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Introduction and Purpose: Mouse mesenchymal stem cells (MSCs) provide a resourceful tool to study physiological and pathological aspects of adipogenesis. Bone marrow-derived MSCs (BM-MSCs) and adipose tissue-derived MSCs (ASCs) are widely used for these studies. Since there is a wide spectrum of methods available, the purpose is to provide a focused hands-on procedural guide for isolation and characterization of murine BM-MSCs and ASCs and to effectively differentiate them into adipocytes. Methods and Results: Optimized harvesting procedures for murine BM-MSCs and ASCs are described and graphically documented. Since macrophages reside in bone-marrow and fat tissues and regulate the biological behaviour of BM-MSCs and ASCs, we included a procedure to deplete macrophages from the MSC preparations. The identity and stemness of BM-MSCs and ASCs were confirmed by flow cytometry using established markers. Since the composition and concentrations of adipogenic differentiation cocktails differ widely, we present a standardized four-component adipogenic cocktail, consisting of insulin, dexamethasone, 3-isobutyl-1-methylxanthine, and indomethacin to efficiently differentiate freshly isolated or frozen/thawed BM-MSCs and ASCs into adipocytes. We further included visualization and quantification protocols of the differentiated adipocytes. Conclusion: This laboratory protocol was designed as a step-by-step procedure for harvesting murine BM-MSCs and ASCs and differentiating them into adipocytes. [ABSTRACT FROM AUTHOR]

Exogenous gibberellic acid was applied to regulate fruit growth of grapes to acquire high quality seedless berries. The vascular bundles provide the pathway of water and nutrient transport into the fruit and play an important role in berry growth and sugar accumulation. Therefore, changes in berry size and quality are closely related to the structure and function of the vascular tissue. In this study, 10-year-old "Shine Muscat" grape vines were treated with GA3 in grapevine production. Based on previous research and experimental environmental conditions, four treatments were applied: elongating cluster（5 mg L−1 GA3 on Apr. 28）+ seedless（25 mg L−1 GA3 on May. 24）+ expanding（50 mg L−1 GA3 on Jun. 7） (T1), seedless（25 mg L−1 GA3 on May. 24）+ expanding（50 mg L−1 GA3 on Jun. 7） (T2), expanding（50 mg L−1 GA3 on Jun. 7） (T3) and water (CK). Compared to CK, all fruits treated with GA3 had greater berry size. In addition, GA3 treated grapes had greater vascular bundle areas, including the areas of both phloem and xylem, as well as a greater number of vessels compared to control fruit. During the first rapid growth stage, water transport into the grape was rapid and did not differ among treatments. During veraison, the water transport rate among the four treatments differed, and the rank of speed was T2>T3>CK>T1. Therefore, we found that GA3 treatment can significantly promote the differentiation of vascular tissues and improve water transport capacity and phloem sugar unloading; T2 promoted the development of vascular bundles, enhanced water transport speed and phloem sugar unloading of fruit after veraison, and increased berry size. [ABSTRACT FROM AUTHOR]

In this study, we assessed the effects of MFG-E8 on the biological characteristics of ovarian cancer cells and explored the underlying mechanisms. Human ovarian cancer SKOV3 cells were transfected with MFG-E8 siRNA or NC siRNA. CCK-8, cell adhesion, scratch-wound, and Transwell assays were used to detect changes in cell metastatic processes. Effects of MFG-E8 silencing on the proteins involved in AKT/mTOR/S6K signalling pathway were assessed using qRT-PCR and Western blotting. Transient silencing of MFG-E8 in SKOV3 cells decreased cell proliferation and downregulated the expression of CDK4, cyclin D1, and caspase-3 proteins. Cell adhesion, migration, and invasion were also suppressed. p-AKT, p-mTORC1, and p-p70S6K levels decreased following MFG-E8 knockdown. Hence, MFG-E8 enhances carcinogenesis and affects the AKT/mTOR/S6K signalling pathway in ovarian cancer cells. In conclusion, our results suggested that MFG-E8 could promote ovarian cancer via AKT/mTOR/S6K signalling pathway which improved our understanding of the molecular mechanisms involved in ovarian cancer. What is already known on this subject? Milk fat globule-epidermal growth factor 8 (MFG-E8) is expressed in several types of cancers such as oesophageal, breast, and liver. However, the mechanism of MFG-E8 involving in EOC remains unknown. We previously found that MFG-E8 expression was related to pathological staging, tissue differentiation, platinum sensitivity, ascites state, and other clinicopathological characteristics. What the results of this study add? Due to a series of in vitro studies, we confirmed that MFG-E8 is involved in the process of proliferation, invasion and metastasis. Our results show that silencing MFG-E8 can significantly inhibit the expression of cyclin D1 and CDK4 in EOC SKOV3 cells. MFG-E8 enhances carcinogenesis and affects the AKT/mTOR/S6K signaling pathway in ovarian cancer. What the implications are of these findings for clinical practice and/or further research? Taken together, our findings suggest that MFG-E8 may be an oncogene in EOC and provide new insights into the mechanism of MFG-E8 in the progression of EOC. [ABSTRACT FROM AUTHOR]

Theropods comprise a successful group of mostly predatory dinosaurs with varied growth rates that colonized all continents. Much research has addressed the histology of the Global North's Mesozoic populations, especially coelurosaurians and allosauroids. However, little has been done to understand the histological patterns of the Gondwanan populations, especially abelisauroids. Previous studies detected disparate (parallel-fibered or fibrolamellar) bone profiles between noasaurids and abelisaurids but did not include broader quantitative analyses. Here we describe the femoral histology of a mid-sized abelisaurid from the Upper Cretaceous Serra da Galga Formation, Bauru Group, Southeast Brazil. Despite the harsh semiarid paleotropical context, our specimen shows a growth rate more similar to the Patagonian abelisaurids, challenging a previous hypothesis on environmental pressure selecting taxa with lower growth rates and parallel-fibered bone tissue. We also bring data to bear from several taxa to test the hypothesis of tissue differentiation within abelisauroid clades. Our logistic regression and correlation analyses show that the variation in histology in noasaurids and abelisaurids can be explained by body size and phylogeny when considering fibrolamellar tissue, but not parallel-fibered tissue. A decrease in growth rate through the deposition of parallel-fibered bone tissue may be an example of evolutionary convergence between noasaurids and some small-bodied sauropods. [ABSTRACT FROM AUTHOR]

A lot of evidence has shown the importance of stimulating cell mechanically during bone repair. In this study, we modeled the challenging fracture healing of a large bone defect in tibial diaphysis. To fill the fracture gap, we considered the implantation of a porous osteoconductive biomaterial made of poly-lactic acid wrapped by a hydrogel membrane mimicking osteogenic properties of the periosteum. We identified the optimal loading case that best promotes the formation and differentiation into bone tissue. Our results support the idea that a patient's rehabilitation program should be adapted to reproduce optimal mechanical stimulations. [ABSTRACT FROM AUTHOR]

Considered to be a field that is continuously growing, epitranscriptomics analyzes the modifications that occur in RNA transcripts and their downstream effects. As epigenetic modifications found in DNA and histones exhibit specific roles on various biological processes, also epitranscriptomic marks control gene expression patterns that are crucial for proper cell proliferation, differentiation and tissue development. Thus, various epitranscriptomic signatures have been identified to play specific roles during stem cell differentiation towards the neuronal and glial lineages, axonal guidance, synaptic plasticity, thus leading to the development of the mature brain tissue. Here we describe in-depth molecular mechanism underlying the most important RNA modifications with emerging roles in the nervous system. [ABSTRACT FROM AUTHOR]

During endochondral bone development, a complex process that leads to the formation of the majority of skeletal elements, mesenchymal cells condense, differentiating into chondrocytes and producing the foetal growth plate. Chondrocytes progressively hypertrophy, induce angiogenesis and are then gradually replaced by bone. Epidermal Growth Factor (EGF), one of many growth factors, is the prototype of the EGF-ligand family, which comprises several proteins involved in cell proliferation, migration and survival. In bone, EGF pathway signalling finely tunes the first steps of chondrogenesis by maintaining mesenchymal cells in an undifferentiated stage, and by promoting hypertrophic cartilage replacement. Moreover, EGF signalling modulates bone homeostasis by stimulating osteoblast and osteoclast proliferation, and by regulating osteoblast differentiation under specific spatial and temporal conditions. This evidence-based narrative review describes the EGF pathway in bone metabolism and endochondral bone development. This comprehensive description may be useful in light of possible clinical applications in orthopaedic practice. A deeper knowledge of the role of EGF in bone may be useful in musculoskeletal conditions which may benefit from the modulation of this signalling pathway. The EGF pathway is involved in bone metabolism. EGF signalling is essential in the very early stages of limb development by maintaining cells in an undifferentiated stage. EGF pathway positively regulates chondrocyte proliferation, negatively modulates hypertrophy, and favours cartilage replacement by bone. EGF and EGF-like proteins finely tune the proliferation and differentiation of bone tissue cells, and they also regulate the initial phases of endochondral ossification. [ABSTRACT FROM AUTHOR]

Tendon injuries are a challenging clinical problem with few treatment options. Identifying the molecular regulators of tendon is required for the development of new therapies. While the Wnt pathway is critical for the maintenance and differentiation of many tissues, the role of Wnt signaling in tendon cell biology remains largely unexplored. The effects of Wnt activation were tested in vitro using neonatal tendon-derived cells cultured in 2D and 3D conditions. The inducible Axin2CreERT2 was then used to label Axin2+ cells in vivo and cells were traced during neonatal tendon regeneration. We showed that activation of Wnt signaling results in proliferation of neonatal tendon cells. While tendon marker expression was inhibited by Wnt activation under 2D conditions, Scx expression was not affected under 3D uniaxial tension, suggesting that the microenvironment contextualizes tendon cell response to Wnt signaling. Using an in vivo model of neonatal tendon regeneration, we further showed that Wnt signaling cells comprise a subpopulation of tenocyte and epitenon cells that proliferate after injury and are recruited during regeneration. Collectively, these studies suggest that Wnt signaling may play a role in tendon cell proliferation, differentiation, and regeneration. [ABSTRACT FROM AUTHOR]

Epidermal growth factor (EGF) has many important biological functions. It plays an important role in regulating the growth, survival, migration, apoptosis, proliferation, and differentiation of intestinal tissues and cells. However, until now, the effect of inflammation on the biological activity of EGF in intestinal cells or tissues is still unclear. For this reason, in the current research, we have conducted a detailed study on this issue. Using the rat small intestinal crypt epithelial cell line (IEC6) was used as an in vitro model, and Confocal laser scanning microscope (CLSM), Flow cytometry (FCM), Indirect immunofluorescence assay (IFA), Western-blotting (WB), and Quantitative real-time RT-PCR (QRT-PCR) methods were used to explore the effects of inflammation on EGF/EGFR biological activity and signal transduction profiles. We found that the EGF/EGFR nuclear signal almost disappeared in the inflammatory state, and the phosphorylation levels of EGFR, AKT, and STAT3 were all significantly down-regulated. In addition, we also studied the effect of β-carotene on the biological activity of EGF, and found that when cells were pretreated with β-carotene, the cellular behavior, biological activity, and nuclear signal of EGF/EGFR under inflammation stimulation were partially restored. In summary, the current study shows that inflammation can disrupt EGF/EGFR-mediated signaling in IEC6 cells, suggesting that inflammation negatively regulates the biological activity of EGF/EGFR. Furthermore, we found that β-carotene not only attenuated lipopolysaccharide (LPS)-induced inflammation but also partially restored the biological activity of EGF in IEC6 cells, laying a solid foundation for studying the biological functions of EGF and β-carotene. [ABSTRACT FROM AUTHOR]

Intramedullary implant fixation is achieved through a press-fit between the implant and the host bone. A stronger press-fit between the bone and the prosthesis often introduces damage to the bone canal creating micro-gaps. The aim of the present investigation is to study the influences of simultaneous opening/closing of gaps on bone growth over macro-textured implant surfaces. Models based on textures available on CORAIL and SP-CL hip stems have been considered and 3D finite element (FE) analysis has been carried out in conjunction with mechanoregulation based tissue differentiation algorithm. Additionally, using a full-factorial approach, different combinations (between 5 µm to 15 µm) of sliding and gap distances at the bone-implant interface were considered to understand their combined influences on bone growth. All designs show an elevated fibrous tissue formation (10.96% at 5 µm to 29.38% at 40 µm for CORAIL based textured model; 11.45% at 5 µm to 32.25% at 40 µm for SP-CL based textured model) and inhibition of soft cartilaginous tissue (75.64% at 5 µm to 53.94% at 40 µm for CORAIL based model; 76.02% at 5 µm to 53.60% at 40 µm SP-CL based model) at progressively higher levels of normal micromotion, leading to a fragile bone-implant interface. These results highlight the importance of minimizing both sliding and gap distances simultaneously to enhance bone growth and implant stability. Further, results from the studies with differential texture density over CORAIL based implant reveal a non-linear complex relationship between tissue growth and texture density which might be investigated in a machine learning framework. [ABSTRACT FROM AUTHOR]

Aim of the study: Postoperative peritoneal adhesions are a common cause of morbidity after surgery, resulting in multiple complications. Macrophage-mediated inflammation and myofibroblast differentiation after tissue injury play central roles in the pathogenesis and progression of adhesion formation. Calponin 2 is an actin cytoskeleton regulatory protein in endothelial cells, macrophages and fibroblasts that are key players in the development of fibrosis. Deletion of calponin 2 has been shown to attenuate inflammatory arthritis, atherosclerosis and fibrocalcification of the aortic valves. The present study investigated the effect of calponin 2 deletion on attenuating the formation of peritoneal adhesions in a mouse model for potential use as a new therapeutic target. Materials and methods: Sterile surgical procedures under general anesthesia were used on paired wild type (WT) and calponin 2 knockout (KO) mice to generate mild injury on the cecal and abdominal wall peritonea. Three and seven days post-operation, the mice were compared postmortem for the formation of peritoneal adhesions. Tissues at the adhesion sites were examined with histology and immunofluorescent studies for macrophage and myofibroblast activations. Results: Quantitative scoring demonstrated that calponin 2 KO mice developed significantly less postoperative peritoneal adhesions than that in WT mice. Calponin 2 deletion resulted in less infiltration of F4/80+ macrophages at the adhesion sites with less myofibroblast differentiation and collagen deposition than WT controls. Conclusions: The data show that deletion of calponin 2 effectively reduces postoperative peritoneal adhesion, presenting a novel molecular target for clinical prevention. [ABSTRACT FROM AUTHOR]

Relatively quiescent tissues like salivary glands (SGs) respond to stimuli such as injury to expand, replace and regenerate. Resident stem/progenitor cells are key in this process because, upon activation, they possess the ability to self-renew. Macroautophagy/autophagy contributes to and regulates differentiation in adult tissues, but an important question is whether this pathway promotes stem cell self-renewal in tissues. We took advantage of a 3D organoid system that allows assessing the self-renewal of mouse SGs stem cells (SGSCs). We found that autophagy in dormant SGSCs has slower flux than self-renewing SGSCs. Importantly, autophagy enhancement upon SGSCs activation is a self-renewal feature in 3D organoid cultures and SGs regenerating in vivo. Accordingly, autophagy ablation in SGSCs inhibits self-renewal whereas pharmacological stimulation promotes self-renewal of mouse and human SGSCs. Thus, autophagy is a key pathway for self-renewal activation in low proliferative adult tissues, and its pharmacological manipulation has the potential to promote tissue regeneration. [ABSTRACT FROM AUTHOR]

Lung tumor-infiltrating neutrophils are known to support growth and dissemination of cancer cells and to suppress T cell responses. However, the precise impact of tissue neutrophils on programming and differentiation of anticancer CD8 T cells in vivo remains poorly understood. Here, we identified cancer cellautonomous secretion of CXCL5 as sufficient to drive infiltration of mature, protumorigenic neutrophils in a mouse model of non-small cell lung cancer (NSCLC). Consistently, CXCL5 transcripts correlate with neutrophil density and poor prognosis in a large human lung adenocarcinoma compendium. CXCL5 genetic deletion, unlike antibody-mediated depletion, completely and selectively prevented neutrophils accumulation in lung tissues. Depletion of tumor-infiltrating neutrophils promoted expansion of tumorspecific CD8 T cells, differentiation into effector cells and acquisition of cytolytic functions. Transfer of effector CD8 T cells into neutrophil-rich tumors, inhibited IFN-γ production, indicating active suppression of effector functions. Importantly, blocking neutrophils infiltration in the lung, overcame resistance to checkpoint blockade. Hence, this study demonstrates that neutrophils curb acquisition of cytolytic functions in lung tumor tissues and suggests targeting of CXCL5 as a strategy to restore anti-tumoral T cell functions. [ABSTRACT FROM AUTHOR]

Considered to be a field that is continuously growing, epitranscriptomics analyzes the modifications that occur in RNA transcripts and their downstream effects. As epigenetic modifications found in DNA and histones exhibit specific roles on various biological processes, also epitranscriptomic marks control gene expression patterns that are crucial for proper cell proliferation, differentiation and tissue development. Thus, various epitranscriptomic signatures have been identified to play specific roles during stem cell differentiation towards the neuronal and glial lineages, axonal guidance, synaptic plasticity, thus leading to the development of the mature brain tissue. Here we describe in-depth molecular mechanism underlying the most important RNA modifications with emerging roles in the nervous system. [ABSTRACT FROM AUTHOR]

Differentiation status of tumors is correlated with metastatic potential and malignancy. FOXA1 (forkhead box A1) is a transcription factor known to regulate differentiation in certain tissues. Here, we investigate FOXA1 function in human colorectal cancer (CRC). We found that FOXA1 is robustly expressed in the normal human colon but significantly downregulated in colon adenocarcinoma. Applying FOXA1 chromatin immunoprecipitation coupled with deep sequencing and transcriptome analysis upon FOXA1 knockdown in well-differentiated CRC cells and FOXA1 overexpression in poorly differentiated CRC cells, we identified novel proteincoding and lncRNA genes regulated by FOXA1. Among the numerous novel FOXA1 targets we identified, we focused on CEACAM5, a tumor marker and facilitator of cell adhesion. We show that FOXA1 binds to a distal enhancer downstream of CEACAM5 and strongly activates its expression. Consistent with these data, we show that FOXA1 inhibits anoikis in CRC cells. Collectively, our results uncover novel proteincoding and noncoding targets of FOXA1 and suggest a vital role of FOXA1 in enhancing CEACAM5 expression and anoikis resistance in CRC cells. [ABSTRACT FROM AUTHOR]

Polybrominated diphenyl ethers (PBDEs) have been highly concerned as environmental organic pollutants. 4-Bromodiphenyl ether (BDE-3) is one of the lowest brominated diphenyl ethers used as a representative of monobromobiphenyl ethers for exploring the environmental behavior and toxicology of PBDEs. The root differentiation is the critical response to the exposure of persistent organic pollutants (POPs) for understanding the phytoremediation mechanism. In this article, the adventitious root differentiation of tissue cultural seedlings of Triarrhena sacchariflora was observed under BDE-3 exposure conditions. The results showed that 3.0 mg·L−1 BDE-3 had significant positive effects on the adventitious root differentiation and the biomass, in which the higher dosage of 30.0 mg·L−1 showed inhibition effects and symptoms of injury of seedlings. The endogenous IAA/ZR ratio was at higher level than the controls and coincident with the adventitious roots differentiation in the same treatment of 3.0 mg·L−1 BDE-3. However, the responses of coleoptile elongation of Zea mays and the DR5::GUS reporter gene of Arabidopsis thaliana to BDE-3 exposure were all negative comparing with the positive controls. It could be inferred from the results that the BDE-3 may not be an auxin-like substance, and its hormesis on the adventitious root differentiation of T. sacchariflora might result from changes of endogenous IAA/ZR due to the action of BDE-3. In our knowledge, it was the first report concerning the BDE-3 hormesis on the adventitious root differentiation of T. sacchariflora tissue culture seedlings. The findings are meaningful to the further understanding of the BDE-3 effects on the plant endogenous signal substances that regulate the plant growth and development which are closely related to the phytoremediation of POPs. [ABSTRACT FROM AUTHOR]

Platelet-rich plasma (PRP) has a potential effect on tissue repair through proliferation and differentiation of tissue progenitor cells. The aim of this study was to evaluate the effect of PRP on the testis structure and function in infertile rat model by stereological method. Thirty-two male rats were divided into four groups. Infertility was induced by the administration of busulfan (BUS) (10mg/kg, I.P., single dose). PRP (80μl, testis local injected, single dose) was administered for the subjects. After 48 days, semen analysis was performed and blood samples were taken from the heart to measure the testosterone. Then, the left testis was removed, fixed, embedded, sectioned, and stained by H&E; after that the testes were analyzed. The results showed that BUS can decrease the sperm count, motility, normal morphology, length of the spermatozoon tail, volume of the testis, seminiferous tubules, germinal epithelium height, and the number of spermatogenesis lineage cells in comparison with the control group (p < 0.01). PRP increased the number of spermatogenic stem cell, count, motility and tail length of the sperm and testosterone level in BUS-treated animal significantly, but it did not have any effect on the volume of the testis, germinal epithelium height, Sertoli and Leydig cells number, and seminiferous tubules length. It concluded that PRP can improve the structural and functional impairment of the testis in treatment by BUS. [ABSTRACT FROM AUTHOR]

We present a novel numerical model of the fracture-healing process using interface-capturing techniques, a well-known approach from fields like fluid dynamics, to describe tissue growth. One advantage of this method is its direct connection to experimentally observable parameters, including tissue-growth velocities. In our model, osteogenesis, chondrogenesis and revascularisation are triggered by mechanical stimuli via mechano-transduction based on previously established hypothesis of Claes and Heigele. After experimentally verifying the convergence of the numerical method, we compare the predictions of our model with those of the already established Ulm bone-healing model, which serves as a benchmark, and corroborate our results with existing animal experiments. We demonstrate that the new model can predict the history of the interfragmentary movement and forecast a tissue evolution that appears similar to the experimental results. Furthermore, we compare the relative tissue concentration in the healing domain with outcomes of animal experiments. Finally, we discuss the possible application of the model to new fields, where numerical simulations could also prove beneficial. [ABSTRACT FROM AUTHOR]

Transplantation of islet is a promising method in treatment of patients with type 1 diabetes mellitus (T1DM), however, is limited by islet shortage. The aim of this study was to prepare a polyethersulfone (PES) nanofibrous scaffolds to evaluate the pancreatic differentiation of human induced pluripotent stem cells (hiPSCs). The differentiation process in tissue culture dishes and PES scaffolds was evaluated at mRNA and protein level by RT-qPCR and immunofluorescence assay, respectively. The functionality of differentiated cells was determined by insulin and C-peptide release in response to glucose challenges. The results of this study showed that cells cultured on PES nanofibrous scaffolds exhibit more pancreatic β-cell characteristics as they express more pancreatic tissue-specific genes and proteins. Furthermore, the immunoassay showed that differentiated cells in both culture plates and PES scaffolds groups are functional and secrete C-peptide and insulin in response to glucose challenges. Altogether, the results of this study demonstrated that PES nanofibrous scaffold could provide the microenvironment that promotes the differentiation of induced pluripotent stem cells (iPSCs) into insulin producing cells. [ABSTRACT FROM AUTHOR]

Different cell types exhibit distinct patterns of 3D genome organization that correlate with changes in gene expression in tissue and differentiation systems. Several tissue-specific nuclear envelope transmembrane proteins (NETs) have been found to influence the spatial positioning of genes and chromosomes that normally occurs during tissue differentiation. Here we study 3 such NETs: NET29, NET39, and NET47, which are expressed preferentially in fat, muscle and liver, respectively. We found that even when exogenously expressed in a heterologous system they can specify particular genome organization patterns and alter gene expression. Each NET affected largely different subsets of genes. Notably, the liver-specific NET47 upregulated many genes in HT1080 fibroblast cells that are normally upregulated in hepatogenesis, showing that tissue-specific NETs can favor expression patterns associated with the tissue where the NET is normally expressed. Similarly, global profiling of peripheral chromatin after exogenous expression of these NETs using lamin B1 DamID revealed that each NET affected the nuclear positioning of distinct sets of genomic regions with a significant tissue-specific component. Thus NET influences on genome organization can contribute to gene expression changes associated with differentiation even in the absence of other factors and overt cellular differentiation changes. [ABSTRACT FROM AUTHOR]

Humanized mouse models currently have seen improved development and have received wide applications. Its usefulness is observed in cell and tissue transplant involving basic and applied human disease research. In this article, the development of a new generation of humanized mice was discussed as well as their relevant application in HIV disease. Furthermore, current techniques employed to overcome the initial limitations of mouse model were reviewed. Highly immunodeficient mice which support cell and tissue differentiation and do not reject xenografts are indispensable for generating additional appropriate models useful in disease study, this phenomenom deserves emphases, scientific highlight and a definitive research focus. Since the early 2000s, a series of immunodeficient mice appropriate for generating humanized mice has been successively developed by introducing theIL-2Rγnullgene (e.g. NOD/SCID/γcnulland Rag2nullγcnullmice) through various genomic approaches. These mice were generated by genetically introducing human cytokine genes into NOD/SCID/γcnulland Rag2nullγcnullmouse backgrounds. The application of these techniques serves as a quick and appropriate mechanistic model for basic and therapeutic investigations of known and emerging infections. [ABSTRACT FROM AUTHOR]

In the pupal stage, the fly body undergoes extensive metamorphic remodeling, in which programmed cell death plays a critical role. We studied two of the constituent processes in this remodeling, salivary gland degeneration and breakdown of the eclosion muscle, which are triggered by an increase and a decrease in the circulating steroid hormone ecdysone at the start and end of metamorphosis, respectively. We found that knockdown of zeste (z), a gene encoding a sequence-specific DNA-binding protein implicated in transvection, in salivary gland cells advances the initiation of their degeneration, whereas z knockdown in neurons delays muscle breakdown. We further showed that knockdown of an ecdysone-inducible gene, E74, retards salivary gland degeneration with little effect on eclosion muscle breakdown. We propose that Z tunes the sensitivity of ecdysone targets to this hormone in order to ensure a high safety margin so that the cell death program will be activated when the ecdysone titer is at a sufficiently high level that is reached only at a defined stage during metamorphosis. [ABSTRACT FROM AUTHOR]

Flexible fixation or the so-called 'biological fixation' has been shown to encourage the formation of fracture callus, leading to better healing outcomes. However, the nature of the relationship between the degree of mechanical stability provided by a flexible fixation and the optimal healing outcomes has not been fully understood. In this study, we have developed a validated quantitative model to predict how cells in fracture callus might respond to change in their mechanical microenvironment due to different configurations of locking compression plate (LCP) in clinical practice, particularly in the early stage of healing. The model predicts that increasing flexibility of the LCP by changing the bone-plate distance (BPD) or the plate working length (WL) could enhance interfragmentary strain in the presence of a relatively large gap size (>3 mm). Furthermore, conventional LCP normally results in asymmetric tissue development during early stage of callus formation, and the increase of BPD or WL is insufficient to alleviate this problem. [ABSTRACT FROM AUTHOR]

HIV-associated lipodystrophy is a heterogeneous, evolving condition associated with fundamental defects in adipose tissue differentiation, turnover and function. Although many antiretroviral drugs can affect adipose tissues adversely, clinical evidence suggests that factors associated with the virus per se could play a role. We have focused on the possibility that an HIV accessory protein, viral protein R (Vpr) could dysregulate metabolically critical transcription factors to cause the adipose dysfunction. In a recent study published inScience Translational Medicine,we utilized 2 animal models to show that Vpr, produced in tissues that sequester HIV after antiretroviral therapy, can act in a paracrine or endocrine fashion to disrupt adipocyte differentiation and function by inhibiting PPARγ target gene expression and activating glucocorticoid target gene expression. The phenotypic consequences included many features typical of the human syndrome, including accelerated lipolysis, increased macrophage infiltration in adipose tissue, diminished size of white adipose depots and hepatic steatosis. In this commentary, we summarize the background, results, and implications of these studies, and raise important questions for future investigation. More broadly, these studies suggest that chronic viral infections may be a causative factor in the pathogenesis of some forms of lipid metabolic disease, insulin resistance, and diabetes. [ABSTRACT FROM AUTHOR]

As a basis for model-based analysis of the processes in secondary fracture healing, a dynamical model is presented that characterises the physiological status in the fracture area by the location-dependent composition of tissues. Five types of tissue are distinguished: connective tissue, cartilage, bone, haematoma and avascular bone. A rule base is given that describes dynamical tissue differentiation processes. The rules consider not only a mechanical stimulus but also osteogenic and a vasculative factors as biological stimuli. Within this model structure, it is possible, e.g., to distinguish intramembranous from endochondral ossification processes. An objective function is introduced to assess accordance between the model-based simulation results and reference healing stages. By minimising this objective function, relevant tissue differentiation rates can be determined. For a reference process of secondary fracture healing it could be shown that the intramembranous ossification rate of 0.313%/day (from connective tissue to bone) is much smaller than the endochondral ossification rate of 1.136%/day (from cartilage to bone). In order to verify the model approach, it is transferred to simulate long bone distraction. Results show that healing patterns of bone distraction can be predicted. Using this method, it is possible to identify model parameters for individual subjects. This will allow a patient-specific analysis of tissue healing processes in future. [ABSTRACT FROM AUTHOR]

Infantile hemangioma is a benign vascular tumor that affects 4 to 10% of neonates. a unique feature of hemangiomas is the natural lifecycle, whereby the tumor rapidly grows and then spontaneously regresses to a fibrofatty residuum. We have shown that hemangiomas are derived from mutlipotential stem cells (hemSCs), which differentiate into endothelial cells during the early proliferating phase and into adipocytes during the later involutive phase. T-box 2 (TBX2) is a transcription factor involved in controlling cell-fate decisions, and is highly expressed during the proliferating phase of hemangioma development. We hypothesize that TBX2 expression would be high in hemSCs derived from human hemangiomas and inhibiting TBX2 would result in changes in hemSC differentiation potential. To test our hypothesis, we analyzed hemSCs for TBX2 mrNa and protein expression. We then used rNa interference and TBX2 overexpression to determine the effect of altering TBX2 levels on hemSC growth and differentiation. Our studies show that TBX2 is highly expressed in hemSCs compared with a panel of normal stem/progenitor cells and mature vascular cells. TBX2 knockdown completely abolished adipogenic differentiation of hemSCs without significantly altering growth. Furthermore, overexpression of TBX2 led to enhanced adipogenic differentiation ability possibly through induction of C/eBPβ. From these findings, we believe that TBX2 is active in hemSCs and that TBX2 maintains adipogenic differentiation-competent state of hemSCs. These findings may be important in the development of better treatment options for hemangiomas to accelerate involution. [ABSTRACT FROM AUTHOR]

Despite the regenerative capability of bone, treatment of large defects often requires bone grafts. The challenge for bone grafting is to establish rapid and sufficient vascularization. Three-dimensional (3D) multicellular spheroids consisting of the relevant cell types can be used as 'mini tissues' to study the complexity of angiogenesis. We investigated two-dimensional (2D) expansion, differentiation and characterization of primary osteoblasts as steps toward the establishment of 3D multicellular spheroids. Supplementation of cell culture medium with vitamin D3 induces the osteocalcin expression of osteoblasts. An increased osteocalcin concentration of 10.8 ± 0.58 ng/ml could be measured after 19 days in supplemented medium. Vitamin D3 has no influence on the expression of alkaline phosphatase or the deposition of calcium. Expression of these additional osteogenic markers requires addition of a cocktail of osteogenic factors that, conversely, have no influence on the expression of osteocalcin. Supplementation of the cell culture medium with both vitamin D3 and a cocktail of osteogenic factors is recommended to produce an osteoblast phenotype that secretes osteocalcin, expresses alkaline phosphatase and deposits calcium. In such a supplemented medium, a mean osteocalcin concentration of 11.63 ± 4.85 ng/ml was secreted by the osteoblasts. Distinguishing osteoblasts and fibroblasts remains a challenge. Neither differentiated nor undifferentiated osteoblasts can be distinguished from fibroblasts by the expression of CD90, ED-A-fibronectin or α-smooth muscle actin; however, these cell types exhibit clear differences in their growth characteristics. Osteoblasts can be arranged as 3D spheroids by coating the bottom of the cell culture device with agarose. The cellular composition of 3D multicellular spheroids can be evaluated quantitatively using vital fluorescence labeling techniques. Spheroids are a promising tool for studying angiogenic and osteogenic phenomena in vivo and in vitro. [ABSTRACT FROM AUTHOR]

The article offers information on Adipose-derived stromal/stem cells (ASCs) which posses the ability to differentiate into various tissue types and can be therapeutically used for the treatment of damaged tissues. It mentions that ASCs deviates immune responses from a pro-inflammatory to anti-inflammatory profile controlling of autoimmune diseases. It reviews developments in the isolation, characterization and preclinical application of ADCs and the challenges facing their translation.

A dynamic model was developed to simulate complex interactions of mechanical stability, revascularisation and tissue differentiation in secondary fracture healing. Unlike previous models, blood perfusion was included as a spatio-temporal state variable to simulate the revascularisation process. A 2D, axisymmetrical finite element model described fracture callus mechanics. Fuzzy logic rules described the following biological processes: angiogenesis, intramembranous ossification, chondrogenesis, cartilage calcification and endochondral ossification, all of which depended on local strain state and local blood perfusion. In order to evaluate how the predicted revascularisation depended on the mechanical environment, we simulated two different healing cases according to two groups of transverse metatarsal osteotomies in sheep with different axial stability. The model predicted slower revascularisation and delayed bony bridging for the less stable case, which corresponded well to the experimental observations. A revascularisation sensitivity analysis demonstrated the potential of the model to account for different conditions regarding the blood supply. [ABSTRACT FROM AUTHOR]

To observe the histological alterations of single nerve fiber structures after nerve elongation by employing a rabbit peroneal nerve stretching model. 14 rabbits weighing mean 3. 0 kg (2.02–3.31kg.) were used in the experiment. Two rabbits were used as control when only a sham operation was done (group one, 0% stretch). Acute stretching of the peroneal nerves to elongate them by 10% was done in 6 rabbits (group two, 10% elongation) and by 20% (group three, 20% elongation) in another 6 rabbits. All animals were evaluated by tissue staining technology in a teased-fiber study. The internodal lengths were measured, and nodes of Ranvier and Schmidt-Lanterman notch were observed. The nerve fiber length was increased after stretching. The mean internodal length was 1208.31μm in group one, 1347.26μm in group two, and 1411.35μm in group three. Compared with the control group, mean internodal length was elongated by 11.50% in group two and 16.80% in group three. The difference was statistically significant. The node of Ranvier and Schmidt-Lanterman notch was wider in both group two and group three. Rupture of nerve fiber at the node of Ranvier was observed in group three. The peroneal nerve in rabbits can adapt to mild stretching by internodal length elongation. Elongation by 20% will cause structural rupture and therefore is the limit for nerve elongation. [ABSTRACT FROM AUTHOR]

In this novel study the breasts of 15 women with palpable breast cancer were preoperatively imaged with three technically different infrared (IR) cameras - micro bolometer (MB), quantum well (QWIP) and photo voltaic (PV) - to compare their ability to differentiate breast cancer from normal tissue. The IR images were processed, the data for frequency analysis were collected from dynamic IR images by pixel-based analysis and from each image selectively windowed regional analysis was carried out, based on angiogenesis and nitric oxide production of cancer tissue causing vasomotor and cardiogenic frequency differences compared to normal tissue. Our results show that the GaAs QWIP camera and the InSb PV camera demonstrate the frequency difference between normal and cancerous breast tissue; the PV camera more clearly. With selected image processing operations more detailed frequency analyses could be applied to the suspicious area. The MB camera was not suitable for tissue differentiation, as the difference between noise and effective signal was unsatisfactory. [ABSTRACT FROM AUTHOR]

The histological grading of meningiomas underwent substantial revision and standardization in a WHO review of 2000. Prior to this the histological definition of atypical and malignant meningiomas was less tightly defined. We conducted a retrospective analysis of all meningiomas operated on between 1993 and 2003 in our unit (n = 565), to assess whether the WHO changes had altered the proportion of tumours diagnosed as atypical. The percentage of tumours graded WHO II (atypical meningiomas) has increased significantly since these changes were adopted (18.3 - 23.1%, p = 0.0408). We also examined the epidemiology of meningioma, finding that previous irradiation is associated with atypical meningiomas (p = 0.038) and surgeons find that complete excision is also more difficult with atypical tumours (p = 0.010), reporting poorer Simpson grades intraoperatively before the tumour grade is known. The increase in atypical lesions caused by the grading changes may lead to a corresponding increase in the numbers of patients referred for radiotherapy/radiosurgery, and we examine the evidence base for this strategy and whether our experience is replicated in other units. [ABSTRACT FROM AUTHOR]

DNA methylation is known to be associated with the transcriptional silencing in eukaryotes. In this study, the genome-wide DNA methylation patterns of CCGG sites were detected with fluorescent-labeled methylation sensitive amplified polymorphism (F-MSAP) in three chicken strains (White Leghorn, White Plymouth Rock, and their F1 hybrids). The average incidence of DNA methylation was approximately 29.4% in muscle, 27.2% in liver, 27.2% in heart, and 26.1% in kidney, respectively. Also, the significant differences of the DNA methylation levels were found among the different tissues (P < 0.05) or strains (P < 0.05), implying that such differences may be related to gene expression during tissue differentiation, growth, and development though the relation between methylation and gene expression is currently hard to assess. [ABSTRACT FROM AUTHOR]

Background Pluripotent unrestricted somatic stem cells (USSC) from UC blood can differentiate into hepatic cells in the in utero sheep model, resulting in 20% human albumin-producing parenchymal hepatic cells without cell fusion or tumor-formation events. Additionally, we have shown in vitro differentiation of USSC by hepatocyte growth factor and oncostatin M induction, causing changes in the gene expression towards the endodermal lineage. Positive glycogen synthase expression and a positive periodic acid-schiff reaction demonstrated a functional production of polysaccharides in the cells. Methods We describe the in vitro differentiation of USSC towards an endodermal pathway using different matrices, growth factors and organic substances. Also, co-cultures of USSC with primary cells of endodermal tissue were prepared to mimic the biologic niche. We investigated the effect of direct co-culture of USSC with primary rat hepatocytes or with sheep tissue of endodermal origin. Direct co-cultures were set up to ensure cell-cell contacts. For co-cultures without cell-cell contacts, transwell inlays with 1-µm membranes were used to separate the cells. Furthermore, the effect of endodermally conditioned medium was investigated. Changes in the gene expression patterns were analyzed by RT-PCR. Results We have shown that USSC can differentiate in vitro into an endodermal-like cell with a phenotype similar to hepatic cells. Differentiation of USSC with growth factors, retinoic acid, matrigel matrix and different co-cultures led to an increased expression of albumin and also to the detection of GSC, SOX 17, Cyp2B6, Cyp3A4, Gys2, HNF4a, ISL-1 and Nkx6.1. In addition, functional albumin secretion was observed. Discussion Although the differentiation assays demonstrated here produce only an immature hepatocyte-like cell, endodermaly differentiated USSC might be a useful alternative for cell replacement in the future. [ABSTRACT FROM AUTHOR]

Welders can be exposed to high levels of manganese through welding fumes. Although it has already been suggested that excessive manganese exposure causes neurotoxicity, called manganism, the pathway of manganese transport to the brain with welding-fume exposure remains unclear. Iron is an essential metal that maintains a homeostasis in the body. The divalent metal transporter 1 (DMT1) transports iron and other divalent metals, such as manganese, and the depletion of iron is known to upregulate DMT1 expression. Accordingly, this study investigated the tissue distribution of manganese in iron-sufficient and iron-deficient rats after welding-fume exposure. The feeding of an iron-deficient diet for 4 wk produced a depletion of body iron, such as decreased iron levels in the serum and tissues, and upregulated the DMT1 expression in the rat duodenum. The iron-sufficient and iron-deficient rats were then exposed to welding fumes generated from manual metal arc stainless steel at a concentration of 63.5 ± 2.3 mg/m3 for 2 h per day over a 30-day period. Animals were sacrificed on days 1, 15, and 30. The level of body iron in the iron-deficient rats was restored to the control level after the welding-fume exposure. However, the tissue distributions of manganese after the welding-fume exposure showed similar patterns in both the iron-sufficient and iron-deficient groups. The concentration of manganese increased in the lungs and liver on days 15 and 30, and increased in the olfactory bulb on day 30. Slight and heterogeneous increases of manganese were observed in different brain regions. Consequently, these findings suggest that the presence of Fe in the inhaled welding fumes may not have a significant effect on the uptake of Mn into the brain. Thus, the condition of iron deficiency did not seem to have any apparent effect on the transport of Mn into the brain after the inhalation of welding fumes. [ABSTRACT FROM AUTHOR]

The Iroquois homeobox (Irx) genes have been implicated in the specification and patterning of several organs in Drosophila and several vertebrate species. Misexpression studies of chick, Xenopus, and zebra fish embryos have demonstrated that Irx genes are involved in the specification of the midbrain-hindbrain boundary. All six murine Irx genes are expressed in the developing heart, suggesting that they might possess distinct functions during heart development, and a role for Irx4 in normal heart development has been recently demonstrated by gene-targeting experiments. Here we describe the generation and phenotypic analysis of an Irx2-deficient mouse strain. By targeted insertion of a lacZ reporter gene into the Irx2 locus, we show that lacZ expression reproduces most of the endogenous Irx2 expression pattern. Despite the dynamic expression of Irx2 in the developing heart, nervous system, and other organs, Irx2-deficient mice are viable, are fertile, and appear to be normal. Although chick Irx2 has been implicated in the development of the midbrain-hindbrain region, we show that Irx2-deficient mice develop a normal midbrain-hindbrain boundary. Furthermore, Irx2-deficient mice have normal cardiac morphology and function. Functional compensation by other Irx genes might account for the absence of a phenotype in Irx2-deficient mice. Further studies of mutant mice of other Irx genes as well as compound mutant mice will be necessary to uncover the functional roles of these evolutionarily conserved transcriptional regulators in development and disease. [ABSTRACT FROM AUTHOR]

Nowadays, there is a growing consensus on the impact of mechanical loading on bone biology. A bone chamber provides a mechanically isolated in vivo environment in which the influence of different parameters on the tissue response around loaded implants can be investigated. This also provides data to assess the feasibility of different mechanobiological models that mathematically describe the mechanoregulation of tissue differentiation. Before comparing numerical results to animal experimental results, it is necessary to investigate the influence of the different model parameters on the outcome of the simulations. A 2D finite element model of the tissue inside the bone chamber was created. The differentiation models developed by Prendergast, et al. ["Biophysical stimuli on cells during tissue differentiation at implant interfaces", Journal of Biomechanics , 30 (6), (1997), 539-548], Huiskes et al. ["A biomechanical regulatory model for periprosthetic fibrous-tissue differentiation", Journal of Material Science: Materials in Medicine , 8 (1997) 785-788] and by Claes and Heigele ["Magnitudes of local stress and strain along bony surfaces predict the course and type of fracture healing", Journal of Biomechanics , 32 (3), (1999) 255-266] were implemented and integrated in the finite element code. The fluid component in the first model has an important effect on the predicted differentiation patterns. It has a direct effect on the predicted degree of maturation of bone and a substantial indirect effect on the simulated deformations and hence the predicted phenotypes of the tissue in the chamber. Finally, the presence of fluid also causes time-dependent behavior. Both models lead to qualitative and quantitative differences in predicted differentiation patterns. Because of the different nature of the tissue phenotypes used to describe the differentiation processes, it is however hard to compare both models in terms of their validity. [ABSTRACT FROM AUTHOR]

Finite element models of bones can be generated based on images obtained non-invasively in the clinic. One area where such models may prove useful is in the assessment of fracture healing of long bones. To establish the feasibility of such a proposal, a three dimensional finite element model of a fractured tibia was generated, and a model of tissue differentiation and bone regeneration was used to simulate the progress of healing under two different loading magnitudes. Healing is successful under the lower load and unsuccessful under the higher load--this proves that the model has the potential to identify loads that would cause healing to fail. Following a proposal by Richardson et al. [ J. Bone Jt Surg. Vol. 76B (1994) pp. 389-394] that the bending stiffness can be used to assess the extent of healing, the bending stiffness was computed during healing--it was shown that the stiffness changed in a similar manner that observed clinically. In conclusion, the paper establishes that 3D computer simulation could be a tool for assessment of the fracture healing under different orthopedic treatments. [ABSTRACT FROM AUTHOR]

Examines the link between mechanical stimuli and tissue differentiation. Factors influencing cartilage differentiation; Relation between mechanical signaling and morphogen expression; Effects of BMP on the cartilage.

Highlights from the article: B Article title: b Role of abnormal microRNA expression in Helicobacter pylori associated gastric cancer B Authors: b Dan Zou., Ling Xu., Heming Li., Yanju Ma., Yuehua Gong., Tianshu Guo., Zhitao Jing., Xiuying Xu., & Ye Zhang B Journal: b I Critical Reviews in Microbiology i B DOI: b http://dx.doi.org/10.1080/1040841X.2019.1575793 Abnormal miRNA expression in HP-associated GC and molecular mechanism underlying the miRNAs regulation of carcinogenesis.

The article presents a study on the genetic algorithm (GA) approach on the segmentation of cortical and trabecular bone tissue in computed tomography (CT) scans. It states that the researchers identified the cortical and trabecular tissues in bone scans and they applied the procedure in GA, which correct the correct image processing filters. It concludes that GA method can successfully be use to distinguish cortical and trabecular tissues in CT images.

The article investigates the influence of mechanical parameters on the phenomena of tissue differentiation, appositional bone growth and de nova bone formation around a cylindrical turned acid-etched titanium immediately loaded implant. A description is given on the highly controlled immediate loading experiments. The degree of tissue differentiation in the bone chamber, expressed by the variable bone and osteoid volume fraction, was found to be influenced by the duration of immediate loading.

The article examines the effect of various degrees of implant micromotion on the tissue differentiation around immediately loaded titanium implants. The experiments involving the tibia of rabbits are described. The smaller total tissue volume for the unloaded condition is probably due to the fact that implant motion initially helped to spread blood and cells around in the bone chamber.