PHF6-mediated transcriptional control of NSC via Ephrin receptors is impaired in the intellectual disability syndrome BFLS.

The plant homeodomain zinc-finger protein, PHF6, is a transcriptional regulator, and PHF6 germline mutations cause the X-linked intellectual disability (XLID) Börjeson-Forssman-Lehmann syndrome (BFLS). The mechanisms by which PHF6 regulates transcription and how its mutations cause BFLS remain poorly characterized. Here, we show genome-wide binding of PHF6 in the developing cortex in the vicinity of genes involved in central nervous system development and neurogenesis. Characterization of BFLS mice harbouring PHF6 patient mutations reveals an increase in embryonic neural stem cell (eNSC) self-renewal and a reduction of neural progenitors. We identify a panel of Ephrin receptors (EphRs) as direct transcriptional targets of PHF6. Mechanistically, we show that PHF6 regulation of EphR is impaired in BFLS mice and in conditional Phf6 knock-out mice. Knockdown of EphR-A phenocopies the PHF6 loss-of-function defects in altering eNSCs, and its forced expression rescues defects of BFLS mice-derived eNSCs. Our data indicate that PHF6 directly promotes Ephrin receptor expression to control eNSC behaviour in the developing brain, and that this pathway is impaired in BFLS.

Pathogenic variants in SMARCA1 cause an X-linked neurodevelopmental disorder modulated by NURF complex composition.

Pathogenic variants in ATP-dependent chromatin remodeling proteins are a recurrent cause of neurodevelopmental disorders (NDDs). The NURF complex consists of BPTF and either the SNF2H (SMARCA5) or SNF2L (SMARCA1) ISWI-chromatin remodeling enzyme. Pathogenic variants in BPTF and SMARCA5 were previously implicated in NDDs. Here, we describe 40 individuals from 30 families with de novo or maternally inherited pathogenic variants in SMARCA1. This novel NDD was associated with mild to severe ID/DD, delayed or regressive speech development, and some recurrent facial dysmorphisms. Individuals carrying SMARCA1 loss-of-function variants exhibited a mild genome-wide DNA methylation profile and a high penetrance of macrocephaly. Genetic dissection of the NURF complex using Smarca1, Smarca5, and Bptfsingle and double mouse knockouts revealed the importance of NURF composition and dosage for proper forebrain development. Finally, we propose that genetic alterations affecting different NURF components result in a NDD with a broad clinical spectrum.

A new mouse model of ATR-X syndrome carrying a common patient mutation exhibits neurological and morphological defects.

ATRX is a chromatin remodelling ATPase that is involved in transcriptional regulation, DNA damage repair and heterochromatin maintenance. It has been widely studied for its role in ALT-positive cancers, but its role in neurological function remains elusive. Hypomorphic mutations in the X-linked ATRX gene cause a rare form of intellectual disability combined with alpha-thalassemia called ATR-X syndrome in hemizygous males. Clinical features also include facial dysmorphism, microcephaly, short stature, musculoskeletal defects and genital abnormalities. As complete deletion of ATRX in mice results in early embryonic lethality, the field has largely relied on conditional knockout models to assess the role of ATRX in multiple tissues. Given that null alleles are not found in patients, a more patient-relevant model was needed. Here, we have produced and characterized the first patient mutation knock-in model of ATR-X syndrome, carrying the most common causative mutation, R246C. This is one of a cluster of missense mutations located in the chromatin-binding domain and disrupts its function. The knock-in mice recapitulate several aspects of the patient disorder, including craniofacial defects, microcephaly, reduced body size and impaired neurological function. They provide a powerful model for understanding the molecular mechanisms underlying ATR-X syndrome and testing potential therapeutic strategies.

VGF is required for recovery after focal stroke.

The high incidence of ischemic stroke worldwide and poor efficacy of neuroprotective drugs has increased the need for novel therapies in stroke recovery. Transcription of the neurosecretory protein VGF (non-acronym) is enhanced following ischemic stroke and proposed to be important for stroke recovery. To determine the requirement for VGF in recovery, we created Vgffl/fl:Nestin-Cre conditional knockout (Vgf cKO) mice and induced a photothrombotic focal ischemic stroke. Naïve Vgf cKO mice had significant less body weight in the absence of gross defects in brain size, cortical lamination, or deficits in locomotor activity compared to wildtype controls. Following a focal stroke, the Vgf cKO mice had greater deficits including impaired recovery of forepaw motor deficits at 2- and 4-weeks post stroke. The increase in deficits occurred in the absence of any difference in lesion size and was accompanied by a striking loss of stroke-induced migration of SVZ-derived immature neurons to the peri-infarct region. Importantly, exogenous adenoviral delivery of VGF (AdVGF) significantly improved recovery in the Vgf cKO mice and was able to rescue the immature neuron migration defect observed. Taken together, our results define a requirement for VGF in post stroke recovery and identify VGF peptides as a potential future therapeutic.

Generation of a mouse model of the neurodevelopmental disorder with dysmorphic facies and distal limb anomalies syndrome.

Heterozygous variants in bromodomain and plant homeodomain containing transcription factor (BPTF) cause the neurodevelopmental disorder with dysmorphic facies and distal limb anomalies (NEDDFL) syndrome (MIM#617755) characterized by intellectual disability, speech delay and postnatal microcephaly. BPTF functions within nucleosome and remodeling factor (NURF), a complex comprising sucrose non-fermenting like (SNF2L), an Imitation SWItching (ISWI) chromatin remodeling protein encoded by the SWI/SNF related, matrix associated, actin dependent regulator of chromatin, subfamily a, member 1 (SMARCA1) gene. Surprisingly, ablation of Smarca1 resulted in mice with enlarged brains, a direct contrast to the phenotype of NEDDFL patients. To model the NEDDFL syndrome, we generated forebrain-specific Bptf knockout (Bptf conditional Knockout (cKO)) mice. The Bptf cKO mice were born in normal Mendelian ratios, survived to adulthood but were smaller in size with severe cortical hypoplasia. Prolonged progenitor cell cycle length and a high incidence of cell death reduced the neuronal output. Cortical lamination was also disrupted with reduced proportions of deep layer neurons, and neuronal maturation defects that impaired the acquisition of distinct cell fates (e.g. COUP-TF-interacting protein 2 (Ctip2)+ neurons). RNAseq and pathway analysis identified altered expression of fate-determining transcription factors and the biological pathways involved in neural development, apoptotic signaling and amino acid biosynthesis. Dysregulated genes were enriched for MYC Proto-Oncogene, BHLH Transcription Factor (Myc)-binding sites, a known BPTF transcriptional cofactor. We propose the Bptf cKO mouse as a valuable model for further study of the NEDDFL syndrome.

Wnt3a/ß-Catenin/CBP Activation in the Progression of Cervical Intraepithelial Neoplasia.

Piwil2 reprograms HPV-infected reserve cells in the cervix into tumor-initiated cells (TICs) and upregulates Wnt3a expression sequentially, which leads to cervical intraepithelial neoplasia (CIN) and ultimately squamous cell carcinoma (SCC). However, little is known regarding Wnt signaling in the maintenance of TIC stemness during the progression of cervical lesions. We herein investigated the expression of canonical Wnt3a signaling and related genes by microarray data set analysis and immunohistochemical (IHC) staining of samples obtained by biopsy of normal cervix, low- and high-grade CIN, and invasive SCC tissue. Array data analyzed by GEO2R showed higher expression levels of Wnt signaling and their target genes, significant upregulation of stemness-associated markers, and notably downregulated cell differentiation markers in CIN and SCC tissues compared with those in the normal cervix tissue. Further, Gene Set Enrichment Analysis (GSEA) revealed that Wnt pathway-related genes significantly enriched in SCC. IHC staining showed gradually increased immunoreactivity score of Wnt3a and CBP and notable translocation of ß-catenin from the membrane to the cytoplasm and nucleus during the lesion progression. The intensity and proportion of P16, Ki67 and CK17 staining also increased with the progression of cervical lesions, whereas minimal to negative Involucrin expression was observed in CIN2/3 and SCC. Therefore, canonical Wnt signaling may contribute to the progression of CIN to SCC and may be a potential therapeutic target.

Transgenic mice with an R342X mutation in Phf6 display clinical features of Börjeson-Forssman-Lehmann Syndrome.

The PHF6 mutation c.1024C > T; p.R342X, is a recurrent cause of Börjeson-Forssman-Lehmann Syndrome (BFLS), a neurodevelopmental disorder characterized by moderate-severe intellectual disability, truncal obesity, gynecomastia, hypogonadism, long tapering fingers and large ears (MIM#301900). Here, we generated transgenic mice with the identical substitution (R342X mice) using CRISPR technology. We show that the p.R342X mutation causes a reduction in PHF6 protein levels, in both human and mice, from nonsense-mediated decay and nonsense-associated alternative splicing, respectively. Magnetic resonance imaging studies indicated that R342X mice had a reduced brain volume on a mixed genetic background but developed hydrocephaly and a high incidence of postnatal death on a C57BL/6 background. Cortical development proceeded normally, while hippocampus and hypothalamus relative brain volumes were altered. A hypoplastic anterior pituitary was also observed that likely contributes to the small size of the R342X mice. Behavior testing demonstrated deficits in associative learning, spatial memory and an anxiolytic phenotype. Taken together, the R342X mice represent a good preclinical model of BFLS that will allow further dissection of PHF6 function and disease pathogenesis.

CBP-mediated Wnt3a/ß-catenin signaling promotes cervical oncogenesis initiated by Piwil2.

Our previous work demonstrated that Piwil2 reactivated by the human papillomavirus oncoproteins E6 and E7 may reprogram somatic cells into tumor-initiating cells (TICs), which contribute to cervical neoplasia lesions. Maintaining the stemness of TICs is critical for the progression of cervical lesions. Here, we determined that canonical Wnt signaling was aberrantly activated in HaCaT cells transfected with lentivirus expressing Piwil2 and in cervical lesion specimens of low-grade squamous intraepithelial lesion, high-grade squamous intraepithelial lesion, and invasive carcinoma. Blocking the ß-catenin and CREB binding protein interaction with ICG-001 significantly downregulated the reprogramming factors c-Myc, Nanog, Oct4, Sox2, and Klf4, thus leading to cell differentiation and preventing tumorigenicity in Piwil2-overexpressing HaCaT cells. Similarly, Piwil2 also critically regulated the canonical Wnt signaling pathway in cervical cancer. We further demonstrated that ICG-001 increased cisplatin sensitivity and significantly suppressed tumor growth of cervical cancer alone or in combination with cisplatin both in vitro and in vivo. The ß-catenin/ CREB binding protein-mediated transcription activated by Piwil2 is essential for the maintenance of TICs, therefore contributing to the progression of cervical oncogenesis.

Sensory Experience Modulates Atrx-mediated Neuronal Integrity in the Mouse Retina.

Mutation of the α-thalassemia/mental retardation syndrome X-linked protein, ATRX, causes intellectual disability and is associated with pleiotropic defects including ophthalmological abnormalities. We have previously demonstrated that Atrx deficiency in the mouse retina leads to the selective loss of inhibitory interneurons and inner retinal dysfunction. Onset of the amacrine cell neurodegenerative phenotype in Atrx-deficient retinas occurs postnatally after neuronal specification, and coincides with eye opening. Given this timing, we sought to interrogate the influence of light-dependent visual signaling on Atrx-mediated neuronal survival and function in the mouse retina. Retina-specific Atrx conditional knockout (cKO) mice were subjected to light deprivation using two different paradigms: (1) a dark-rearing regime, and (2) genetic deficiency of metabotropic glutamate receptor 6 (mGluR6) to block the ON retinal signaling pathway. Scotopic electroretinography was performed for adult dark-reared Atrx cKO mice and controls to measure retinal neuron function in vivo. Retinal immunohistochemistry and enumeration of amacrine cells were performed for both light deprivation paradigms. We observed milder normalized a-wave, b-wave and oscillatory potential (OP) deficits in electroretinograms of dark-reared Atrx cKO mice compared to light-exposed counterparts. In addition, amacrine cell loss was partially limited by genetic restriction of retinal signaling through the ON pathway. Our results suggest that the temporal features of the Atrx cKO phenotype are likely due to a combined effect of light exposure upon eye opening and coincident developmental processes impacting the retinal circuitry. In addition, this study reveals a novel activity-dependent role for Atrx in mediating post-replicative neuronal integrity in the CNS.

Correction to: C3aR signaling and gliosis in response to neurodevelopmental damage in the cerebellum.

Following publication of the original article, the authors noticed missing labels in Fig. 1a.

Cyclooxygenase 2 Promotes Proliferation and Invasion in Ovarian Cancer Cells via the PGE2/NF-κB Pathway.

Ovarian cancer is the leading cause of death among gynecological malignancies. Cyclooxygenase 2 is widely expressed in various cancer cells and participates in the occurrence and development of tumors by regulating a variety of downstream signaling pathways. However, the function and molecular mechanisms of cyclooxygenase 2 remain unclear in ovarian cancer. Here, we demonstrated that cyclooxygenase 2 was highly expressed in ovarian cancer and the expression level was highly correlated with ovarian tumor grades. Further, ovarian cancer cells with high expression of cyclooxygenase 2 exhibit enhanced proliferation and invasion abilities. Specifically, cyclooxygenase 2 promoted the release of prostaglandin E2 upregulated the phosphorylation levels of phospho-nuclear factor-kappa B p65. Celecoxib, AH6809, and BAY11-7082 all can inhibit the promoting effect of cyclooxygenase 2 on SKOV3 and OVCAR3 cell proliferation and invasion. Besides, celecoxib inhibited SKOV3 cell growth in the xenograft tumor model. These data suggest that high expression of cyclooxygenase 2 promotes the proliferation and invasion of ovarian cancer cells through the prostaglandin E2/nuclear factor-kappa B signaling pathway. Cyclooxygenase 2 may be a potential therapeutic target for the treatment of ovarian cancer.

Snf2h Drives Chromatin Remodeling to Prime Upper Layer Cortical Neuron Development.

Alterations in the homeostasis of either cortical progenitor pool, namely the apically located radial glial (RG) cells or the basal intermediate progenitors (IPCs) can severely impair cortical neuron production. Such changes are reflected by microcephaly and are often associated with cognitive defects. Genes encoding epigenetic regulators are a frequent cause of intellectual disability and many have been shown to regulate progenitor cell growth, including our inactivation of the Smarca1 gene encoding Snf2l, which is one of two ISWI mammalian orthologs. Loss of the Snf2l protein resulted in dysregulation of Foxg1 and IPC proliferation leading to macrocephaly. Here we show that inactivation of the closely related Smarca5 gene encoding the Snf2h chromatin remodeler is necessary for embryonic IPC expansion and subsequent specification of callosal projection neurons. Telencephalon-specific Smarca5 cKO embryos have impaired cell cycle kinetics and increased cell death, resulting in fewer Tbr2+ and FoxG1+ IPCs by mid-neurogenesis. These deficits give rise to adult mice with a dramatic reduction in Satb2+ upper layer neurons, and partial agenesis of the corpus callosum. Mice survive into adulthood but molecularly display reduced expression of the clustered protocadherin genes that may further contribute to altered dendritic arborization and a hyperactive behavioral phenotype. Our studies provide novel insight into the developmental function of Snf2h-dependent chromatin remodeling processes during brain development.

C3aR signaling and gliosis in response to neurodevelopmental damage in the cerebellum.

BACKGROUND: Conditional ablation of the Smarca5 gene in mice severely impairs the postnatal growth of the cerebellum and causes an ataxic phenotype. Comparative gene expression studies indicated that complement-related proteins were upregulated in the cerebellum of Smarca5 mutant mice. Complement proteins play critical roles within innate immune signaling pathways and, in the brain, are produced by glial cells under both normal and pathological conditions. The C3 complement protein-derived signaling peptide, C3a, has been implicated in contributing to both tissue damage and repair in conditions such as multiple sclerosis and stroke. Here, we investigated whether C3a receptor (C3aR) signaling promoted damage or repair in the developing cerebellum of Smarca5 mutant mice. METHODS: Brain and cerebellum lysates from single Smarca5 conditional knockout (Smarca5 cKO) mice, C3aR1 KO mice, or double mutant mice were used for qRT-PCR and immunoblotting to assess the contribution of C3aR to the Smarca5 cKO brain pathology. Immunohistochemistry was used to characterize alterations to astroglia and phagocyte cells in the developing cerebellum of each of the genotypes. RESULTS: C3aR signaling was observed to limit gliosis and promote granule neuron survival during postnatal cerebellar development. In Smarca5 cKO mice, disorganized astroglia with increased GFAP expression develops concurrently with cerebellar granule neuron loss and phagocyte invasion over the first 10 days following birth. Potential ligand precursors of C3aR-VGF and C3-were found to have upregulated expression and/or altered processing during this time. Phagocytes (microglia and macrophages) in both the control and Smarca5 mutant mice were the only cells observed to express C3aR. Loss of C3aR in the Smarca5 cKO cerebellum resulted in increased numbers of apoptotic cells and early phagocyte invasion into the external granule cell layer, as well as an exacerbated disorganization of the Bergmann glia. The loss of C3aR expression also attenuated an increase in the expression of the efferocytosis-related protein, MerTK, whose transcript was upregulated ~ 2.5-fold in the Smarca5 mutant cerebellum at P10. CONCLUSIONS: This data indicates that C3aR can play an important role in limiting astrogliosis and regulating phagocyte phenotypes following developmental cell loss in the brain.

Polyinosinic-polycytidylic acid induces innate immune responses via Toll-like receptor 3 in human ovarian granulosa cells.

The ovary can be infected by a variety of viruses, which may come from the female reproductive tract or the peritoneum. The innate immune responses to viral infection in the human ovary are poorly understood. The present study demonstrated that human ovarian granulosa cells had innate immune activity in response to viral RNA challenge through Toll-like receptor 3 (TLR3) activation. TLR3 was constitutively expressed in the human ovary and predominantly located in granulosa cells of developmental follicles at all stages. Polyinosinic-polycytidylic acid [poly (I:C)], a synthetic viral double-stranded RNA analog, induced innate immune responses in human ovarian granulosa cells and affected endocrine function. Poly (I:C) significantly upregulated proinflammatory cytokines, including tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, IL-1ß and type I interferon (IFN-α/ß), and the innate immune responses were significantly reduced by blocking TLR3 signaling. Furthermore, poly (I:C) induced antiviral genes expression, including 2'-5'-oligoadenylate synthetase, Mx GTPase 1, IFN-stimulating gene 15 and double-stranded RNA-activated protein kinase R. In contrast, the expression of P450 aromatase and inhibin was dramatically inhibited by poly (I:C). Both silencing of TLR3 and neutralizing TNF-α reversed the inhibitory effect of poly (I:C) on P450 aromatase and inhibin expression. Our study demonstrates that granulosa cells play a potential role in innate immune protection against viral infection in the normal human ovary, and the innate immune response perturbs cell endocrine function.

Recovery from impaired muscle growth arises from prolonged postnatal accretion of myonuclei in Atrx mutant mice.

Reduced muscle mass due to pathological development can occur through several mechanisms, including the loss or reduced proliferation of muscle stem cells. Muscle-specific ablation of the α-thalassemia mental retardation syndrome mutant protein, Atrx, in transgenic mice results in animals with a severely reduced muscle mass at three weeks of age; yet this muscle mass reduction resolves by adult age. Here, we explore the cellular mechanism underlying this effect. Analysis of Atrx mutant mice included testing for grip strength and rotorod performance. Muscle fiber length, fiber volume and numbers of myofiber-associated nuclei were determined from individual EDL or soleus myofibers isolated at three, five, or eight weeks. Myofibers from three week old Atrx mutant mice are smaller with fewer myofiber-associated nuclei and reduced volume compared to control animals, despite similar fiber numbers. Nonetheless, the grip strength of Atrx mutant mice was comparable to control mice when adjusted for body weight. Myofiber volume remained smaller at five weeks, becoming comparable to controls by 8 weeks of age. Concomitantly, increased numbers of myofiber-associated nuclei and Ki67+ myoblasts indicated that the recovery of muscle mass likely arises from the prolonged accretion of new myonuclei. This suggests that under disease conditions the muscle satellite stem cell niche can remain in a prolonged active state, allowing for the addition of a minimum number of myonuclei required to achieve a normal muscle size.

Gonadotropins promote human ovarian cancer cell migration and invasion via a cyclooxygenase 2-dependent pathway.

It is generally accepted that ovarian cancer is associated with local elevation of gonadotropins (FSH and LH), with repeated ovulation and accompanying expression of inducible cyclooxygenase 2 (COX2). However, the roles of gonadotropins and the concomitant elevation of COX2 in the development of ovarian cancer have not been fully characterized. Herein, we report that excessive FSH/LH exposure did not induce proliferation in ovarian cancer cell lines but significantly promoted cell migration and invasion. Moreover, FSH/LH treatment rapidly upregulated COX2 expression within 24 h, whereas COX1 expression remained unchanged. Further results showed that enhancement of epithelial-mesenchymal transition (EMT) and upregulation of matrix metalloproteinase (MMP)2 and MMP9 contributed to the stimulatory effect of gonadotropins on cell migration and invasion; these effects were sufficiently blocked by a selective COX2 inhibitor. In conclusion, the present study suggests that gonadotropin-induced migration and invasion in ovarian cancer may be caused by EMT and MMP upregulation via a COX2-dependent pathway.

Cytosolic DNA sensor-initiated innate immune responses in mouse ovarian granulosa cells.

Viral infections of the ovary may perturb ovarian functions. However, the mechanisms underlying innate immune responses in the ovary are poorly understood. The present study demonstrates that cytosolic viral DNA sensor signaling initiates the innate immune response in mouse ovarian granulosa cells and affects endocrine function. The cytosolic DNA sensors p204 and cGAS and their common signaling adaptor stimulator of interferon (IFN) genes (STING) were constitutively expressed in granulosa cells. Transfection with VACV70, a synthetic vaccinia virus (VACV) DNA analog, induced the expression of type I interferons (IFNA/B) and major inflammatory cytokines (TNFA and IL6) through IRF3 and NF-κB activation respectively. Moreover, several IFN-inducible antiviral proteins, including 2',5'-oligoadenylate synthetase, IFN-stimulating gene 15 and Mx GTPase 1, were also induced by VACV70 transfection. The innate immune responses in granulosa cells were significantly reduced by the transfection of specific small-interfering RNAs targeting p204, cGas or Sting Notably, the VACV70-triggered innate immune responses affected steroidogenesis in vivo and in vitro The data presented in this study describe the mechanism underlying ovarian immune responses to viral infection.

Voluntary Running Triggers VGF-Mediated Oligodendrogenesis to Prolong the Lifespan of Snf2h-Null Ataxic Mice.

Exercise has been argued to enhance cognitive function and slow progressive neurodegenerative disease. Although exercise promotes neurogenesis, oligodendrogenesis and adaptive myelination are also significant contributors to brain repair and brain health. Nonetheless, the molecular details underlying these effects remain poorly understood. Conditional ablation of the Snf2h gene impairs cerebellar development producing mice with poor motor function, progressive ataxia, and death between postnatal days 25-45. Here, we show that voluntary running induced an endogenous brain repair mechanism that resulted in a striking increase in hindbrain myelination and the long-term survival of Snf2h cKO mice. Further experiments identified the VGF growth factor as a major driver underlying this effect. VGF neuropeptides promote oligodendrogenesis in vitro, whereas Snf2h cKO mice treated with full-length VGF-encoding adenoviruses removed the requirement of exercise for survival. Together, these results suggest that VGF delivery could represent a therapeutic strategy for cerebellar ataxia and other pathologies of the CNS.

Piwil2 is reactivated by HPV oncoproteins and initiates cell reprogramming via epigenetic regulation during cervical cancer tumorigenesis.

The human papillomavirus (HPV) oncoproteins E6 and E7 are risk factors that are primarily responsible for the initiation and progression of cervical cancer, and they play a key role in immortalization and transformation by reprogramming differentiating host epithelial cells. It is unclear how cervical epithelial cells transform into tumor-initiating cells (TICs). Here, we observed that the germ stem cell protein Piwil2 is expressed in pre-cancerous and malignant lesions of the cervix and cervical cancer cell lines with the exception of the non-HPV-infected C33a cell line. Knockdown of Piwil2 by shRNA led to a marked reduction in proliferation and colony formation, in vivo tumorigenicity, chemo-resistance, and the proportion of cancer stem-like cells. In contrast, Piwil2 overexpression induced malignant transformation of HaCaT cells and the acquisition of tumor-initiating capabilities. Gene-set enrichment analysis revealed embryonic stem cell (ESC) identity, malignant biological behavior, and specifically, activation targets of the cell reprogramming factors c-Myc, Klf4, Nanog, Oct4, and Sox2 in Piwil2-overexpressing HaCaT cells. We further confirmed that E6 and E7 reactivated Piwil2 and that E6 and E7 overexpression resulted in a similar gene-set enrichment pattern as Piwil2 overexpression in HaCaT cells. Moreover, Piwil2 overexpression or E6 and E7 activation induced H3K9 acetylation but reduced H3K9 trimethylation, which contributed to the epigenetic reprogramming and ESC signature maintenance, as predicted previously. Our study demonstrates that Piwil2, reactivated by the HPV oncoproteins E6 and E7, plays an essential role in the transformation of cervical epithelial cells to TICs via epigenetics-based cell reprogramming.

Mumps virus induces innate immune responses in mouse ovarian granulosa cells through the activation of Toll-like receptor 2 and retinoic acid-inducible gene I.

Mumps virus (MuV) infection may lead to oophoritis and perturb ovarian function. However, the mechanisms underlying the activation of innate immune responses to MuV infection in the ovary have not been investigated. This study showed that Toll-like receptor 2 (TLR2) and retinoic acid-inducible gene I (RIG-I) cooperatively initiate innate immune responses to MuV infection in mouse ovarian granulosa cells. Ovarian granulosa cells infected with MuV significantly produced pro-inflammatory cytokines and chemokines, including interleukin-1ß (IL-1ß), tumor necrosis factor α (TNF-α), monocyte chemotactic protein 1 (MCP-1), and type 1 interferons (IFN-α and IFN-ß). Knockdown of RIG-I significantly decreased MuV-induced cytokine expression. TLR2 deficiency reduced the expression of IL-1ß, TNF-α, and MCP-1 but did not affect the expression of IFN-α and IFN-ß in granulosa cells after infection with MuV. Intraperitoneal injection of MuV induced the ovarian innate immune responses in vivo, which suppressed estradiol synthesis and induced granulosa cell apoptosis. The results provide novel insights into the mechanisms underlying MuV-induced innate immune responses in the mouse ovary.