Pax genes and organogenesis

Identification and function of the Pax gene Bmgsb in the silk gland of Bombyx mori

Paired box (Pax) genes are highly conserved throughout evolution, and the Pax protein is an important transcription factor of embryonic development. The Pax gene Bmgsb is expressed in the silk glands of silkworm, but its biological functions remain unclear. This study aimed to investigate the expression pattern of Bmgsb in the silk gland and explore its functions using RNA interference (RNAi). Here, we identified eight Pax genes in Bombyx mori. Phylogenetic analysis showed that the B. mori Pax genes were highly homologous to the Pax genes in other insects and highly evolutionarily conserved. The tissue expression profile showed that Bmgsb was expressed in the anterior silk gland and anterior part of the middle silk gland (AMSG). RNAi of Bmgsb resulted in defective development of the AMSG, and the larvae were mostly unable to cocoon in the wandering stage. RNA-seq analysis showed that the fibroin genes fib-l, fib-h and p25, cellular heat shock response-related genes and phenol oxidase genes were considerably upregulated upon Bmgsb knockdown. Furthermore, quantitative reverse transcription-PCR results showed that the fibroin genes and ubiquitin proteolytic enzyme-related genes were significantly upregulated in the AMSG after Bmgsb knockdown. This study provides a foundation for future research on the biological functions of B. mori Pax genes. In addition, it demonstrates the important roles of Bmgsb in the transcriptional regulation of fibroin genes and silk gland development.

Pax-8: Molecular biology, pathophysiology, and potential pathogenesis

Transcription factors, as the convergence points of multiple signaling pathways in eukaryotic cells, are closely involved in disease development. Pax-8, an important transcription factor belonging to the Pax family, exerts a crucial influence on the regulation of gene expression required for both physiological conditions and pathological processes. Pax-8 contributes to the pathogenesis of many human diseases, ranging from cardiovascular disease to many cancers, and therefore, it can be imagined that Pax-8 holds great therapeutic potential. In this review, we summarize the structure, distribution, function, and regulatory mechanisms of Pax-8 to provide a new research direction for Pax-8.

Expanding the clinical and immunological phenotypes of PAX1-deficient SCID and CID patients

Paired box 1 (PAX1) deficiency has been reported in a small number of patients diagnosed with otofaciocervical syndrome type 2 (OFCS2). We described six new patients who demonstrated variable clinical penetrance. Reduced transcriptional activity of pathogenic variants confirmed partial or complete PAX1 deficiency. Thymic aplasia and hypoplasia were associated with impaired T cell immunity. Corrective treatment was required in 4/6 patients. Hematopoietic stem cell transplantation resulted in poor immune reconstitution with absent naïve T cells, contrasting with the superior recovery of T cell immunity after thymus transplantation. Normal ex vivo differentiation of PAX1-deficient CD34+ cells into mature T cells demonstrated the absence of a hematopoietic cell-intrinsic defect. New overlapping features with DiGeorge syndrome included primary hypoparathyroidism (n = 5) and congenital heart defects (n = 2), in line with PAX1 expression during early embryogenesis. Our results highlight new features of PAX1 deficiency, which are relevant to improving early diagnosis and identifying patients requiring corrective treatment.

Transcriptional control of embryonic and adult neural progenitor activity

Neural precursors generate neurons in the embryonic brain and in restricted niches of the adult brain in a process called neurogenesis. The precise control of cell proliferation and differentiation in time and space required for neurogenesis depends on sophisticated orchestration of gene transcription in neural precursor cells. Much progress has been made in understanding the transcriptional regulation of neurogenesis, which relies on dose- and context-dependent expression of specific transcription factors that regulate the maintenance and proliferation of neural progenitors, followed by their differentiation into lineage-specified cells. Here, we review some of the most widely studied neurogenic transcription factors in the embryonic cortex and neurogenic niches in the adult brain. We compare functions of these transcription factors in embryonic and adult neurogenesis, highlighting biochemical, developmental, and cell biological properties. Our goal is to present an overview of transcriptional regulation underlying neurogenesis in the developing cerebral cortex and in the adult brain.

PAX5 fusion genes in acute lymphoblastic leukemia: A literature review

Acute lymphoblastic leukemia (ALL) is a common cancer affecting children worldwide. The development of ALL is driven by several genes, some of which can be targeted for treatment by inhibiting gene fusions. PAX5 is frequently mutated in ALL and is involved in chromosomal rearrangements and translocations. Mutations in PAX5 interact with other genes, such as ETV6 and FOXP1, which influence B-cell development. PAX5/ETV6 has been observed in both B-ALL patients and a mouse model. The interaction between PAX5 and FOXP1 negatively suppresses the Pax5 gene in B-ALL patients. Additionally, ELN and PML genes have been found to fuse with PAX5, leading to adverse effects on B-cell differentiation. ELN-PAX5 interaction results in the decreased expression of LEF1, MB1, and BLNK, while PML-PAX5 is critical in the early stages of leukemia. PAX5 fusion genes prevent the transcription of the PAX5 gene, making it an essential target gene for the study of leukemia progression and the diagnosis of B-ALL.

Advances in tooth agenesis and tooth regeneration

The lack of treatment options for congenital (0.1%) and partial (10%) tooth anomalies highlights the need to develop innovative strategies. Over two decades of dedicated research have led to breakthroughs in the treatment of congenital and acquired tooth loss. We revealed that by inactivating USAG-1, congenital tooth agenesis can be successfully ameliorated during early tooth development and that the inactivation promotes late-stage tooth morphogenesis in double knockout mice. Furthermore, Anti- USAG-1 antibody treatment in mice is effective in tooth regeneration and can be a breakthrough in treating tooth anomalies in humans. With approximately 0.1% of the population suffering from congenital tooth agenesis and 10% of children worldwide suffering from partial tooth loss, early diagnosis will improve outcomes and the quality of life of patients. Understanding the role of pathogenic USAG-1 variants, their interacting gene partners, and their protein functions will help develop critical biomarkers. Advances in next-generation sequencing, mass spectrometry, and imaging technologies will assist in developing companion and predictive biomarkers to help identify patients who will benefit from tooth regeneration.

PAX8 as a Potential Target for Ovarian Cancer: What We Know so Far

The Fallopian tube epithelium harbors the origin cells for the majority of high-grade serous ovarian carcinomas (HGSCs), the most lethal form of gynecologic malignancies. PAX8 belongs to the paired-box gene family of transcription factors and it is a marker of the FTE secretory cell lineage. Its role has been investigated in migration, invasion, proliferation, cell survival, stem cell maintenance, angiogenesis and tumor growth. In this review, we focus on the pro-tumorigenic role of PAX8 in ovarian cancer; in this context, PAX8 possibly continues to exert its transcriptional activity on its physiological targets but may also function on newly available targets after the tumorigenic hits. Acquiring new insights into the different PAX8 mechanism(s) of action in the tumor microenvironment could uncover new viable therapeutic targets and thus improve the current treatment regimen.

MYB transcription factors and their role in Medicinal plants

Transcription factors are multi-domain proteins that regulate gene expression in eukaryotic organisms. They are one of the largest families of proteins, which are structurally and functionally diverse. While there are transcription factors that are plant-specific, such as AP2/ERF, B3, NAC, SBP and WRKY, some transcription factors are present in both plants as well as other eukaryotic organisms. MYB transcription factors are widely distributed among all eukaryotes. In plants, the MYB transcription factors are involved in the regulation of numerous functions such as gene regulation in different metabolic pathways especially secondary metabolic pathways, regulation of different signalling pathways of plant hormones, regulation of genes involved in various developmental and morphological processes etc. Out of the thousands of MYB TFs that have been studied in plants, the majority of them have been studied in the model plants like Arabidopsis thaliana, Oryza sativa etc. The study of MYBs in other plants, especially medicinal plants, has been comparatively limited. But the increasing demand for medicinal plants for the production of biopharmaceuticals and important bioactive compounds has also increased the need to explore more number of these multifaceted transcription factors which play a significant role in the regulation of secondary metabolic pathways. These studies will ultimately contribute to medicinal plants' research and increased production of secondary metabolites, either through transgenic plants or through synthetic biology approaches. This review compiles studies on MYB transcription factors that are involved in the regulation of diverse functions in medicinal plants.

Clinicopathological Relevance of PAX8 Expression Patterns in Acute Kidney Injury and Chronic Kidney Diseases

Transcription factor PAX8, expressed during embryonic kidney development, has been previously detected in various kidney tumors. In order to investigate expression of PAX8 transcription factor in acute kidney injury (AKI) and chronic kidney diseases (CKD), immunohistochemical analysis was performed. Presence, location and extent of PAX8 expression were analyzed among 31 human kidney samples of AKI (25 autopsy cases, 5 kidney biopsies with unknown etiology and 1 AKI with confirmed myoglobin cast nephropathy), as well as in animals with induced postischemic AKI. Additionally, expression pattern was analyzed in 20 kidney biopsy samples of CKD. Our study demonstrates that various kidney diseases with chronic disease course that results in the formation of tubular atrophy and interstitial fibrosis, lead to PAX8 expression in the nuclei of proximal tubules. Furthermore, patients with PAX8 detected within the damaged proximal tubuli would be carefully monitored, since deterioration in kidney function was observed during follow-up. We also showed that myoglobin provoked acute kidney injury followed with large extent of renal damage, was associated with strong nuclear expression of PAX8 in proximal tubular cells. These results were supported and followed by data obtained in experimental model of induced postischemic acute kidney injury. Considering these findings, we can assume that PAX8 protein might be involved in regeneration process and recovery after acute kidney injury. Thus, accordingly, all investigation concerning PAX8 immunolabeling should be performed on biopsy samples of the living individuals.

Identification of sex-biased and neurodevelopment genes via brain transcriptome in Ostrinia furnacalis

Insect brains play important roles in the regulation of sex-biased behaviors such as mating and oviposition. The neural structure and function of brain differences between males and females have been identified, in which the antenna lobes (AL) showed the most discrepancy, however, the whole repertoire of the genes expressed in the brains and the molecular mechanism of neural signaling and structural development are still unclear. In this study, high-throughput transcriptome analysis of male and female brains was carried on in the Asia corn borer, Ostrinia furnacalis, and a total of 39.23 Gb data and 34,092 unigenes were obtained. Among them, 276 genes displayed sex-biased expression by DEG analysis, of which 125 genes were highly expressed in the males and 151 genes were highly expressed in the females. Besides, by homology analysis against genes that have been confirmed to be related to brain neurodevelopment, a total of 24 candidate genes were identified in O. furnacalis. In addition, to further screen the core genes that may be important for sex-biased nerve signaling and neurodevelopment, protein-protein interaction networks were constructed for the sex-biased genes and neurodevelopment genes. We identified 10 (Mhc, Mlc1, Mlc2, Prm, Mf, wupA, TpnC25D, fln, l(2)efl, and Act5C), 11 (PPO2, GNBP3, Spn77Ba, Ppn, yellow-d2, PGRP-LB, PGRP-SD, PGRP-SC2, Hml, Cg25C, and vkg) and 8 (dac, wg, hh, ci, run, Lim1, Rbp9, and Bx) core hub genes that may be related to brain neural development from male-biased, female-biased, and neurodevelopment gene groups. Our results provide a reference for further analysis of the dimorphism of male and female brain structures in agricultural pests.

Monoclonal/polyclonal PAX-8, PTH and GATA3 immunohistochemistry in parathyroid lesions

BACKGROUND

Parathyroid gland (PG) is an endocrine organ which may display different immunohistochemical stainings with chief cells and oxyphilic cells in normal as well as hyperplasic/tumoral lesions.

PURPOSE

In this study, we aimed to identify the demographic properties and diagnostic value of the GATA3 antibody, which is a transcription factor in addition to PTH, and of PAX-8 (monoclonal and polyclonal) antibody.

METHODS

We have analyzed in detail the cellular components and staining intensities of 46 adenomas all of which contained parathyroid rims, 12 hyperplasia and 5 adjacent non-neoplastic thyroidectomy materials (63 patients, 114 tissues).

RESULTS

While no staining was identified in the thyroid tissue, cytoplasmic PTH immunoreactivity was observed in all (100%) normal parathyroid tissues, rim of PGs and hyperplasia, and in 43/46 cases (93.4%) of adenomas. Adenoma and hyperplasia were less stained than normal PG (p < 0.05). We detected GATA3 staining in all cases except for the thyroid (100%). Weak positivity (1+) was most apparent in adenoma cases (p < 0.05). Monoclonal PAX-8 immunoreactivity was not identified in any normal parathyroid tissue and rim of PG but positive immunoreactivity was detected in 83.3% of hyperplasia cases (10/12), 84.8% of adenoma (39/46) and 100% of thyroid tissues (5/5) (p < 0.05). However, polyclonal PAX-8 immunoreactivity was detected in one normal parathyroid tissue (1/5) and seven (7/46) rim of PGs. In cases of hyperplasia and adenoma, positive immunoreactivity was 75% (9/12) and 74% (34/46), respectively.

CONCLUSION

In conclusion, we have observed that PTH and GATA3 constitute a much more reliable and sensitive marker for parathyroid and are stained less in adenomas. While monoclonal PAX-8 (MRQ-50) never stains normal parathyroid and rim of PGs, it may help in the differential diagnosis of proliferated parathyroid lesions as a considerably sensitive and relatively specific marker by staining hyperplasic parathyroid, adenomas and the thyroid.

New Genes Born-In or Invading Vertebrate Genomes

Which is the origin of genes is a fundamental question in Biology, indeed a question older than the discovery of genes itself. For more than a century, it was uneven to think in origins other than duplication and divergence from a previous gene. In recent years, however, the intersection of genetics, embryonic development, and bioinformatics, has brought to light that de novo generation from non-genic DNA, horizontal gene transfer and, noticeably, virus and transposon invasions, have shaped current genomes, by integrating those newcomers into old gene networks, helping to shape morphological and physiological innovations. We here summarized some of the recent research in the field, mostly in the vertebrate lineage with a focus on protein-coding novelties, showing that the placenta, the adaptative immune system, or the highly developed neocortex, among other innovations, are linked to de novo gene creation or domestication of virus and transposons. We provocatively suggest that the high tolerance to virus infections by bats may also be related to previous virus and transposon invasions in the bat lineage.

Dynamic Molecular Evolution of Mammalian Homeobox Genes: Duplication, Loss, Divergence and Gene Conversion Sculpt PRD Class Repertoires

The majority of homeobox genes are highly conserved across animals, but the eutherian-specific ETCHbox genes, embryonically expressed and highly divergent duplicates of CRX, are a notable exception. Here we compare the ETCHbox genes of 34 mammalian species, uncovering dynamic patterns of gene loss and tandem duplication, including the presence of a large tandem array of LEUTX loci in the genome of the European rabbit (Oryctolagus cuniculus). Despite extensive gene gain and loss, all sampled species possess at least two ETCHbox genes, suggesting their collective role is indispensable. We find evidence for positive selection and show that TPRX1 and TPRX2 have been the subject of repeated gene conversion across the Boreoeutheria, homogenising their sequences and preventing divergence, especially in the homeobox region. Together, these results are consistent with a model where mammalian ETCHbox genes are dynamic in evolution due to functional overlap, yet have collective indispensable roles.

Predicted regulatory SNPs reveal potential drug targets and novel companion diagnostics in psoriasis

Psoriasis is an autoimmune disease associated with interleukins, their receptors, key transcription factors and more recently, antimicrobial peptides (AMPs). Cathelicidin LL-37 is an AMP proposed to play a fundamental role in psoriasis etiology. With our proprietary software SNPClinic v.1.0, we analyzed 203 common SNPs (MAF frequency ​> ​1%) in proximal promoters of 22 genes associated with psoriasis. These include nine genes which protein products are classic drug targets for psoriasis (TNF, IL17A, IL17B, IL17C, IL17F, IL17RA, IL12A, IL12B and IL23A). SNPClinic predictions were run with DNAseI-HUP chromatin accessibility data in eight psoriasis/epithelia-relevant cell lines from ENCODE including keratinocytes (NHEK), T_H1 and T_H17 lymphocytes. Results were ranked quantitatively by transcriptional relevance according to our novel Functional Impact Factor (FIF) parameter. We found six rSNPs in five genes (CAMP/cathelicidin, S100A7/psoriasin, IL17C, IL17RA and TNF) and each was confirmed as true rSNP in at least one public eQTL database including GTEx portal and ENCODE (Phase 3). Predicted regulatory SNPs in cathelicidin, IL17C and IL17RA genes may explain hyperproliferation of keratinocytes. Predicted rSNPs in psoriasin, IL17C and cathelicidin may contribute to activation and polarization of lymphocytes. Predicted rSNPs in TNF gene are concordant with the epithelium-mesenchymal transition. In spite that these results must be validated in vitro and in vivo with a functional genomics approach, we propose FOXP2, RUNX2, NR2F1, ELF1 and HESX1 transcription factors (those with the highest FIF on each gene) as novel drug targets for psoriasis. Furthermore, four out of six rSNPs uncovered by SNPClinic v.1.0 software, could also be validated in the clinic as companion diagnostics/pharmacogenetics assays for psoriasis prescribed drugs that block TNF-α (e.g. Etanercept), IL-17 (e.g. Secukinumab) and IL-17 receptor (Brodalumab).

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We found six putative regulatory SNPs in cathelicidin (LL-37), psoriasin (S100A7), IL17C, IL17RA and TNF genes.

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These rSNPs could be validated also as companion diagnostics/pharmacogenetics assays for most approved psoriasis drugs.

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Regulatory SNPs in TNF gene are concordant with the epithelial-mesenchymal transition.

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Regulatory SNPs in IL17C and IL17RA may partially explain hyperproliferation of keratinocytes.

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Regulatory SNP rs12049559 in psoriasin (S100A7) may contribute to T-cell polarization.

Overview of PAX gene family: analysis of human tissue-specific variant expression and involvement in human disease

Paired-box (PAX) genes encode a family of highly conserved transcription factors found in vertebrates and invertebrates. PAX proteins are defined by the presence of a paired domain that is evolutionarily conserved across phylogenies. Inclusion of a homeodomain and/or an octapeptide linker subdivides PAX proteins into four groups. Often termed "master regulators", PAX proteins orchestrate tissue and organ development throughout cell differentiation and lineage determination, and are essential for tissue structure and function through maintenance of cell identity. Mutations in PAX genes are associated with myriad human diseases (e.g., microphthalmia, anophthalmia, coloboma, hypothyroidism, acute lymphoblastic leukemia). Transcriptional regulation by PAX proteins is, in part, modulated by expression of alternatively spliced transcripts. Herein, we provide a genomics update on the nine human PAX family members and PAX homologs in 16 additional species. We also present a comprehensive summary of human tissue-specific PAX transcript variant expression and describe potential functional significance of PAX isoforms. While the functional roles of PAX proteins in developmental diseases and cancer are well characterized, much remains to be understood regarding the functional roles of PAX isoforms in human health. We anticipate the analysis of tissue-specific PAX transcript variant expression presented herein can serve as a starting point for such research endeavors.

Unraveling the Mysteries of PAX8 in Reproductive Tract Cancers

Paired Box 8 (PAX8) is a lineage-specific transcription factor that has essential roles during embryogenesis and tumorigenesis. The importance of PAX8 in the development of the reproductive system is highlighted by abnormalities observed upon the loss or mutation of this PAX family member. In cancer, PAX8 expression is deregulated in a key set of neoplasms, including those arising from the Müllerian ducts. The roles of PAX8 in oncogenesis are diverse and include epigenetic remodeling, stimulation of proliferation, inhibition of apoptosis, and regulation of angiogenesis. PAX8 can interact with different protein partners during cancer progression and may exhibit significant function-altering alternative splicing. Moreover, expression of PAX8 in cancer can also serve as a biomarker for diagnostic and prognostic purposes. In this review, we focus on the roles of PAX8 in cancers of the reproductive system. Understanding the diverse mechanisms of action of PAX8 in development and oncogenesis may identify new vulnerabilities in malignancies that currently lack effective therapies.

Genome-wide association study of body size traits in Wenshang Barred chickens based on the specific-locus amplified fragment sequencing technology

Chicken body size (BS) is an economically important trait, which has been assessed in many studies for genetic selection. However, previous reports detected functional chromosome mutations or regions using gene chips. The present study used the specific-locus amplified fragment sequencing (SLAF-seq) technology to perform a genome-wide association study (GWAS) of purebred Wenshang Barred chickens. A total of 250 one-day-old male chickens were assessed in this study. Body size in individual birds was measured at 56 days. SLAF-seq was used to genotype and GWAS analysis was carried out using the general linear model (GLM) of the TASSEL program. A total of 1,286,715 single-nucleotide polymorphisms (SNPs) were detected, of which 175,211 were tested as candidate SNPs for genome-wide association analysis using the TASSEL general linear model. Three SNPs markers reached genome-wide significance. Of these, chrZ:81729634, chrZ:81841715, and chrZ:81954149 at 81,729,634, 81,841,715, and 81,954,149 bp of GGA Z were significantly associated with body diagonal length at 56 days (BDL56); and tibia length at 56 days (TL56). These SNPs were close to three genes, including ZCCHC7, PAX5, and MELK. These results open new horizons for studies on BS and should promote the use of Chinese chickens, especially Wenshang Barred chickens.

The Role of PAX2 in Neurodevelopment and Disease

In developmental biology, transcription factors are involved in regulating the process of neural development, controlling the differentiation of nerve cells, and affecting the normal functioning of neural circuits. Transcription factors regulate the expression of multiple genes at the same time and have become a key gene category that is recognized to be disrupted in neurodevelopmental disorders such as autism spectrum disorders. This paper briefly introduces the expression and role of PAX2 in neurodevelopment and discusses the neurodevelopmental disorders associated with Pax2 mutations and its possible mechanism. Firstly, mutations in the human Pax2 gene are associated with abnormalities in multiple systems which can result in neurodevelopmental disorders such as intellectual disability, epilepsy and autism spectrum disorders. Secondly, the structure of Pax2 gene and PAX2 protein, as well as the function of Pax2 gene in neural development, was discussed. Finally, a diagram of the PAX2 protein regulatory network was made and a possible molecular mechanism of Pax2 mutations leading to neurodevelopmental disorders from the perspectives of developmental process and protein function was proposed.

PAX8, an Emerging Player in Ovarian Cancer

Ovarian Cancer is one of the most lethal and widespread gynecological malignancies. It is the seventh leading cause of all cancer deaths worldwide. High-Grade Serous Cancer (HGSC), the most commonly occurring subtype, alone contributes to 70% of all ovarian cancer deaths. This is mainly attributed to the complete lack of symptoms during the early stages of the disease and absence of an early diagnostic marker.PAX8 is emerging as an important histological marker for most of the epithelial ovarian cancers, as it is expressed in about 90% of malignant ovarian cancers, specifically in HGSC. PAX8 is a member of the Paired-Box gene family (PAX1-9) of transcription factors whose expression is tightly controlled temporally and spatially. The PAX genes are well known for their role in embryonic development and their expression continues to persist in some adult tissues. PAX8 is required for the normal development of Müllerian duct that includes Fallopian tube, uterus, cervix, and upper part of vagina. In adults, it is expressed in the Fallopian tube and uterine epithelium and not in the ovarian epithelium. Considering the recent studies that predict the events preceding the tumorigenesis of HGSC from the Fallopian tube, PAX8 appears to have an important role in the development of ovarian cancer.In this chapter, we review some of the published findings to highlight the significance of PAX8 as an important marker and an emerging player in the pathogenesis of ovarian cancer. We also discuss regarding the future perspectives of PAX8 wherein it could contribute to the betterment of ovarian cancer diagnosis and treatment.

PAX8: A Highly Sensitive Marker for the Glands in Extragenital Endometriosis

In cases of extragenital endometriosis or microscopic endometriosis lesions, pathological diagnosis can be challenging because endometriotic stroma and glands represent only a minor component of fibrotic endometriotic lesions. For better accuracy of diagnosis, the development of a sensitive and specific epithelial marker is beneficial. Previous studies showed that PAX8 is a highly sensitive and specific marker for primary and metastatic Mullerian epithelial tumors. Therefore, we sought to examine whether PAX8 is a highly sensitive marker for glands in extragenital endometriosis. Eight and 47 samples of ovarian endometrioma and extragenital endometriosis, respectively, were evaluated in this study. We calculated the percentage of samples positively immunostained for PAX8, CD10, estrogen receptor (ER), and progesterone receptor (PR). PAX8 was positive for endometriotic epithelial cells in 95.7% (45/47) of extragenital endometrioses and in 100% (8/8) of ovarian endometrioses. CD10 was positive for endometriotic stromal cells in 97.9% (46/47) of extragenital endometrioses. PAX8 was strongly positive for glands, even in a CD10-negative case. The expression of PAX8, CD10, and PR was not affected by preoperative hormonal therapy, and the positive rate of ER staining was significantly reduced by preoperative hormonal therapy. In conclusion, PAX8 is a highly sensitive epithelial marker for extragenital endometriosis. This specific expression was maintained under hormonal therapy. It is noteworthy that extragenital endometriosis maintains the expression of this lineage marker, although it occurs at various sites, and its cause and mechanism of development might be different. PAX8 nuclear expression can be useful in detecting extragenital endometriosis in clinical practice.

Immunohistochemical expression of PAX-8 in Sudanese patients diagnosed with malignant female reproductive tract tumors

Objectives

Paired box protein-8 (PAX-8) immunohistochemical expression can be used as a diagnostic marker for epithelial cells tumors. This study aimed at investigating the immunohistochemical expression of PAX-8 among Sudanese females diagnosed with cervical, endometrial, and ovarian cancers between December 2017 and May 2019 by studying their Formalin-fixed paraffin embedded blocks.

Results

Sixty patients diagnosed with female reproductive tract cancers were included who aged 58.7 ± 6.9 years (range, 43—71). Cervix was the most common cancer site in 51/60 (85%) patients. Regarding cancer stage, there was 17 (28%) and 14 (23%) of the study population had stage 3B and 2B, respectively. The histopathological diagnosis included 20 (44%), 13 (29%), and 12 (27%) poorly, moderately, and well differentiated cervical squamous cell carcinoma (SCC) as well as 11 (73%), 2 (13%), 1 (7%), and 1 (7%) endometrial adenocarcinoma, metastatic adenocarcinoma, endocervical adenocarcinoma, and ovarian mucinous cyst adenocarcinoma, respectively. PAX-8 was positively expressed in 9 endometrial adenocarcinoma, 1 endocervical adenocarcinoma and 1 ovarian mucinous cyst adenocarcinoma, 2 poorly, and 1 moderately differentiated SCC. All patients diagnosed with well differentiated SCC and metastatic adenocarcinoma showed no expression of PAX-8. A statistically significant was seen for PAX-8 expression and the different histopathological diagnosis, P value < 0.001.

Evolutionary and Developmental Associations of Neural Crest and Placodes in the Vertebrate Head: Insights From Jawless Vertebrates

Neural crest and placodes are key innovations of the vertebrate clade. These cells arise within the dorsal ectoderm of all vertebrate embryos and have the developmental potential to form many of the morphological novelties within the vertebrate head. Each cell population has its own distinct developmental features and generates unique cell types. However, it is essential that neural crest and placodes associate together throughout embryonic development to coordinate the emergence of several features in the head, including almost all of the cranial peripheral sensory nervous system and organs of special sense. Despite the significance of this developmental feat, its evolutionary origins have remained unclear, owing largely to the fact that there has been little comparative (evolutionary) work done on this topic between the jawed vertebrates and cyclostomes—the jawless lampreys and hagfishes. In this review, we briefly summarize the developmental mechanisms and genetics of neural crest and placodes in both jawed and jawless vertebrates. We then discuss recent studies on the role of neural crest and placodes—and their developmental association—in the head of lamprey embryos, and how comparisons with jawed vertebrates can provide insights into the causes and consequences of this event in early vertebrate evolution.

Thymus Inception: Molecular Network in the Early Stages of Thymus Organogenesis

The thymus generates central immune tolerance by producing self-restricted and self-tolerant T-cells as a result of interactions between the developing thymocytes and the stromal microenvironment, mainly formed by the thymic epithelial cells. The thymic epithelium derives from the endoderm of the pharyngeal pouches, embryonic structures that rely on environmental cues from the surrounding mesenchyme for its development. Here, we review the most recent advances in our understanding of the molecular mechanisms involved in early thymic organogenesis at stages preceding the expression of the transcription factor Foxn1, the early marker of thymic epithelial cells identity. Foxn1-independent developmental stages, such as the specification of the pharyngeal endoderm, patterning of the pouches, and thymus fate commitment are discussed, with a special focus on epithelial–mesenchymal interactions.

Increased repetitive self-grooming occurs in Pax2 mutant mice generated using CRISPR/Cas9

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impaired social interaction and communication, and repetitive or restricted interest and behaviors. However, the specific pathogenesis of ASD is still unclear. It has been widely accepted that genetic and environmental risk factors are associated with the pathogenesis of ASD. Paired box2 (Pax2) gene encodes a transcription factor that plays an important role in the development of the central nervous system of humans and mice. In this study, we constructed Pax2 heterozygous gene knockout (Pax2^+/-) mice using CRISPR/Cas9 technology and performed several autistic-like behavioral assays, including self-grooming test, sociability approach, the elevated plus maze test and Y maze test. Results showed increased repetitive self-grooming and possible abnormal anxiety-like behavior occur in Pax2^+/- mice. Furthermore, no changes were observed in the abilities of sociability and working memory in Pax2^+/- mice compared to wild-type C57BL/6 J mice. Finally, we speculated that possible mechanism of abnormal autistic-like behaviors due to the deletion of Pax2 gene.

Ocular and brain imaging findings in Peters' anomaly: A case report and literature review

Peters’ anomaly is a rare congenital eye condition characterized by anterior segment dysgenesis and commonly presents as unilateral or bilateral corneal opacity in the early neonatal period. Peters’ anomaly is often associated with congenital brain and skull abnormalities, which are frequently overlooked. In this paper, we present a case of a 5-day-old female neonate with Peters’ anomaly, and review the literature for similar reports that describe associated brain imaging findings. In our case, imaging studies show abnormalities involving the anterior segments of both globes with absent intracranial manifestations. Although Peters’ anomaly is a condition of interest for ophthalmologists, radiological studies should be performed, and neuroradiologists should be aware of the imaging findings associated with this rare entity.

PTEN-knockdown disrupts the morphology, growth pattern and function of Nthy-Ori 3-1 cells by downregulating PAX8 expression

The incidence of thyroid disorders, which are common endocrine diseases, has rapidly increased in recent years. However, the etiology and pathogenesis of these disorders remain unclear. Phosphatase and tension homolog (PTEN) is a dual-specific phosphatase that is associated with multiple thyroid disorders; however, the role of PTEN in thyroid disorders remains unknown. In the present study, the human thyroid follicular epithelial cell line Nthy-Ori 3-1 was used to determine the role of PTEN in thyroid disorders. PTEN expression was knocked down using a PTEN-specific short hairpin RNA. Western blotting was subsequently used to determine protein expression, the Matrigel tube formation assay and iodide uptake assay were applied for evaluating the morphology and function of thyroid cells. The results showed that PTEN knockdown decreased the protein expression of paired box 8 (PAX8). The morphology and tubular-like growth pattern of thyroid cells were therefore disrupted, and restoration of PAX8 expression reversed these effects. Furthermore, PTEN-knockdown decreased the expression of specific thyroid proteins (thyroglobulin, TG; thyroid peroxidase, TPO; and sodium/iodide symporter, NIS) and inhibited the iodide uptake ability of thyroid cells by downregulating PAX8, suggesting that PTEN deficiency may impair the function of thyroid cells. In conclusion, the present study reported an important function of PTEN in normal thyroid cells and identified the involvement of PAX8. These results may improve understanding of the role of PTEN in the pathogenesis of thyroid disorders.

Aniridia with lenticular and choroidal coloboma

This case report presents a rare association of a complete aniridia with lenticular and choroidal coloboma. An 8-year-old female patient was referred to our glaucoma clinic with aniridia, nystagmus and bilateral corneal opacity with right eye being phthisical. Ultrasonography of the phthisical eye revealed the presence of an old closed funnel retinal detachment. Further examination under anaesthesia revealed lens coloboma in the inferonasal quadrant and presence of a choroidal coloboma in the left eye. The intraocular pressure was 28 mmHg with a central corneal thickness of 693 µm. A macula sparing laser barrage around the colobomatous area was done in the left eye and topical ocular hypotensives were started.

PAX8: A Highly Sensitive Marker for the Glands in Extragenital Endometriosis

In cases of extragenital endometriosis or microscopic endometriosis lesions, pathological diagnosis can be challenging because endometriotic stroma and glands represent only a minor component of fibrotic endometriotic lesions. For better accuracy of diagnosis, the development of a sensitive and specific epithelial marker is beneficial. Previous studies showed that PAX8 is a highly sensitive and specific marker for primary and metastatic Mullerian epithelial tumors. Therefore, we sought to examine whether PAX8 is a highly sensitive marker for glands in extragenital endometriosis. Eight and 47 samples of ovarian endometrioma and extragenital endometriosis, respectively, were evaluated in this study. We calculated the percentage of samples positively immunostained for PAX8, CD10, estrogen receptor (ER), and progesterone receptor (PR). PAX8 was positive for endometriotic epithelial cells in 95.7% (45/47) of extragenital endometrioses and in 100% (8/8) of ovarian endometrioses. CD10 was positive for endometriotic stromal cells in 97.9% (46/47) of extragenital endometrioses. PAX8 was strongly positive for glands, even in a CD10-negative case. The expression of PAX8, CD10, and PR was not affected by preoperative hormonal therapy, and the positive rate of ER staining was significantly reduced by preoperative hormonal therapy. In conclusion, PAX8 is a highly sensitive epithelial marker for extragenital endometriosis. This specific expression was maintained under hormonal therapy. It is noteworthy that extragenital endometriosis maintains the expression of this lineage marker, although it occurs at various sites, and its cause and mechanism of development might be different. PAX8 nuclear expression can be useful in detecting extragenital endometriosis in clinical practice.

The promising role of PAX1 (aliases: HUP48, OFC2) gene methylation in cancer screening

Background

Paired‐box gene 1 (PAX1), a member of the PAX family, plays a role in pattern formation during embryogenesis, and might be essential for development of the vertebral column.

Methods

PAX1 is silenced by methylation in several cancers and is considered a tumor suppressor gene. Our previous studies reported PAX1 as hypermethylated in cervical cancer tissues, thereby suggesting it as a potential screening marker. Recently, an increasing number of studies have confirmed PAX1 methylation as a promising biomarker in cervical cancer based on its excellent discriminatory ability between high‐grade cervical lesions and normal tissues, resulting in a reduced necessity for referral for colposcopy and biopsy. Additionally, PAX1 is also hypermethylated in other tumors, including those associated with epithelial ovarian cancer, esophageal squamous cell carcinoma, head and neck squamous cell carcinoma, and endometrial carcinoma, and shows relatively good sensitivity and specificity for the detection of these tumors.

Results

This review summarizes reports of PAX1 methylation and its promising role in cancer screening, especially that associated with cervical cancer.

Conclusion

According to current evidence, combined testing for human papillomavirus and PAX1 methylation analysis represents an efficacious cervical cancer‐screening protocol.

Activating β-catenin/Pax6 axis negatively regulates osteoclastogenesis by selectively inhibiting phosphorylation of p38/MAPK

Balance of osteoclast formation is regulated by the receptor activator of NF-κB ligand and extracellular negative regulators such as IFN-γ and IFN-β. However, very little is known about the intrinsic negative regulatory factors of osteoclast differentiation. Recently, the paired-box homeodomain transcription factor Pax6 was shown to negatively regulate receptor activator of NF-κB ligand-mediated osteoclast differentiation. However, the mechanism underlying this regulation is still unclear. In this study, we show that a p38 inhibitor (VX-745) up-regulates the expression of Pax6 during osteoclast differentiation. Subsequently, we found that β-catenin could bind to the proximal region of Pax6 promoter to induce its expression, and this action could be impaired by p38-induced ubiquitin-mediated degradation of β-catenin. Our results suggest that Pax6 is regulated by a novel p38/β-catenin pathway. Pax6 can further regulate the nuclear translocation of NF of activated T cells, cytoplasmic 1. Our study indicates that this novel p38/β-catenin/Pax6 axis contributes to negative regulation of osteoclastogenesis. In addition, our study proposes a novel approach to treat osteoclast-related diseases through the use of VX-745 complemented with the β-catenin activator SKL2001.-Jie, Z., Shen, S., Zhao, X., Xu, W., Zhang, X., Huang, B., Tang, P., Qin, A., Fan, S., Xie, Z. Activating β-catenin/Pax6 axis negatively regulates osteoclastogenesis by selectively inhibiting phosphorylation of p38/MAPK.

The role of PAX9 promoter gene polymorphisms in causing hypodontia: a study in the Jordanian population

Background

The congenital absence of one or few teeth, hypodontia, is considered one of the utmost dental ageneses in human beings. Several genes have been shown to be involved in the development of hypodontia such as paired box gene 9 (PAX9). The expression of PAX9 is controlled by several polymorphic elements in the promoter region of the gene on 14q13.3 locus. The aim of this study was to find any association between PAX9 c.-912T>C (rs2073247) and c.-1031G>A (rs2073244) promoter polymorphisms and the development of hypodontia among the Jordanian population.

Methods

Genotyping of the polymorphisms in 72 unrelated subjects with hypodontia was performed using PCR-restriction fragment length polymorphism (RFLP) technique and compared with that of 72 normal healthy unrelated control individuals.

Results

The hypodontia group had a significantly higher -1031GG genotype (P<0.01) and a significantly lower -912TC genotype (P<0.01) compared with the control group. The results suggest that the transcriptional activity of PAX9 gene is affected by polymorphisms in the promoter region of this gene and is associated with hypodontia phenotype.

Conclusion

The rs2073247) and rs2073244 promoter polymorphisms of PAX9 might play a role in the development of hypodontia in the Jordanian population.

Fbxo2VHC mouse and embryonic stem cell reporter lines delineate in vitro-generated inner ear sensory epithelia cells and enable otic lineage selection and Cre-recombination

While the mouse has been a productive model for inner ear studies, a lack of highly specific genes and tools has presented challenges. The absence of definitive otic lineage markers and tools is limiting in vitro studies of otic development, where innate cellular heterogeneity and disorganization increase the reliance on lineage-specific markers. To address this challenge in mice and embryonic stem (ES) cells, we targeted the lineage-specific otic gene Fbxo2 with a multicistronic reporter cassette (Venus/Hygro/CreER = VHC). In otic organoids derived from ES cells, Fbxo2^VHC specifically delineates otic progenitors and inner ear sensory epithelia. In mice, Venus expression and CreER activity reveal a cochlear developmental gradient, label the prosensory lineage, show enrichment in a subset of type I vestibular hair cells, and expose strong expression in adult cerebellar granule cells. We provide a toolbox of multiple spectrally distinct reporter combinations for studies that require use of fluorescent reporters, hygromycin selection, and conditional Cre-mediated recombination.

UnPAXing the Divergent Roles of PAX2 and PAX8 in High-Grade Serous Ovarian Cancer

High-grade serous ovarian cancer is a deadly disease that can originate from the fallopian tube or the ovarian surface epithelium. The PAX (paired box) genes PAX2 and PAX8 are lineage-specific transcription factors required during development of the fallopian tube but not in the development of the ovary. PAX2 expression is lost early in serous cancer progression, while PAX8 is expressed ubiquitously. These proteins are implicated in migration, invasion, proliferation, cell survival, stem cell maintenance, and tumor growth. Hence, targeting PAX2 and PAX8 represents a promising drug strategy that could inhibit these pro-tumorigenic effects. In this review, we examine the implications of PAX2 and PAX8 expression in the cell of origin of serous cancer and their potential efficacy as drug targets by summarizing their role in the molecular pathogenesis of ovarian cancer.

SMAD proteins directly suppress PAX2 transcription downstream of transforming growth factor-beta 1 (TGF-β1) signalling in renal cell carcinoma

Canonical TGF-β1 signalling promotes tumor progression by facilitating invasion and metastasis, whereby release of TGF-β1, by (for example) infiltrating immune cells, induces epithelial to mesenchymal transition (EMT). PAX2, a member of the Paired box family of transcriptional regulators, is normally expressed during embryonic development, including in the kidney, where it promotes mesenchymal to epithelial transition (MET). PAX2 expression is silenced in many normal adult tissues. However, in contrast, PAX2 is expressed in several cancer types, including kidney, prostate, breast, and ovarian cancer. While multiple studies have implicated TGF-β superfamily members in modulating expression of Pax genes during embryonic development, few have investigated direct regulation of Pax gene expression by TGF-β1. Here we have investigated direct regulation of PAX2 expression by TGF-β1 in clear cell renal cell carcinoma (CC-RCC) cell lines. Treatment of PAX2-expressing 786-O and A498 CC-RCC cell lines with TGF-β1 resulted in inhibition of endogenous PAX2 mRNA and protein expression, as well as expression from transiently transfected PAX2 promoter constructs; this inhibition was abolished in the presence of expression of the inhibitory SMAD, SMAD7. Using ChIP-PCR we showed TGF-β1 treatment induced SMAD3 protein phosphorylation in 786-O cells, and direct SMAD3 binding to the human PAX2 promoter, which was inhibited by SMAD7 over-expression. Overall, these data suggest that canonical TGF-β signalling suppresses PAX2 transcription in CC-RCC cells due to the direct binding of SMAD proteins to the PAX2 promoter. These studies improve our understanding of tumor progression and epithelial to mesenchyme transition (EMT) in CC-RCC and in other PAX2-expressing cancer types.

Neurocristopathies: New insights 150 years after the neural crest discovery

The neural crest (NC) is a transient, multipotent and migratory cell population that generates an astonishingly diverse array of cell types during vertebrate development. These cells, which originate from the ectoderm in a region lateral to the neural plate in the neural fold, give rise to neurons, glia, melanocytes, chondrocytes, smooth muscle cells, odontoblasts and neuroendocrine cells, among others. Neurocristopathies (NCP) are a class of pathologies occurring in vertebrates, especially in humans that result from the abnormal specification, migration, differentiation or death of neural crest cells during embryonic development. Various pigment, skin, thyroid and hearing disorders, craniofacial and heart abnormalities, malfunctions of the digestive tract and tumors can also be considered as neurocristopathies. In this review we revisit the current classification and propose a new way to classify NCP based on the embryonic origin of the affected tissues, on recent findings regarding the molecular mechanisms that drive NC formation, and on the increased complexity of current molecular embryology techniques.

Alpha-Secretase ADAM10 Regulation: Insights into Alzheimer's Disease Treatment

ADAM (a disintegrin and metalloproteinase) is a family of widely expressed, transmembrane and secreted proteins of approximately 750 amino acids in length with functions in cell adhesion and proteolytic processing of the ectodomains of diverse cell-surface receptors and signaling molecules. ADAM10 is the main α-secretase that cleaves APP (amyloid precursor protein) in the non-amyloidogenic pathway inhibiting the formation of β-amyloid peptide, whose accumulation and aggregation leads to neuronal degeneration in Alzheimer’s disease (AD). ADAM10 is a membrane-anchored metalloprotease that sheds, besides APP, the ectodomain of a large variety of cell-surface proteins including cytokines, adhesion molecules and notch. APP cleavage by ADAM10 results in the production of an APP-derived fragment, sAPPα, which is neuroprotective. As increased ADAM10 activity protects the brain from β-amyloid deposition in AD, this strategy has been proved to be effective in treating neurodegenerative diseases, including AD. Here, we describe the physiological mechanisms regulating ADAM10 expression at different levels, aiming to propose strategies for AD treatment. We report in this review on the physiological regulation of ADAM10 at the transcriptional level, by epigenetic factors, miRNAs and/or translational and post-translational levels. In addition, we describe the conditions that can change ADAM10 expression in vitro and in vivo, and discuss how this knowledge may help in AD treatment. Regulation of ADAM10 is achieved by multiple mechanisms that include transcriptional, translational and post-translational strategies, which we will summarize in this review.

Candidate genes and pathways downstream of PAX8 involved in ovarian high-grade serous carcinoma

Understanding the biology and molecular pathogenesis of ovarian epithelial cancer (EOC) is key to developing improved diagnostic and prognostic indicators and effective therapies. Although research has traditionally focused on the hypothesis that high-grade serous carcinoma (HGSC) arises from the ovarian surface epithelium (OSE), recent studies suggest that additional sites of origin exist and a substantial proportion of cases may arise from precursor lesions located in the Fallopian tubal epithelium (FTE). In FTE cells, the transcription factor PAX8 is a marker of the secretory cell lineage and its expression is retained in 96% of EOC. We have recently reported that PAX8 is involved in the tumorigenic phenotype of ovarian cancer cells. In this study, to uncover genes and pathways downstream of PAX8 involved in ovarian carcinoma we have determined the molecular profiles of ovarian cancer cells and in parallel of Fallopian tube epithelial cells by means of a silencing approach followed by an RNA-seq analysis. Interestingly, we highlighted the involvement of pathways like WNT signaling, epithelial-mesenchymal transition, p53 and apoptosis. We believe that our analysis has led to the identification of candidate genes and pathways regulated by PAX8 that could be additional targets for the therapy of ovarian carcinoma.

Monogenic diabetes associated with PAX4 gene mutations (MODY9): first description in Russia

Maturity-onset diabetes of the young (MODY) is a heterogeneous group of disorders characterised by autosomal dominant type of inheritance and caused by genetic defects leading to dysfunction of pancreatic beta-cells. To date, at least 13 subtypes of MODY have been described in the literature, the most frequent of which are MODY types 13. MODY2 and MODY3 are the most prevalent subtypes, and were previously described in our country, Russia. Several cases of rare MODY subtypes were subsequently described in the Russian literature. The current report is the first in the Russian literature to present clinical and molecular genetic characteristics of two cases of another rare MODY subtypeMODY9. This type of MODY is associated with mutations in the PAX4 gene, which encodes transcription factor PAX4, one of the factors essential for pancreatic beta-cell differentiation. Molecular genetic analysis was performed using next-generation sequencing, a new method recently applied to verify monogenic diseases and, in particular, MODY. This study reports a novel mutation in the PAX4 gene in MODY patients.

Matrine suppresses the migration and invasion of NSCLC cells by inhibiting PAX2-induced epithelial-mesenchymal transition

Non-small cell lung cancer (NSCLC) is the major cause of deaths among all the cancer types worldwide. Most of the NSCLC is diagnosed at an advanced stage and the 5-year overall survival rate is low. The reason for the low survival rate of patients with NSCLC is mainly due to distant metastasis. Matrine, a traditional Chinese medicine, has been shown a significant anti-proliferation and anti-invasive effect in tumors. However, little is known on the anti-invasive mechanism of matrine in lung cancer. Therefore, we tried to investigate the molecular mechanism of matrine on the invasive ability of NSCLC cells in vitro. Cell Counting Kit-8 assay was used to evaluate the cell viability. Transwell assay was used to detect the migration and invasion abilities. Microarray assay was used to analyze the differentiated expression genes with or without matrine treatment. Western blotting and real-time polymerase chain reaction were applied to detect the expressions of PAX2, E-cadherin and N-cadherin. Our study showed that matrine could suppress the proliferative activity of NSCLC cells in a dose- and time-dependent manner. Further investigation discovered that the migration and invasion of NSCLC cells were significantly inhibited by treatment with different concentrations of matrine. Microarray assay, real-time polymerase chain reaction and western blotting showed that matrine could significantly decrease the expression of PAX2. In addition, epithelial-mesenchymal transition and related proteins were decreased. In conclusion, matrine may block PAX2 expression to interfere with epithelial-mesenchymal transition signaling pathway that ultimately inhibit the migration and invasion of NSCLC cells in vitro. Matrine might serve as a potential agent for NSCLC treatment.

Skeletal Muscle Cell Induction from Pluripotent Stem Cells

Embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) have the potential to differentiate into various types of cells including skeletal muscle cells. The approach of converting ESCs/iPSCs into skeletal muscle cells offers hope for patients afflicted with the skeletal muscle diseases such as the Duchenne muscular dystrophy (DMD). Patient-derived iPSCs are an especially ideal cell source to obtain an unlimited number of myogenic cells that escape immune rejection after engraftment. Currently, there are several approaches to induce differentiation of ESCs and iPSCs to skeletal muscle. A key to the generation of skeletal muscle cells from ESCs/iPSCs is the mimicking of embryonic mesodermal induction followed by myogenic induction. Thus, current approaches of skeletal muscle cell induction of ESCs/iPSCs utilize techniques including overexpression of myogenic transcription factors such as MyoD or Pax3, using small molecules to induce mesodermal cells followed by myogenic progenitor cells, and utilizing epigenetic myogenic memory existing in muscle cell-derived iPSCs. This review summarizes the current methods used in myogenic differentiation and highlights areas of recent improvement.

Ancestral and novel roles of Pax family genes in mollusks

Background

Pax genes are transcription factors with significant roles in cell fate specification and tissue differentiation during animal ontogeny. Most information on their tempo-spatial mode of expression is available from well-studied model organisms where the Pax-subfamilies Pax2/5/8, Pax6, and Paxα/β are mainly involved in the development of the central nervous system (CNS), the eyes, and other sensory organs. In certain taxa, Pax2/5/8 seems to be additionally involved in the development of excretion organs. Data on expression patterns in lophotrochozoans, and in particular in mollusks, are very scarce for all the above-mentioned Pax-subfamilies, which hampers reconstruction of their putative ancestral roles in bilaterian animals. Thus, we studied the developmental expression of Pax2/5/8, Pax6, and the lophotrochozoan-specific Paxβ in the worm-shaped mollusk Wirenia argentea, a member of Aplacophora that together with Polyplacophora forms the Aculifera, the proposed sister taxon to all primarily single-shelled mollusks (Conchifera).

Results

All investigated Pax genes are expressed in the developing cerebral ganglia and in the ventral nerve cords, but not in the lateral nerve cords of the tetraneural nervous system. Additionally, Pax2/5/8 is expressed in epidermal spicule-secreting or associated cells of the larval trunk and in the region of the developing protonephridia. We found no indication for an involvement of the investigated Pax genes in the development of larval or adult sensory organs of Wirenia argentea.

Conclusions

Pax2/5/8 seems to have a conserved role in the development of the CNS, whereas expression in the spicule-secreting tissues of aplacophorans and polyplacophorans suggests co-option in aculiferan skeletogenesis. The Pax6 expression pattern in Aculifera largely resembles the common bilaterian expression during CNS development. All data available on Paxβ expression argue for a common role in lophotrochozoan neurogenesis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12862-017-0919-x) contains supplementary material, which is available to authorized users.

Pax3 overexpression induces cell aggregation and perturbs commissural axon projection during embryonic spinal cord development

Pax3 is a transcription factor that belongs to the paired box family. In the developing spinal cord it is expressed in the dorsal commissural neurons, which project ascending axons contralaterally to form proper spinal cord-brain circuitry. While it has been shown that Pax3 induces cell aggregation in vitro, little is known about the role of Pax3 in cell aggregation and spinal circuit formation in vivo. We have reported that Pax3 is involved in neuron differentiation and that its overexpression induces ectopic cadherin-7 expression. In this study we report that Pax3 overexpression also induces cell aggregation in vivo. Tissue sections and open book preparations revealed that Pax3 overexpression prevents commissural axons from projecting to the contralateral side of the spinal cord. Cells overexpressing Pax3 aggregated in cell clusters that contained shortened neurites with perturbed axon growth and elongation. Pax3-specific shRNA partially rescued the morphological change induced by Pax3 overexpression in vivo. Our results indicate that the normal expression of Pax3 is necessary for proper axonal pathway finding and commissural axon projection. In conclusion, Pax3 regulates neural circuit formation during embryonic development. J. Comp. Neurol. 525:1618-1632, 2017. © 2016 Wiley Periodicals, Inc.

Cloning and Functional Analysis of Pax6 from the Hydrothermal Vent Tubeworm Ridgeia piscesae

The paired box 6 (Pax6) gene encodes a transcription factor essential for eye development in a wide range of animal lineages. Here we describe the cloning and characterization of Pax6 gene from the blind hydrothermal vent tubeworm Ridgeia piscesae (RpPax6). The deduced RpPax6 protein shares extensive sequence identity with Pax6 proteins from other species and contains both the paired domain and a complete homeodomain. Phylogenetic analysis indicates that it clusters with the corresponding sequence from the closely related species Platynereis dumerilii (P. dumerilii) of Annelida. Luciferase reporter assay indicate that RpPax6 protein suppresses the transcription of sine oculis (so) in D. melanogaster, interfering with the C-terminal of RpPax6. Taking advantage of Drosophila model, we show that RpPax6 expression is not able to rescue small eye phenotype of ey² mutant, only to cause a more severe headless phenotype. In addition, RpPax6 expression induced apoptosis and inhibition of apoptosis can partially rescue RpPax6-induced headless phenotype. We provide evidence RpPax6 plays at least two roles: it blocks the expression of later-acting transcription factors in the eye development cascade, and it promotes cell apoptosis. Our results indicate alternation of the Pax6 function may be one of the possible causes that lead the eye absence in vestimentiferan tubeworms.

Targeting pancreatic expressed PAX genes for the treatment of diabetes mellitus and pancreatic neuroendocrine tumors

INTRODUCTION

Four members of the PAX family, PAX2, PAX4, PAX6 and PAX8 are known to be expressed in the pancreas. Accumulated evidences indicate that several pancreatic expressed PAX genes play a significant role in pancreatic development/functionality and alterations in these genes are involved in the pathogenesis of pancreatic diseases. Areas covered: In this review, we summarize the ongoing research related to pancreatic PAX genes in diabetes mellitus and pancreatic neuroendocrine tumors. We dissect the current knowledge at different levels; from mechanistic studies in cell lines performed to understand the molecular processes controlled by pancreatic PAX genes, to in vivo studies using rodent models that over-express or lack specific PAX genes. Finally, we describe human studies associating variants on pancreatic-expressed PAX genes with pancreatic diseases. Expert opinion: Based on the current literature, we propose that future interventions to treat pancreatic neuroendocrine tumors and diabetes mellitus could be developed via the modulation of PAX4 and/or PAX6 regulated pathways.

Peters Anomaly in Twins: A Case Report of a Rare Incident with Novel Comorbidities

INTRODUCTION

Peters anomaly is a rare developmental malformation involving the anterior segment of the eye, which culminates in amblyopia or congenital blindness. Multiple ocular and/or systemic malformations have been observed with this anomaly, and novel comorbidities continue to be reported.

CASE PRESENTATION

The probands were monozygotic twin boys (twin I and twin II) born to consanguineous parents at 36 weeks of gestation. Coarse facial features and deep-seated eyes were noted at birth. At 6 months, ophthalmic examination revealed that both twins were unable to blink in response to light, or to fixate and follow a moving object. Both twins had prominent horizontal nystagmus. Slit-lamp examination demonstrated varying degrees of central leukoma (corneal opacity) associated with iridocorneal adhesion, which is characteristic of type I Peters anomaly. No cataractous changes were observed. Normal intraocular pressure and disorganized retina were observed. Pupillary abnormalities included bilaterally underdeveloped pupils and bilateral absence of pupils was noted. Ocular MRI showed bilateral microphthalmia and optic nerve hypoplasia, with a small optic chiasm in both twins. At this age, the diagnosis of Peters anomaly was made. At 16 months of age, both twins developed deep venous thrombosis and purpuric skin lesions. Investigations revealed a hereditary thrombophilia secondary to a homozygous mutation causing protein C deficiency, which is a rare thrombotic condition. Ocular ultrasonography revealed bilateral vitreous hemorrhaging linked to altered coagulation. One twin developed bilateral inguinal hernia and cryptorchidism.

CONCLUSION

The novel concordance of Peters anomaly in these monozygotic twins sharing a mutation in PROC gene provides further evidence that this anomaly has a genetic basis. Hypoplasia of the optic nerves and optic chiasm, along with severe protein C deficiency and bilateral absence of the pupils, are associated comorbidities that have not previously been reported with this anomaly.