FOXP Genes, Neural Development, Speech and Language Disorders

LncRNA MIR181A1HG Deficiency Attenuates Vascular Inflammation and Atherosclerosis

BACKGROUND

Endothelial cell (EC) dysfunction and vascular inflammation are critical in the initiation and progression of atherosclerosis. Long noncoding RNAs play a critical role in vascular pathology, but relatively little is known about their involvement in controlling vascular inflammation. MIR181A1HG is a conserved long noncoding RNA located in juxtaposition with miR-181a1 and miR-181b1, both involved in vascular inflammation. The study aims to investigate the role of MIR181A1HG in regulating vascular inflammation.

METHODS

We examined the expression of MIR181A1HG in both human and mouse atherosclerotic lesions. Loss-of-function and gain-of-function studies, and multiple RNA-protein interaction assays were used to investigate the role and molecular mechanisms of MIR181A1HG in vascular inflammation and atherosclerosis. The atherosclerotic phenotypes of MIR181A1HG-/-ApoE-/- mice were analyzed in combination with single-cell RNA sequencing. The transcriptional regulation of MIR181A1HG was verified through luciferase reporter and chromatin immunoprecipitation assays.

RESULTS

MIR181A1HG expression was abundant in ECs and significantly increased in both human and mouse atherosclerotic lesions. MIR181A1HG-/-ApoE-/- mice had reduced NLRP (NLR family pyrin domain containing) 3 inflammasome signaling, EC activation, monocyte infiltration, and atherosclerotic lesion formation. Genetic deletion of MIR181A1HG in myeloid sells did not alter the progression of atherosclerosis. Single-cell RNA sequencing analysis revealed that MIR181A1HG deficiency reduced the proportion of immune cells and enriched anti-inflammation pathways in EC clusters in atherosclerotic lesions. In contrast, EC-specific MIR181A1HG overexpression promoted NLRP3 inflammasome signaling, EC activation, and atherosclerotic lesion formation, effects that were reversed by pharmacological inhibition of NLRP3 (MCC950). MIR181A1HG was transcriptionally activated via an NF-κB (nuclear factor kappa B)/p65-dependent pathway. Mechanistically, MIR181A1HG mediated these effects on regulating NLRP3 inflammasome and EC activation in part through decoying Foxp1 (forkhead box transcription factor 1) away from the promoters of target genes, which was independent of the miR-181a1/b1 cluster. Finally, EC-specific Foxp1 silencing reversed the antiatherosclerotic effect mediated by MIR181A1HG-deletion in vivo.

CONCLUSIONS

These findings identify MIR181A1HG as a central driver of vascular inflammation in atherosclerosis by its ability to decoy Foxp1 away from target gene promoters and activate NLRP3 inflammasome in the vascular endothelium. Our study suggests MIR181A1HG as a future therapeutic target for vascular inflammatory disease states.

Wings of Change: aPKC/FoxP-dependent plasticity in steering motor neurons underlies operant self-learning in Drosophila

Background

Motor learning is central to human existence, such as learning to speak or walk, sports moves, or rehabilitation after injury. Evidence suggests that all forms of motor learning share an evolutionarily conserved molecular plasticity pathway. Here, we present novel insights into the neural processes underlying operant self-learning, a form of motor learning in the fruit fly Drosophila.

Methods

We operantly trained wild type and transgenic Drosophila fruit flies, tethered at the torque meter, in a motor learning task that required them to initiate and maintain turning maneuvers around their vertical body axis (yaw torque). We combined this behavioral experiment with transgenic peptide expression, CRISPR/Cas9-mediated, spatio-temporally controlled gene knock-out and confocal microscopy.

Results

We find that expression of atypical protein kinase C (aPKC) in direct wing steering motoneurons co-expressing the transcription factor FoxP is necessary for this type of motor learning and that aPKC likely acts via non-canonical pathways. We also found that it takes more than a week for CRISPR/Cas9-mediated knockout of FoxP in adult animals to impair motor learning, suggesting that adult FoxP expression is required for operant self-learning.

Conclusions

Our experiments suggest that, for operant self-learning, a type of motor learning in Drosophila, co-expression of atypical protein kinase C (aPKC) and the transcription factor FoxP is necessary in direct wing steering motoneurons. Some of these neurons control the wing beat amplitude when generating optomotor responses, and we have discovered modulation of optomotor behavior after operant self-learning. We also discovered that aPKC likely acts via non-canonical pathways and that FoxP expression is also required in adult flies.

Transcription Factor Forkhead Box P (Foxp) 1 Reduces Brain Damage During Cerebral Ischemia-Reperfusion Injury in Mice Through FUN14 Domain-containing Protein 1

Mitophagy plays a significant role in modulating the activation of pyrin domain-containing protein 3 (NLRP3) inflammasome, which is a major contributor to the inflammatory response that exacerbates cerebral ischemia-reperfusion (I/R) injury. Despite this, the transcriptional regulation mechanism that governs mitophagy remains unclear. This study sought to explore the potential mechanism of Forkhead Box P1 (Foxp1) and its impact on cerebral I/R injury. We investigated the potential neuroprotective role of Foxp1 in cerebral I/R injury by the middle cerebral artery occlusion (MCAO) mouse model. Additionally, we assessed whether FUN14 domain-containing protein 1 (FUNDC1) could rescue the protective effect of Foxp1. Our results showed that overexpression of Foxp1 prevented brain damage during cerebral I/R injury and promoted NLRP3 inflammasome activation, whereas knockdown of Foxp1 had the opposite effect. Notably, Foxp1 overexpression directly promotes FUNDC1 expression, enhanced mitophagy activation, and inhibited the inflammatory response mediated by the NLRP3 inflammasome. Furthermore, we confirmed through chromatin immunoprecipitation (ChIP) and luciferase reporter assays that FUNDC1 is a direct target gene of Foxp1 downstream. Furthermore, the knockdown of FUNDC1 reversed the increased activation of mitophagy and suppressed NLRP3 inflammasome activation induced by Foxp1 overexpression. Collectively, our findings suggest that Foxp1 inhibits NLRP3 inflammasome activation through FUNDC1 to reduce cerebral I/R injury.

Conceptualizing Epigenetics and the Environmental Landscape of Autism Spectrum Disorders

Complex interactions between gene variants and environmental risk factors underlie the pathophysiological pathways in major psychiatric disorders. Autism Spectrum Disorder is a neuropsychiatric condition in which susceptible alleles along with epigenetic states contribute to the mutational landscape of the ailing brain. The present work reviews recent evolutionary, molecular, and epigenetic mechanisms potentially linked to the etiology of autism. First, we present a clinical vignette to describe clusters of maladaptive behaviors frequently diagnosed in autistic patients. Next, we microdissect brain regions pertinent to the nosology of autism, as well as cell networks from the bilateral body plan. Lastly, we catalog a number of pathogenic environments associated with disease risk factors. This set of perspectives provides emerging insights into the dynamic interplay between epigenetic and environmental variation in the development of Autism Spectrum Disorders.

The Expansion of the Spectrum in Stuttering Disorders to a Novel ARMC Gene Family (ARMC3)

Stuttering is a common neurodevelopment speech disorder that negatively affects the socio-psychological dimensions of people with disability. It displays many attributes of a complex genetic trait, and a few genetic loci have been identified through linkage studies. Stuttering is highly variable regarding its phenotypes and molecular etiology. However, all stutters have some common features, including blocks in speech, prolongation, and repetition of sounds, syllables, and words. The involuntary actions associated with stuttering often involve increased eye blinking, tremors of the lips or jaws, head jerks, clenched fists, perspiration, and cardiovascular changes. In the present study, we recruited a consanguineous Pakistani family showing an autosomal recessive mode of inheritance. The exome sequencing identified a homozygous splice site variant in ARMC3 (Armadillo Repeat Containing 3) in a consanguineous Pashtun family of Pakistani origin as the underlying genetic cause of non-syndromic stuttering. The homozygous splice site variant (NM_173081.5:c.916 + 1G > A) segregated with the stuttering phenotype in this family. The splice change leading to the skipping of exon-8 is a loss of function (LoF) variant, which is predicted to undergo NMD (Nonsense mediated decay). Here, we report ARMC3 as a novel candidate gene causing the stuttering phenotype. ARMC3 may lead to neurodevelopmental disorders, including stuttering in humans.

FOXR1 regulates stress response pathways and is necessary for proper brain development

The forkhead box (Fox) family of transcription factors are highly conserved and play essential roles in a wide range of cellular and developmental processes. We report an individual with severe neurological symptoms including postnatal microcephaly, progressive brain atrophy and global developmental delay associated with a de novo missense variant (M280L) in the FOXR1 gene. At the protein level, M280L impaired FOXR1 expression and induced a nuclear aggregate phenotype due to protein misfolding and proteolysis. RNAseq and pathway analysis showed that FOXR1 acts as a transcriptional activator and repressor with central roles in heat shock response, chaperone cofactor-dependent protein refolding and cellular response to stress pathways. Indeed, FOXR1 expression is increased in response to cellular stress, a process in which it directly controls HSPA6, HSPA1A and DHRS2 transcripts. The M280L mutant compromises FOXR1's ability to respond to stress, in part due to impaired regulation of downstream target genes that are involved in the stress response pathway. Quantitative PCR of mouse embryo tissues show Foxr1 expression in the embryonic brain. Using CRISPR/Cas9 gene editing, we found that deletion of mouse Foxr1 leads to a severe survival deficit while surviving newborn Foxr1 knockout mice have reduced body weight. Further examination of newborn Foxr1 knockout brains revealed a decrease in cortical thickness and enlarged ventricles compared to littermate wild-type mice, suggesting that loss of Foxr1 leads to atypical brain development. Combined, these results suggest FOXR1 plays a role in cellular stress response pathways and is necessary for normal brain development.

A Transcriptome Community-and-Module Approach of the Human Mesoconnectome

Graph analysis allows exploring transcriptome compartments such as communities and modules for brain mesostructures. In this work, we proposed a bottom-up model of a gene regulatory network to brain-wise connectome workflow. We estimated the gene communities across all brain regions from the Allen Brain Atlas transcriptome database. We selected the communities method to yield the highest number of functional mesostructures in the network hierarchy organization, which allowed us to identify specific brain cell functions (e.g., neuroplasticity, axonogenesis and dendritogenesis communities). With these communities, we built brain-wise region modules that represent the connectome. Our findings match with previously described anatomical and functional brain circuits, such the default mode network and the default visual network, supporting the notion that the brain dynamics that carry out low- and higher-order functions originate from the modular composition of a GRN complex network.

The Forkhead Box Transcription Factor FoxP4 Regulates Thermogenic Programs in Adipocytes

Forkhead box transcription factors have been shown to be involved in various developmental and differentiation processes. In particular, members of the FoxP family have been previously characterized in depth for their participation in the regulation of lung and neuronal cell differentiation and T-cell development and function; however, their role in adipocyte functionality has not yet been investigated. Here, we report for the first time that Forkhead box P4 (FoxP4) is expressed at high levels in subcutaneous fat depots and mature thermogenic adipocytes. Through molecular and gene expression analyses, we revealed that FoxP4 is induced in response to thermogenic stimuli, both in vivo and in isolated cells, and is regulated directly by the heat shock factor protein 1 through a heat shock response element identified in the proximal promoter region of FoxP4. Further detailed analysis involving chromatin immunoprecipitation and luciferase assays demonstrated that FoxP4 directly controls the levels of uncoupling protein 1, a key regulator of thermogenesis that uncouples fatty acid oxidation from ATP production. In addition, through our gain-of-function and loss-of-function studies, we showed that FoxP4 regulates the expression of a number of classic brown and beige fat genes and affects oxygen consumption in isolated adipocytes. Overall, our data demonstrate for the first time the novel role of FoxP4 in the regulation of thermogenic adipocyte functionality.

DNA Methylation Regulates Transcription Factor-Specific Neurodevelopmental but Not Sexually Dimorphic Gene Expression Dynamics in Zebra Finch Telencephalon

Song learning in zebra finches (Taeniopygia guttata) is a prototypical example of a complex learned behavior, yet knowledge of the underlying molecular processes is limited. Therefore, we characterized transcriptomic (RNA-sequencing) and epigenomic (RRBS, reduced representation bisulfite sequencing; immunofluorescence) dynamics in matched zebra finch telencephalon samples of both sexes from 1 day post hatching (1 dph) to adulthood, spanning the critical period for song learning (20 and 65 dph). We identified extensive transcriptional neurodevelopmental changes during postnatal telencephalon development. DNA methylation was very low, yet increased over time, particularly in song control nuclei. Only a small fraction of the massive differential expression in the developing zebra finch telencephalon could be explained by differential CpG and CpH DNA methylation. However, a strong association between DNA methylation and age-dependent gene expression was found for various transcription factors (i.e., OTX2, AR, and FOS) involved in neurodevelopment. Incomplete dosage compensation, independent of DNA methylation, was found to be largely responsible for sexually dimorphic gene expression, with dosage compensation increasing throughout life. In conclusion, our results indicate that DNA methylation regulates neurodevelopmental gene expression dynamics through steering transcription factor activity, but does not explain sexually dimorphic gene expression patterns in zebra finch telencephalon.

Case Report: Expressive Speech Disorder in a Family as a Hallmark of 7q31 Deletion Involving the FOXP2 Gene

Pathogenic variants of FOXP2 gene were identified first as a monogenic cause of childhood apraxia of speech (CAS), a complex disease that is associated with an impairment of the precision and consistency of movements underlying speech, due to deficits in speech motor planning and programming. FOXP2 variants are heterogenous; single nucleotide variants and small insertions/deletions, intragenic and large-scale deletions, as well as disruptions by structural chromosomal aberrations and uniparental disomy of chromosome 7 are the most common types of mutations. FOXP2-related speech and language disorders can be classified as "FOXP2-only," wherein intragenic mutations result in haploinsufficiency of the FOXP2 gene, or "FOXP2-plus" generated by structural genomic variants (i.e., translocation, microdeletion, etc.) and having more likely developmental and behavioral disturbances adjacent to speech and language impairment. The additional phenotypes are usually related to the disruption/deletion of multiple genes neighboring FOXP2 in the affected chromosomal region. We report the clinical and genetic findings in a family with four affected individuals having expressive speech impairment as the dominant symptom and additional mild dysmorphic features in three. A 7.87 Mb interstitial deletion of the 7q31.1q31.31 region was revealed by whole genome diagnostic microarray analysis in the proband. The FOXP2 gene deletion was confirmed by multiplex ligation-dependent probe amplification (MLPA), and all family members were screened by this targeted method. The FOXP2 deletion was detected in the mother and two siblings of the proband using MLPA. Higher resolution microarray was performed in all the affected individuals to refine the extent and breakpoints of the 7q31 deletion and to exclude other pathogenic copy number variants. To the best of our knowledge, there are only two family-studies reported to date with interstitial 7q31 deletion and showing the core phenotype of FOXP2 haploinsufficiency. Our study may contribute to a better understanding of the behavioral phenotype of FOXP2 disruptions and aid in the identification of such patients. We illustrate the importance of a targeted MLPA analysis suitable for the detection of FOXP2 deletion in selected cases with a specific phenotype of expressive speech disorder. The "phenotype first" and targeted diagnostic strategy can improve the diagnostic yield of speech disorders in the routine clinical practice.

The Role of Forkhead Box Family in Bone Metabolism and Diseases

Forkhead box (Fox) family, an evolutionarily conserved family of transcription factors carrying the "Forkhead" motif, plays an indispensable role in human health and disease. Fox family genes are involved in cell differentiation, proliferation and apoptosis, embryonic development, aging, glucose and lipid metabolism, and immune regulation. The regulatory role of the Fox family in the context of bone metabolism and orthopedic diseases is an emerging research hotspot. In this review, we highlight the major molecular mechanisms underlying the regulatory role of Fox factors in bone metabolism, bone development, bone homeostasis, and bone diseases associated with inhibition or upregulation of Fox factors. In addition, we discuss the emerging evidence in the realm of Fox factor-based therapeutics.

A synonymous UPF3B variant causing a speech disorder implicates NMD as a regulator of neurodevelopmental disorder gene networks

Loss-of-function mutations of the X-chromosome gene UPF3B cause male neurodevelopmental disorders (NDDs) via largely unknown mechanisms. We investigated initially by interrogating a novel synonymous UPF3B variant in a male with absent speech. In silico and functional studies using cell lines derived from this individual show altered UPF3B RNA splicing. The resulting mRNA species encodes a frame-shifted protein with a premature termination codon (PTC) predicted to elicit degradation via nonsense-mediated mRNA decay (NMD). UPF3B mRNA was reduced in the cell line, and no UPF3B protein was produced, confirming a loss-of-function allele. UPF3B is itself involved in the NMD mechanism which degrades both PTC-bearing mutant transcripts and also many physiological transcripts. RNAseq analysis showed that ~1.6% of mRNAs exhibited altered expression. These mRNA changes overlapped and correlated with those we identified in additional cell lines obtained from individuals harbouring other UPF3B mutations, permitting us to interrogate pathogenic mechanisms of UPF3B-associated NDDs. We identified 102 genes consistently deregulated across all UPF3B mutant cell lines. Of the 51 upregulated genes, 75% contained an NMD-targeting feature, thus identifying high-confidence direct NMD targets. Intriguingly, 22 of the dysregulated genes encoded known NDD genes, suggesting UPF3B-dependent NMD regulates gene networks critical for cognition and behaviour. Indeed, we show that 78.5% of all NDD genes encode a transcript predicted to be targeted by NMD. These data describe the first synonymous UPF3B mutation in a patient with prominent speech and language disabilities and identify plausible mechanisms of pathology downstream of UPF3B mutations involving the deregulation of NDD-gene networks.

Age, but Not Sex, Modulates Foxp3 Expression in the Rat Brain across Development

The interconnectivity between brain development and the immune system has become an area of interest for many neuroscientists. However, to date, a limited number of known immune mediators of the peripheral nervous system (PNS) have been found to influence the development of the central nervous system (CNS). FOXP3 is a well-established mediator of regulatory T-cells in the PNS. However, the expression pattern of FOXP3 in the CNS and the PNS throughout development is unknown. To fill this void, we have characterized, in several brain regions, the developmental profile of Foxp3 for both sexes using rats. We found different patterns of Foxp3 in the CNS and PNS. In the CNS, we found Foxp3 was ubiquitously expressed, with the levels of Foxp3 varying by brain region. We also found both Foxp3 mRNA and protein levels peak during embryonic development and then steadily decrease with a peak increase during adulthood. In adulthood, the protein but not mRNA increases to the equivalent levels found at the embryonic stage of life. In the PNS, Foxp3 protein levels were low embryonically and increased steadily over the life of the animal with maximal levels reached in adulthood. Patterns observed for both the PNS and CNS were similar in males and females across all developmental timepoints. Our novel findings have implications for understanding how the neural immune system impacts neurodevelopmental disorders such as autism and schizophrenia.

Differential Song Deficits after Lentivirus-Mediated Knockdown of FoxP1, FoxP2, or FoxP4 in Area X of Juvenile Zebra Finches

Mutations in the transcription factors FOXP1 and FOXP2 are associated with speech impairments. FOXP1 is additionally linked to cognitive deficits, as is FOXP4. These FoxP proteins are highly conserved in vertebrates and expressed in comparable brain regions, including the striatum. In male zebra finches, experimental manipulation of FoxP2 in Area X, a striatal song nucleus essential for vocal production learning, affects song development, adult song production, dendritic spine density, and dopamine-regulated synaptic transmission of striatal neurons. We previously showed that, in the majority of Area X neurons FoxP1, FoxP2, and FoxP4 are coexpressed, can dimerize and multimerize with each other and differentially regulate the expression of target genes. These findings raise the possibility that FoxP1, FoxP2, and FoxP4 (FoxP1/2/4) affect neural function differently and in turn vocal learning. To address this directly, we downregulated FoxP1 or FoxP4 in Area X of juvenile zebra finches and compared the resulting song phenotypes with the previously described inaccurate and incomplete song learning after FoxP2 knockdown. We found that experimental downregulation of FoxP1 and FoxP4 led to impaired song learning with partly similar features as those reported for FoxP2 knockdowns. However, there were also specific differences between the groups, leading us to suggest that specific features of the song are differentially impacted by developmental manipulations of FoxP1/2/4 expression in Area X.SIGNIFICANCE STATEMENT We compared the effects of experimentally reduced expression of the transcription factors FoxP1, FoxP2, and FoxP4 in a striatal song nucleus, Area X, on vocal production learning in juvenile male zebra finches. We show, for the first time, that these temporally and spatially precise manipulations of the three FoxPs affect spectral and temporal song features differentially. This is important because it raises the possibility that the different FoxPs control different aspects of vocal learning through combinatorial gene expression or by acting in different microcircuits within Area X. These results are consistent with the deleterious effects of human FOXP1 and FOXP2 mutations on speech and language and add FOXP4 as a possible candidate gene for vocal disorders.

Conserved regulation of neurodevelopmental processes and behavior by FoxP in Drosophila

FOXP proteins form a subfamily of evolutionarily conserved transcription factors involved in the development and functioning of several tissues, including the central nervous system. In humans, mutations in FOXP1 and FOXP2 have been implicated in cognitive deficits including intellectual disability and speech disorders. Drosophila exhibits a single ortholog, called FoxP, but due to a lack of characterized mutants, our understanding of the gene remains poor. Here we show that the dimerization property required for mammalian FOXP function is conserved in Drosophila. In flies, FoxP is enriched in the adult brain, showing strong expression in ~1000 neurons of cholinergic, glutamatergic and GABAergic nature. We generate Drosophila loss-of-function mutants and UAS-FoxP transgenic lines for ectopic expression, and use them to characterize FoxP function in the nervous system. At the cellular level, we demonstrate that Drosophila FoxP is required in larvae for synaptic morphogenesis at axonal terminals of the neuromuscular junction and for dendrite development of dorsal multidendritic sensory neurons. In the developing brain, we find that FoxP plays important roles in α-lobe mushroom body formation. Finally, at a behavioral level, we show that Drosophila FoxP is important for locomotion, habituation learning and social space behavior of adult flies. Our work shows that Drosophila FoxP is important for regulating several neurodevelopmental processes and behaviors that are related to human disease or vertebrate disease model phenotypes. This suggests a high degree of functional conservation with vertebrate FOXP orthologues and established flies as a model system for understanding FOXP related pathologies.

The forkhead domain hinge-loop plays a pivotal role in DNA binding and transcriptional activity of FOXP2

Forkhead box (FOX) proteins are a ubiquitously expressed family of transcription factors that regulate the development and differentiation of a wide range of tissues in animals. The FOXP subfamily members are the only known FOX proteins capable of forming domain-swapped forkhead domain (FHD) dimers. This is proposed to be due to an evolutionary mutation (P539A) that lies in the FHD hinge loop, a key region thought to fine-tune DNA sequence specificity in the FOX transcription factors. Considering the importance of the hinge loop in both the dimerisation mechanism of the FOXP FHD and its role in tuning DNA binding, a detailed investigation into the implications of mutations within this region could provide important insight into the evolution of the FOX family. Isothermal titration calorimetry and hydrogen exchange mass spectroscopy were used to study the thermodynamic binding signature and changes in backbone dynamics of FOXP2 FHD DNA binding. Dual luciferase reporter assays were performed to study the effect that the hinge-loop mutation has on FOXP2 transcriptional activity in vivo. We demonstrate that the change in dynamics of the hinge-loop region of FOXP2 alters the energetics and mechanism of DNA binding highlighting the critical role of hinge loop mutations in regulating DNA binding characteristics of the FOX proteins.

The untold stories of the speech gene, the FOXP2 cancer gene

FOXP2 encodes a transcription factor involved in speech and language acquisition. Growing evidence now suggests that dysregulated FOXP2 activity may also be instrumental in human oncogenesis, along the lines of other cardinal developmental transcription factors such as DLX5 and DLX6 [1-4]. Several FOXP familymembers are directly involved during cancer initiation, maintenance and progression in the adult [5-8]. This may comprise either a pro-oncogenic activity or a deficient tumor-suppressor role, depending upon cell types and associated signaling pathways. While FOXP2 is expressed in numerous cell types, its expression has been found to be down-regulated in breast cancer [9], hepatocellular carcinoma [8] and gastric cancer biopsies [10]. Conversely, overexpressed FOXP2 has been reported in multiple myelomas, MGUS (Monoclonal Gammopathy of Undetermined Significance), several subtypes of lymphomas [5,11], as well as in neuroblastomas [12] and ERG fusion-negative prostate cancers [13]. According to functional evidences reported in breast cancer [9] and survey of recent transcriptomic and proteomic analyses of different tumor biopsies, we postulate that FOXP2 dysregulation may play a main role throughout cancer initiation and progression. In some cancer conditions, FOXP2 levels are now considered as a critical diagnostic marker of neoplastic cells, and in many situations, they even bear strong prognostic value [5]. Whether FOXP2 may further become a therapeutic target is an actively explored lead. Knowledge reviewed here may help improve our understanding of FOXP2 roles during oncogenesis and provide cues for diagnostic, prognostic and therapeutic analyses.

Suppressor of cytokine signaling 2-12 regulates antimicrobial peptides and ecdysteroid signaling pathways in Bombyx mori (Dazao)

Suppressors of cytokine signaling (SOCS) are a potent negative regulator of diverse cytokine-related responses to maintain various physiological processes in animals. Here, we obtained the SOCS2-12 gene sequence of Bombyx mori (Dazao) (BmSOCS2-12) from the National Center for Biotechnology Information (NCBI) to study its expression profile in different tissues, as well as in the immune tissues following larval exposure to pathogens. Further, we investigated the role of BmSOCS2-12 in producing antimicrobial peptides (AMPs) and as a regulator of ecdysteroid signaling transduction. The quantitative real-time PCR analysis revealed unequal transcript levels of BmSOCS2-12 in the different tissues, however the gene's expression was highest in those of fat body and hemocyte. The challenge with pathogens significantly upregulated the transcript level of BmSOCS2-12 in both fat body and hemocyte when compared with the control. By contrast, recombinant BmSOCS2-12 protein injections strongly suppressed the expression of AMPs, while the knockdown of BmSOCS2-12 by double-stranded RNA enhanced their production. Administration of 20-hydroxyecdysone significantly downregulated the BmSOCS2-12 expression in fat body, and the depletion of BmSOCS2-12 enhanced the transcript levels of 20-hydroxyecdysone-responsive genes at 48 h. Altogether, BmSOCS2-12 may have multiple functional roles in the physiology of B. mori (Dazao), since it negatively regulates the expression of AMPs and ecdysteroid signaling transduction.

FOXP1 haploinsufficiency: Phenotypes beyond behavior and intellectual disability?

The forkhead box (FOX) transcription factors have roles in development, carcinogenesis, metabolism, and immunity. In humans FOXP1 mutations have been associated with language and speech defects, intellectual disability, autism spectrum disorder, facial dysmorphisms, and congenital anomalies of the kidney and urinary tract. In mice, Foxp1 plays critical roles in development of the spinal motor neurons, lymphocytes, cardiomyocytes, foregut, and skeleton. We hypothesized therefore that mutations of FOXP1 affect additional tissues in some humans. Supporting this hypothesis, we describe two individuals with novel variants of FOXP1 (NM_032682.5:c.975-2A>C and NM_032682.5:c.1574G>A) and additional features. One had a lung disease resembling neuroendocrine cell hyperplasia of infancy (NEHI), and the second had a skeletal disorder with undertubulation of the long bones and relapsing-remitting fevers associated with flushing and edema. Although attribution of these traits to mutation of FOXP1 requires ascertainment of additional patients, we hypothesize that the variable expression of these additional features might arise by means of stochastic developmental variation.

Fox transcription factors: from development to disease

Forkhead box (Fox) transcription factors are evolutionarily conserved in organisms ranging from yeast to humans. They regulate diverse biological processes both during development and throughout adult life. Mutations in many Fox genes are associated with human disease and, as such, various animal models have been generated to study the function of these transcription factors in mechanistic detail. In many cases, the absence of even a single Fox transcription factor is lethal. In this Primer, we provide an overview of the Fox family, highlighting several key Fox transcription factor families that are important for mammalian development.

Expression of forkhead box transcription factor genes Foxp1 and Foxp2 during jaw development

Development of the face is regulated by a large number of genes that are expressed in temporally and spatially specific patterns. While significant progress has been made on characterizing the genes that operate in the oral region of the face, those regulating development of the aboral (lateral) region remain largely unknown. Recently, we discovered that transcription factors LIM homeobox (LHX) 6 and LHX8, which are key regulators of oral development, repressed the expression of the genes encoding forkhead box transcription factors, Foxp1 and Foxp2, in the oral region. To gain insights into the potential role of the Foxp genes in region-specific development of the face, we examined their expression patterns in the first pharyngeal arch (primordium for the jaw) of mouse embryos at a high spatial and temporal resolution. Foxp1 and Foxp2 were preferentially expressed in the aboral and posterior parts of the first pharyngeal arch, including the developing temporomandibular joint. Through double immunofluorescence and double fluorescent RNA in situ hybridization, we found that Foxp1 was expressed in the progenitor cells for the muscle, bone, and connective tissue. Foxp2 was expressed in subsets of bone and connective tissue progenitors but not in the myoblasts. Neither gene was expressed in the dental mesenchyme nor in the oral half of the palatal shelf undergoing extensive growth and morphogenesis. Together, we demonstrated for the first time that Foxp1 and Foxp2 are expressed during craniofacial development. Our data suggest that the Foxp genes may regulate development of the aboral and posterior regions of the jaw.

Risperidone and NAP protect cognition and normalize gene expression in a schizophrenia mouse model

Mutated disrupted in schizophrenia 1 (DISC1), a microtubule regulating protein, leads to schizophrenia and other psychiatric illnesses. It is hypothesized that microtubule stabilization may provide neuroprotection in schizophrenia. The NAP (NAPVSIPQ) sequence of activity-dependent neuroprotective protein (ADNP) contains the SxIP motif, microtubule end binding (EB) protein target, which is critical for microtubule dynamics leading to synaptic plasticity and neuroprotection. Bioinformatics prediction for FDA approved drugs mimicking SxIP-like motif which displace NAP-EB binding identified Risperidone. Risperidone or NAP effectively ameliorated object recognition deficits in the mutated DISC1 mouse model. NAP but not Risperidone, reduced anxiety in the mutated mice. Doxycycline, which blocked the expression of the mutated DISC1, did not reverse the phenotype. Transcripts of Forkhead-BOX P2 (Foxp2), a gene regulating DISC1 and associated with human ability to acquire a spoken language, were increased in the hippocampus of the DISC1 mutated mice and were significantly lowered after treatment with NAP, Risperidone, or the combination of both. Thus, the combination of NAP and standard of care Risperidone in humans may protect against language disturbances associated with negative and cognitive impairments in schizophrenia.

A Proposed Neurological Interpretation of Language Evolution

Since the very beginning of the aphasia history it has been well established that there are two major aphasic syndromes (Wernicke's-type and Broca's-type aphasia); each one of them is related to the disturbance at a specific linguistic level (lexical/semantic and grammatical) and associated with a particular brain damage localization (temporal and frontal-subcortical). It is proposed that three stages in language evolution could be distinguished: (a) primitive communication systems similar to those observed in other animals, including nonhuman primates; (b) initial communication systems using sound combinations (lexicon) but without relationships among the elements (grammar); and (c) advanced communication systems including word-combinations (grammar). It is proposed that grammar probably originated from the internal representation of actions, resulting in the creation of verbs; this is an ability that depends on the so-called Broca's area and related brain networks. It is suggested that grammar is the basic ability for the development of so-called metacognitive executive functions. It is concluded that while the lexical/semantic language system (vocabulary) probably appeared during human evolution long before the contemporary man (Homo sapiens sapiens), the grammatical language historically represents a recent acquisition and is correlated with the development of complex cognition (metacognitive executive functions).

Drosophila FoxP mutants are deficient in operant self-learning

Intact function of the Forkhead Box P2 (FOXP2) gene is necessary for normal development of speech and language. This important role has recently been extended, first to other forms of vocal learning in animals and then also to other forms of motor learning. The homology in structure and in function among the FoxP gene members raises the possibility that the ancestral FoxP gene may have evolved as a crucial component of the neural circuitry mediating motor learning. Here we report that genetic manipulations of the single Drosophila orthologue, dFoxP, disrupt operant self-learning, a form of motor learning sharing several conceptually analogous features with language acquisition. Structural alterations of the dFoxP locus uncovered the role of dFoxP in operant self-learning and habit formation, as well as the dispensability of dFoxP for operant world-learning, in which no motor learning occurs. These manipulations also led to subtle alterations in the brain anatomy, including a reduced volume of the optic glomeruli. RNAi-mediated interference with dFoxP expression levels copied the behavioral phenotype of the mutant flies, even in the absence of mRNA degradation. Our results provide evidence that motor learning and language acquisition share a common ancestral trait still present in extant invertebrates, manifest in operant self-learning. This 'deep' homology probably traces back to before the split between vertebrate and invertebrate animals.

The Fox/Forkhead transcription factor family of the hemichordate Saccoglossus kowalevskii

Background

The Fox gene family is a large family of transcription factors that arose early in organismal evolution dating back to at least the common ancestor of metazoans and fungi. They are key components of many gene regulatory networks essential for embryonic development. Although much is known about the role of Fox genes during vertebrate development, comprehensive comparative studies outside vertebrates are sparse. We have characterized the Fox transcription factor gene family from the genome of the enteropneust hemichordate Saccoglossus kowalevskii, including phylogenetic analysis, genomic organization, and expression analysis during early development. Hemichordates are a sister group to echinoderms, closely related to chordates and are a key group for tracing the evolution of gene regulatory mechanisms likely to have been important in the diversification of the deuterostome phyla.

Results

Of the 22 Fox gene families that were likely present in the last common ancestor of all deuterostomes, S. kowalevskii has a single ortholog of each group except FoxH, which we were unable to detect, and FoxQ2, which has three paralogs. A phylogenetic analysis of the FoxQ2 family identified an ancestral duplication in the FoxQ2 lineage at the base of the bilaterians. The expression analyses of all 23 Fox genes of S. kowalevskii provide insights into the evolution of components of the regulatory networks for the development of pharyngeal gill slits (foxC, foxL1, and foxI), mesoderm patterning (foxD, foxF, foxG), hindgut development (foxD, foxI), cilia formation (foxJ1), and patterning of the embryonic apical territory (foxQ2).

Conclusions

Comparisons of our results with data from echinoderms, chordates, and other bilaterians help to develop hypotheses about the developmental roles of Fox genes that likely characterized ancestral deuterostomes and bilaterians, and more recent clade-specific innovations.

Rapid diversification of FoxP2 in teleosts through gene duplication in the teleost-specific whole genome duplication event

As one of the most conserved genes in vertebrates, FoxP2 is widely involved in a number of important physiological and developmental processes. We systematically studied the evolutionary history and functional adaptations of FoxP2 in teleosts. The duplicated FoxP2 genes (FoxP2a and FoxP2b), which were identified in teleosts using synteny and paralogon analysis on genome databases of eight organisms, were probably generated in the teleost-specific whole genome duplication event. A credible classification with FoxP2, FoxP2a and FoxP2b in phylogenetic reconstructions confirmed the teleost-specific FoxP2 duplication. The unavailability of FoxP2b in Danio rerio suggests that the gene was deleted through nonfunctionalization of the redundant copy after the Otocephala-Euteleostei split. Heterogeneity in evolutionary rates among clusters consisting of FoxP2 in Sarcopterygii (Cluster 1), FoxP2a in Teleostei (Cluster 2) and FoxP2b in Teleostei (Cluster 3), particularly between Clusters 2 and 3, reveals asymmetric functional divergence after the gene duplication. Hierarchical cluster analyses of hydrophobicity profiles demonstrated significant structural divergence among the three clusters with verification of subsequent stepwise discriminant analysis, in which FoxP2 of Leucoraja erinacea and Lepisosteus oculatus were classified into Cluster 1, whereas FoxP2b of Salmo salar was grouped into Cluster 2 rather than Cluster 3. The simulated thermodynamic stability variations of the forkhead box domain (monomer and homodimer) showed remarkable divergence in FoxP2, FoxP2a and FoxP2b clusters. Relaxed purifying selection and positive Darwinian selection probably were complementary driving forces for the accelerated evolution of FoxP2 in ray-finned fishes, especially for the adaptive evolution of FoxP2a and FoxP2b in teleosts subsequent to the teleost-specific gene duplication.

Strong expression of the neuronal transcription factor FOXP2 is linked to an increased risk of early PSA recurrence in ERG fusion-negative cancers

BACKGROUND AND AIMS

Transcription factors of the forkhead box P (FOXP1-4) family have been implicated in various human cancer types before. The relevance and role of neuronal transcription factor FOXP2 in prostate cancer is unknown.

METHODS

A tissue microarray containing samples from more than 11 000 prostate cancers from radical prostatectomy specimens with clinical follow-up data was analysed for FOXP2 expression by immunohistochemistry. FOXP2 data were also compared with pre-existing ERG fusion (by fluorescence in situ hybridisation and immunohistochemistry) and cell proliferation (Ki67 labelling index) data.

RESULTS

There was a moderate to strong FOXP2 protein expression in basal and secretory cells of normal prostatic glands. As compared with normal cells, FOXP2 expression was lost or reduced in 25% of cancers. Strong FOXP2 expression was linked to advanced tumour stage, high Gleason score, presence of lymph node metastases and early tumour recurrence (p<0.0001; each) in ERG fusion-negative, but not in ERG fusion-positive cancers. High FOXP2 expression was linked to high Ki67 labelling index (p<0.0001) in all cancers irrespective of ERG fusion status.

CONCLUSIONS

These data demonstrate that similar high FOXP2 protein levels as in normal prostate epithelium exert a 'paradoxical' oncogenic role in 'non fusion-type' prostate cancer. It may be speculated that interaction of FOXP2 with members of pathways that are specifically activated in 'non fusion-type' cancers may be responsible for this phenomenon.

Convergent repression of Foxp2 3'UTR by miR-9 and miR-132 in embryonic mouse neocortex: implications for radial migration of neurons

MicroRNAs (miRNAs) are rapidly emerging as a new layer of regulation of mammalian brain development. However, most of the miRNA target genes remain unidentified. Here, we explore gene expression profiling upon miRNA depletion and in vivo target validation as a strategy to identify novel miRNA targets in embryonic mouse neocortex. By this means, we find that Foxp2, a transcription factor associated with speech and language development and evolution, is a novel miRNA target. In particular, we find that miR-9 and miR-132 are able to repress ectopic expression of Foxp2 protein by targeting its 3' untranslated region (3'UTR) in vivo. Interestingly, ectopic expression of Foxp2 in cortical projection neurons (a scenario that mimics the absence of miRNA-mediated silencing of Foxp2 expression) delays neurite outgrowth in vitro and impairs their radial migration in embryonic mouse neocortex in vivo. Our results uncover a new layer of control of Foxp2 expression that may be required for proper neuronal maturation.