•BMPs act as homodimers or heterodimers.•BMPs interfere in cell proliferation/differentiation, morphogenesis, organogenesis.•BMPs signaling involves Smad or Ras/ERK/MAPK complex cell signaling ...pathways.•Clinical use of human recombinant BMPs accelerates bone regeneration.•Studies are required to better understand the limitations of the clinical use of BMPs.
Bone Morphogenetic Proteins (BMPs) are multifunctional secreted cytokines, which belong to the TGF-β superfamily. These glycoproteins act as a disulfide-linked homo- or heterodimers, being potent regulators of bone and cartilage formation and repair, cell proliferation during embryonic development and bone homeostasis in the adult. BMPs are promising molecules for tissue engineering and bone therapy. The present review discusses this family of proteins, their structure and biological function, their therapeutic applications and drawbacks, their effects on mesenchymal stem cells differentiation, and the cell signaling pathways involved in this process.
The large use of silver nanoparticles (AgNPs) has provided safety concerns due to the risks of exposure to this nanomaterial caused by the possibility of transfer of the AgNP from the polymer to the ...food. The gap in scientific knowledge regarding AgNP's migration capacity has been high in the number of publications. This article critically analyzes AgNP migration studies in food packaging, showing which parameters should be followed to ensure reliability in the results found. A systematic review (SR) of the literature was performed in the electronic databases PubMed, SCOPUS, SciELO, LILACS/BVS, and Embase and in the gray literature, without date restrictions, until August 21, 2017, to identify studies who evaluated the migration of AgNP in food packaging. Among the 26 articles that have been part of this SR, only 2 (M3 and M5) showed no migration evidence; however, these results are questionable, because all studies present conflicting, contradictory, or questionable results. From this RS, it was not possible to assure that the AgNPs present in food packages tend to migrate to the food matrix, since some methodological inconsistences were identified in all studies evaluated, demonstrating the need for standardization of methodological guidelines for the new migration studies.
Objective
The goal of this review was to determine whether calcium silicate (wollastonite) as a bone graft material is a viable alternative to autogenous bone or whether the evidence base for its use ...is weak.
Methods
In this systematic review, electronic databases (MEDLINE/PubMed and BVS) were searched for relevant articles in indexed journals. Articles published in a 10-year period were identified (n = 48). After initial selection, 17 articles were assessed for eligibility; subsequently, seven articles were excluded and 10 articles were included.
Results
Among the studies included, 20% emphasized the importance of randomization, which adds reliability to the study, minimizing the risk of bias. High variability was observed in the material used, such as additives, amounts, dosage, and chemical alterations, rendering direct comparison among these studies impossible. The experimental periods varied considerably; one of the studies did not include statistical analysis, weakening the evaluation. Nonetheless, the true potential of wollastonite as a graft material conducive to new bone formation was reported in all studies.
Conclusion
The results support the use of wollastonite as a bone graft material. The initial research question was answered despite the significant variability observed among these preclinical studies, which hindered the precision of this analysis.
Introduction Our goal was to verify the association between candidate polymorphisms and skeletal Class III malocclusion in a well-characterized homogeneous sample set. Methods Thirty-five ...single-nucleotide polymorphisms were studied from 10 candidate loci in 54 Class III subjects and 120 controls. Skeletal Class III characteristics included ANB angle less than 0°, SNB angle greater than 83° (mandibular prognathism), SNA angle less than 79° (maxillary deficiency), Class III molar relationship, and negative overjet. Inclusion criteria for the controls were ANB angle between 0° and 4°, Class I molar relationship, and normal overjet. Chi-square and Fisher exact tests and principal component (PC) analysis were used to determine overrepresentation of marker alleles with alpha of 0.05. Odds ratios and 95% confidence intervals were calculated. Results MYO1H (rs10850110 A<G) ( P <0.01; odds ratio, 7.44 4.02-13.77) was associated with an increased risk for the mandibular prognathism phenotype. These results were confirmed by PC analysis, which showed 4 PCs representing the sample variations (PC1, 37.24%; PC2, 20.02%; PC3, 12.18%; and PC4, 11.40%), and PC1 was associated with MYO1H ( P <0.001). We also found by PC analysis associations between MYO1H ( P <0.001) and GHR (rs2973015 A>G) ( P = 0.001) with PC2 and between FGF10 (rs593307 A<G) ( P = 0.001) with PC4. Conclusions Polymorphism in MYO1H could be used as a marker for genetic susceptibility to Class III malocclusion with mandibular prognathism, and polymorphisms in GHR and FGF were associated with maxillomandibular discrepancies. This study may contribute to improved diagnosis and further research assessing possible differences in treatment responses based on genetic polymorphisms.
Top-down tissue engineering aims to produce functional tissues using biomaterials as scaffolds, thus providing cues for cell proliferation and differentiation. Conversely, the bottom-up approach aims ...to precondition cells to form modular tissues units (building-blocks) represented by spheroids. In spheroid culture, adult stem cells are responsible for their extracellular matrix synthesis, re-creating structures at the tissue level. Spheroids from adult stem cells can be considered as organoids, since stem cells recapitulate differentiation pathways and also represent a promising approach for identifying new molecular targets (biomarkers) for diagnosis and therapy. Currently, spheroids can be used for scaffold-free (developmental engineering) or scaffold-based approaches. The scaffold promotes better spatial organization of individual spheroids and provides a defined geometry for their 3D assembly in larger and complex tissues. Furthermore, spheroids exhibit potent angiogenic and vasculogenic capacity and serve as efficient vascularization units in porous scaffolds for bone tissue engineering. An automated combinatorial approach that integrates spheroids into scaffolds is starting to be investigated for macro-scale tissue biofabrication.
Background
The SARS‐CoV‐2 pandemic has spurred an unparalleled scientific endeavor to elucidate the virus’ structure, infection mechanisms, and pathogenesis. Two‐dimensional culture systems have been ...instrumental in shedding light on numerous aspects of COVID‐19. However, these in vitro systems lack the physiological complexity to comprehend the infection process and explore treatment options. Three‐dimensional (3D) models have been proposed to fill the gap between 2D cultures and in vivo studies. Specifically, spheroids, composed of lung cell types, have been suggested for studying SARS‐CoV‐2 infection and serving as a drug screening platform.
Methods
3D lung spheroids were prepared by coculturing human alveolar or bronchial epithelial cells with human lung stromal cells. The morphology, size, and ultrastructure of spheroids before and after SARS‐CoV‐2 infection were analyzed using optical and electron microscopy. Immunohistochemistry was used to detect spike protein and, thus, the virus presence in the spheroids. Multiplex analysis elucidated the cytokine release after virus infection.
Results
The spheroids were stable and kept their size and morphology after SARS‐CoV‐2 infection despite the presence of multivesicular bodies, endoplasmic reticulum rearrangement, tubular compartment‐enclosed vesicles, and the accumulation of viral particles. The spheroid responded to the infection releasing IL‐6 and IL‐8 cytokines.
Conclusion
This study demonstrates that coculture spheroids of epithelial and stromal cells can serve as a cost‐effective infection model for the SARS‐CoV‐2 virus. We suggest using this 3D spheroid as a drug screening platform to explore new treatments related to the cytokines released during virus infection, especially for long COVID treatment.
Scientists have been working on potential treatments for SARS‐CoV‐2 (A) using 3D lung spheroids (B) formed by alveolar epithelial, bronchial, and stromal cells (C). Ultrastructural changes occur within the spheroid after SARS‐CoV‐2 infection, resulting in cytokines secretion (D). Spheroids can be used for drug screening (E) and drug design (F) specifically to tackle cytokines release in long‐COVID cases (G and H).
Abstract
Background
Coronavirus disease 2019 (COVID-19) can progress to severe pneumonia with respiratory failure and is aggravated by the deregulation of the immune system causing an excessive ...inflammation including the cytokine storm.
Methods
In this study, we report that severe acutely infected patients have high levels of both type-1 and type-2 cytokines.
Results
Our results show abnormal cytokine levels upon T-cell stimulation, in a nonpolarized profile. Furthermore, our findings indicate that this hyperactive cytokine response is associated with a significantly increased frequency of late-differentiated T cells with particular phenotype of effector exhausted/senescent CD28−CD57+ cells. Of note, we demonstrated for the first time an increased frequency of CD3+CD4+CD28−CD57+ T cells with expression of programmed death 1, one of the hallmarks of T-cell exhaustion.
Conclusions
These findings reveal that COVID-19 is associated with acute immunodeficiency, especially within the CD4+ T-cell compartment, and points to possible mechanisms of loss of clonal repertoire and susceptibility to viral relapse and reinfection events.
Platelet-rich plasma (PRP) is nowadays widely applied in different clinical scenarios, such as orthopedics, ophthalmology and healing therapies, as a growth factor pool for improving tissue ...regeneration. Studies into its clinical efficiency are not conclusive and one of the main reasons for this is that different PRP preparations are used, eliciting different responses that cannot be compared. Platelet quantification and the growth factor content definition must be defined in order to understand molecular mechanisms behind PRP regenerative strength. Standardization of PRP preparations is thus urgently needed.
PRP was prepared by centrifugation varying the relative centrifugal force, temperature, and time. Having quantified platelet recovery and yield, the two-step procedure that rendered the highest output was chosen and further analyzed. Cytokine content was determined in different fractions obtained throughout the whole centrifugation procedure.
Our method showed reproducibility when applied to different blood donors. We recovered 46.9 to 69.5% of total initial platelets and the procedure resulted in a 5.4-fold to 7.3-fold increase in platelet concentration (1.4 × 10(6) to 1.9 × 10(6) platelets/μl). Platelets were highly purified, because only <0.3% from the initial red blood cells and leukocytes was present in the final PRP preparation. We also quantified growth factors, cytokines and chemokines secreted by the concentrated platelets after activation with calcium and calcium/thrombin. High concentrations of platelet-derived growth factor, endothelial growth factor and transforming growth factor (TGF) were secreted, together with the anti-inflammatory and proinflammatory cytokines interleukin (IL)-4, IL-8, IL-13, IL-17, tumor necrosis factor (TNF)-α and interferon (IFN)-α. No cytokines were secreted before platelet activation. TGF-β3 and IFNγ were not detected in any studied fraction. Clots obtained after platelet coagulation retained a high concentration of several growth factors, including platelet-derived growth factor and TGF.
Our study resulted in a consistent PRP preparation method that yielded a cytokine and growth factor pool from different donors with high reproducibility. These findings support the use of PRP in therapies aiming for tissue regeneration, and its content characterization will allow us to understand and improve the clinical outcomes.
Different mesenchymal stromal cells (MSC) have been successfully isolated and expanded in vitro and nowadays they are tested in clinical trials for a wide variety of diseases. Whether all MSC express ...the same cell surface markers or have a similar secretion profile is still controversial, making it difficult to decide which stromal cell may be better for a particular application.
We isolated human mesenchymal stromal cells from bone marrow (BM), adipose tissue (AT) and Wharton's jelly (WJ) and cultured them in fetal bovine serum supplemented media. We evaluated proliferation, in vitro differentiation (osteogenic, adipogenic and chondrogenic potential), expression of cell surface markers and protein secretion using Luminex and ELISA assays.
Cell proliferation was higher for WJ-MSC, followed by AT-MSC. Differences in surface expression markers were observed only for CD54 and CD146. WJ-MSC secreted higher concentrations of chemokines, pro-inflammatory proteins and growth factors. AT-MSC showed a better pro-angiogenic profile and secreted higher amounts of extracellular matrix components and metalloproteinases.
Mesenchymal stromal cells purified from different tissues have different angiogenic, inflammatory and matrix remodeling potential properties. These abilities should be further characterized in order to choose the best protocols for their therapeutic use.
•MMPs are the most important collagenases during bone development in vivo.•Depletion for specific MMPs demonstrates skeletal abnormal phenotypes.•MMPs are required for appropriate matrix remodeling ...during bone healing.•MMPs are important for the maintenance of bone quality (biomechanical properties).•MMPs are interesting candidates for design protocols in Bone Bioengineering.
Bone-forming cells originate from distinct embryological layers, mesoderm (axial and appendicular bones) and ectoderm (precursor of neural crest cells, which mainly form facial bones). These cells will develop bones by two principal mechanisms: intramembranous and endochondral ossification. In both cases, condensation of multipotent mesenchymal cells occurs, at the site of the future bone, which differentiate into bone and cartilage-forming cells. During long bone development, an initial cartilaginous template is formed and replaced by bone in a coordinated and refined program involving chondrocyte proliferation and maturation, vascular invasion, recruitment of adult stem cells and intense remodeling of cartilage and bone matrix. Matrix metalloproteinases (MMPs) are the most important enzymes for cleaving structural components of the extracellular matrix (ECM), as well as other non-ECM molecules in the ECM space, pericellular perimeter and intracellularly. Thus, the bioactive molecules generated act on several biological events, such as development, tissue remodeling and homeostasis. Since the discovery of collagenase in bone cells, more than half of the MMP members have been detected in bone tissues under both physiological and pathological conditions. Pivotal functions of MMPs during development and bone regeneration have been revealed by knockout mouse models, such as chondrocyte proliferation and differentiation, osteoclast recruitment and function, bone modeling, coupling of bone resorption and formation (bone remodeling), osteoblast recruitment and survival, angiogenesis, osteocyte viability and function (biomechanical properties); as such alterations in MMP function may alter bone quality. In this review, we look at the principal properties of MMPs and their inhibitors (TIMPs and RECK), provide an up-date on their known functions in bone development and remodeling and discuss their potential application to Bone Bioengineering.
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