Myeloproliferative neoplasm-associated myelofibrosis is a clonal stem cell process characterized by pronounced bone marrow fibrosis associated with extramedullary hematopoiesis and splenomegaly. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) represents the only curative treatment leading to bone marrow fibrosis regression. Here we provide an in-depth skeletal characterization of myelofibrosis patients before and after allo-HSCT utilizing clinical high-resolution imaging, laboratory analyses, and bone biopsy studies.
View Article and Find Full Text PDFBone is a dynamic tissue that is constantly remodeled throughout adult life. Recently, it has been shown that bone turnover decreases shortly after food consumption. This process has been linked to the fermentation of non-digestible food ingredients such as inulin by gut microbes, which results in the production of the short-chain fatty acids (SCFAs) acetate, propionate and butyrate.
View Article and Find Full Text PDFSpermine synthase, encoded by the SMS gene, is involved in polyamine metabolism, as it is required for the synthesis of spermine from its precursor molecule spermidine. Pathogenic variants of SMS are known to cause Snyder-Robinson syndrome (SRS), an X-linked recessive disorder causing various symptoms, including intellectual disability, muscular hypotonia, infertility, but also skeletal abnormalities, such as facial dysmorphisms and osteoporosis. Since the impact of a murine SMS deficiency has so far only been analyzed in Gy mice, where a large genomic deletion also includes the neighboring Phex gene, there is only limited knowledge about the potential role of SMS in bone cell regulation.
View Article and Find Full Text PDFMTX is an effective and widely used immunomodulatory drug for rheumatoid diseases. MTX osteopathy is a very rare and specific side effect, characterized by stress fractures at multiple locations in the lower extremity, hampering the patient's mobility by pain and loss of function. In clinical practice, osteoporosis and MTX osteopathy are repeatedly confused and a comparative workup is needed to clarity it's specifics.
View Article and Find Full Text PDFAim: The aim of this study was to investigate the role of pyridoxal-5-phosphate (PLP) level on the oral health status as a predictive marker in patients with hypophosphatasia (HPP).
Materials And Methods: Throughout a systematic retrospective assessment both bone metabolism and oral health status were analyzed. The oral health status was assessed by the decayed/missing/filled teeth index (DMFT), clinical attachment level (CAL), probing pocket depth (PPD), and the periodontal screening index (PSI).
Skeletal growth, modeling, and remodeling are regulated by various molecules, one of them being the recently identified osteoanabolic factor WNT1. We have previously reported that WNT1 transcriptionally activates the expression of Omd, encoding Osteomodulin (OMD), in a murine mesenchymal cell line, which potentially explained the skeletal fragility of mice with mutational WNT1 inactivation, since OMD has been shown to regulate type I collagen fibril formation in vitro. In this study we confirmed the strong induction of Omd expression in a genome-wide expression analysis of transfected cells, and we obtained further evidence for Omd being a direct target gene of WNT1.
View Article and Find Full Text PDFPhysical activity-induced mechanical stimuli play a crucial role in preserving bone mass and structure by promoting bone formation. While the Wnt pathway is pivotal for mediating the osteoblast response to loading, the exact mechanisms are not fully understood. Here, we found that mechanical stimulation induces osteoblastic Wnt1 expression, resulting in an upregulation of key osteogenic marker genes, including Runx2 and Sp7, while Wnt1 knockdown using siRNA prevented these effects.
View Article and Find Full Text PDFObjective: The subchondral bone is an emerging regulator of osteoarthritis (OA). However, knowledge of how specific subchondral alterations relate to cartilage degeneration remains incomplete.
Method: Femoral heads were obtained from 44 patients with primary OA during total hip arthroplasty and from 30 non-OA controls during autopsy.
Piezo proteins are mechanically activated ion channels, which are required for mechanosensing functions in a variety of cell types. While we and others have previously demonstrated that the expression of Piezo1 in osteoblast lineage cells is essential for bone-anabolic processes, there was only suggestive evidence indicating a role of Piezo1 and/or Piezo2 in cartilage. Here we addressed the question if and how chondrocyte expression of the mechanosensitive proteins Piezo1 or Piezo2 controls physiological endochondral ossification and pathological osteoarthritis (OA) development.
View Article and Find Full Text PDFThe age-related maturation of the human midpalatal suture is challenging to predict, but critical for successful non-surgical rapid maxillary expansion (RME). While cone-beam computed tomography (CBCT) can be used to categorize the suture into stages, it remains unclear how well the stages predict the actual micromorphology of the palate. To address this clinically relevant question, we used CBCT together with three-dimensional micro-computed tomography (μCT) analysis on 24 human palate specimens from individuals aged 14-34 years.
View Article and Find Full Text PDFCholesteatoma can lead to progressive destruction of the auditory ossicles along with conductive hearing loss but precise data on the microstructural, cellular, and compositional aspects of affected ossicles are not available. Here, we obtained incus specimens from patients who had cholesteatoma with conductive hearing loss. Incudes were evaluated by micro-computed tomography, histomorphometry on undecalcified sections, quantitative backscattered electron imaging, and nanoindentation.
View Article and Find Full Text PDFHypophosphatasia (HPP) is characterized by severe skeletal symptoms including mineralization defects, insufficiency fractures, and delayed facture healing or non-unions. HPP is caused by mutations of the tissue non-specific alkaline phosphatase (TNSALP). Zinc is a cofactor of TNSALP and vitamin D an important regulator of bone matrix mineralization.
View Article and Find Full Text PDFBackground: Heterotopic ossification (HO) is a common complication after THA. Although current research primarily focuses on treatment and prevention, little is known about the local bone metabolism of HO and clinical contributing factors.
Questions/purposes: We aimed to assess bone remodeling processes in HO using histomorphometry, focusing on the effects of inflammation and prior NSAID treatment.
Mechanosensory ion channels are proteins that are sensitive to mechanical forces. They are found in tissues throughout the body and play an important role in bone remodeling by sensing changes in mechanical stress and transmitting signals to bone-forming cells. Orthodontic tooth movement (OTM) is a prime example of mechanically induced bone remodeling.
View Article and Find Full Text PDFHypophosphatasia (HPP) is an inborn disease that causes a rare form of osteomalacia, a mineralization disorder affecting mineralized tissues. Identification of patients at high risk for fractures or other skeletal manifestations (such as insufficiency fractures or excessive bone marrow edema) by bone densitometry and laboratory tests remains clinically challenging. Therefore, we examined two cohorts of patients with variants in the ALPL gene grouped by bone manifestations.
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