EDA2R knockdown alleviates myocardial ischemia/reperfusion injury through inhibiting the activation of the NF-κB signaling pathway.

Ischemia/reperfusion (I/R) is a pathological process that occurs in numerous organs and is often associated with severe cellular damage and death. Ectodysplasin-A2 receptor (EDA2R) is a member of the TNF receptor family that has anti-inflammatory and antioxidant effects. However, to the best of our knowledge, its role in the progression of myocardial I/R injury remains unclear. The present study aimed to investigate the role of EDA2R during myocardial I/R injury and the molecular mechanisms involved. In vitro, dexmedetomidine (DEX) exhibited a protective effect on hypoxia/reoxygenation (H/R)-induced cardiomyocyte injury and downregulated EDA2R expression. Subsequently, EDA2R silencing enhanced cell viability and reduced the apoptosis of cardiomyocytes. Furthermore, knockdown of EDA2R led to an elevated mitochondrial membrane potential (MMP), repressed the release of Cytochrome C and upregulated Bcl-2 expression. EDA2R knockdown also resulted in downregulated expression of Bax, and decreased activity of Caspase-3 and Caspase-9 in cardiomyocytes, reversing the effects of H/R on mitochondria-mediated apoptosis. In addition, knockdown of EDA2R suppressed H/R-induced oxidative stress. Mechanistically, EDA2R knockdown inactivated the NF-κB signaling pathway. Additionally, downregulation of EDA2R weakened myocardial I/R injury in mice, as reflected by improved left ventricular function and reduced infarct size, as well as suppressed apoptosis and oxidative stress. Additionally, EDA2R knockdown repressed the activation of NF-κB signal in vivo. Collectively, knockdown of EDA2R exerted anti-apoptotic and antioxidant effects against I/R injury in vivo and in vitro by suppressing the NF-κB signaling pathway.

Characterization of age-associated gene expression changes in mouse sweat glands.

Evaporation of sweat on the skin surface is the major mechanism for dissipating heat in humans. The secretory capacity of sweat glands (SWGs) declines during aging, leading to heat intolerance in the elderly, but the mechanisms responsible for this decline are poorly understood. We investigated the molecular changes accompanying SWG aging in mice, where sweat tests confirmed a significant reduction of active SWGs in old mice relative to young mice. We first identified SWG-enriched mRNAs by comparing the skin transcriptome of Eda mutant Tabby male mice, which lack SWGs, with that of wild-type control mice by RNA-sequencing analysis. This comparison revealed 171 mRNAs enriched in SWGs, including 47 mRNAs encoding 'core secretory' proteins such as transcription factors, ion channels, ion transporters, and trans-synaptic signaling proteins. Among these, 28 SWG-enriched mRNAs showed significantly altered abundance in the aged male footpad skin, and 11 of them, including Foxa1, Best2, Chrm3, and Foxc1 mRNAs, were found in the 'core secretory' category. Consistent with the changes in mRNA expression levels, immunohistology revealed that higher numbers of secretory cells from old SWGs express the transcription factor FOXC1, the protein product of Foxc1 mRNA. In sum, our study identified mRNAs enriched in SWGs, including those that encode core secretory proteins, and altered abundance of these mRNAs and proteins with aging in mouse SWGs.

Ectodysplasin A2 receptor signaling in skeletal muscle pathophysiology.

Skeletal muscle is essential in generating mechanical force and regulating energy metabolism and body temperature. Pathologies associated with muscle tissue often lead to impaired physical activity and imbalanced metabolism. Recently, ectodysplasin A2 receptor (EDA2R) signaling has been shown to promote muscle loss and glucose intolerance. Upregulated EDA2R expression in muscle tissue was associated with aging, denervation, cancer cachexia, and muscular dystrophies. Here, we describe the roles of EDA2R signaling in muscle pathophysiology, including muscle atrophy, insulin resistance, and aging-related sarcopenia. We also discuss the EDA2R pathway, which involves EDA-A2 as the ligand and nuclear factor (NF)κB-inducing kinase (NIK) as a downstream mediator, and the therapeutic potential of targeting these proteins in the treatment of muscle wasting and metabolic dysfunction.

Mesenchyme instructs growth while epithelium directs branching in the mouse mammary gland.

The mammary gland is a unique organ that undergoes dynamic alterations throughout a female's reproductive life, making it an ideal model for developmental, stem cell and cancer biology research. Mammary gland development begins in utero and proceeds via a quiescent bud stage before the initial outgrowth and subsequent branching morphogenesis. How mammary epithelial cells transit from quiescence to an actively proliferating and branching tissue during embryogenesis and, importantly, how the branch pattern is determined remain largely unknown. Here, we provide evidence indicating that epithelial cell proliferation and onset of branching are independent processes, yet partially coordinated by the Eda signaling pathway. Through heterotypic and heterochronic epithelial-mesenchymal recombination experiments between mouse mammary and salivary gland tissues and ex vivo live imaging, we demonstrate that unlike previously concluded, the mode of branching is an intrinsic property of the mammary epithelium whereas the pace of growth and the density of ductal tree are determined by the mesenchyme. Transcriptomic profiling and ex vivo and in vivo functional studies in mice disclose that mesenchymal Wnt/ß-catenin signaling, and in particular IGF-1 downstream of it critically regulate mammary gland growth. These results underscore the general need to carefully deconstruct the different developmental processes producing branched organs.

Spatial and Temporal Expression of Ectodysplasin-A Signaling Pathway Members During Mandibular Condylar Development in Postnatal Mice.

A growing body of evidence emerging supported that ectodysplasin-A (EDA) signaling pathway contributed to craniofacial development. However, their expression in condyle has not been elucidated yet. This study investigated the expression patterns of EDA, EDA receptor (EDAR), and EDAR-associated death domain (EDARADD) in condyle of postnatal mice. Histological staining and micro-computed tomography (CT) scanning showed that as endochondral ossification proceeded, the thickness of chondrocyte layer decreased, and the volume of mandibular condyle increased. Osteoclasts remained active throughout the condylar development. Immunohistochemistry staining demonstrated that EDA was expressed in almost all layers during the first 2 weeks after birth. EDA shifted from the mature and hypertrophic layers to fibrous and proliferating layers at postnatal 3 weeks. As condyle matured, the distribution of EDA tended to be limited to hypertrophic layer. The distribution patterns of EDAR and EDARADD were consistent with EDA, while the level of EDAR expression was slightly lower. mRNA expression levels of EDA signaling pathway-related components increased after birth. Furthermore, we evaluated the expression of EDA using ATDC5 in vitro. EDA increased during the late stage of chondrogenesis. These findings proved that EDA signaling pathway was involved in condylar development and acted as a regulatory factor in condylar maturation and differentiation.

Dendritic atoh1a+ cells serve as transient intermediates during zebrafish Merkel cell development and regeneration.

Sensory cells often adopt specific morphologies that aid in the detection of external stimuli. Merkel cells encode gentle touch stimuli in vertebrate skin and adopt a reproducible shape characterized by spiky, actin-rich microvilli that emanate from the cell surface. The mechanism by which Merkel cells acquire this stereotyped morphology from basal keratinocyte progenitors is unknown. Here, we establish that dendritic Merkel cells (dMCs) express atonal homolog 1a (atoh1a), extend dynamic filopodial processes, and arise in transient waves during zebrafish skin development and regeneration. We find that dMCs share molecular similarities with both basal keratinocytes and Merkel cells, yet display mesenchymal-like behaviors, including local cell motility and proliferation within the epidermis. Furthermore, dMCs can directly adopt the mature, microvilliated Merkel cell morphology through substantial remodeling of the actin cytoskeleton. Loss of Ectodysplasin A signaling alters the morphology of dMCs and Merkel cells within specific skin regions. Our results show that dMCs represent an intermediate state in the Merkel cell maturation program and identify Ectodysplasin A signaling as a key regulator of Merkel cell morphology.

Erratum: Functional and clinical analysis of five EDA variants associated with ectodermal dysplasia but with a hard-to-predict significance.

[This corrects the article DOI: 10.3389/fgene.2022.934395.].

A Causal Treatment for X-Linked Hypohidrotic Ectodermal Dysplasia: Long-Term Results of Short-Term Perinatal Ectodysplasin A1 Replacement.

X-linked hypohidrotic ectodermal dysplasia (XLHED), caused by a genetic deficiency of ectodysplasin A1 (EDA1), is a rare developmental disorder of ectodermal derivatives such as hair, sweat glands, and teeth. The absence of sweat glands and perspiration can evoke life-threatening hyperthermia. As molecular genetic findings are not always conclusive, the concentrations of circulating EDA1 may help to distinguish between total and partial EDA1 deficiencies. We previously treated nine male patients with obvious signs of XLHED with a recombinant EDA1 replacement protein, Fc-EDA, either shortly after birth (n = 3) or by prenatal administration in gestational week 26 and beyond (n = 6). Here, we present the long-term follow-up for up to six years. In patients who had received Fc-EDA after birth, neither sweat glands nor sweating ability were detected at the age of 12-60 months. In contrast, prenatal EDA1 replacement resulted in ample sweat gland development and pilocarpine-inducible sweating in all treated subjects, who also attained more permanent teeth than their untreated affected relatives. Normal perspiration has persisted for six years in the two oldest boys treated repeatedly with Fc-EDA in utero. When they had a sauna, adequate thermoregulation was evidenced. Lower sweat production after single prenatal dosing may indicate a dose-response relationship. The absence of circulating EDA1 in five prenatally treated subjects proved that these children would have been unable to perspire if they had been left untreated. The sixth infant was shown to produce an EDA1 molecule that, albeit interacting with its cognate receptor, cannot activate EDA1 signaling. In conclusion, a causal treatment of XLHED before birth is feasible.

A novel deletion of exon 4 in the Ectodysplasin A gene associated with X-linked hypohidrotic ectodermal dysplasia.

OBJECTIVE: Identify the disease-causing mutation in a patient with features of X-linked hypohidrotic ectodermal dysplasia, which is a genetic disorder characterized by hypodontia, hypohidrosis and hypotrichosis. It is caused by mutations in Ectodysplasin A gene, which encodes ectodysplasin A, a member of the tumor necrosis factor superfamily. DESIGN: Genetic analysis, was performed using chromosomal microarray analysis, whole exome sequencing and multiplex ligation-dependent probe amplification analysis in a 4-year-old boy with hypohidrotic ectodermal dysplasia features. Moreover, the boy's parents were tested for clinically significant findings identified in order to elucidate the pattern of inheritance of the finding detected in the proband. RESULTS: A novel deletion of entire exon 4 in Ectodysplasin A gene identified in the 4-year-old patient. This deletion was found in heterozygous state in the mother of the proband and was not detected in his father. RNA analysis revealed an in-frame deletion r.527_706del, p.(176_236del) in exon 4 of the Ectodysplasin A gene. CONCLUSION: We identified a novel gross deletion in the Ectodysplasin A gene in a male patient with X-linked hypohidrotic ectodermal dysplasia. Clinical and molecular genetic analysis are crucial to set an accurate diagnosis in patients with hypohidrotic ectodermal dysplasia. These results highlight the importance of the collagen domain of Ectodysplasin A, encoded by exon 4, for its function in vivo.

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.

Dermal appendage-dependent patterning of zebrafish atoh1a+ Merkel cells.

Touch system function requires precise interactions between specialized skin cells and somatosensory axons, as exemplified by the vertebrate mechanosensory Merkel cell-neurite complex. Development and patterning of Merkel cells and associated neurites during skin organogenesis remain poorly understood, partly due to the in utero development of mammalian embryos. Here, we discover Merkel cells in the zebrafish epidermis and identify Atonal homolog 1a (Atoh1a) as a marker of zebrafish Merkel cells. We show that zebrafish Merkel cells derive from basal keratinocytes, express neurosecretory and mechanosensory machinery, extend actin-rich microvilli, and complex with somatosensory axons, all hallmarks of mammalian Merkel cells. Merkel cells populate all major adult skin compartments, with region-specific densities and distribution patterns. In vivo photoconversion reveals that Merkel cells undergo steady loss and replenishment during skin homeostasis. Merkel cells develop concomitant with dermal appendages along the trunk and loss of Ectodysplasin signaling, which prevents dermal appendage formation, reduces Merkel cell density by affecting cell differentiation. By contrast, altering dermal appendage morphology changes the distribution, but not density, of Merkel cells. Overall, our studies provide insights into touch system maturation during skin organogenesis and establish zebrafish as an experimentally accessible in vivo model for the study of Merkel cell biology.

Protocol for the Phase 2 EDELIFE Trial Investigating the Efficacy and Safety of Intra-Amniotic ER004 Administration to Male Subjects with X-Linked Hypohidrotic Ectodermal Dysplasia.

X-linked hypohidrotic ectodermal dysplasia (XLHED) is a rare genetic disorder characte-rised by abnormal development of the skin and its appendages, such as hair and sweat glands, the teeth, and mucous glands of the airways, resulting in serious, sometimes life-threatening complications like hyperthermia or recurrent respiratory infections. It is caused by pathogenic variants of the ectodysplasin A gene (EDA). Most affected males are hemizygous for EDA null mutations that lead to the absence or inactivity of the signalling protein ectodysplasin A1 (EDA1) and, thus, to the full-blown phenotype with inability to perspire and few if any teeth. There are currently no long-term treatment options for XLHED. ER004 represents a first-in-class protein replacement molecule designed for specific, high-affinity binding to the endogenous EDA1 receptor (EDAR). Its proposed mechanism of action is the replacement of missing EDA1 in yet unborn patients with XLHED. Once bound to EDAR, ER004 activates the EDA/NFκB signalling pathway, which triggers the transcription of genes involved in the normal development of multiple tissues. Following preclinical studies, named-patient use cases demonstrated significant potential of ER004 in affected males treated in utero during the late second and third trimesters of pregnancy. In order to confirm these results, we started the EDELIFE trial, a prospective, open-label, genotype-match controlled, multicentre clinical study to investigate the efficacy and safety of intra-amniotic ER004 administration as a prenatal treatment for male subjects with XLHED. This article summarises the rationale, the study protocol, ethical issues of the trial, and potential pitfalls.

Divergent tooth development mechanisms of Mexican tetra fish (Astyanax mexicanus) of Pachón cave origin.

The Mexican tetra (Astyanax mexicanus) is one of the fresh water teleost fish models in evolutionary developmental biology. The existence of two morphs: eyed, pigmented surface fish and blind depigmented cavefish from multiple cave populations, provides a unique system to study adaptive radiation. Compared to the adult surface fish, cavefish have large oral jaws with an increased number of structurally-complex teeth. Early tooth development has not been studied in detail in cavefish populations. In this study, bone-stained growth series and vital dye staining was used to trace the development and replacement of dentitions in Pachón cavefish. Our results show that first tooth eruption was delayed in cavefish compared to the surface fish. In particular, the first tooth eruption cycle persisted until 35 days post fertilization (dpf). Unlike surface fish, there are multicuspid teeth in cavefish first generation dentition. In addition to the teeth in the marginal oral jaw bones, Pachón cavefish have teeth in the ectopterygoid bone of the palatine roof. Next, we characterised the expression of ectodysplasin signalling pathway genes in tooth-forming regions of surface and cavefish. Interestingly, higher expression of Eda and Edar was found in cavefish compared to the surface fish. The altered ectodysplasin expression needs further investigation to confirm the different molecular mechanisms for tooth development in the oral and pharyngeal regions of surface fish and cavefish.

Ectodysplasin A is associated with the presence and severity of coronary artery disease and poor long-term clinical outcome in patients presenting with ST-elevation myocardial infarction.

OBJECTIVES: Hepatokines are proteins secreted by hepatocytes and many hepatokines such as fetuin A/B, selenoprotein P have been shown to play a role in the pathogenesis of many metabolic dysfunctions such as diabetes, insulin resistance, hypertension, and metabolic syndrome by showing autocrine, paracrine and systemic effects. Ectodysplasin A (EDA) is a recently discovered hepatokine that plays a role in the development of ectodermal structures. In recent studies, it has been revealed that EDA may be associated with the pathogenesis of non-alcoholic liver disease, insulin resistance, Type 2 diabetes mellitus. The close relationship between these metabolic diseases and coronary artery disease (CAD), which may be associated with insulin resistance, has been well documented in previous studies. However, until now, there is no study examining the relationship of EDA with CAD and its effect on long-term outcomes. In this study, we aim to reveal this relationship on patients presenting with ST elevation myocardial infarction (STEMI). METHODS: EDA levels of 544 patients who applied to the study with STEMI and 544 people without coronary artery disease were included in the control group, and the patients with STEMI were followed for median of 33.7 ± 6.8 months. RESULTS: We found that EDA levels were significantly higher in patients with STEMI and that EDA levels were proportional to the severity of CAD (p < 0.001) also EDA levels may be an independent predictor of poor clinical outcome in patients with STEMI. CONCLUSION: These results suggest that EDA is closely related to the presence and severity of CAD.

Preliminary study of familial nonsyndromic tooth agenesis caused by ectodysplasin A mutation / 口腔疾病防治

Objective@# To explore the pathogenic genes in a Chinese family affected by nonsyndromic tooth agenesis so as to study the pathogenesis of oligodontia.@*Methods @# Hospital ethical approval and informed consent of the patients and family members were obtained. Clinical data of the proband and close family members were collected, peripheral venous blood was collected, and DNA was extracted. Gene sequencing was performed through whole-exome sequencing, and then the screened pathogenic genes were verified by Sanger sequencing. The three-dimensional structure of the mutant proteins was analyzed and compared with the wild-type using bioinformatics tools.@*Results@#The two patients with congenital majority tooth loss in this family were cousins, and there were no other patients with congenital majority tooth loss in the family. Besides congenital multiple tooth loss, the two patients had no obvious hair abnormalities, finger/toe abnormalities, sweating abnormalities or other abnormal manifestations of ectodermal tissue. We found a mutant gene that in this family by carrying out gene sequencing of the patients and their close family members. A novel EDA (ectodysplasin A) missense mutation c.983C>T (p. Pro328Leu) was identified, which changed the encoded amino acid from proline (Pro) to leucine (Leu). Analysis of the mutation site showed that the site was highly conserved, and three-dimensional structure modeling also found that it changed the structure of EDA. @* Conclusion@#A novel EDA missense variant (c.983C>T, p.Pro328Leu) was first identified in a Chinese family with nonsyndromic tooth agenesis, extending the mutation spectrum of the EDA gene.

A Missense Mutation in the Collagen Triple Helix of EDA Is Associated with X-Linked Recessive Hypohidrotic Ectodermal Dysplasia in Fleckvieh Cattle.

Mutations within the ectodysplasin A (EDA) gene have been associated with congenital hypotrichosis and anodontia (HAD/XHED) in humans, mice, dogs and cattle. We identified a three-generation family of Fleckvieh cattle with male calves exhibiting clinical and histopathological signs consistent with an X-linked recessive HAD (XHED). Whole genome and Sanger sequencing of cDNA showed a perfect association of the missense mutation g.85716041G>A (ss2019497443, rs1114816375) within the EDA gene with all three cases following an X-linked recessive inheritance, but normal EDAR and EDARADD. This mutation causes an exchange of glycine (G) with arginine (R) at amino acid position 227 (p.227G>R) in the second collagen triple helix repeat domain of EDA. The EDA variant was associated with a significant reduction and underdevelopment of hair follicles along with a reduced outgrowth of hairs, a complete loss of seromucous nasolabial and mucous tracheal and bronchial glands and a malformation of and reduction in number of teeth. Thermostability of EDA G227R was reduced, consistent with a relatively mild hair and tooth phenotype. However, incisors and canines were more severely affected in one of the calves, which correlated with the presence of a homozygous missense mutation of RNF111 (g.51306765T>G), a putative candidate gene possibly associated with tooth number in EDA-deficient Fleckvieh calves.

The Role of Ectodysplasin A on the Ocular Surface Homeostasis.

Ectodysplasin A (EDA), a ligand of the TNF family, plays an important role in maintaining the homeostasis of the ocular surface. EDA is necessary for the development of the meibomian gland, the lacrimal gland, as well as the proliferation and barrier function of the corneal epithelium. The mutation of EDA can induce the destruction of the ocular surface resulting in keratopathy, abnormality of the meibomian gland and maturation of the lacrimal gland. Experimental animal studies showed that a prenatal ultrasound-guided intra-amniotic injection or postnatal intravenous administration of soluble recombinant EDA protein can efficiently prevent the development of ocular surface abnormalities in EDA mutant animals. Furthermore, local application of EDA could restore the damaged ocular surface to some extent. Hence, a recombinant EDA-based therapy may serve as a novel paradigm to treat ocular surface disorders, such as meibomian gland dysfunction and corneal epithelium abnormalities.

Rare X-Linked Hypohidrotic Ectodermal Dysplasia in Females Associated with Ectodysplasin-A Variants and the X-Chromosome Inactivation Pattern.

The goal of this study was to identify the pathogenic gene variants in female patients with severe X-linked hypohidrotic ectodermal dysplasia (XLHED). Whole-exome sequencing (WES) and Sanger sequencing were used to screen for the pathogenic gene variants. The harmfulness of these variations was predicted by bioinformatics. Then, skewed X-chromosome inactivation (XCI) was measured by PCR analysis of the CAG repeat region in the human androgen receptor (AR) gene in peripheral blood cells. Two novel Ectodysplasin-A (EDA) heterozygous variants (c.588_606del19bp and c.837G>A) and one heterozygous variant (c.1045G>A, rs132630317) were identified in the three female XLHED patients. The bioinformatics analysis showed that these variants might be pathogenic. The tertiary structure analysis showed that these variants could cause structural damage to EDA proteins. Analysis of the skewed X-chromosome inactivation revealed that extreme skewed X-chromosome inactivation was found in patient #35 (98:2), whereas it was comparatively moderate in patients #347 and #204 (21:79 and 30:70). Our results broaden the variation spectrum of EDA and the phenotype spectrum of XLHED, which could help with clinical diagnosis, treatment, and genetic counseling.

Ectodysplasin A1 Deficiency Leads to Osteopetrosis-like Changes in Bones of the Skull Associated with Diminished Osteoclastic Activity.

Pathogenic variants of the gene Eda cause X-linked hypohidrotic ectodermal dysplasia (XLHED), which is characterized by structural abnormalities or lack of ectodermal appendages. Signs of dysplasia are not restricted to derivatives of the ectodermal layer, but mesodermal abnormalities, such as craniofacial dysmorphism, are also frequently observed, suggesting close reciprocal interactions between the ectoderm and mesoderm; however, a causal link has remained unsubstantiated. We investigated the functional impact of defective ectodysplasin A1 (Eda1) signaling on postnatal bone homeostasis in Eda1-deficient Tabby mice. Interestingly, Eda1 was detected in wild-type mouse calvariae throughout postnatal lifetime. In calvariae, bone-lining Osterix (Osx)+ osteoblasts stained positive for Eda1, and osteoclasts were revealed as Eda receptor (Edar)-positive. Moreover, adult Eda1-deficient calvarial bone showed osteopetrosis-like changes with significantly diminished marrow space, which was maintained during adulthood. Concomitantly with osteopetrosis-like changes, Tabby calvarial bone and Tabby bone marrow-derived osteoclasts had far less osteoclastic activity-associated co-enzymes including cathepsin K, Mmp9, Trap, and Tcirg1 (V-type proton ATPase a3 subunit) compared with wild-type calvariae in vivo or osteoclasts in vitro, indicating that Eda1 deficiency may affect the activity of osteoclasts. Finally, we confirmed that nuclear Nfatc1-positive osteoclasts were strongly diminished during mature osteoclastic differentiation under M-CSF and RANKL in the Tabby model, while Fc-EDA treatment of Tabby-derived osteoclasts significantly increased nuclear translocation of Nfatc1. Furthermore, we identified enhanced Nfatc1 and NF-κB transcriptional activity following Fc-EDA treatment in vitro using luciferase assays. Overall, the results indicate that diminished expressions of osteoclastic activity-associated co-enzymes may lead to disturbed bone homeostasis in Tabby calvariae postnatally.