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1.
Stem Cell Res Ther ; 15(1): 203, 2024 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-38971808

RESUMO

BACKGROUND: Skeletal Stem Cells (SSCs) are required for skeletal development, homeostasis, and repair. The perspective of their wide application in regenerative medicine approaches has supported research in this field, even though so far results in the clinic have not reached expectations, possibly due also to partial knowledge of intrinsic, potentially actionable SSC regulatory factors. Among them, the pleiotropic cytokine RANKL, with essential roles also in bone biology, is a candidate deserving deep investigation. METHODS: To dissect the role of the RANKL cytokine in SSC biology, we performed ex vivo characterization of SSCs and downstream progenitors (SSPCs) in mice lacking Rankl (Rankl-/-) by means of cytofluorimetric sorting and analysis of SSC populations from different skeletal compartments, gene expression analysis, and in vitro osteogenic differentiation. In addition, we assessed the effect of the pharmacological treatment with the anti-RANKL blocking antibody Denosumab (approved for therapy in patients with pathological bone loss) on the osteogenic potential of bone marrow-derived stromal cells from human healthy subjects (hBMSCs). RESULTS: We found that, regardless of the ossification type of bone, osteochondral SSCs had a higher frequency and impaired differentiation along the osteochondrogenic lineage in Rankl-/- mice as compared to wild-type. Rankl-/- mice also had increased frequency of committed osteochondrogenic and adipogenic progenitor cells deriving from perivascular SSCs. These changes were not due to the peculiar bone phenotype of increased density caused by lack of osteoclast resorption (defined osteopetrosis); indeed, they were not found in another osteopetrotic mouse model, i.e., the oc/oc mouse, and were therefore not due to osteopetrosis per se. In addition, Rankl-/- SSCs and primary osteoblasts showed reduced mineralization capacity. Of note, hBMSCs treated in vitro with Denosumab had reduced osteogenic capacity compared to control cultures. CONCLUSIONS: We provide for the first time the characterization of SSPCs from mouse models of severe recessive osteopetrosis. We demonstrate that Rankl genetic deficiency in murine SSCs and functional blockade in hBMSCs reduce their osteogenic potential. Therefore, we propose that RANKL is an important regulatory factor of SSC features with translational relevance.


Assuntos
Diferenciação Celular , Osteogênese , Ligante RANK , Animais , Ligante RANK/metabolismo , Ligante RANK/genética , Camundongos , Osteogênese/genética , Humanos , Células-Tronco/metabolismo , Células-Tronco/citologia , Camundongos Knockout , Denosumab/farmacologia , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/citologia , Células Cultivadas , Camundongos Endogâmicos C57BL
2.
J Neurosurg Case Lessons ; 8(2)2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38976922

RESUMO

BACKGROUND: Congenital optic canal stenosis causing compressive optic neuropathy is a rare disorder that presents unique diagnostic and treatment challenges. Endoscopic endonasal optic nerve decompression (EOND) has been described for optic nerve compression in adults and adolescents but has never been reported for young children without pneumatized sphenoid sinuses. The authors describe preoperative and intraoperative considerations for three patients younger than 2 years of age with congenital optic canal stenosis due to genetically confirmed osteopetrosis or chondrodysplasia. OBSERVATIONS: Serial ophthalmological examinations, with a particular focus on object tracking ability, fundoscopic examination, and visual evoked potential trends in preverbal children, are important for detecting progressive optic neuropathy. The lack of pneumatization of the sphenoid sinus presents unique challenges and requires the surgical creation of a sphenoid sinus with the use of neuronavigation to determine the limits of bony exposure given the lack of easily identifiable anatomical landmarks such as the opticocarotid recess. There were no perioperative complications. LESSONS: EOND for congenital optic canal stenosis is safe and technically feasible even given the lack of pneumatization of the sphenoid sinus in young patients. The key operative step is surgically creating the sphenoid sinus through careful bony removal with the aid of neuronavigation. https://thejns.org/doi/10.3171/CASE23559.

3.
Biochem Biophys Res Commun ; 727: 150317, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38959733

RESUMO

Abnormalities in osteoclastic generation or activity disrupt bone homeostasis and are highly involved in many pathologic bone-related diseases, including rheumatoid arthritis, osteopetrosis, and osteoporosis. Control of osteoclast-mediated bone resorption is crucial for treating these bone diseases. However, the mechanisms of control of osteoclastogenesis are incompletely understood. In this study, we identified that inosine 5'-monophosphate dehydrogenase type II (Impdh2) positively regulates bone resorption. By histomorphometric analysis, Impdh2 deletion in mouse myeloid lineage cells (Impdh2LysM-/- mice) showed a high bone mass due to the reduced osteoclast number. qPCR and western blotting results demonstrated that the expression of osteoclast marker genes, including Nfatc1, Ctsk, Calcr, Acp5, Dcstamp, and Atp6v0d2, was significantly decreased in the Impdh2LysM-/- mice. Furthermore, the Impdh inhibitor MPA treatment inhibited osteoclast differentiation and induced Impdh2-cytoophidia formation. The ability of osteoclast differentiation was recovered after MPA deprivation. Interestingly, genome-wide analysis revealed that the osteoclastic mitochondrial biogenesis and functions, such as oxidative phosphorylation, were impaired in the Impdh2LysM-/- mice. Moreover, the deletion of Impdh2 alleviated ovariectomy-induced bone loss. In conclusion, our findings revealed a previously unrecognized function of Impdh2, suggesting that Impdh2-mediated mechanisms represent therapeutic targets for osteolytic diseases.

4.
J Biol Chem ; 300(7): 107437, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38838776

RESUMO

Together with its ß-subunit OSTM1, ClC-7 performs 2Cl-/H+ exchange across lysosomal membranes. Pathogenic variants in either gene cause lysosome-related pathologies, including osteopetrosis and lysosomal storage. CLCN7 variants can cause recessive or dominant disease. Different variants entail different sets of symptoms. Loss of ClC-7 causes osteopetrosis and mostly neuronal lysosomal storage. A recently reported de novo CLCN7 mutation (p.Tyr715Cys) causes widespread severe lysosome pathology (hypopigmentation, organomegaly, and delayed myelination and development, "HOD syndrome"), but no osteopetrosis. We now describe two additional HOD individuals with the previously described p.Tyr715Cys and a novel p.Lys285Thr mutation, respectively. Both mutations decreased ClC-7 inhibition by PI(3,5)P2 and affected residues lining its binding pocket, and shifted voltage-dependent gating to less positive potentials, an effect partially conferred to WT subunits in WT/mutant heteromers. This shift predicts augmented pH gradient-driven Cl- uptake into vesicles. Overexpressing either mutant induced large lysosome-related vacuoles. This effect depended on Cl-/H+-exchange, as shown using mutants carrying uncoupling mutations. Fibroblasts from the p.Y715C patient also displayed giant vacuoles. This was not observed with p.K285T fibroblasts probably due to residual PI(3,5)P2 sensitivity. The gain of function caused by the shifted voltage-dependence of either mutant likely is the main pathogenic factor. Loss of PI(3,5)P2 inhibition will further increase current amplitudes, but may not be a general feature of HOD. Overactivity of ClC-7 induces pathologically enlarged vacuoles in many tissues, which is distinct from lysosomal storage observed with the loss of ClC-7 function. Osteopetrosis results from a loss of ClC-7, but osteoclasts remain resilient to increased ClC-7 activity.

5.
J Pediatr Clin Pract ; 11: 200100, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38827482

RESUMO

We present a newborn with transient generalized osteosclerosis and negative genetic workup. The etiology of this condition is unknown. Given overlapping radiologic signs with severe forms of osteopetrosis, familiarity with this condition is crucial for correct diagnosis and management.

6.
Nat Commun ; 15(1): 5202, 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38898004

RESUMO

Acoustic vibrations of matter convey fundamental viscoelastic information that can be optically retrieved by hyperfine spectral analysis of the inelastic Brillouin scattered light. Increasing evidence of the central role of the viscoelastic properties in biological processes has stimulated the rise of non-contact Brillouin microscopy, yet this method faces challenges in turbid samples due to overwhelming elastic background light. Here, we introduce a common-path Birefringence-Induced Phase Delay (BIPD) filter to disentangle the polarization states of the Brillouin and Rayleigh signals, enabling the rejection of the background light using a polarizer. We demonstrate a 65 dB extinction ratio in a single optical pass collecting Brillouin spectra in extremely scattering environments and across highly reflective interfaces. We further employ the BIPD filter to image bone tissues from a mouse model of osteopetrosis, highlighting altered biomechanical properties compared to the healthy control. Results herald new opportunities in mechanobiology where turbid biological samples remain poorly characterized.


Assuntos
Elasticidade , Animais , Birrefringência , Camundongos , Viscosidade , Fenômenos Biomecânicos , Osso e Ossos/diagnóstico por imagem , Luz , Espalhamento de Radiação
7.
Radiologie (Heidelb) ; 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38842551

RESUMO

BACKGROUND: We were looking for an osteoporosis screening in computed tomography (CT) exams, simple and without additional examinations. We hypothesized that the criterion of "decreasing cortical thickness", may have an influence on the hard palate. Therefore, we investigated whether thickness of the hard palate (HPT) may serve as an indicator of osteoporosis for patients imaged for other reasons. METHODS: Patients with dual-energy x-ray absorptiometry (DXA) and CT were identified by a radiology information system (RIS)-based, full-text search. Measurement of thickness of hard palate done in existing CT image by radiologist and dentist and compared with available findings and DXA measurements. RESULTS: We identified a "test group": 57 patients with DXA and CT available out of 449 patient population and we selected further 70 patients without bone diseases as "control groups". The measurements showed that HPT correlated with age and bone density. The mean HPT was 2.4 mm in normal, 0.9 mm in osteopenia, 0.8 mm in osteoporosis and 5.3 mm in osteopetrosis case. No bone "healthy" patient fell below 1 mm. The relationship between bone density and HPT has not been described previously. HPT was highest in the bone-healthy group and decreased with age, osteopenia, and osteoporosis. Osteopetrosis, as a disease with increased bone density showed an increase in HPT. CONCLUSIONS: HPT correlates with bone disease. We propose a new criterion for assessment on CT and digital volume tomography (DVT) or cone beam computed tomography (CBCT). A threshold of 1.0 mm when applying a simple measurement of HPT on Head CT or DVT may serve as an indicator for potential osteopenia or osteoporosis as incidental finding without extra imaging further diagnosis and treatment leading to early notice of Osteoporosis.

8.
Bone Res ; 12(1): 35, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38849345

RESUMO

DNAX-associated protein 12 kD size (DAP12) is a dominant immunoreceptor tyrosine-based activation motif (ITAM)-signaling adaptor that activates costimulatory signals essential for osteoclastogenesis. Although several DAP12-associated receptors (DARs) have been identified in osteoclasts, including triggering receptor expressed on myeloid cells 2 (TREM-2), C-type lectin member 5 A (CLEC5A), and sialic acid-binding Ig-like lectin (Siglec)-15, their precise role in the development of osteoclasts and bone remodeling remain poorly understood. In this study, mice deficient in Trem-2, Clec5a, Siglec-15 were generated. In addition, mice double deficient in these DAR genes and FcεRI gamma chain (FcR)γ, an alternative ITAM adaptor to DAP12, were generated. Bone mass analysis was conducted on all mice. Notably, Siglec-15 deficient mice and Siglec-15/FcRγ double deficient mice exhibited mild and severe osteopetrosis respectively. In contrast, other DAR deficient mice showed normal bone phenotype. Likewise, osteoclasts from Siglec-15 deficient mice failed to form an actin ring, suggesting that Siglec-15 promotes bone resorption principally by modulating the cytoskeletal organization of osteoclasts. Furthermore, biochemical analysis revealed that Sigelc-15 activates macrophage colony-stimulating factor (M-CSF)-induced Ras-associated protein-1 (RAP1)/Ras-related C3 botulinum toxin substrate 1 (Rac1) pathway through formation of a complex with p130CAS and CrkII, leading to cytoskeletal remodeling of osteoclasts. Our data provide genetic and biochemical evidence that Siglec-15 facilitates M-CSF-induced cytoskeletal remodeling of the osteoclasts.


Assuntos
Fator Estimulador de Colônias de Macrófagos , Osteoclastos , Transdução de Sinais , Proteínas rap1 de Ligação ao GTP , Animais , Osteoclastos/metabolismo , Fator Estimulador de Colônias de Macrófagos/metabolismo , Fator Estimulador de Colônias de Macrófagos/genética , Proteínas rap1 de Ligação ao GTP/metabolismo , Proteínas rap1 de Ligação ao GTP/genética , Camundongos , Citoesqueleto/metabolismo , Camundongos Knockout , Camundongos Endogâmicos C57BL , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Proteínas rac de Ligação ao GTP/metabolismo , Proteínas rac de Ligação ao GTP/genética , Glicoproteínas de Membrana/metabolismo , Glicoproteínas de Membrana/genética , Receptores Imunológicos/metabolismo , Receptores Imunológicos/genética , Imunoglobulinas
9.
Calcif Tissue Int ; 115(1): 85-96, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38733412

RESUMO

Autosomal dominant osteopetrosis type 2 (ADO2) is a rare inherited bone disorder characterised by dense but brittle bones. It displays striking phenotypic variability, with the most severe symptoms, including blindness and bone marrow failure. Disease management largely relies on symptomatic treatment since there is no safe and effective treatment. Most ADO2 cases are caused by heterozygous loss-of-function mutations in the CLCN7 gene, which encodes an essential Cl-/H+ antiporter for proper bone resorption by osteoclasts. Thus, siRNA-mediated silencing of the mutant allele is a promising therapeutic approach, but targeting bone for first-in-human translation remains challenging. Here, we demonstrate the utility of silicon-stabilised hybrid lipid nanoparticles (sshLNPs) as a next-generation nucleic acid nanocarrier capable of delivering allele-specific siRNA to bone. Using a Clcn7G213R knock-in mouse model recapitulating one of the most common human ADO2 mutations and based on the 129S genetic background (which produces the most severe disease phenotype amongst current models), we show substantial knockdown of the mutant allele in femur when siRNA targeting the pathogenic variant is delivered by sshLNPs. We observed lower areal bone mineral density in femur and reduced trabecular thickness in femur and tibia, when siRNA-loaded sshLNPs were administered subcutaneously (representing the most relevant administration route for clinical adoption and patient adherence). Importantly, sshLNPs have improved stability over conventional LNPs and enable 'post hoc loading' for point-of-care formulation. The treatment was well tolerated, suggesting that sshLNP-enabled gene therapy might allow successful clinical translation of essential new treatments for ADO2 and potentially other rare genetic bone diseases.


Assuntos
Alelos , Canais de Cloreto , Nanopartículas , Osteopetrose , Fenótipo , RNA Interferente Pequeno , Animais , Canais de Cloreto/genética , Osteopetrose/genética , Osteopetrose/terapia , Camundongos , RNA Interferente Pequeno/administração & dosagem , RNA Interferente Pequeno/genética , Osso e Ossos/metabolismo , Osso e Ossos/efeitos dos fármacos , Modelos Animais de Doenças
11.
JBJS Case Connect ; 14(2)2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38728525

RESUMO

CASE: Two patients with osteopetrosis underwent conversion total hip arthroplasty (THA) after failure of internal fixation due to hip fractures. We experienced challenges, including difficulty of hardware removal, remaining of previous broken screws in the canal, difficulty in finding the femoral canal, and an intraoperative acetabulum fracture. Despite complications, both patients achieved satisfactory functional outcome after surgery at the latest follow-up. CONCLUSION: Our cases showed that previous hip fracture and failed internal fixation make conversion THA more complex and unpredictable in patients with osteopetrosis. This in turn underscores the critical need for advanced preoperative planning, intraoperative flexibility, and meticulous postoperative care.


Assuntos
Artroplastia de Quadril , Osteopetrose , Humanos , Artroplastia de Quadril/métodos , Osteopetrose/cirurgia , Osteopetrose/complicações , Feminino , Fraturas do Quadril/cirurgia , Masculino , Pessoa de Meia-Idade , Fixação Interna de Fraturas/métodos , Idoso
12.
J Craniofac Surg ; 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38752749

RESUMO

Osteopetrosis (OP) is a heterogeneous group of rare, heredity bone disorders with variable clinical features involving the bones of the body. OP is characterized by increased bone density, which is caused by aberrant osteoclast-mediated bone resorption. This syndromic disorder comes with a series of problems and, unless recognized and treated early, can lead to a multitude of further grave complications. We report a rare case of a female patient who reported chronic unhealed extraoral draining sinus present over the left submandibular region with pathologic fracture of the left mandibular angle, which, if, was diagnosed early with the identification of the osteopetrosis syndrome, could have been managed more conservatively.

13.
Tissue Cell ; 88: 102412, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38776732

RESUMO

Tumor necrosis factor superfamily member 11 (TNFSF11), or receptor activator of nuclear factor-κB ligand (RANKL), is a crucial osteoclast-stimulating factor binding to RANK on osteoclast membranes. Mouse models are powerful tools for understanding the genetic mechanisms of related diseases. Here, we examined the utility of Tnfsf11 mutation in mice for understanding the mechanisms of bone remodeling and dysmorphology. The Tnfsf11gum mouse, discovered in 2011 at Jackson Laboratory, was used to study the genetic landscape associated with TNFSF11 inactivation in bone marrow tissues. Tnfsf11gum/+ and Tnfsf11+/+ mice were subjected to Micro-CT observation, ELISA analysis, histological evaluation, and massively-parallel mRNA sequencing (RNA-Seq) analysis. Tnfsf11gum/+ mice exhibited severe osteopetrotic changes in the bone marrow cavity, along with significantly lower serum RANKL levels and a reduced number of tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts in the bone marrow compared to those in Tnfsf11+/+ mice. However, tooth eruption between Tnfsf11gum/+ and Tnfsf11+/+ mice did not differ. Furthermore, genes involved in osteoblast proliferation and differentiation, including Gli1, Slc35b2, Lrrc17, and Junb were differentially expressed. Heterozygous mutation of TNFSF11 was also associated with a slightly increased expression of genes involved in osteoclast proliferation and differentiation, including Tcirg1, Junb, Anxa2, and Atp6ap1. Overall, we demonstrate that single gene mutations in Tnfsf11 cause bone resorption instability without significantly altering the genes related to osteoblast and osteoclast activity in the bone marrow cavity, thus establishing an optimal resource as an experimental animal model for bone resorption in bone biology research.


Assuntos
Modelos Animais de Doenças , Osteoclastos , Osteopetrose , Ligante RANK , Animais , Osteopetrose/genética , Osteopetrose/patologia , Osteopetrose/metabolismo , Ligante RANK/metabolismo , Ligante RANK/genética , Camundongos , Osteoclastos/metabolismo , Osteoclastos/patologia , Mutação
14.
Eur J Med Genet ; 69: 104936, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38593953

RESUMO

Osteopetrosis refers to a group of related rare bone diseases characterized by a high bone mass due to impaired bone resorption by osteoclasts. Despite the high bone mass, skeletal strength is compromised and the risk of fracture is high, particularly in the long bones. Osteopetrosis was classically categorized by inheritance pattern into autosomal recessive forms (ARO), which are severe and diagnosed within the first years of life, an intermediate form and an autosomal dominant (ADO) form; the latter with variable clinical severity and typically diagnosed during adolescence or in young adulthood. Subsequently, the AD form was shown to be a result of mutations in the gene CLCN7 encoding for the ClC-7 chloride channel). Traditionally, the diagnosis of osteopetrosis was made on radiograph appearance alone, but recent molecular and genetic advances have enabled a greater fidelity in classification of osteopetrosis subtypes. In the more severe ARO forms (e.g., malignant infantile osteopetrosis MIOP) typical clinical features have severe consequences and often result in death in early childhood. Major complications of ADO are atypical fractures with delay or failure of repair and challenge in orthopedic management. Bone marrow failure, dental abscess, deafness and visual loss are often underestimated and neglected in relation with lack of awareness and expertise. Accordingly, the care of adult patients with osteopetrosis requires a multidisciplinary approach ideally in specialized centers. Apart from hematopoietic stem cell transplantation in certain infantile forms, the treatment of patients with osteopetrosis, has not been standardized and remains supportive. Further clinical studies are needed to improve our knowledge of the natural history, optimum management and impact of osteopetrosis on the lives of patients living with the disorder.


Assuntos
Osteoclastos , Osteopetrose , Osteopetrose/genética , Osteopetrose/patologia , Humanos , Osteoclastos/patologia , Adulto , Canais de Cloreto/genética , Mutação
15.
JBMR Plus ; 8(5): ziae034, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38586475

RESUMO

Mutations in PLEKHM1 cause osteopetrosis in humans and rats. The germline and osteoclast conditional deletions of Plekhm1 gene in mice lead to defective osteoclast bone resorption and increased trabecular bone mass without overt abnormalities in other organs. As an adaptor protein, pleckstrin homology and RUN domain containing M1 (PLEKHM1) interacts with the key lysosome regulator small GTPase RAB7 via its C-terminal RUBICON homologous (RH) domain. In this study, we have conducted a structural-functional study of the PLEKHM1 RH domain and RAB7 interaction in osteoclasts in vitro. The single mutations of the key residues in the Plekhm1 RH predicted from the crystal structure of the RUBICON RH domain and RAB7 interface failed to disrupt the Plekhm1-Rab7 binding, lysosome trafficking, and bone resorption. The compound alanine mutations at Y949-R954 and L1011-I1018 regions decreased Plekhm1 protein stability and Rab7-binding, respectively, thereby attenuated lysosome trafficking and bone resorption in osteoclasts. In contrast, the compound alanine mutations at R1060-Q1068 region were dispensable for Rab7-binding and Plekhm1 function in osteoclasts. These results indicate that the regions spanning Y949-R954 and L1011-I1018 of Plekhm1 RH domain are functionally important for Plekhm1 in osteoclasts and offer the therapeutic targets for blocking bone resorption in treatment of osteoporosis and other metabolic bone diseases.

16.
Pediatr Transplant ; 28(3): e14689, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38655726

RESUMO

BACKGROUND: Osteopetrosis is a group of geneticall heterogeneous disorders resulting from impaired osteoclast function and bone resorption. The identification of specific genetic mutations can yield important prognostic and therapeutic implications. Herein, we present the diagnosis and successful application of hematopoietic stem cell transplantation (HSCT) in a patient with osteopetrosis caused by carbonic anhydrase II deficiency (Intermediate osteopetrosis). CASE PRESENTATION: Herein, we describe a 2.5-year-old male patient born to consanguineous parents who presented at 8-month-old with hydrocephaly, brain shunt, and developmental delay. Later at 9 months old, he was found to have eye disorder such as nystagmus, fracture of the elbow, abnormal skeletal survey, normal cell blood count (CBC), and severe hypocellularity in the bone marrow. Further evaluation showed renal tubular acidosis type 2. Whole-exome sequencing revealed a pathogenic homozygous variant in intron 2 of the carbonic anhydrase 2 gene (CA2) gene (c.232 + 1 G>T). The diagnosis of intermediate autosomal recessive osteopetrosis was established, and allogenic HSCT from his mother, a full-matched related donor (MRD), was planned. The conditioning regimen included Busulfan, Fludarabine, and Rabbit anti-thymocyte globulin. Cyclosporine and Mycophenolate Mofetil were used for graft-versus-host-disease prophylaxis. He Engrafted on day +13, and 95% chimerism was achieved. He is currently doing well without immunosuppressive therapy, now 12 months post HSCT, with normal calcium level and improving visual quality and FISH analysis revealed complete donor chimerism. DISCUSSION: HSCT could be a promising curative treatment for intermediate osteopetrosis and can provide long-term survival. Ongoing challenges in various aspects of HSCT remain to be addressed.


Assuntos
Anidrases Carbônicas/deficiência , Transplante de Células-Tronco Hematopoéticas , Osteopetrose , Distúrbios Congênitos do Ciclo da Ureia , Humanos , Masculino , Osteopetrose/genética , Osteopetrose/terapia , Pré-Escolar , Irã (Geográfico) , Anidrase Carbônica II/genética , Anidrase Carbônica II/deficiência , Acidose Tubular Renal/genética , Acidose Tubular Renal/terapia , Transplante Homólogo
17.
JBMR Plus ; 8(5): ziae028, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38655459

RESUMO

Purpose: The purpose of this study was to identify new independent significant SNPs associated with osteoporosis using data from the Taiwan Biobank (TWBB). Material and Methods: The dataset was divided into discovery (60%) and replication (40%) subsets. Following data quality control, genome-wide association study (GWAS) analysis was performed, adjusting for sex, age, and the top 5 principal components, employing the Scalable and Accurate Implementation of the Generalized mixed model approach. This was followed by a meta-analysis of TWBB1 and TWBB2. The Functional Mapping and Annotation (FUMA) platform was used to identify osteoporosis-associated loci. Manhattan and quantile-quantile plots were generated using the FUMA platform to visualize the results. Independent significant SNPs were selected based on genome-wide significance (P < 5 × 10-8) and independence from each other (r2 < 0.6) within a 1 Mb window. Positional, eQTL(expression quantitative trait locus), and Chromatin interaction mapping were used to map SNPs to genes. Results: A total of 29 084 individuals (3154 osteoporosis cases and 25 930 controls) were used for GWAS analysis (TWBB1 data), and 18 918 individuals (1917 cases and 17 001 controls) were utilized for replication studies (TWBB2 data). We identified a new independent significant SNP for osteoporosis in TWBB1, with the lead SNP rs76140829 (minor allele frequency = 0.055, P-value = 1.15 × 10-08). Replication of the association was performed in TWBB2, yielding a P-value of 6.56 × 10-3. The meta-analysis of TWBB1 and TWBB2 data demonstrated a highly significant association for SNP rs76140829 (P-value = 7.52 × 10-10). In the positional mapping of rs76140829, 6 genes (HABP2, RP11-481H12.1, RNU7-165P, RP11-139 K1.2, RP11-57H14.3, and RP11-214 N15.5) were identified through chromatin interaction mapping in mesenchymal stem cells. Conclusions: Our GWAS analysis using the Taiwan Biobank dataset unveils rs76140829 in the VTI1A gene as a key risk variant associated with osteoporosis. This finding expands our understanding of the genetic basis of osteoporosis and highlights the potential regulatory role of this SNP in mesenchymal stem cells.

18.
Artigo em Inglês | MEDLINE | ID: mdl-38661205

RESUMO

CONTEXT: Autosomal dominant osteopetrosis (ADO) is a rare sclerotic bone disease characterized by impaired osteoclast activity, resulting in high bone mineral density and skeletal fragility. The full phenotype and disease burden on patients' daily lives has not been systematically measured. OBJECTIVE: We developed an online registry to ascertain population-based data on the spectrum and rate of progression of disease and to identify relevant patient centered outcomes that could be used to measure treatment effects and guide the design of future clinical trials. DESIGN: Cross-sectional data from participants with osteopetrosis were collected using an online REDCap-based database. PARTICIPANTS: Thirty-four participants with a confirmed diagnosis of ADO, aged 4-84 years. MAIN OUTCOME MEASURES: Participants aged 18 years and older completed the PROMIS 57, participants aged 8 to 17 years completed the PROMIS Pediatric 49, and parents of participants aged <18 years completed the PROMIS Parent Proxy 49. RESULTS: Based on the PROMIS 57, relative to the general population, adults with ADO reported low physical function and low ability to participate in social roles and activities, and high levels of anxiety, fatigue, sleep problems, and pain interference. Daily pain medications were reported by 24% of the adult population. In contrast, neither pediatric participants, nor their parent proxy reported a negative impact on health-related quality of life. CONCLUSIONS: Data from this registry demonstrate the broad spectrum of ADO disease severity and high impact on health-related quality of life in adults with ADO.

19.
Paediatr Int Child Health ; : 1-3, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38577960

RESUMO

Osteopetrosis encompasses rare inherited metabolic bone disorders with defect in the osteoclast activity. Severe forms of presentation such as malignant infantile osteopetrosis are seen in infants and milder forms in older children. The clinical presentation includes failure to thrive, severe pallor, optic atrophy and hepatosplenomegaly. The disorder is characterised by dense bone on radiography, hence the name marble bone disease. A 10-month-old boy who presented with developmental delay, failure to thrive, nystagmus (which the mother described as wandering eye movements), splenomegaly of 16 cm and hepatomegaly of 8 cm. Investigations demonstrated severe anaemia (5.7 g/dL) and thrombocytopenia (34 x 109/L). Radiological signs which help in the diagnosis include diffuse sclerosis, bone within bone appearance, sandwich vertebrae and Erlenmeyer flask deformity. Plain radiography is an easily available and cost effective tool which can aid in the diagnosis of osteopetrosis.

20.
Pediatr Radiol ; 54(7): 1105-1115, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38483591

RESUMO

Osteopetrosis describes several types of rare sclerosing bone dysplasias of varying clinical and radiographic severity. The classic autosomal dominant subtype emerges most often in adolescence but can present from infancy through adulthood. The autosomal recessive osteopetrosis, or "malignant infantile osteopetrosis," presents in infancy with a grimmer prognosis, though the autosomal dominant forms (often mislabeled as "benign") actually can have life-threatening consequences as well. Often osteopetrosis is detected due to skeletal findings on radiographs performed to evaluate injury or as an incidental finding during evaluation for illness. Given the varied phenotypic severity and presentations at different ages, radiologists play an integral role in the care of these patients both in diagnosis and in clinical evaluation and monitoring. A deeper understanding of the underlying genetic basis of the disease can aid in the radiologist in diagnosis and in anticipation of unique complications. An overview of current clinical management is also discussed.


Assuntos
Osteopetrose , Humanos , Osteopetrose/diagnóstico por imagem , Criança , Diagnóstico Diferencial , Adolescente , Lactente
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