Search bioRxiv⌕ Search

Biology subjects

Teitelbaum, S. L.

Publications and source records attributed to Teitelbaum, S. L..

5 recordsLinked to original sources

Pulmonary osteoclast-like cells in silica induced pulmonary fibrosis

The pathophysiology of silicosis is poorly understood, limiting development of therapies for those who have been exposed to the respirable particle. We explored the mechanisms of silica-induced pulmonary fibrosis in a mouse model using multiple modalities including wholelung single-nucleus RNA sequencing. These analyses revealed that in addition to pulmonary inflammation and fibrosis, intratracheal silica challenge induced osteoclast-like differentiation of alveolar macrophages and recruited monocytes, driven by induction of the osteoclastogenic cytokine, receptor activator of nuclear factor-{kappa}B ligand (RANKL) in pulmonary lymphocytes and alveolar type II cells. Furthermore, anti-RANKL monoclonal antibody treatment suppressed silica-induced osteoclast-like differentiation in the lung and attenuated silica-induced pulmonary fibrosis. We conclude that silica induces osteoclast-like differentiation of distinct recruited and tissue resident monocyte populations, leading to progressive lung injury, likely due to sustained elaboration of bone resorbing proteases and hydrochloric acid. Interrupting osteoclast-like differentiation may therefore constitute a promising avenue for moderating lung damage in silicosis. One Sentence SummarySilica induces the alveolar epithelium to reprogram recruited and resident pulmonary myeloid cells to become osteoclasts that contribute to pulmonary fibrosis.

pathology↗

IDSL.CCDB: a database for exploring inter-chemical correlations in metabolomics and exposomics datasets

Inter-chemical correlations in metabolomics and exposomics datasets provide valuable information for studying relationships among reported chemicals measured in human specimens. With an increase in the size of these datasets, a network graph analysis and visualization of the correlation structure is difficult to interpret. While co-regulatory genes databases have been developed, a similar database for metabolites and chemicals have not been developed yet. We have developed the Integrated Data Science Laboratory for Metabolomics and Exposomics - Chemical Correlation Database (IDSL.CCDB), as a systematic catalogue of inter-chemical correlation in publicly available metabolomics and exposomics studies. The database has been provided via an online interface to create single compound-centric views that are clear, readable and meaningful. We have demonstrated various applications of the database to explore: 1) the chemicals from a chemical class such as Per- and Polyfluoroalkyl Substances (PFAS), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), phthalates and tobacco smoke related metabolites; 2) xenobiotic metabolites such as caffeine and acetaminophen; 3) endogenous metabolites (acyl-carnitines); and 4) unannotated peaks for PFAS. The database has a rich collection of 36 human studies, including the National Health and Nutrition Examination Survey (NHANES) and high-quality untargeted metabolomics datasets. IDSL.CCDB is supported by a simple, interactive and user-friendly web-interface to retrieve and visualize the inter-chemical correlation data. The IDSL.CCDB has the potential to be a key computational resource in metabolomics and exposomics facilitating the expansion of our understanding about biological and chemical relationships among metabolites and chemical exposures in the human body. The database is available at www.ccdb.idsl.me site.

bioinformatics↗

Novel insights into pulmonary phosphate homeostasis and osteoclastogenesis emerge from the study of pulmonary alveolar microlithiasis.

Pulmonary alveolar microlithiasis (PAM) is an autosomal recessive lung disease caused by a deficiency in the pulmonary epithelial Npt2b sodium-phosphate co-transporter that results in accumulation of phosphate and formation of hydroxyapatite microliths in the alveolar space. The single cell transcriptomic analysis of a PAM lung explant showing a robust osteoclast gene signature in alveolar monocytes and the finding that calcium phosphate microliths contain a rich protein and lipid matrix that includes bone resorbing osteoclast enzymes suggested a role for osteoclast-like cells in the defense against microliths. While investigating the mechanisms of microlith clearance, we found that Npt2b modulates pulmonary phosphate homeostasis through effects on alternative phosphate transporter activity and alveolar osteoprotegerin, and that microliths induce osteoclast formation and activity in a receptor activator of nuclear factor-{kappa}B ligand (RANKL) and dietary phosphate dependent manner. This work reveals that Npt2b and pulmonary osteoclast-like cells play key roles in pulmonary homeostasis and suggest potential new therapeutic targets for the treatment of lung disease.

molecular biology↗

Adipose Tissue is a Critical Regulator of Osteoarthritis

Osteoarthritis (OA), the leading cause of pain and disability worldwide, disproportionally affects obese individuals. The mechanisms by which adipose tissue leads to the onset and progression of OA are unclear due to the complex interactions between the metabolic, biomechanical, and inflammatory factors that accompany obesity. We used a murine model of lipodystrophy (LD) to examine the direct contribution of adipose tissue to OA. Knee joints of LD mice were protected from spontaneous or post-traumatic OA, on either a chow and high fat diet, despite similar body weight and the presence of systemic inflammation. These findings indicate that adipose tissue itself plays a critical role in the pathophysiology of OA. Susceptibility to post-traumatic OA was reintroduced into LD mice using implantation of adipose tissue derived from wildtype animals or mouse embryonic fibroblasts that undergo spontaneous adipogenesis, implicating paracrine signaling from fat, rather than body weight, as a critical mediator of joint degeneration.Competing Interest StatementThe authors have declared no competing interest.View Full Text

physiology↗

Novel Pure αVβ3 Integrin Antagonists That Do Not Induce Receptor Extension, Prime the Receptor, or Enhance Angiogenesis at Low Concentrations

The integrin V{beta}3 receptor has been implicated in several important diseases, but no V{beta}3 antagonists are approved for human therapy. One possible limitation of current small-molecule antagonists is their ability to induce a major conformational change in the receptor that induces it to adopt a high-affinity ligand-binding state. In response, we used structural inferences from a pure peptide antagonist to design the small-molecule pure antagonists TDI-4161 and TDI-3761. Both compounds inhibit V{beta}3-mediated cell adhesion to V{beta}3 ligands, but do not induce the conformational change as judged by antibody binding, electron microscopy, X-ray crystallography, and receptor priming studies. Both compounds demonstrated the favorable property of inhibiting bone resorption in vitro, supporting potential value in treating osteoporosis. Neither, however, had the unfavorable property of the V{beta}3 antagonist cilengitide of paradoxically enhancing aortic sprout angiogenesis at concentrations below its IC50, which correlates with cilengitides enhancement of tumor growth in vivo.\n\nSignificance StatementV{beta}3 is a potential therapeutic target for several important human diseases, but there are currently no V{beta}3 antagonists approved for human therapy. Current candidates are primarily based on the Arg-Gly-Asp (RGD) motif and act as partial agonists in that they induce V{beta}3 to undergo a conformational change that converts it into a high-affinity ligand-binding state. We have used structure-guided design to produce pure small-molecule V{beta}3 antagonists that do not induce the conformational change as judged by protein crystallography, electron microscopy, and receptor priming. These compounds inhibit V{beta}3-mediated bone resorption in vitro, but unlike the partial agonist cilengitide, do not enhance angiogenesis at low doses, a property that correlates with low-dose cilengitides enhancement of tumor growth in vivo. These pure V{beta}3 antagonists can help define V{beta}3s role in animal models. If they demonstrate benefits over partial agonists in these model systems, they may be appropriate to consider for human therapy.

pharmacology and toxicology↗