pathway modulates the code via regulation during axial patterning in vertebrates.

The body plan along the anteroposterior axis and regional identities are specified by the spatiotemporal expression of genes. Multistep controls are required for their unique expression patterns; however, the molecular mechanisms behind the tight control of genes are not fully understood. In this study, we demonstrated that the / pathway is critical for axial elongation.

Wwp2 maintains cartilage homeostasis through regulation of Adamts5.

The WW domain-containing protein 2 (Wwp2) gene, the host gene of miR-140, codes for the Wwp2 protein, which is an HECT-type E3 ubiquitin ligases abundantly expressed in articular cartilage. However, its function remains unclear. Here, we show that mice lacking Wwp2 and mice in which the Wwp2 E3 enzyme is inactivated (Wwp2-C838A) exhibit aggravated spontaneous and surgically induced osteoarthritis (OA).

Combinatorial CRISPR/Cas9 Approach to Elucidate a Far-Upstream Enhancer Complex for Tissue-Specific Sox9 Expression.

SRY-box 9 (SOX9) is a master transcription factor that regulates cartilage development. SOX9 haploinsufficiency resulting from breakpoints in a ∼1-Mb region upstream of SOX9 was reported in acampomelic campomelic dysplasia (ACD) patients, suggesting that essential enhancer regions of SOX9 for cartilage development are located in this long non-coding sequence. However, the cis-acting enhancer region regulating cartilage-specific SOX9 expression remains to be identified.

CDKL5 controls postsynaptic localization of GluN2B-containing NMDA receptors in the hippocampus and regulates seizure susceptibility.

Mutations in the Cyclin-dependent kinase-like 5 (CDKL5) gene cause severe neurodevelopmental disorders accompanied by intractable epilepsies, i.e. West syndrome or atypical Rett syndrome.

Analysis of transcription factors expressed at the anterior mouse limb bud.

Limb bud patterning, outgrowth, and differentiation are precisely regulated in a spatio-temporal manner through integrated networks of transcription factors, signaling molecules, and downstream genes. However, the exact mechanisms that orchestrate morphogenesis of the limb remain to be elucidated. Previously, we have established EMBRYS, a whole-mount in situ hybridization database of transcription factors.

Bhlha9 regulates apical ectodermal ridge formation during limb development.

Split hand/foot malformation (SHFM) and SHFM combined with long-bone deficiency (SHFLD) are congenital dysgeneses of the limb. Although six different loci/mutations (SHFM1-SHFM6) have been found from studies on families with SHFM, the causes and associated pathogenic mechanisms for a large number of patients remain unidentified. On the basis of the identification of a duplicated gene region involving BHLHA9 in some affected families, BHLHA9 was identified as a novel SHFM/SHFLD-related gene.

Secreted Metalloproteinase ADAMTS-3 Inactivates Reelin.

The secreted glycoprotein Reelin regulates embryonic brain development and adult brain functions. It has been suggested that reduced Reelin activity contributes to the pathogenesis of several neuropsychiatric and neurodegenerative disorders, such as schizophrenia and Alzheimer's disease; however, noninvasive methods that can upregulate Reelin activity have yet to be developed. We previously found that the proteolytic cleavage of Reelin within Reelin repeat 3 (N-t site) abolishes Reelin activity , but it remains controversial as to whether this effect occurs Here we partially purified the enzyme that mediates the N-t cleavage of Reelin from the culture supernatant of cerebral cortical neurons.

The transcription factor mohawk homeobox regulates homeostasis of the periodontal ligament.

The periodontal ligament (PDL), which connects the teeth to the alveolar bone, is essential for periodontal tissue homeostasis. Although the significance of the PDL is recognized, molecular mechanisms underlying PDL function are not well known. We report that mohawk homeobox (Mkx), a tendon-specific transcription factor, regulates PDL homeostasis by preventing its degeneration.

Targeted gene deletion of miRNAs in mice by TALEN system.

Mice are among the most valuable model animal species with an enormous amount of heritage in genetic modification studies. However, targeting genes in mice is sometimes difficult, especially for small genes, such as microRNAs (miRNAs) and targeting genes in repeat sequences. Here we optimized the application of TALEN system for mice and successfully obtained gene targeting technique in mice for intergenic region and series of microRNAs.

MicroRNAs-140-5p/140-3p modulate Leydig cell numbers in the developing mouse testis.

MicroRNAs (miRNAs) have been shown to play key regulatory roles in a range of biological processes, including cell differentiation and development. To identify miRNAs that participate in gonad differentiation, a fundamental and tightly regulated developmental process, we examined miRNA expression profiles at the time of sex determination and during the early fetal differentiation of mouse testes and ovaries using high-throughput sequencing. We identified several miRNAs that were expressed in a sexually dimorphic pattern, including several members of the let-7 family, miR-378, and miR-140-3p.

L-Sox5 and Sox6 proteins enhance chondrogenic miR-140 microRNA expression by strengthening dimeric Sox9 activity.

Sox9 plays a critical role in early chondrocyte initiation and promotion as well as repression of later maturation. Fellow Sox family members L-Sox5 and Sox6 also function as regulators of cartilage development by boosting Sox9 activation of chondrocyte-specific genes such as Col2a1 and Agc1; however, the regulatory mechanism and other target genes are largely unknown. MicroRNAs are a class of short, non-coding RNAs that act as negative regulators of gene expression by promoting target mRNA degradation and/or repressing translation.

MicroRNA-140 plays dual roles in both cartilage development and homeostasis.

Osteoarthritis (OA), the most prevalent aging-related joint disease, is characterized by insufficient extracellular matrix synthesis and articular cartilage degradation, mediated by several proteinases, including Adamts-5. miR-140 is one of a very limited number of noncoding microRNAs (miRNAs) specifically expressed in cartilage; however, its role in development and/or tissue maintenance is largely uncharacterized. To examine miR-140 function in tissue development and homeostasis, we generated a mouse line through a targeted deletion of miR-140.

MicroRNA-140 is expressed in differentiated human articular chondrocytes and modulates interleukin-1 responses.

Objective: MicroRNA (miRNA) are a class of noncoding small RNAs that act as negative regulators of gene expression. MiRNA exhibit tissue-specific expression patterns, and changes in their expression may contribute to pathogenesis. The objectives of this study were to identify miRNA expressed in articular chondrocytes, to determine changes in osteoarthritic (OA) cartilage, and to address the function of miRNA-140 (miR-140).

Sox9 directly promotes Bapx1 gene expression to repress Runx2 in chondrocytes.

The transcription factor, Sry-related High Mobility Group (HMG) box containing gene 9 (Sox9), plays a critical role in cartilage development by initiating chondrogenesis and preventing the subsequent maturation process called chondrocyte hypertrophy. This suppression mechanism by Sox9 on late-stage chondrogenesis partially results from the inhibition of Runt-related transcription factor 2 (Runx2), the main activator of hypertrophic chondrocyte differentiation. However, the precise mechanism by which Sox9 regulates late chondrogenesis is poorly understood.