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Communications Biology Jul 2023Skull bone mineral density (SK-BMD) provides a suitable trait for the discovery of key genes in bone biology, particularly to intramembranous ossification, not captured... (Meta-Analysis)
Meta-Analysis
Skull bone mineral density (SK-BMD) provides a suitable trait for the discovery of key genes in bone biology, particularly to intramembranous ossification, not captured at other skeletal sites. We perform a genome-wide association meta-analysis (n ~ 43,800) of SK-BMD, identifying 59 loci, collectively explaining 12.5% of the trait variance. Association signals cluster within gene-sets involved in skeletal development and osteoporosis. Among the four novel loci (ZIC1, PRKAR1A, AZIN1/ATP6V1C1, GLRX3), there are factors implicated in intramembranous ossification and as we show, inherent to craniosynostosis processes. Functional follow-up in zebrafish confirms the importance of ZIC1 on cranial suture patterning. Likewise, we observe abnormal cranial bone initiation that culminates in ectopic sutures and reduced BMD in mosaic atp6v1c1 knockouts. Mosaic prkar1a knockouts present asymmetric bone growth and, conversely, elevated BMD. In light of this evidence linking SK-BMD loci to craniofacial abnormalities, our study provides new insight into the pathophysiology, diagnosis and treatment of skeletal diseases.
Topics: Animals; Bone Density; Genome-Wide Association Study; Zebrafish; Skull; Craniosynostoses; Transcription Factors
PubMed: 37402774
DOI: 10.1038/s42003-023-04869-0 -
Regenerative Therapy Dec 2023Duchenne muscular dystrophy (DMD) is a hereditary neuromuscular disorder caused by mutation in the dystrophin gene () on the X chromosome. Female DMD carriers...
INTRODUCTION
Duchenne muscular dystrophy (DMD) is a hereditary neuromuscular disorder caused by mutation in the dystrophin gene () on the X chromosome. Female DMD carriers occasionally exhibit symptoms such as muscle weakness and heart failure. Here, we investigated the characteristics and representativeness of female DMD carrier (XX) pigs as a suitable disease model.
METHODS
In vitro fertilization using sperm from a -XY↔XX chimeric boar yielded XX females, which were used to generate F2 and F3 progeny, including XX females. F1-F3 piglets were genotyped and subjected to biochemical analysis for blood creatine kinase (CK), aspartate aminotransferase, and lactate dehydrogenase. Skeletal muscle and myocardial tissue were analyzed for the expression of dystrophin and utrophin, as well as for lymphocyte and macrophage infiltration.
RESULTS
-XX pigs exhibited various characteristics common to human DMD carrier patients, namely, asymptomatic hyperCKemia, dystrophin expression patterns in the skeletal and cardiac muscles, histopathological features of skeletal muscle degeneration, myocardial lesions in adulthood, and sporadic death. Pathological abnormalities observed in the skeletal muscles in -XX pigs point to a frequent incidence of pathological abnormalities in the musculoskeletal tissues of latent DMD carriers. Our findings suggest a higher risk of myocardial abnormalities in DMD carrier women than previously believed.
CONCLUSIONS
We demonstrated that XX pigs could serve as a suitable large animal model for understanding the pathogenic mechanism in DMD carriers and developing therapies for female DMD carriers.
PubMed: 37772130
DOI: 10.1016/j.reth.2023.09.010 -
Materials Today. Bio Dec 2023Bone regeneration following trauma, tumor resection, infection, or congenital disease is challenging. Diabetes mellitus (DM) is a metabolic disease characterized by... (Review)
Review
Bone regeneration following trauma, tumor resection, infection, or congenital disease is challenging. Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia. It can result in complications affecting multiple systems including the musculoskeletal system. The increased number of diabetes-related fractures poses a great challenge to clinical specialties, particularly orthopedics and dentistry. Various pathological factors underlying DM may directly impair the process of bone regeneration, leading to delayed or even non-union of fractures. This review summarizes the mechanisms by which DM hampers bone regeneration, including immune abnormalities, inflammation, reactive oxygen species (ROS) accumulation, vascular system damage, insulin/insulin-like growth factor (IGF) deficiency, hyperglycemia, and the production of advanced glycation end products (AGEs). Based on published data, it also summarizes bone repair strategies in diabetic conditions, which include immune regulation, inhibition of inflammation, reduction of oxidative stress, promotion of angiogenesis, restoration of stem cell mobilization, and promotion of osteogenic differentiation, in addition to the challenges and future prospects of such approaches.
PubMed: 37928253
DOI: 10.1016/j.mtbio.2023.100835 -
Orphanet Journal of Rare Diseases Jul 2023Noonan syndrome spectrum disorders (NSSDs) constitute a group within the Rasopathies, and are one of the largest groups of syndromes with impact on multi-organ...
BACKGROUND
Noonan syndrome spectrum disorders (NSSDs) constitute a group within the Rasopathies, and are one of the largest groups of syndromes with impact on multi-organ involvement known. The extreme variability of the clinical phenotype is, among others, due to the numerous different genes that are involved, and the differences in clinical presentation over the life span. We have studied the needs of patients and their relatives aiming to develop, evaluate and choose focus in research, medical care and policy to better meet their perspectives.
METHODS
Using the participatory and interactive Dialogue method, 80 patients and relatives mentioned 53 different problems or needs (topics) that were categorized into eight themes. These themes and the topics within each theme, were subsequently prioritized by putting them in order of importance methodologically.
RESULTS
The four highest prioritized themes were: (1) Physical problems (non-musculoskeletal related); (2) Social, emotional and behavioral problems; (3) Cognitive functioning and information processing; and (4) Problems related to the musculoskeletal system. Nineteen out of the 53 topics were physical problems. According to the total group of respondents, the top 3 prioritized topics within theme 1 were coagulation problems, heart problems, and feeding problems. Also data stratified by age groups, phenotype (NS and other NSSDs) and gender showed some remarkable results. For instance, feeding problems were prioritized as the most important topic of the highest prioritized theme, according to patients aged 0-12 years. Also feeding problems show a significant difference in its prioritization according to female patients (2) compared to male patients (7). On the other hand, heart problems were not mentioned in the top three prioritized topics in the youngest age groups, although heart problems are generally considered most important for patients with NSSD.
CONCLUSIONS
With our results we underline the importance of methodologically inventorying the needs of NSSD patients, not only at the group level, but to also focus on specific needs according to e.g. age, phenotype and gender. For instance, it is remarkable that both the current Clinical Guidelines and the Noonan Syndrome diagnostic criteria give little to no attention to feeding problems, though our results indicate that, to the youngest patients, these problems have top priority. A similar situation appears to apply to the clinical management of e.g. coagulation, neuropsychological and musculoskeletal problems (like physiotherapy or occupational therapy) and to a need for (educational) tools to support patients at school or at work. Our study may help to shape targeted (clinical) management, research and policy inside and outside medical (research) institutes and shed light on the complex phenotypes of NSSDs, the families' and patients' perspectives on the everyday consequences of the many different problems, as well as their needs.
Topics: Humans; Male; Female; Noonan Syndrome; Cognition; Phenotype
PubMed: 37480127
DOI: 10.1186/s13023-023-02818-y -
Journal of Bone and Mineral Research :... Dec 2023Patients with classical melorheostosis exhibit exuberant bone overgrowth in the appendicular skeleton, resulting in pain and deformity with no known treatment. Most...
Patients with classical melorheostosis exhibit exuberant bone overgrowth in the appendicular skeleton, resulting in pain and deformity with no known treatment. Most patients have somatic, mosaic mutations in MAP2K1 (encoding the MEK1 protein) in osteoblasts and overlying skin. As with most rare bone diseases, lack of affected tissue has limited the opportunity to understand how the mutation results in excess bone formation. The aim of this study was to create a cellular model to study melorheostosis. We obtained patient skin cells bearing the MAP2K1 mutation (affected cells), and along with isogenic control normal fibroblasts reprogrammed them using the Sendai virus method into induced pluripotent stem cells (iPSCs). Pluripotency was validated by marker staining and embryoid body formation. iPSCs were then differentiated to mesenchymal stem cells (iMSCs) and validated by flow cytometry. We confirmed retention of the MAP2K1 mutation in iMSCs with polymerase chain reaction (PCR) and confirmed elevated MEK1 activity by immunofluorescence staining. Mutation-bearing iMSCs showed significantly elevated vascular endothelial growth factor (VEGF) secretion, proliferation and collagen I and IV secretion. iMSCs were then differentiated into osteoblasts, which showed increased mineralization at 21 days and increased VEGF secretion at 14 and 21 days of differentiation. Administration of VEGF to unaffected iMSCs during osteogenic differentiation was sufficient to increase mineralization. Blockade of VEGF by bevacizumab reduced mineralization in iMSC-derived affected osteoblasts and in affected primary patient-derived osteoblasts. These data indicate that patient-derived induced pluripotent stem cells recreate the elevated MEK1 activity, increased mineralization, and increased proliferation seen in melorheostosis patients. The increased bone formation is driven, in part, by abundant VEGF secretion. Modifying the activity of VEGF (a known stimulator of osteoblastogenesis) represents a promising treatment pathway to explore. iPSCs may have wide applications to other rare bone diseases. © 2023 American Society for Bone and Mineral Research (ASBMR).
Topics: Humans; Bone and Bones; Cell Differentiation; MAP Kinase Kinase 1; Melorheostosis; Osteogenesis; Vascular Endothelial Growth Factor A
PubMed: 37737377
DOI: 10.1002/jbmr.4915 -
Archives of Orthopaedic and Trauma... Jul 2023To prevent further spread of the disease and secondary deformity, musculoskeletal tuberculosis (TB) remains a challenge in terms of early diagnosis and treatment. This... (Observational Study)
Observational Study
BACKGROUND
To prevent further spread of the disease and secondary deformity, musculoskeletal tuberculosis (TB) remains a challenge in terms of early diagnosis and treatment. This study gives an overview on TB trends in Austria (pulmonary and extrapulmonary TB) (A) and analyses a retrospective series of musculoskeletal TB cases diagnosed and treated at an Austrian tertiary centre (B).
METHODS
(A) We analysed data obtained from the Austrian national TB registry to provide information on TB patients´ demographics and manifestation sites between 1995 and 2019. (B) Furthermore, we performed an observational study of all patients with a confirmed diagnosis of musculoskeletal TB who were admitted to the Department of Orthopaedics and Trauma, Medical University of Graz (2005-2019). Demographic, diagnostic, clinical and follow-up data were retrieved from the medical records.
RESULTS
(A) From 1995 to 2019, a significant linear reduction in overall Austrian tuberculosis incidence rates occurred (p < 0.001). In the period investigated, Austria recorded a total of 307 patients with musculoskeletal TB. (B) Our retrospective case-series included 17 individuals (9 males, 8 females; average follow-up 48.4 months; range 0-116). There was a biphasic age distribution with a peak in elderly native Austrians (median 69, range 63-92), and a second peak in younger patients with a migration background (median 29, range 18-39). Sites of manifestation were the spine (n = 10), peripheral joints (n = 5), and the soft tissues (n = 2). Diagnosis was based on histology (n = 13), PCR (n = 14), and culture (n = 12). Eleven patients underwent surgery (64.7%). Secondary deformities were frequent (n = 9), and more often observed in patients with spinal TB (n = 6).
CONCLUSION
Musculoskeletal TB should be considered if untypical joint infections or nonspecific bone lesions occur in younger patients with a migration background or in patients with specific risk factors.
Topics: Male; Female; Humans; Aged; Austria; Retrospective Studies; Tuberculosis, Osteoarticular; Risk Factors; Registries
PubMed: 36149487
DOI: 10.1007/s00402-022-04615-x -
Cureus Dec 2023Charcot Neuroarthropathy (CN) is a complex and incapacitating disorder characterized by neuropathy, progressive deformity, and joint destruction. It is of substantial... (Review)
Review
Charcot Neuroarthropathy (CN) is a complex and incapacitating disorder characterized by neuropathy, progressive deformity, and joint destruction. It is of substantial interest within the diabetic population as this ailment chiefly affects individuals with diabetes. The pathophysiology of CN is multidimensional, connecting peripheral neuropathy, repetitive trauma, and autonomic dysfunction. The review analyses the mechanisms directing the development of CN, emphasizing the influence of diabetes in individuals who lean toward this condition. Clinical presentation and diagnosis of CN in diabetic patients present unique challenges. Complex clinical features have also been discussed, including joint deformities, insidious onset, and painless swelling, which mimic other musculoskeletal conditions. The diagnostic approaches, involving clinical examination and radiological imaging, are analyzed for early and accurate diagnosis. Risk factors and epidemiology emphasize the prevalence of CN within the diabetic population and draw attention to common risk factors contributing to its development. Significant factors such as glycemic control, duration of the disease, and type of diabetes are important in estimating an individual's risk for CN. Complications, such as foot ulcers and amputations, provide an understanding of the severe outcome of this condition on patients' quality of life. Management approaches and treatment involving conservative and surgical approaches are reviewed in depth. A multidisciplinary approach to patient care is emphasized, given the complex nature of CN and the comorbidities existing in diabetic individuals. Prognosis and prevention comprise approaches for mitigating the risk of CN in diabetic patients, such as glycemic control, regular foot examinations, and patient education. This thorough review aims to outline the intricate relationship between CN and diabetes, offering an understanding of pathophysiology, clinical complexities, diagnostic nuances, treatment modalities, and prevention strategies.
PubMed: 38259415
DOI: 10.7759/cureus.50988 -
JCI Insight Aug 2023Gene therapy is under advanced clinical development for several lysosomal storage disorders. Pompe disease, a debilitating neuromuscular illness affecting infants,...
Gene therapy is under advanced clinical development for several lysosomal storage disorders. Pompe disease, a debilitating neuromuscular illness affecting infants, children, and adults with different severity, is caused by a deficiency of lysosomal glycogen-degrading enzyme acid α-glucosidase (GAA). Here, we demonstrated that adeno-associated virus-mediated (AAV-mediated) systemic gene transfer reversed glycogen storage in all key therapeutic targets - skeletal and cardiac muscles, the diaphragm, and the central nervous system - in both young and severely affected old Gaa-knockout mice. Furthermore, the therapy reversed secondary cellular abnormalities in skeletal muscle, such as those in autophagy and mTORC1/AMPK signaling. We used an AAV9 vector encoding a chimeric human GAA protein with enhanced uptake and secretion to facilitate efficient spread of the expressed protein among multiple target tissues. These results lay the groundwork for a future clinical development strategy in Pompe disease.
Topics: Child; Mice; Humans; Animals; alpha-Glucosidases; Glycogen Storage Disease Type II; Dependovirus; Genetic Vectors; Mice, Knockout; Glycogen
PubMed: 37463048
DOI: 10.1172/jci.insight.170199 -
Nature Communications Jan 2024WDR44 prevents ciliogenesis initiation by regulating RAB11-dependent vesicle trafficking. Here, we describe male patients with missense and nonsense variants within the...
WDR44 prevents ciliogenesis initiation by regulating RAB11-dependent vesicle trafficking. Here, we describe male patients with missense and nonsense variants within the WD40 repeats (WDR) of WDR44, an X-linked gene product, who display ciliopathy-related developmental phenotypes that we can model in zebrafish. The patient phenotypic spectrum includes developmental delay/intellectual disability, hypotonia, distinct craniofacial features and variable presence of brain, renal, cardiac and musculoskeletal abnormalities. We demonstrate that WDR44 variants associated with more severe disease impair ciliogenesis initiation and ciliary signaling. Because WDR44 negatively regulates ciliogenesis, it was surprising that pathogenic missense variants showed reduced abundance, which we link to misfolding of WDR autonomous repeats and degradation by the proteasome. We discover that disease severity correlates with increased RAB11 binding, which we propose drives ciliogenesis initiation dysregulation. Finally, we discover interdomain interactions between the WDR and NH-terminal region that contains the RAB11 binding domain (RBD) and show patient variants disrupt this association. This study provides new insights into WDR44 WDR structure and characterizes a new syndrome that could result from impaired ciliogenesis.
Topics: Animals; Humans; Male; Brain; Ciliopathies; Cognition; WD40 Repeats; Zebrafish; Genes, X-Linked
PubMed: 38191484
DOI: 10.1038/s41467-023-44611-2