scholarly journals MyD88 Is Not Required for Muscle Injury-Induced Endochondral Heterotopic Ossification in a Mouse Model of Fibrodysplasia Ossificans Progressiva

Biomedicines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 630
Author(s):  
Huili Lyu ◽  
Cody M. Elkins ◽  
Jessica L. Pierce ◽  
C. Henrique Serezani ◽  
Daniel S. Perrien

Excess inflammation and canonical BMP receptor (BMPR) signaling are coinciding hallmarks of the early stages of injury-induced endochondral heterotopic ossification (EHO), especially in the rare genetic disease fibrodysplasia ossificans progressiva (FOP). Multiple inflammatory signaling pathways can synergistically enhance BMP-induced Smad1/5/8 activity in multiple cell types, suggesting the importance of pathway crosstalk in EHO and FOP. Toll-like receptors (TLRs) and IL-1 receptors mediate many of the earliest injury-induced inflammatory signals largely via MyD88-dependent pathways. Thus, the hypothesis that MyD88-dependent signaling is required for EHO was tested in vitro and in vivo using global or Pdgfrα-conditional deletion of MyD88 in FOP mice. As expected, IL-1β or LPS synergistically increased Activin A (ActA)-induced phosphorylation of Smad 1/5 in fibroadipoprogenitors (FAPs) expressing Alk2R206H. However, conditional deletion of MyD88 in Pdgfrα-positive cells of FOP mice did not significantly alter the amount of muscle injury-induced EHO. Even more surprisingly, injury-induced EHO was not significantly affected by global deletion of MyD88. These studies demonstrate that MyD88-dependent signaling is dispensable for injury-induced EHO in FOP mice.

Biomolecules ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1306
Author(s):  
Ann-Kristin Afflerbach ◽  
Mark D. Kiri ◽  
Tahir Detinis ◽  
Ben M. Maoz

The human-relevance of an in vitro model is dependent on two main factors—(i) an appropriate human cell source and (ii) a modeling platform that recapitulates human in vivo conditions. Recent years have brought substantial advancements in both these aspects. In particular, mesenchymal stem cells (MSCs) have emerged as a promising cell source, as these cells can differentiate into multiple cell types, yet do not raise the ethical and practical concerns associated with other types of stem cells. In turn, advanced bioengineered in vitro models such as microfluidics, Organs-on-a-Chip, scaffolds, bioprinting and organoids are bringing researchers ever closer to mimicking complex in vivo environments, thereby overcoming some of the limitations of traditional 2D cell cultures. This review covers each of these advancements separately and discusses how the integration of MSCs into novel in vitro platforms may contribute enormously to clinical and fundamental research.


2008 ◽  
Vol 13 (5) ◽  
pp. 275-279 ◽  
Author(s):  
Nicole V. Tolan ◽  
Luiza I. Genes ◽  
Dana M. Spence

Detecting multiple components from a single red blood cell (RBC) sample within a flow-based system in less than 20 min will enable improved in vitro determinations of drug efficacy and cellular response to administered drugs. Here, an example of an improved in vitro measurement involving iloprost, a pharmaceutical reported to improve blood flow, has been determined by incorporating multiple cell types onto a single device. The method allows fluid flow to address individual rows of wells contained within an 18-well microfluidic array that serves as a precursor to a 96-well microtitre plate device. The ability to better mimic the in vivo circulation by incorporating the flow of blood components, coupled with simultaneous detection and laboratory automation in place for microtitre plates, suggests that the microfluidic array presented here will allow for improved mechanistic drug research studies. Using fluorescence microscopy, concentrations of multiple metabolites present within the RBC can also be determined using the microfluidic array. The current progress toward using this device for personalized medicine is presented here.


2020 ◽  
Author(s):  
Maria-Bernadette Madel ◽  
He Fu ◽  
Dominique D. Pierroz ◽  
Mariano Schiffrin ◽  
Carine Winkler ◽  
...  

SummaryLong bones from mammals host blood cell formation and contain multiple cell types, including adipocytes. Physiological functions of bone marrow adipocytes are poorly documented. Herein, we used adipocyte-deficient PPARγ-whole body null mice to investigate the consequence of total adipocyte deficiency on bone homeostasis in mice. We first highlight the dual bone phenotype of PPARγ null mice: on the one hand the increase bone formation and subsequent trabecularization extending in the long bone diaphysis, due to the well-known impact of PPARγ deficiency on osteoblasts formation and activity; on the other hand, an increased osteoclastogenesis in the cortical bone. We then further explore the cause of this unexpected increased osteoclastogenesis using two independent models of lipoatrophy, which recapitulated this phenotype. This demonstrates that hyperosteoclastogenesis is not intrinsically linked to PPARγ deficiency, but is a consequence of the total lipodystrophy. We further showed that adiponectin, a cytokine produced by adipocytes and mesenchymal stromal cells is a potent inhibitor of osteoclastogenesis in vitro and in vivo. Moreover, pharmacological activation of adiponectin receptors by the synthetic agonist AdipoRon inhibits mature osteoclast activity both in mouse and human cells by blocking podosome formation through AMPK activation. Finally, we demonstrated that AdipoRon treatment blocks bone erosion in vivo in a murine model of inflammatory bone loss, providing potential new approaches to treat osteoporosis.


Author(s):  
Maria Veronica Lipreri ◽  
Nicola Baldini ◽  
Gabriela Graziani ◽  
Sofia Avnet

As life expectancy increases, the population experiences progressive ageing. Ageing, in turn, is connected to an increase in bone-related diseases (i.e., osteoporosis and increased risk of fractures). Hence, the search for new approaches to study the occurrence of bone-related diseases and to develop new drugs for their prevention and treatment becomes more pressing. However, to date, a reliable in vitro model that can fully recapitulate the characteristics of bone tissue, either in physiological or altered conditions, is not available. Indeed, current methods for modelling normal and pathological bone are poor predictors of treatment outcomes in humans, as they fail to mimic the in vivo cellular microenvironment and tissue complexity. Bone, in fact, is a dynamic network including differently specialized cells and the extracellular matrix, constantly subjected to external and internal stimuli. To this regard, perfused vascularized models are a novel field of investigation that can offer a new technological approach to overcome the limitations of traditional cell culture methods. It allows the combination of perfusion, mechanical and biochemical stimuli, biological cues, biomaterials (mimicking the extracellular matrix of bone), and multiple cell types. This review will discuss macro, milli, and microscale perfused devices designed to model bone structure and microenvironment, focusing on the role of perfusion and encompassing different degrees of complexity. These devices are a very first, though promising, step for the development of 3D in vitro platforms for preclinical screening of novel anabolic or anti-catabolic therapeutic approaches to improve bone health.


Author(s):  
Xiaohua Duan ◽  
Yuling Han ◽  
Liuliu Yang ◽  
Benjamin E. Nilsson-Payant ◽  
Pengfei Wang ◽  
...  

Summary ParagraphThe current COVID-19 pandemic is caused by SARS-coronavirus 2 (SARS-CoV-2). There are currently no therapeutic options for mitigating this disease due to lack of a vaccine and limited knowledge of SARS-CoV-2 biology. As a result, there is an urgent need to create new disease models to study SARS-CoV-2 biology and to screen for therapeutics using human disease-relevant tissues. COVID-19 patients typically present with respiratory symptoms including cough, dyspnea, and respiratory distress, but nearly 25% of patients have gastrointestinal indications including anorexia, diarrhea, vomiting, and abdominal pain. Moreover, these symptoms are associated with worse COVID-19 outcomes1. Here, we report using human pluripotent stem cell-derived colonic organoids (hPSC-COs) to explore the permissiveness of colonic cell types to SARS-CoV-2 infection. Single cell RNA-seq and immunostaining showed that the putative viral entry receptor ACE2 is expressed in multiple hESC-derived colonic cell types, but highly enriched in enterocytes. Multiple cell types in the COs can be infected by a SARS-CoV-2 pseudo-entry virus, which was further validated in vivo using a humanized mouse model. We used hPSC-derived COs in a high throughput platform to screen 1280 FDA-approved drugs against viral infection. Mycophenolic acid and quinacrine dihydrochloride were found to block the infection of SARS-CoV-2 pseudo-entry virus in COs both in vitro and in vivo, and confirmed to block infection of SARS-CoV-2 virus. This study established both in vitro and in vivo organoid models to investigate infection of SARS-CoV-2 disease-relevant human colonic cell types and identified drugs that blocks SARS-CoV-2 infection, suitable for rapid clinical testing.


2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Rahul Rai ◽  
Asish K Ghosh ◽  
Layton H Smith ◽  
Douglas E Vaughan

Background: Apelinergic signaling is a recently discovered GPCR mediated pathway. Endothelial cells are the main source of endogenous apelin (apln) while apelin receptor (aplnr) is present on multiple cell types. Since the role of endogenous apelinergic pathway within the context of senescence is largely unknown, we ask if levels of apln- aplnr vary with aging. We also investigate the effects of downregulated apln- aplnr on cellular and organismal aging. Approach and Results: To assess variations in endogenous apln- aplnr with aging, we compared their levels in 1 month (young) and 1 year old (old) WT mice. We noticed significant downregulation of apln- aplnr with chronological senescence in multiple tissues. Expression of apelin was also reduced with replicative senescence of endothelial cells. L-NAME administration, a model of stress induced senescence, also repressed aortic and cardiac apln. To address the mechanism involved in downregulation of apln- aplnr, we administered young wild type mice with Ang II. After a week of Ang II, there was significant downregulation of aortic apln and aplnr. Ang II and TGF-β also repressed apln and aplnr in vitro . Next we investigated the effects of downregulated apln on endothelial cells. In response to shRNA mediated apelin knockdown, cells exhibited slower proliferation and upregulated senescence associated markers. We observed similar results when endothelial aplnr was blocked with an antagonist, ML221. In addition, apln and aplnr deficient mice also exhibited features of cardiovascular aging, including ventricular hypertrophy and lower EF. Importantly, aplnr deficient mice at eight months of age were also hypertensive. Conclusion: We provide a systematic assessment of senescence associated variation in levels of apln- aplnr. We demonstrate the role of Ang II- TGF-β axis in downregulating apln- aplnr during chronological and stress induced senescence in vivo and in vitro . We propose a novel model of Ang II- TGF-β induced senescence. Where in, with aging Ang II and TGF-β repress endogenous apln- aplnr. Downregulation of endogenous apln- aplnr axis decreases beneficial “youthful” effects of apelin, resulting in endothelial dysfunction and accelerated organismal aging.


2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Virginia J. Savin ◽  
Mukut Sharma ◽  
Jianping Zhou ◽  
David Gennochi ◽  
Timothy Fields ◽  
...  

CLCF-1 is a cytokine known for B-cell stimulation and for neurotrophic properties. We have identified CLCF-1 as a potential injurious factor in the human renal disease focal segmental glomerulosclerosis (FSGS). We investigated its effects on renal cells and renal function inin vitroandin vivostudies. Methods include measurement of the effect of CLCF-1 on phosphorylation of target molecules of the JAK/STAT pathway, on cytoskeleton and cell morphology in cultured podocytes, on albumin permeability of isolated rat glomeruli, and on tissue phosphorylation and urine albumin after acute or chronic CLCF-1 injection. In addition, cell sorting was performed to determine the presence of cells expressing CLCF-1 in spleen and bone marrow of normal mice and the effect of CLCF-1 infusion on splenic B-cell populations. CLCF-1 increased phosphorylation of STAT3 in multiple cell types, activated podocytes leading to formation of lamellipodia and decrease in basal stress fibers, increased glomerular albumin permeability, and increased STAT3 phosphorylation of peripheral blood cells and renal cortex. CLCF-1 increased urine albumin/creatinine ratio in mice and increased B-cell expression of IgG in mouse spleen. We conclude that CLCF-1 has potentially important systemic effects, alters podocyte function, and may contribute to renal dysfunction and albuminuria.


PPAR Research ◽  
2008 ◽  
Vol 2008 ◽  
pp. 1-13 ◽  
Author(s):  
Dorina Veliceasa ◽  
Frank Thilo Schulze-Hoëpfner ◽  
Olga V. Volpert

PPAR is a member of the ligand-activated nuclear receptor superfamily: its ligands act as insulin sensitizers and some are approved for the treatment of metabolic disorders in humans. PPAR has pleiotropic effects on survival and proliferation of multiple cell types, including cancer cells, and is now subject of intensive preclinical cancer research. Studies of the recent decade highlighted PPAR role as a potential modulator of angiogenesis in vitro and in vivo. These observations provide an additional facet to the PPAR image as potential anticancer drug. Currently PPAR is regarded as an important target for the therapies against angiogenesis-dependent pathological states including cancer and vascular complications of diabetes. Some of the studies, however, identify pro-angiogenic and tumor-promoting effects of PPAR and its ligands pointing out the need for further studies. Below, we summarize current knowledge of PPAR regulatory mechanisms and molecular targets, and discuss ways to maximize the beneficial activity of the PPAR agonists.


Author(s):  
Maria-Bernadette Madel ◽  
He Fu ◽  
Dominique D. Pierroz ◽  
Mariano Schiffrin ◽  
Carine Winkler ◽  
...  

Long bones from mammals host blood cell formation and contain multiple cell types, including adipocytes. Physiological functions of bone marrow adipocytes are poorly documented. Herein, we used adipocyte-deficient PPARγ-whole body null mice to investigate the consequence of total adipocyte deficiency on bone homeostasis in mice. We first highlighted the dual bone phenotype of PPARγ null mice: one the one hand, the increased bone formation and subsequent trabecularization extending in the long bone diaphysis, due to the well-known impact of PPARγ deficiency on osteoblasts formation and activity; on the other hand, an increased osteoclastogenesis in the cortical bone. We then further explored the cause of this unexpected increased osteoclastogenesis using two independent models of lipoatrophy, which recapitulated this phenotype. This demonstrates that hyperosteoclastogenesis is not intrinsically linked to PPARγ deficiency, but is a consequence of the total lipodystrophy. We further showed that adiponectin, a cytokine produced by adipocytes and mesenchymal stromal cells is a potent inhibitor of osteoclastogenesis in vitro and in vivo. Moreover, pharmacological activation of adiponectin receptors by the synthetic agonist AdipoRon inhibited mature osteoclast activity both in mouse and human cells by blocking podosome formation through AMPK activation. Finally, we demonstrated that AdipoRon treatment blocks bone erosion in vivo in a murine model of inflammatory bone loss, providing potential new approaches to treat osteoporosis.


2020 ◽  
Vol 6 (30) ◽  
pp. eaba5672 ◽  
Author(s):  
Kalina Paunovska ◽  
Alejandro Da Silva Sanchez ◽  
Matthew T. Foster ◽  
David Loughrey ◽  
Emmeline L. Blanchard ◽  
...  

The biological pathways that affect drug delivery in vivo remain poorly understood. We hypothesized that altering cell metabolism with phosphatidylinositol (3,4,5)-triphosphate (PIP3), a bioactive lipid upstream of the metabolic pathway PI3K (phosphatidylinositol 3-kinase)/AKT/ mTOR (mammalian target of rapamycin) would transiently increase protein translated by nanoparticle-delivered messenger RNA (mRNA) since these pathways increase growth and proliferation. Instead, we found that PIP3 blocked delivery of clinically-relevant lipid nanoparticles (LNPs) across multiple cell types in vitro and in vivo. PIP3-driven reductions in LNP delivery were not caused by toxicity, cell uptake, or endosomal escape. Interestingly, RNA sequencing and metabolomics analyses suggested an increase in basal metabolic rate. Higher transcriptional activity and mitochondrial expansion led us to formulate two competing hypotheses that explain the reductions in LNP-mediated mRNA delivery. First, PIP3 induced consumption of limited cellular resources, “drowning out” exogenously-delivered mRNA. Second, PIP3 triggers a catabolic response that leads to protein degradation and decreased translation.


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