FGF9 variant in 46,XY DSD patient suggests a role for dimerization in sex determination.

46,XY gonadal dysgenesis (GD) is a Disorder/Difference of Sex Development (DSD) that can present with phenotypes ranging from ambiguous genitalia to complete male-to-female sex reversal. Around 50% of 46,XY DSD cases receive a molecular diagnosis. In mice, Fibroblast growth factor 9 (FGF9) is an important component of the male sex-determining pathway. Two FGF9 variants reported to date disrupt testis development in mice, but not in humans. Here, we describe a female patient with 46,XY GD harbouring the rare FGF9 variant (missense mutation), NM_002010.2:c.583G > A;p.(Asp195Asn) (D195N). By biochemical and cell-based approaches, the D195N variant disrupts FGF9 protein homodimerisation and FGF9-heparin-binding, and reduces both Sertoli cell proliferation and Wnt4 repression. XY Fgf9D195N/D195N foetal mice show a transient disruption of testicular cord development, while XY Fgf9D195N/- foetal mice show partial male-to-female gonadal sex reversal. In the general population, the D195N variant occurs at an allele frequency of 2.4 × 10-5 , suggesting an oligogenic basis for the patient's DSD. Exome analysis of the patient reveals several known and novel variants in genes expressed in human foetal Sertoli cells at the time of sex determination. Taken together, our results indicate that disruption of FGF9 homodimerization impairs testis determination in mice and, potentially, also in humans in combination with other variants.

The role of FGF9-mediated TGF-ß1/Smad signaling in enamel hypoplasia induced by exposure to fluoride and SO2 in rats.

Many geographical areas of the world are polluted by both fluoride and sulfur dioxide (SO2). However, the effects of simultaneous exposure to fluoride and SO2 on teeth are unknown. Fibroblast growth factor-9 (FGF9) and transforming growth factor-ß1 (TGF-ß1) are key signaling molecules in enamel development. The purpose of the study was to explore the effects of co-exposure to fluoride and sulfur dioxide on enamel and to investigate the role and mechanism of FGF9 and TGF-ß1. First, sodium fluoride (NaF) and SO2 derivatives were used to construct rat models and evaluate the enamel development of rats. Then, TGF-ß1 (cytokine) treatment, SIS3 (inhibitor) treatment and FGF9 gene knockdown were used to explore the mechanism of enamel damage in vitro. The results showed that enamel column crystals in the exposed group were characterized by enamel hypoplasia, as indicated by alterations such as disarrangement of enamel column crystals, space widening and breakage. Ameloblasts also showed pathological changes such as ribosome loss, mitochondrial swelling, nuclear fragmentation and chromatin aggregation. The protein expression of FGF9 was higher and the protein expression of AMBN, TGF-ß1 and p-Smad2/3 protein was lower in the groups treated with fluoride and SO2 individually or in combination compared with the control group. Further studies showed that TGF-ß1 significantly upregulated p-Smad2/3 and AMBN protein expression and reduced the inhibitory effects of fluoride and SO2; furthermore, SISI blocked the effect of TGF-ß1. In addition, knockdown of FGF9 upregulated TGF-ß1 protein expression, further activated Smad2/3 phosphorylation, eliminated the inhibitory effects of fluoride and SO2, and increased the protein expression of AMBN. In brief, the study confirms that co-exposure to fluoride and SO2 can result in enamel hypoplasia in rats and indicates that the underlying mechanism may be closely related to the effect of FGF9 on enamel matrix protein secretion through inhibition of the TGF-ß1/Smad signaling pathway.

FGF4 and FGF9 have synergistic effects on odontoblast differentiation.

The purpose of this study was to investigate whether fibroblast growth factor 4 (FGF4) and FGF9 are active in dentin differentiation. Dentin matrix protein 1 (Dmp1) -2A-Cre transgenic mice, which express the Cre-recombinase in Dmp1-expressing cells, were crossed with CAG-tdTomato mice as reporter mouse. The cell proliferation and tdTomato expressions were observed. The mesenchymal cell separated from neonatal molar tooth germ were cultured with or without FGF4, FGF9, and with or without their inhibitors ferulic acid and infigratinib (BGJ398) for 21 days. Their phenotypes were evaluated by cell count, flow cytometry, and real-time PCR. Immunohistochemistry for FGFR1, 2, and 3 expression and the expression of DMP1 were performed. FGF4 treatment of mesenchymal cells obtained promoted the expression of all odontoblast markers. FGF9 failed to enhance dentin sialophosphoprotein (Dspp) expression levels. Runt-related transcription factor 2 (Runx2) was upregulated until day 14 but was downregulated on day 21. Compared to Dmp1-negative cells, Dmp1-positive cells expressed higher levels of all odontoblast markers, except for Runx2. Simultaneous treatment with FGF4 and FGF9 had a synergistic effect on odontoblast differentiation, suggesting that they may play a role in odontoblast maturation.

Ovotesticular disorders of sex development in FGF9 mouse models of human synostosis syndromes.

In mice, male sex determination depends on FGF9 signalling via FGFR2c in the bipotential gonads to maintain the expression of the key testis gene SOX9. In humans, however, while FGFR2 mutations have been linked to 46,XY disorders of sex development (DSD), the role of FGF9 is unresolved. The only reported pathogenic mutations in human FGF9, FGF9S99N and FGF9R62G, are dominant and result in craniosynostosis (fusion of cranial sutures) or multiple synostoses (fusion of limb joints). Whether these synostosis-causing FGF9 mutations impact upon gonadal development and DSD etiology has not been explored. We therefore examined embryonic gonads in the well-characterized Fgf9 missense mouse mutants, Fgf9S99N and Fgf9N143T, which phenocopy the skeletal defects of FGF9S99N and FGF9R62G variants, respectively. XY Fgf9S99N/S99N and XY Fgf9N143T/N143T fetal mouse gonads showed severely disorganized testis cords and partial XY sex reversal at 12.5 days post coitum (dpc), suggesting loss of FGF9 function. By 15.5 dpc, testis development in both mutants had partly recovered. Mitotic analysis in vivo and in vitro suggested that the testicular phenotypes in these mutants arise in part through reduced proliferation of the gonadal supporting cells. These data raise the possibility that human FGF9 mutations causative for dominant skeletal conditions can also lead to loss of FGF9 function in the developing testis, at least in mice. Our data suggest that, in humans, testis development is largely tolerant of deleterious FGF9 mutations which lead to skeletal defects, thus offering an explanation as to why XY DSDs are rare in patients with pathogenic FGF9 variants.

Novel FGF9 variant contributes to multiple synostoses syndrome 3.

Multiple synostoses syndromes (SYNS) are autosomal dominant syndromes characterized by multiple joint fusions commonly involving the carpal-tarsal, interphalangeal, humeroradial, and cervical spine joints. They display genetic heterogeneity with pathogenic variants reported in four separate genes (NOG, GDF5, FGF9, and GDF6) defining four different SYNS forms. FGF9 variants have been reported in SYNS3, a SYNS with multiple synostoses, normal cognition, normal hearing, and craniosynostosis. Here, we report a novel FGF9 c.569G > C p.(Arg190Thr) variant identified by whole-exome sequencing in a patient with multiple bony abnormalities. The patient initially presented with elbow instability and decreased range of motion. Imaging revealed bilateral radial head deformities, carpal-tarsal fusions, brachydactyly, and osteoarthritis of the sacroiliac joints. In silico protein modeling of the identified FGF9 variant predicts decreased stability of ligand-receptor binding supporting the pathogenicity of this finding. This finding expands the repertoire of FGF9 variants and phenotypic information reported for SYNS3 and suggest that genotype phenotype correlations due to localization seem less likely and more so due to the consequence of the pathogenic variant on the receptor. This is useful in the counseling in families as more de novo variants emerge.

A novel heterozygous variant in FGF9 associated with previously unreported features of multiple synostosis syndrome 3.

Human multiple synostoses syndrome 3 is an autosomal dominant disorder caused by pathogenic variants in FGF9. Only two variants have been described in FGF9 in humans so far, and one in mice. Here we report a novel missense variant c.566C > G, p.(Pro189Arg) in FGF9. Functional studies showed this variant impairs FGF9 homodimerization, but not FGFR3c binding. We also review the findings of cases reported previously and report on additional features not described previously.

Identification of the third FGF9 variant in a girl with multiple synostosis-comparison of the genotype:phenotype of FGF9 variants in humans and mice.

Multiple synostosis syndrome (SYNS) is a heterogeneous group of genetic disorders mainly characterized by multiple joint synostosis due to variants in either NOG, GDF5, FGF9 or GDF6. To date, only two FGF9 variants have been associated with SYNS, characterized with hand and feet joint synostosis and fusion of the elbow and vertebral lumbar joints. Craniosynostosis was also observed in one family. Here, we report the clinical and radiological description of a young girl with a third heterozygous FGF9 variant, NM_002010.2:c.427A>T;p.(Asn143Tyr), which interestingly, is located at the same amino acid as the well characterized spontaneous Eks mouse variant. We also compare the genotype: phenotypes observed between humans and mice with SYNS.

Effect of lentivirus-mediated miR-182 targeting FGF9 on hallux valgus.

The pathogenesis of hallux valgus is not clearly understood. However, genetics research about hallux valgus is rare. Therefore, the present study aimed to explore the pathogeny of hallux valgus from the perspective of genetics. Human samples were collected from normal bone tissue and hallux valgus region bone tissue. The bone samples were studied using real time-PCR, western blot and immunohistochemical. Lentivirus-mediated miR-182 transfected osteoblasts and tested the expression of FGF9 mRNA with real time-PCR. To test alkaline phosphatase activity, number of calcium nodules and proliferation of osteoblast with enzymatic activity analysis, calcium nodules stained and MTT assay. We found that (1) FGF9 expressed in hallux valgus region bone tissue was significantly higher than normal bone tissue. (2) miR-182 expression levels in hallux valgus region bone tissue were notably lower than those of normal bone tissue. (3) miR-182 could negatively regulate the expression of FGF9 in osteoblasts. (4) FGF9 may enhance osteoblasts proliferation. We have demonstrated that miR-182 promotes the formation of bone by targeting FGF9, implicating an essential role of miR-182 in the etiology of hallux valgus. Moreover, miR-182 might potentially be a therapeutic target for hallux valgus treatment.

Long non-coding RNA SNHG7 upregulates FGF9 to alleviate oxygen and glucose deprivation-induced neuron cell injury in a miR-134-5p-dependent manner.

Long non-coding RNA small nucleolar RNA host gene 7 (SNHG7) was reported to regulate the pathogenesis of ischemic stroke. The study aimed to disclose SNHG7 role in oxygen and glucose deprivation (OGD)-induced Neuro-2a (N2a) cell disorders. An OGD injury cell model was established using N2a cells. The expression of SNHG7, microRNA-134-5p (miR-134-5p) and fibroblast growth factor 9 (FGF9) was determined by quantitative real-time polymerase chain reaction. Protein expression was detected by western blot. Cell viability and Lactate Dehydrogenase (LDH) leakage were determined by cell counting kit-8 and LDH activity detection assays. Oxidative stress was investigated by Superoxide Dismutase and Catalase activity assays as well as Malondialdehyde and Reactive Oxygen Species detection kits. Cell apoptosis and caspase-3 activity were severally demonstrated by flow cytometry and caspase-3 activity assays. The interaction between miR-134-5p and SNHG7 or FGF9 was predicted by online databases, and identified by mechanism assays. OGD treatment decreased SNHG7 and FGF9 expression, but increased miR-134-5p expression. OGD treatment repressed cell viability, promoted LDH leakage and induced oxidative stress and apoptosis in N2a cells, which was rescued by SNHG7 overexpression. SNHG7 acted as a sponge for miR-134-5p, and regulated OGD-triggered cell damage by associating with miR-134-5p. Additionally, miR-134-5p depletion protected N2a cells from OGD-induced injury by targeting FGF9. Ectopic SNHG7 expression protected against OGD-induced neuronal cell injury by inducing FGF9 through sponging miR-134-5p, providing a novel therapeutic target for ischemic stroke.

Altrenogest affects expression of galectin-3 and fibroblast growth factor 9 in the reproductive tract of sows.

A synthetic progestin altrenogest (ALT) is used to synchronize the estrus cycle of swine for fixed-time artificial insemination (AI) and has been shown to improve follicular development and reproductive performances in post-weaning sows. However, the effects of ALT treatment on reproductive tracts, including the ovaries, oviducts and uterus have not been yet clarified. In this study, we examined the expression of genes involved in endometrial responses in ALT-treated sows. ALT did not significantly alter luteinizing hormone (LH), follicle-stimulating hormone (FSH) and estradiol profiles in blood compared to untreated control. Quantitative RT-polymerase chain reaction (qRT-PCR) analysis showed that the expression of genes encoding galectin-3 (LGALS3) and fibroblast growth factor 9 (FGF9) was upregulated in the reproductive tracts of ALT-treated sows, including the ovaries, oviducts and uteri. Moreover, ALT treatment induced the expression of FGF9 and galectin-3 proteins, and promoted their localization to the luminal epithelium of the oviducts and uterus. Our findings suggest that the enhancement of reproductive performance shown by ALT-treated sows is associated with the upregulation of galectin-3 and FGF9, which are essential for endometrial receptivity, successful implantation, and pregnancy.

Carnosic acid ameliorates depressive-like symptoms along with the modulation of FGF9 in the hippocampus of middle carotid artery occlusion-induced Sprague Dawley rats.

The increased survival rate of stroke patients has led to the higher incidences of post-stroke depression. Carnosic acid has the ability to cross blood brain barrier with good neuro-modulatory actions. Recently, inclined level of fibroblast growth factor 9 (FGF9) in the postmortem brain of the depressed patients was noted. Therefore, in the present study, the effect of carnosic acid on post-stroke depression-like behavior, and the expression of FGF9 were evaluated. After 3 weeks of middle carotid artery occlusion in Sprague Dawley rats, carnosic acid (20 and 40 mg/kg) was administered for 2 weeks. Sucrose preference test, forced swimming test, and open field test were performed and hippocampi were analyzed for FGF9 and FGFR-3. In comparison to post-stroke depressed rats, carnosic acid increased the sucrose preference, and reduced the immobility time of the rats by ~2×. The speed and distance-covered were also increased. At 40 mg/kg, FGF9 was reduced by ~3× while FGFR-3/Actin was increased by ~1.5×. Altogether results suggest anti-depressant-like activity of carnosic acid in post-stroke depressed rats with decreased expression of hippocampal FGF9.

[Zbtb33 Gene Knockout Changes Transcription of the Fgf9, Fgfr3, с-Мус and FoxG1 Genes in the Developing Mouse Brain].

The transcription factor KAISO is important for proper development of animal embryos. In the cell, KAISO regulates cell division and apoptosis. KAISO is abundant in the central nervous system. Here we describe the effects of Zbtb33 gene knockout on the transcription of several genes that regulate the development of the central nervous system, including Fgf9, Fgfr3, Sox9, Sox2, c-Myc, NeuroD1 and FoxG1. These genes are related to the Wnt/ß-catenin signaling pathway, which is closely connected to KAISO. Hippocampal, frontal cortical, and striatal tissue from C57BL/6j mice with a knockout in the Zbtb33 gene encoding KAISO (ZBTB33-) and wild-type mice (ZBTB33+) were collected and profiled at different stages of development. Age-dependent and region-specific differences in the mRNA levels of the Fgf9, Fgfr3, c-Myc, FoxG1 genes in the developing brain of ZBTB33- and ZBTB33+ mice were described and discussed.

miR-140-5p targeted FGF9 and inhibited the cell growth of laryngeal squamous cell carcinoma.

Increasing evidence has suggested that microRNAs (miRNAs) play critical roles in the initiation and development of cancers. Here, we found that miR-140-5p was significantly downregulated in both laryngeal squamous cell carcinoma (LSCC) tissues and cell lines. Decreased expression of miR-140-5p was significantly associated with the metastasis of LSCC. Overexpression of miR-140-5p inhibited proliferation and induced apoptosis of LSCC cells. Mechanistically, the fibroblast growth factor 9 (FGF9) was identified as the target of miR-140-5p. miR-140-5p bound the 3'-untranslated region (3'-UTR) of FGF9 and suppressed the expression of FGF9 in LSCC cells. Additionally, the level of FGF9 was upregulated in LSCC tissues and negatively correlated with the expression of miR-140-5p. Restoration of FGF9 attenuated the suppressive role of miR-140-5p in regulating the growth of LSCC cells. Collectively, these results indicated that the tumor suppressive function of miR-140-5p in LSCC was partially exercised by modulating the expression of FGF9.

LncRNA FAF inhibits fibrosis induced by angiotensinogen II via the TGFß1-P-Smad2/3 signalling by targeting FGF9 in cardiac fibroblasts.

The dysregulation of Long noncoding RNAs (lncRNAs) has been implicated in many cardiovascular diseases, including cardiac fibrosis. However, the functions and mechanisms of lncRNAs in cardiac fibroblasts (CFs) have not been fully elucidated. First, we observed a correlation between cardiac remodeling (CR) and lncRNA FAF (FGF9-associated factor, termed FAF) expression in the heart. In vitro, we found that the expression of lncRNA FAF was altered in CFs, whereas it behaved inconsistently in cardiomyocytes (CMs). Next, we investigated the effects of lncRNA FAF on angiotensinogen II (Ang II)-induced cardiac fibrosis in neonatal rat CFs and explored the mechanism underlying these effects. In this study, lncRNA FAF was enriched in CFs and was associated with cardiac fibrosis. Upregulation of lncRNA FAF significantly restrained Ang II-induced increases in cell proliferation, differentiation and collagen accumulation of CFs. Moreover, we found that the function of lncRNA FAF was mainly realized through Transforming growth factor ß1 (TGFß1) secretion and then downregulated phosphorylation of Smad2/3. Additional analysis revealed that Fibroblast growth factor 9 (FGF9) is a direct target of lncRNA FAF, as the overexpression of lncRNA FAF could increase the expression of FGF9 and knockdown of the FGF9 expression could attenuate the down-regulation of lncRNA FAF on TGFß1-P-Smad2/3 pathway. Furthermore, knockdown of the FGF9 expression also abolished the inhibitory effect of FAF on fibrosis. In summary, we demonstrated that the overexpression of lncRNA FAF could inhibit fibrosis induced by Ang II via the TGFß1-P-Smad2/3 signalling by targeting FGF9 in CFs.