Cryptorchidism and infertility in rats with targeted disruption of the Adamts16 locus

A nonsense mutation in mouse Adamtsl2 causes uterine hypoplasia and an irregular estrous cycle

The spontaneous mutation stubby (stb) in mice causes chondrodysplasia and male infertility due to impotence through autosomal recessive inheritance. In this study, we conducted linkage analysis to localize the stb locus within a 1.6 Mb region on mouse chromosome 2 and identified a nonsense mutation in Adamtsl2 of stb/stb mice. Histological analysis revealed disturbed endochondral ossification with a reduced hypertrophic chondrocyte layer and stiff skin with a thickened dermal layer. These phenotypes are similar to those observed in humans and mice with ADAMTSL2/Adamtsl2 mutations. Moreover, stb/stb female mice exhibited severe uterine hypoplasia at 5 weeks of age and irregular estrous cycles at 10 weeks of age. In normal mice, Adamtsl2 was more highly expressed in the ovary and pituitary gland than in the uterus, and this expression was decreased in stb/stb mice. These findings suggest that Adamtsl2 may function in these organs rather than in the uterus. Thus, we analyzed Gh expression in the pituitary gland and plasma estradiol and IGF1 levels, which are required for the development of the female reproductive tract. There was no significant difference in Gh expression and estradiol levels, whereas IGF1 levels in stb/stb mice were significantly reduced to 54-59% of those in +/+ mice. We conclude that Adamtsl2 is required for the development of the uterus and regulation of the estrous cycle in female mice, and decreased IGF1 may be related to these abnormalities.

Novel Heredity Basis of the Four-Horn Phenotype in Sheep Using Genome-Wide Sequence Data

Horns are an important breeding trait for sheep. However, no widely recognized viewpoint on the regulatory genes and mechanisms of horns is available, and the genetic basis of the four-horn phenotype (FHP) is unclear. This work conducted a genome-wide association study with 100 sheep genomes from multiple breeds to investigate the genetic basis of the FHP. The results revealed three significant associations (corrected as p < 1.64 × 10-8) of the InDels (CHR2: g.133,742,709delA, g.133,743,215insC, and g.133,743,940delT) for FHP in the intergenic sequence (IGS) between the MTX2 and the LOC105609047 of CHR2. Moreover, 14 significant associations (corrected as p < 1.42 × 10-9) of SNPs with the FHP phenotype were identified in CHR2 and CHR16, including five (e.g., CHR16: g.40,351,378G > A and g.40,352,577G > A) located in the intron of the ADAMTS12 gene, eight (e.g., CHR2: g.133,727,513C > T and g.133,732,145T > G) in the IGS between MTX2 and LOC105609047, and only one (CHR2: g.133,930,761A > G) in the IGS between HOXD1 and MTX2. Obvious divergence was also observed in genotype patterns between the FHP and others (two horns and hornless) in the HOXD1 and ADAMTS12 gene regions. An extremely significant linkage also occurred between Loci I and Loci II within 100 individuals (LD = -156.02186, p < 0.00001). In summary, our study indicated that the genomic sequences from CHR2 and CHR16 contributed to the FHP in sheep, specifically the key candidate genes HOXD1 and ADAMTS12. These results improved our understanding of the Mendelian genetic basis of the FHP in sheep.

ADAMTS Proteases: Importance in Animal Reproduction

Many reproductive physiological processes, such as folliculogenesis, ovulation, implantation, and fertilization, require the synthesis, remodeling, and degradation of the extracellular matrix (ECM). The ADAMTS (A Disintegrin and Metalloproteinase with Thrombospondin Motifs) family genes code for key metalloproteinases in the remodeling process of different ECM. Several genes of this family encode for proteins with important functions in reproductive processes; in particular, ADAMTS1, 4, 5 and 9 are genes that are differentially expressed in cell types and the physiological stages of reproductive tissues. ADAMTS enzymes degrade proteoglycans in the ECM of the follicles so that the oocytes can be released and regulate follicle development during folliculogenesis, favoring the action of essential growth factors, such as FGF-2, FGF-7 and GDF-9. The transcriptional regulation of ADAMTS1 and 9 in preovulatory follicles occurs because of the gonadotropin surge in preovulatory follicles, via the progesterone/progesterone receptor complex. In addition, in the case of ADAMTS1, pathways involving protein kinase A (PKA), extracellular signal regulated protein kinase (ERK1/2) and the epidermal growth factor receptor (EGFR) might contribute to ECM regulation. Different Omic studies indicate the importance of genes of the ADAMTS family from a reproductive aspect. ADAMTS genes could serve as biomarkers for genetic improvement and contribute to enhance fertility and animal reproduction; however, more research related to these genes, the synthesis of proteins encoded by these genes, and regulation in farm animals is needed.

Secreted protease ADAMTS18 in development and disease

ADAMTS18 was identified in 2002 as a member of the ADAMTS family of 19 secreted Zinc-dependent metalloproteinases. Prior to 2016, ADAMTS18 was known as a candidate gene associated with a wide range of pathologies, particularly various malignancies and eye disorders. However, functions and substrates of ADAMTS18 in normal conditions were unknown. Since 2016, with the development of Adamts18 knockout models, many studies had been conducted on the Adamts18 gene in vivo. These studies revealed that ADAMTS18 is essential for the morphology and organogenesis of several epithelial organs (e.g., lung, kidney, breast, salivary glands, and lacrimal glands), vascular and neuronal systems, adipose tissue, and reproductive tracts. In this review, we describe the current understanding of ADAMTS18 and its substrates and regulators. Limitations in translating new findings on ADAMTS18 to clinical practice are also discussed.

Metzincin metalloproteases in PGC migration and gonadal sex conversion

Development of a functional gonad includes migration of primordial germ cells (PGCs), differentiations of somatic and germ cells, formation of primary follicles or spermatogenic cysts with somatic gonadal cells, development and maturation of gametes, and subsequent releasing of mature germ cells. These processes require extensive cellular and tissue remodeling, as well as broad alterations of the surrounding extracellular matrix (ECM). Metalloproteases, including MMPs (matrix metalloproteases), ADAMs (a disintegrin and metalloproteinases), and ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs), are suggested to have critical roles in the remodeling of the ECM during gonad development. However, few research articles and reviews are available on the functions and mechanisms of metalloproteases in remodeling gonadal ECM, gonadal development, or gonadal differentiation. Moreover, most studies focused on the roles of transcription and growth factors in early gonad development and primary sex determination, leaving a significant knowledge gap on how differentially expressed metalloproteases exert effects on the ECM, cell migration, development, and survival of germ cells during the development and differentiation of ovaries or testes. We will review gonad development with focus on the evidence of metalloprotease involvements, and with an emphasis on zebrafish as a model for studying gonadal sex differentiation and metalloprotease functions.

Testicular descent: A review of a complex, multistaged process to identify potential hidden causes of UDT

BACKGROUND/PURPOSE

What causes normal descent of the testis in a fetus, and what goes wrong with this complex process to cause undescended testes (UDT), or cryptorchidism? Over the last 2 decades, most authors searching for the cause(s) of UDT have looked at the 2 main hormones involved, insulin-like hormone 3 (Insl3) and testosterone (T)/ dihydrotestosterone (DHT), and their known upstream (hypothalamic-pituitary axis) and intracellular 'downstream' pathways. Despite these detailed searches, the genetic causes of UDT remain elusive, which suggest the aetiology is multifactorial, and/or we are looking in the wrong place.

METHODS

In this review we highlight the intricate morphological steps involved in testicular descent, which we propose may contain the currently 'idiopathic' causes of UDT. By integrating decades of research, we have underlined many areas that have been overlooked in the search for causes of UDT.

RESULTS

It is quite likely that the common causes of UDT are still hidden in these areas, and we suggest examining these processes is worthwhile in the hope of finding the common genetic anomalies that lead to cryptorchidism. Given the fact that a fibrous barrier preventing descent is often described at orchidopexy, examination of the extracellular matrix enzymes needed to allow gubernacular migration may be a fruitful place to start.

CONCLUSION

This review of the complex anatomical steps and hormonal regulation of testicular descent highlights many areas of morphology and signalling pathways that have been overlooked in the search for causes of UDT.

ADAM and ADAMTS disintegrin and metalloproteinases as major factors and molecular targets in vascular malfunction and disease

A Disintegrin and Metalloproteinase (ADAM) and A Disintegrin and Metalloproteinase with Thrombospondin Motifs (ADAMTS) are two closely related families of proteolytic enzymes. ADAMs are largely membrane-bound enzymes that act as molecular scissors or sheddases of membrane-bound proteins, growth factors, cytokines, receptors and ligands, whereas ADAMTS are mainly secreted enzymes. ADAMs have a pro-domain, and a metalloproteinase, disintegrin, cysteine-rich and transmembrane domain. Similarly, ADAMTS family members have a pro-domain, and a metalloproteinase, disintegrin, and cysteine-rich domain, but instead of a transmembrane domain they have thrombospondin motifs. Most ADAMs and ADAMTS are activated by pro-protein convertases, and can be regulated by G-protein coupled receptor agonists, Ca²⁺ ionophores and protein kinase C. Activated ADAMs and ADAMTS participate in numerous vascular processes including angiogenesis, vascular smooth muscle cell proliferation and migration, vascular cell apoptosis, cell survival, tissue repair, and wound healing. ADAMs and ADAMTS also play a role in vascular malfunction and cardiovascular diseases such as hypertension, atherosclerosis, coronary artery disease, myocardial infarction, heart failure, peripheral artery disease, and vascular aneurysm. Decreased ADAMTS13 is involved in thrombotic thrombocytopenic purpura and microangiopathies. The activity of ADAMs and ADAMTS can be regulated by endogenous tissue inhibitors of metalloproteinases and other synthetic small molecule inhibitors. ADAMs and ADAMTS can be used as diagnostic biomarkers and molecular targets in cardiovascular disease, and modulators of ADAMs and ADAMTS activity may provide potential new approaches for the management of cardiovascular disorders.

Proteolysis in Reproduction: Lessons From Gene-Modified Organism Studies

The physiological roles of proteolysis are not limited to degrading unnecessary proteins. Proteolysis plays pivotal roles in various biological processes through cleaving peptide bonds to activate and inactivate proteins including enzymes, transcription factors, and receptors. As a wide range of cellular processes is regulated by proteolysis, abnormalities or dysregulation of such proteolytic processes therefore often cause diseases. Recent genetic studies have clarified the inclusion of proteases and protease inhibitors in various reproductive processes such as development of gonads, generation and activation of gametes, and physical interaction between gametes in various species including yeast, animals, and plants. Such studies not only clarify proteolysis-related factors but the biological processes regulated by proteolysis for successful reproduction. Here the physiological roles of proteases and proteolysis in reproduction will be reviewed based on findings using gene-modified organisms.

Metalloproteases in gonad formation and ovulation

Changes in expression or activation of various metalloproteases including matrix metalloproteases (Mmp), a disintegrin and metalloprotease (Adam) and a disintegrin and metalloprotease with thrombospondin motif (Adamts), and their endogenous inhibitors (tissue inhibitors of metalloproteases, Timp), have been shown to be critical for ovulation in various species from studies in past decades. Some of these metalloproteases such as Adamts1, Adamts9, Mmp2, and Mmp9 have also been shown to be regulated by luteinizing hormone (LH) and/or progestin, which are essential triggers for ovulation in all vertebrate species. Most of these metalloproteases also express broadly in various tissues and cells including germ cells and somatic gonad cells. Thus, metalloproteases likely play roles in gonad formation processes comprising primordial germ cell (PGC) migration, development of germ and somatic cells, and sex determination. However, our knowledge on the functions and mechanisms of metalloproteases in these processes in vertebrates is still lacking. This review will summarize our current knowledge on the metalloproteases in ovulation and gonad formation with emphasis on PGC migration and germ cell development.

ADAMTS18 deficiency leads to preputial gland hypoplasia and fibrosis in male mice

ADAMTSs (A disintegrin and metalloproteinase with thrombospondin motifs) are a family of 19 secreted zinc metalloproteinases that play a major role in the assembly and degradation of the extracellular matrix (ECM) during development, morphogenesis, tissue repair, and remodeling. ADAMTS18 is a poorly characterized member of the ADAMTS family. Previously, ADAMTS18 was found to participate in the development of female reproductive tract in mice. However, whether ADAMTS18 also plays a role in the development of male reproductive system remains unclear. In this study, Adamts18 mRNA was found to be highly expressed in the basal cells of the developing preputial gland. Male Adamts18 knockout (Adamts18^-/-) mice exhibit abnormal preputial gland morphogenesis, including reduced size and sharp outline. Histological analyses of preputial gland from 2-week-old male Adamts18^-/- mice showed significant atrophy of the whole gland. Preputial glands from 7 months and older Adamts18^-/- mice appeared macroscopic swelling on their surface. Histologically, preputial gland swelling is characterized by tissue fibrosis and thicker keratinized squamous cell layer. Preputial gland lesions in age-matched male Adamts18^+/+ mice were barely detected. ADAMTS18 deficiency does not lead to significant changes in morphogenesis of prostate and testis in male mice. These results indicate that ADAMTS18 is required for normal morphogenesis and homeostasis of the preputial gland in male mice.

Adamts18 Deficiency Causes Spontaneous SMG Fibrogenesis in Adult Mice

Chronic sclerosing sialadenitis of the submandibular gland (also known as Küttner tumor) is characterized by concomitant swelling of the submandibular glands secondary to strong lymphocytic infiltration and fibrosis. The pathogenesis of this disease has been unclear, but it is associated with immune disorders. ADAMTS18 is a member of the ADAMTS superfamily of extracellular proteinases. In this study, we showed that Adamts18 is highly expressed in submandibular salivary gland (SMG) during embryonic development and decreases but is retained in adult SMG tissue in mice. Adamts18 deficiency led to reduced cleft formation and epithelial branching in embryonic SMG before embryonic day 15.5 in mice. No significant histologic changes in the later stages of branching or the morphology of SMG were detected in Adamts18^-/- mice. However, Adamts18 deficiency causes spontaneous SMG fibrogenesis and fibrosis in adult mice. At 8 wk of age, Adamts18^-/- mice began to manifest the first signs of pathologic changes of mild fibrosis and CD11b⁺ cell infiltration in SMG tissues. At ≥8 mo, all male and female Adamts18^-/- mice developed unilateral or bilateral SMG scleroma that is similar to patients with chronic sclerosing sialadenitis of the submandibular gland. Adamts18^-/- mice also showed secretory dysfunction and severe dental caries. Histologically, SMG scleroma is characterized by progressive periductal fibrosis, acinar atrophy, irregular duct ectasis, and dense infiltration of IgG-positive plasma cells. A significant infiltration of CD4⁺ T lymphocytes and CD11b⁺ monocytes and macrophages was also detected in the SMG scleroma of Adamts18^-/- mice. The levels of TGF-β1, IL-6, and IL-33 were significantly increased in Adamts18^-/- SMGs, which induces chronic inflammation and myofibroblast activation, ultimately leading to fibrosis. This study indicates that Adamts18 regulates the early branching morphogenesis of embryonic SMG and plays a role in protecting from spontaneous SMG fibrogenesis via modulating local inflammation, autoimmune reaction, and myofibroblast activation in adult mice.

Hyalectanase Activities by the ADAMTS Metalloproteases

The hyalectan family is composed of the proteoglycans aggrecan, versican, brevican and neurocan. Hyalectans, also known as lecticans, are components of the extracellular matrix of different tissues and play essential roles in key biological processes including skeletal development, and they are related to the correct maintenance of the vascular and central nervous system. For instance, hyalectans participate in the organization of structures such as perineural nets and in the regulation of neurite outgrowth or brain recovery following a traumatic injury. The ADAMTS (A Disintegrin and Metalloprotease domains, with thrombospondin motifs) family consists of 19 secreted metalloproteases. These enzymes also perform important roles in the structural organization and function of the extracellular matrix through interactions with other matrix components or as a consequence of their catalytic activity. In this regard, some of their preferred substrates are the hyalectans. In fact, ADAMTSs cleave hyalectans not only as a mechanism for clearance or turnover of proteoglycans but also to generate bioactive fragments which display specific functions. In this article we review some of the physiological and pathological effects derived from cleavages of hyalectans mediated by ADAMTSs.

Mini-Review Regarding the Applicability of Genome Editing Techniques Developed for Studying Infertility

Infertility is a highly debated topic today. It has been long hypothesized that infertility has an idiopathic cause, but recent studies demonstrated the existence of a genetic substrate. Fortunately, the methods of editing the human genome proven to be revolutionary. Following research conducted, we identified a total of 21 relevant studies; 14 were performed on mice, 5 on zebrafish and 2 on rats. We concluded that over forty-four genes in total are dispensable for fertility in both sexes without affecting host homeostasis. However, there are genes whose loss-of-function induces moderate to severe phenotypic changes in both sexes. There were situations in which the authors reported infertility, exhibited by the experimental model, or other pathologies such as cryptorchidism, cataracts, or reduced motor activity. Overall, zinc-finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 are techniques that offer a wide range of possibilities for studying infertility, even to create mutant variants. It can be concluded that ZFNs, TALENs, and CRISPR/Cas9 are crucial tools in biomedical research.

ADAMTS proteases in cardiovascular physiology and disease

The a disintegrin-like and metalloproteinase with thrombospondin motif (ADAMTS) family comprises 19 proteases that regulate the structure and function of extracellular proteins in the extracellular matrix and blood. The best characterized cardiovascular role is that of ADAMTS-13 in blood. Moderately low ADAMTS-13 levels increase the risk of ischeamic stroke and very low levels (less than 10%) can cause thrombotic thrombocytopenic purpura (TTP). Recombinant ADAMTS-13 is currently in clinical trials for treatment of TTP. Recently, new cardiovascular roles for ADAMTS proteases have been discovered. Several ADAMTS family members are important in the development of blood vessels and the heart, especially the valves. A number of studies have also investigated the potential role of ADAMTS-1, -4 and -5 in cardiovascular disease. They cleave proteoglycans such as versican, which represent major structural components of the arteries. ADAMTS-7 and -8 are attracting considerable interest owing to their implication in atherosclerosis and pulmonary arterial hypertension, respectively. Mutations in the ADAMTS19 gene cause progressive heart valve disease and missense variants in ADAMTS6 are associated with cardiac conduction. In this review, we discuss in detail the evidence for these and other cardiovascular roles of ADAMTS family members, their proteolytic substrates and the potential molecular mechanisms involved.

ADAMTS16 activates latent TGF-β, accentuating fibrosis and dysfunction of the pressure-overloaded heart

AIMS

Cardiac fibrosis is a major cause of heart failure (HF), and mediated by the differentiation of cardiac fibroblasts into myofibroblasts. However, limited tools are available to block cardiac fibrosis. ADAMTS16 is a member of the ADAMTS superfamily of extracellular protease enzymes involved in extracellular matrix (ECM) degradation and remodelling. In this study, we aimed to establish ADAMTS16 as a key regulator of cardiac fibrosis.

METHODS AND RESULTS

Western blot and qRT-PCR analyses demonstrated that ADAMTS16 was significantly up-regulated in mice with transverse aortic constriction (TAC) associated with left ventricular hypertrophy and HF, which was correlated with increased expression of Mmp2, Mmp9, Col1a1, and Col3a1. Overexpression of ADAMTS16 accelerated the AngII-induced activation of cardiac fibroblasts into myofibroblasts. Protein structural analysis and co-immunoprecipitation revealed that ADAMTS16 interacted with the latency-associated peptide (LAP)-transforming growth factor (TGF)-β via a RRFR motif. Overexpression of ADAMTS16 induced the activation of TGF-β in cardiac fibroblasts; however, the effects were blocked by a mutation of the RRFR motif to IIFI, knockdown of Adamts16 expression, or a TGF-β-neutralizing antibody (ΝAb). The RRFR tetrapeptide, but not control IIFI peptide, blocked the interaction between ADAMTS16 and LAP-TGF-β, and accelerated the activation of TGF-β in cardiac fibroblasts. In TAC mice, the RRFR tetrapeptide aggravated cardiac fibrosis and hypertrophy by up-regulation of ECM proteins, activation of TGF-β, and increased SMAD2/SMAD3 signalling, however, the effects were blocked by TGF-β-NAb.

CONCLUSION

ADAMTS16 promotes cardiac fibrosis, cardiac hypertrophy, and HF by facilitating cardiac fibroblasts activation via interacting with and activating LAP-TGF-β signalling. The RRFR motif of ADAMTS16 disrupts the interaction between ADAMTS16 and LAP-TGF-β, activates TGF-β, and aggravated cardiac fibrosis and hypertrophy. This study identifies a novel regulator of TGF-β signalling and cardiac fibrosis, and provides a new target for the development of therapeutic treatment of cardiac fibrosis and HF.

Interplay between collagenase and undescended testes in Adamts16 knockout rats

BACKGROUND

The inguinoscrotal stage of testicular descent is characterized by an increase in cell density and collagen fibers as the gubernaculum undergoes cell division and increases Extracellular Matrix (ECM) activity. Rats that lack the enzyme Adamts16, a known ECM proteinase, develop cryptorchidism postnatally and are infertile. Therefore, this study aims to investigate the link between the Adamts16 enzyme and congenital undescended testes (UDT) in Adamts16 knockout (KO) rats during postnatal development.

METHODS

Formalin-fixed specimens of Wild-Type, Adamts16 heterozygous and Adamts16 homozygous KO rats post birth were sectioned and used for standard H&E histology and Masson's trichrome staining. A quantitative analysis on image J was performed to determine the intensity of collagen fibers within the inguinoscrotal fat pad (IFP) (n = 3 age/genotype).

RESULTS

The migration of the gubernaculum within the Adamts16 heterozygous and Adamts16 KO rat was considerably disrupted. Furthermore, the Masson's trichrome staining demonstrated a significant increase in collagen fibers around the gubernaculum of rats that lacked Adamts16 enzyme at day 8.

CONCLUSION

This study reports a failure of gubernacular migration leading to UDT in Adamts16 KO rats during development, suggesting that the expression of Adamts16 gene is critical for normal gubernacular migration through the breakdown of collagen fibers within the IFP.

Rat models of human diseases and related phenotypes: a systematic inventory of the causative genes

The laboratory rat has been used for a long time as the model of choice in several biomedical disciplines. Numerous inbred strains have been isolated, displaying a wide range of phenotypes and providing many models of human traits and diseases. Rat genome mapping and genomics was considerably developed in the last decades. The availability of these resources has stimulated numerous studies aimed at discovering causal disease genes by positional identification. Numerous rat genes have now been identified that underlie monogenic or complex diseases and remarkably, these results have been translated to the human in a significant proportion of cases, leading to the identification of novel human disease susceptibility genes, helping in studying the mechanisms underlying the pathological abnormalities and also suggesting new therapeutic approaches. In addition, reverse genetic tools have been developed. Several genome-editing methods were introduced to generate targeted mutations in genes the function of which could be clarified in this manner [generally these are knockout mutations]. Furthermore, even when the human gene causing a disease had been identified without resorting to a rat model, mutated rat strains (in particular KO strains) were created to analyze the gene function and the disease pathogenesis. Today, over 350 rat genes have been identified as underlying diseases or playing a key role in critical biological processes that are altered in diseases, thereby providing a rich resource of disease models. This article is an update of the progress made in this research and provides the reader with an inventory of these disease genes, a significant number of which have similar effects in rat and humans.

The secreted protease Adamts18 links hormone action to activation of the mammary stem cell niche

Estrogens and progesterone control breast development and carcinogenesis via their cognate receptors expressed in a subset of luminal cells in the mammary epithelium. How they control the extracellular matrix, important to breast physiology and tumorigenesis, remains unclear. Here we report that both hormones induce the secreted protease Adamts18 in myoepithelial cells by controlling Wnt4 expression with consequent paracrine canonical Wnt signaling activation. Adamts18 is required for stem cell activation, has multiple binding partners in the basement membrane and interacts genetically with the basal membrane-specific proteoglycan, Col18a1, pointing to the basement membrane as part of the stem cell niche. In vitro, ADAMTS18 cleaves fibronectin; in vivo, Adamts18 deletion causes increased collagen deposition during puberty, which results in impaired Hippo signaling and reduced Fgfr2 expression both of which control stem cell function. Thus, Adamts18 links luminal hormone receptor signaling to basement membrane remodeling and stem cell activation.

How hormonal signaling in the mammary epithelium controls the surrounding extracellular matrix is unclear. Here, the authors show that a secreted protease, Adamts18, induced by upstream estrogen-progesterone activated Wnt4 in myoepithelial cells, remodels the basement membrane and contributes to mammary epithelial stemness.

Male mice lacking ADAMTS-16 are fertile but exhibit testes of reduced weight

Adamts16 encodes a disintegrin-like and metalloproteinase with thrombospondin motifs, 16, a member of a family of multi-domain, zinc-binding proteinases. ADAMTS-16 is implicated in a number of pathological conditions, including hypertension, cancer and osteoarthritis. A large number of observations, including a recent report of human ADAMTS16 variants in cases of 46,XY disorders/differences of sex development (DSD), also implicate this gene in human testis determination. We used CRISPR/Cas9 genome editing to generate a loss-of-function allele in the mouse in order to examine whether ADAMTS-16 functions in mouse testis determination or testicular function. Male mice lacking Adamts16 on the C57BL/6N background undergo normal testis determination in the fetal period. However, adult homozygotes have an average testis weight that is around 10% lower than age-matched controls. Cohorts of mutant males tested at 3-months and 6-months of age were fertile. We conclude that ADAMTS-16 is not required for testis determination or male fertility in mice. We discuss these phenotypic data and their significance for our understanding of ADAMTS-16 function.

Plasma concentration of MMP-1 and MMP-2 in boys with cryptorchidism and its lack of correlation with INSL3 and inhibin B

The matrix metalloproteinases are enzymes capable of remodeling of extracellular matrix, and modulate the behavior of cells. Maturation of gubernaculum and spermatogenesis demand proper equilibrium of metalloproteinases and their inhibitors. The aim of this survey was to investigate the levels of matrix metalloproteinase type 1 (MMP-1) and matrix metalloproteinase type 2 (MMP-2) in the plasma of children with unilateral cryptorchidism along with levels of Insulin-like Peptide 3 (INSL3) and inhibin B. INSL3 have a role in gubernaculum development. Inhibin B is produced by Sertoli cells, and its levels reflect the status of the testis germinative epithelium. Fifty boys with an undescended testicle, aged 1-4 years (median = 2.4 years) were enrolled into the study. Fifty boys with inguinal hernia aged 1-4 years, served as controls (median age = 2.1 years). Investigators assessed the MMP-1 and MMP-2 concentrations using Surface Plasmon Resonance Imaging. The levels of INSL-3 and inhibin B were assessed using commercial enzyme-linked immunosorbent assay ELISA. The median concentration of MMP-1 and MMP-2 in the blood plasma of patients with unilateral cryptorchidism, was nearly 2-folds higher than in controls. The great area under the ROC curve with the cut off value of 0.865 for MMP-1, and 0.819 for MMP-2, indicates the high clinical sensitivity and specificity of the test of plasma levels of MMP-1 and MMP-2 for boys with cryptorchidism. The increased plasma levels of MMP-1 and MMP-2, probably reflect the level of apoptosis of the germ cells in undescended testicles, in response to the heat stress during the period of prepubertal testis development. In the group of cryptorchid boys, we found slightly lower concentrations of INSL3, without statistical significance and without correlation with MMP-1 and MMP-2 levels. There were no significant differences in the levels of inhibin B in the group of boys with cryptorchidism and boys with inguinal hernia and it also did not correlate with MMP-1 and MMP-2 concentrations.

Morphogenesis of the kidney and lung requires branch-tip directed activity of the Adamts18 metalloprotease

Adamts18 encodes a secreted metalloprotease restricted to branch-tip progenitor pools directing the morphogenesis of multiple mammalian organs. Adamts18 was targeted to explore a potential role in branching morphogenesis. In the kidney, an arborized collecting system develops through extensive branching morphogenesis of an initial epithelial outgrowth of the mesonephric duct, the ureteric bud. Adamts18 mutants displayed a weakly penetrant phenotype: duplicated ureteric outgrowths forming enlarged, bi-lobed kidneys with an increased nephron endowment. In contrast, Adamts18 mutants showed a fully penetrant lung phenotype: epithelial growth was markedly reduced and early secondary branching scaled to the reduced length of the primary airways. Furthermore, there was a pronounced delay in the appearance of differentiated cell types in both proximal and distally positions of the developing airways. Adamts18 is closely related to Adamts16. In the kidney but not the lung, broad epithelial Adamts16 expression overlaps Adamts18 in branch tips. However, compound Adamts16/18 mutants displayed a comparable low penetrance duplicated ureteric phenotype, ruling out a possible role for Adamts16 as a functional modifier of the Adamts18 kidney phenotype. Given the predicted action of secreted Adamts18 metalloprotease, and broad expression of Adamts18 in branching organ systems, these findings suggest distinct requirements for matrix modelling in the morphogenesis of epithelial networks.

Molecular genetics of hypospadias and cryptorchidism recent developments

During the last decade, a tremendous amount of work has been devoted to the study of the molecular genetics of isolated hypospadias and cryptorchidism, two minor forms of disorders of sex development (DSD). Beyond the genes involved in gonadal determination and sex differentiation, including those underlying androgen biosynthesis and signaling, new genes have been identified through genome-wide association study and familial clustering. Even if no single genetic defect can explain the whole spectrum of DSD, these recent studies reinforce the strong role of the genetic background in the occurrence of these defects. The timing of signaling disruption may explain the different phenotypes.

A Selective Extracellular Matrix Proteomics Approach Identifies Fibronectin Proteolysis by A Disintegrin-like and Metalloprotease Domain with Thrombospondin Type 1 Motifs (ADAMTS16) and Its Impact on Spheroid Morphogenesis

Secreted and cell-surface proteases are major mediators of extracellular matrix (ECM) turnover, but their mechanisms and regulatory impact are poorly understood. We developed a mass spectrometry approach using a cell-free ECM produced in vitro to identify fibronectin (FN) as a novel substrate of the secreted metalloprotease ADAMTS16. ADAMTS16 cleaves FN between its (I)5 and (I)6 modules, releasing the N-terminal 30 kDa heparin-binding domain essential for FN self-assembly. ADAMTS16 impairs FN fibrillogenesis as well as fibrillin-1 and tenascin-C assembly, thus inhibiting formation of a mature ECM by cultured fibroblasts. Furthermore ADAMTS16 has a marked morphogenetic impact on spheroid formation by renal tubule-derived MDCKI cells. The N-terminal FN domain released by ADAMTS16 up-regulates MMP3, which cleaves the (I)5-(I)6 linker of FN similar to ADAMTS16, therefore creating a proteolytic feed-forward mechanism. Thus, FN proteolysis not only regulates FN turnover, but also FN assembly, with potential long-term consequences for ECM assembly and morphogenesis.

Identification of novel candidate genes for 46,XY disorders of sex development (DSD) using a C57BL/6J-Y POS mouse model

BACKGROUND

Disorders of sex development (DSD) have an estimated frequency of 0.5% of live births encompassing a variety of urogenital anomalies ranging from mild hypospadias to a discrepancy between sex chromosomes and external genitalia. In order to identify the underlying genetic etiology, we had performed exome sequencing in a subset of DSD cases with 46,XY karyotype and were able to identify the causative genetic variant in 35% of cases. While the genetic etiology was not ascertained in more than half of the cases, a large number of variants of unknown clinical significance (VUS) were identified in those exomes.

METHODS

To investigate the relevance of these VUS in regards to the patient's phenotype, we utilized a mouse model in which the presence of a Y chromosome from the poschiavinus strain (Y POS ) on a C57BL/6J (B6) background results in XY undervirilization and sex reversal, a phenotype characteristic to a large subset of human 46,XY DSD cases. We assessed gene expression differences between B6-Y B6 and undervirilized B6-Y POS gonads at E11.5 and identified 515 differentially expressed genes (308 underexpressed and 207 overexpressed in B6-Y POS males).

RESULTS

We identified 15 novel candidate genes potentially involved in 46,XY DSD pathogenesis by filtering the list of human VUS-carrying genes provided by exome sequencing with the list of differentially expressed genes from B6-Y POS mouse model. Additionally, we identified that 7 of the 15 candidate genes were significantly underexpressed in the XY gonads of mice with suppressed Sox9 expression in Sertoli cells suggesting that some of the candidate genes may be downstream of a well-known sex determining gene, Sox9.

CONCLUSION

The use of a DSD-specific animal model improves variant interpretation by correlating human sequence variants with transcriptome variation.

Parathyroid hormone induces expression and proteolytic processing of Rankl in primary murine osteoblasts

Rankl, the major pro-osteoclastogenic cytokine, is synthesized as a transmembrane protein that can be cleaved by specific endopeptidases to release a soluble form (sRankl). We have previously reported that interleukin-33 (IL-33) induces expression of Tnfsf11, the Rankl-encoding gene, in primary osteoblasts, but we failed to detect sRankl in the medium. Since we also found that PTH treatment caused sRankl release in a similar experimental setting, we directly compared the influence of the two molecules. Here we show that treatment of primary murine osteoblasts with PTH causes sRankl release into the medium, whereas IL-33 only induces Tnfsf11 expression. This difference was not explainable by alternative splicing or by PTH-specific induction of endopeptidases previously shown to facilitate Rankl processing. Since sRankl release after PTH administration was blocked in the presence a broad-spectrum matrix metalloprotease inhibitor, we applied genome-wide expression analyses to identify transcriptional targets of PTH in osteoblasts. We thereby confirmed some of the effects of PTH established in other systems, but additionally identified few PTH-induced genes encoding metalloproteases. By comparing expression of these genes following administration of IL-33, PTH and various other Tnfsf11-inducing molecules, we observed that PTH was the only molecule simultaneously inducing sRankl release and Adamts1 expression. The functional relevance of the putative influence of PTH on Rankl processing was further confirmed in vivo, as we found that daily injection of PTH into wildtype mice did not only increase bone formation, but also osteoclastogenesis and sRankl concentrations in the serum. Taken together, our findings demonstrate that transcriptional effects on Tnfsf11 expression do not generally trigger sRankl release and that PTH has a unique activity to promote the proteolytic processing of Rankl.

Sex Change in Clownfish: Molecular Insights from Transcriptome Analysis

Sequential hermaphroditism is a unique reproductive strategy among teleosts that is displayed mainly in fish species living in the coral reef environment. The reproductive biology of hermaphrodites has long been intriguing; however, very little is known about the molecular pathways underlying their sex change. Here, we provide the first de novo transcriptome analyses of a hermaphrodite teleost´s undergoing sex change in its natural environment. Our study has examined relative gene expression across multiple groups-rather than just two contrasting conditions- and has allowed us to explore the differential expression patterns throughout the whole process. Our analysis has highlighted the rapid and complex genomic response of the brain associated with sex change, which is subsequently transmitted to the gonads, identifying a large number of candidate genes, some well-known and some novel, involved in the process. The present study provides strong evidence of the importance of the sex steroidogenic machinery during sex change in clownfish, with the aromatase gene playing a central role, both in the brain and the gonad. This work constitutes the first genome-wide study in a social sex-changing species and provides insights into the genetic mechanism governing social sex change and gonadal restructuring in protandrous hermaphrodites.

The Investigation of ADAMTS16 in Insulin-Induced Human Chondrosarcoma Cells

OBJECTIVES

A disintegrin-like metalloproteinase with thrombospondin motifs (ADAMTS) is a group of proteins that have enzymatic activity secreted by cells to the outside extracellular matrix. Insulin induces proteoglycan biosynthesis in chondrosarcoma chondrocytes. The purpose of the present in vitro study is to assess the time course effects of insulin on ADAMTS16 expression in OUMS-27 (human chondrosarcoma) cell line to examine whether insulin regulates ADAMTS16 expression as well as proteoglycan biosynthesis with multifaceted properties or not.

METHODS

Chondrosarcoma cells were cultured in Dulbecco's modified Eagle's medium having either 10 μg/mL insulin or not. While the experiment was going on, the medium containing insulin had been changed every other day. Cells were harvested at 1st, 3rd, 7th, and 11th days; subsequently, RNA and proteins were isolated in every experimental group according to their time interval. RNA expression of ADAMTS was estimated by quantitative real-time polymerase chain reaction (qRT-PCR) by using primers. Immunoreactive protein levels were encountered by the western blot protein detection technique by using proper anti-ADAMTS16 antibodies.

RESULTS

ADAMTS16 mRNA expression level of chondrosarcoma cells was found to be insignificantly decreased in chondrosarcoma cells induced by insulin detected by the qRT-PCR instrument. On the other hand, there was a gradual decrease in immune-reactant ADAMTS16 protein amount by the time course in insulin-treated cell groups when compared with control cells.

CONCLUSION

It has been suggested that insulin might possibly regulate ADAMTS16 levels/activities in OUMS-27 chondrosarcoma cells taking a role in extracellular matrix turnover.

Role of ADAMTS1 and ADAMTS5 in male infertility

The aim of this study was to investigate the relationship of infertility with metalloproteinases ADAMTS1 and ADAMTS5, which are known to be responsible for the degradation of extracellular matrix (ECM) proteins associated with many diseases. ECM is the noncellular component that provides structural and biochemical support to the surrounding cells required for tissue morphogenesis, differentiation and homoeostasis. Sixty infertile individuals and 10 healthy semen donors were included in this study. The infertile individuals were classified as normozoospermia (NS; n = 20), oligozoospermia (OS; n = 20), azoospermia (AS; n = 20) groups. ADAMTS1 and ADAMTS5 protein levels in semen were analysed by Western blot. ADAMTS1 protein level was 3.0-, 3.3- and 1.6-fold lower in the OS, AS and NS groups, respectively, than in the control group (P < 0.001). ADAMTS5 protein level was 3.2-, 2.7- and 1.4-fold lower in the OS, AS and NS groups, respectively, than in the control group (P < 0.001). Sperm count and sperm motility showed a negative correlation with the levels of ADAMTS1 and ADAMTS5 protein expression: r = -0.477, r = -0.470; and r = -0.332, r = -0.275 respectively (P < 0.001). In conclusion, ADAMTS1 and ADAMTS5 protein expressions in semen are significantly related with sperm production. It is very important to understand molecular function and organisation of ADAMTSs which will be significant in enlightening the process of spermatogenesis in male infertility.

The Function and Roles of ADAMTS-7 in Inflammatory Diseases

The ADAMTS proteinases are a group of multidomain and secreted metalloproteinases containing the thrombospondin motifs. ADAMTS-7 is a member of ADAMTS family and plays a crucial role in the pathogenesis of arthritis. Overexpression of ADAMTS-7 gene promotes the breakdown of cartilage oligomeric matrix protein (COMP) matrix and accelerates the progression of both surgically induced osteoarthritis and collagen-induced arthritis. Moreover, ADAMTS-7 and tumor necrosis factor-α (TNF-α) form a positive feedback loop in osteoarthritis. More significantly, granulin-epithelin precursor, a growth factor has important roles in bone development and bone-associated diseases, disturbs the interaction between ADAMTS-7 and COMP, and prevents COMP degradation. This review is based on our results and provides an overview of current knowledge of ADAMTS-7, including its structure, function, gene regulation, and inflammatory diseases involvement.

The ADAMTS (A Disintegrin and Metalloproteinase with Thrombospondin motifs) family

The ADAMTS (A Disintegrin and Metalloproteinase with Thrombospondin motifs) enzymes are secreted, multi-domain matrix-associated zinc metalloendopeptidases that have diverse roles in tissue morphogenesis and patho-physiological remodeling, in inflammation and in vascular biology. The human family includes 19 members that can be sub-grouped on the basis of their known substrates, namely the aggrecanases or proteoglycanases (ADAMTS1, 4, 5, 8, 9, 15 and 20), the procollagen N-propeptidases (ADAMTS2, 3 and 14), the cartilage oligomeric matrix protein-cleaving enzymes (ADAMTS7 and 12), the von-Willebrand Factor proteinase (ADAMTS13) and a group of orphan enzymes (ADAMTS6, 10, 16, 17, 18 and 19). Control of the structure and function of the extracellular matrix (ECM) is a central theme of the biology of the ADAMTS, as exemplified by the actions of the procollagen-N-propeptidases in collagen fibril assembly and of the aggrecanases in the cleavage or modification of ECM proteoglycans. Defects in certain family members give rise to inherited genetic disorders, while the aberrant expression or function of others is associated with arthritis, cancer and cardiovascular disease. In particular, ADAMTS4 and 5 have emerged as therapeutic targets in arthritis. Multiple ADAMTSs from different sub-groupings exert either positive or negative effects on tumorigenesis and metastasis, with both metalloproteinase-dependent and -independent actions known to occur. The basic ADAMTS structure comprises a metalloproteinase catalytic domain and a carboxy-terminal ancillary domain, the latter determining substrate specificity and the localization of the protease and its interaction partners; ancillary domains probably also have independent biological functions. Focusing primarily on the aggrecanases and proteoglycanases, this review provides a perspective on the evolution of the ADAMTS family, their links with developmental and disease mechanisms, and key questions for the future.

ADAMTS proteases in fertility

The reproductive organs are unique among adult organs in that they must undergo continual tissue remodelling as a key aspect of their normal function. The processes for persistent maturation and release of new gametes, as well as fertilisation, implantation, placentation, gestation and parturition involve cyclic development and regression of tissues that must continually regenerate to support fertility. The ADAMTS family of proteases has been shown to contribute to many aspects of the tissue morphogenesis required for development and function of each of the reproductive organs. Dysregulation or functional changes in ADAMTS family proteases have been associated with reproductive disorders such as polycystic ovarian syndrome (PCOS) and premature ovarian failure (POF). Likewise, proteolytic substrates of ADAMTS enzymes have also been linked to reproductive function. New insight into the roles of ADAMTS proteases has yielded a deeper understanding of the molecular mechanisms behind fertility with clinical potential to generate therapeutic targets to resolve infertility, develop biomarkers that predict dysfunction of the reproductive organs and potentially offer targets for development of non-hormonal male and female contraceptives.

Insights on ADAMTS proteases and ADAMTS-like proteins from mammalian genetics

The mammalian ADAMTS superfamily comprises 19 secreted metalloproteinases and 7 ADAMTS-like proteins, each the product of a distinct gene. Thus far, all appear to be relevant to extracellular matrix function or to cell-matrix interactions. Most ADAMTS functions first emerged from analysis of spontaneous human and animal mutations and genetically engineered animals. The clinical manifestations of Mendelian disorders resulting from mutations in ADAMTS2, ADAMTS10, ADAMTS13, ADAMTS17, ADAMTSL2 and ADAMTSL4 identified essential roles for each gene, but also suggested potential cooperative functions of ADAMTS proteins. These observations were extended by analysis of spontaneous animal mutations, such as in bovine ADAMTS2, canine ADAMTS10, ADAMTS17 and ADAMTSL2 and mouse ADAMTS20. These human and animal disorders are recessive and their manifestations appear to result from a loss-of-function mechanism. Genome-wide analyses have determined an association of some ADAMTS loci such as ADAMTS9 and ADAMTS7, with specific traits and acquired disorders. Analysis of genetically engineered rodent mutations, now achieved for over half the superfamily, has provided novel biological insights and animal models for the respective human genetic disorders and suggested potential candidate genes for related human phenotypes. Engineered mouse mutants have been interbred to generate combinatorial mutants, uncovering cooperative functions of ADAMTS proteins in morphogenesis. Specific genetic models have provided crucial insights on mechanisms of osteoarthritis (OA), a common adult-onset degenerative condition. Engineered mutants will facilitate interpretation of exome variants identified in isolated birth defects and rare genetic conditions, as well as in genome-wide screens for trait and disease associations. Mammalian forward and reverse genetics, together with genome-wide analysis, together constitute a powerful force for revealing the functions of ADAMTS proteins in physiological pathways and health disorders. Their continuing use, together with genome-editing technology and the ability to generate stem cells from mutants, presents numerous opportunities for advancing basic knowledge, human disease pathways and therapy.