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1.
Artigo em Inglês | MEDLINE | ID: mdl-32413907

RESUMO

CONTEXT: The thrombotic effects of estradiol therapy in transgender women are unclear. Global coagulation assays (GCA) may be better measures of hemostatic function compared to standard coagulation tests. OBJECTIVE: To assess the GCA profiles of transgender women in comparison to cisgender controls and to compare how GCA differ between routes of estradiol therapy in transgender women. DESIGN: Cross-sectional case-control study. SETTING: General community. PARTICIPANTS: Transgender women, cisgender male and cisgender female controls. MAIN OUTCOME MEASURES: Citrated blood samples were analyzed for (i) whole blood thromboelastography (TEG®5000), (ii) platelet-poor plasma thrombin generation (calibrated automated thrombogram); and (iii) platelet-poor plasma fibrin generation (overall hemostatic potential assay). Mean difference (95% confidence intervals) between groups are presented. RESULTS: Twenty-six transgender women (16 oral estradiol, 10 transdermal estradiol) were compared to 98 cisgender women and 55 cisgender men. There were no differences in serum estradiol concentration (p=0.929) and duration of therapy (p=0.496) between formulations. Transgender women demonstrated hypercoagulable parameters on both thromboelastography (maximum amplitude +6.94mm (3.55, 10.33), p<0.001) and thrombin generation (endogenous thrombin potential +192.62nM.min (38.33, 326.91), p=0.009; peak thrombin +38.10nM (2.27, 73.94), p=0.034) but had increased overall fibrinolytic potential (+4.89% (0.52, 9.25), p=0.024) compared to cisgender men. No significant changes were observed relative to cisgender women. Route of estradiol delivery or duration of use did not influence the GCA parameters. CONCLUSION: Transgender women on estradiol therapy demonstrated hypercoagulable GCA parameters compared to cisgender men with a shift towards cisgender female parameters. Route of estradiol delivery did not influence the GCA parameters.

2.
J Appl Microbiol ; 2020 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-32356362

RESUMO

AIMS: To determine the mechanism underlying the serum cholesterol reduction effect by probiotics isolated from local fermented tapioca (Tapai). METHODS AND RESULTS: Lactic acid bacteria strains were isolated and examined for acid tolerance, bile salt resistance and hypocholesterolemic properties. Among the isolates, Lact. plantarum TAR4 showed the highest cholesterol reduction ability (48.01%). The focus in the in vivo trial was to elucidate the cholesterol balance from findings pertaining to serum cholesterol reduction in rat model fed with high fat diet via oral administration. Rats fed with high-cholesterol diet supplemented with Lact. plantarum TAR4 showed significant reduction in serum total cholesterol (29.55%), serum triglyceride (45.31%) and liver triglyceride (23.44%) as compared to high-cholesterol diet (HCD) group. There was a significant increment in faecal triglyceride (45.83%) and faecal total bile acid (384.95%) as compared to HCD group. CONCLUSIONS: The findings showed that probiotic Lact. plantarum TAR4 supplementation reduced the absorption of bile acids for enterohepatic recycling and increase the catabolism of cholesterol to bile acids and not by suppressing the rate of cholesterol synthesis. SIGNIFICANCE AND IMPACT OF STUDY: Probiotics supplements could provide a new non-pharmacological alternative to reduce cardiovascular risk factors.

3.
Nanotechnology ; 2020 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-32428890

RESUMO

Atomic-scale catalysts leverage the advantages of both heterogeneous catalysts for their stability and reusability and homogeneous catalysts for their isolated active sites. Here, a palladium catalyst supported by Si-thiol, a commercially available mercaptopropyl-modified and TMS-passivated amorphous silica, was synthesized and characterized by SEM,TEM, aberration-corrected STEM-HAADF, XRD, FTIR and XPS. Statistical analysis revealed that the catalytic Pd species predominantly consisted of intermediate sized nanoparticles (< 2 nm), small amounts of essentially isolated atoms (ca. 0.1 nm), and limited amounts of somewhat larger nanoparticles (< 5 nm). The nanoscale atomic clusters dominated the reactivity and served as the key active sites for Suzuki coupling. The outcomes of the reaction were greatly affected by the choice of solvents, and Pd/Si-thiol was demonstrated to be reusable for more than three times without a noticeable loss of catalytic activity.

4.
J Proteome Res ; 2020 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-32338005

RESUMO

Shotgun proteomics using liquid chromatography coupled to mass spectrometry (LC-MS) is commonly used to identify peptides containing post-translational modifications. With the emergence of fast database search tools such as MSFragger, the approach of enlarging precursor mass tolerances during the search (termed "open search") has been increasingly used for comprehensive characterization of post-translational and chemical modifications of protein samples. However, not all mass shifts detected using the open search strategy represent true modifications, as artifacts exist from sources such as unaccounted missed cleavages or peptide co-fragmentation (chimeric MS/MS spectra). Here, we present Crystal-C, a computational tool that detects and removes such artifacts from open search results. Our analysis using Crystal-C shows that, in a typical shotgun proteomics data set, the number of such observations is relatively small. Nevertheless, removing these artifacts helps to simplify the interpretation of the mass shift histograms, which in turn should improve the ability of open search-based tools to detect potentially interesting mass shifts for follow-up investigation.

5.
Nat Commun ; 11(1): 1723, 2020 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-32265444

RESUMO

Metaplastic breast carcinoma (MBC) is a highly aggressive form of triple-negative cancer (TNBC), defined by the presence of metaplastic components of spindle, squamous, or sarcomatoid histology. The protein profiles underpinning the pathological subtypes and metastatic behavior of MBC are unknown. Using multiplex quantitative tandem mass tag-based proteomics we quantify 5798 proteins in MBC, TNBC, and normal breast from 27 patients. Comparing MBC and TNBC protein profiles we show MBC-specific increases related to epithelial-to-mesenchymal transition and extracellular matrix, and reduced metabolic pathways. MBC subtypes exhibit distinct upregulated profiles, including translation and ribosomal events in spindle, inflammation- and apical junction-related proteins in squamous, and extracellular matrix proteins in sarcomatoid subtypes. Comparison of the proteomes of human spindle MBC with mouse spindle (CCN6 knockout) MBC tumors reveals a shared spindle-specific signature of 17 upregulated proteins involved in translation and 19 downregulated proteins with roles in cell metabolism. These data identify potential subtype specific MBC biomarkers and therapeutic targets.

6.
Protein Sci ; 29(5): 1211-1227, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32196797

RESUMO

The Escherichia coli single-strand DNA binding protein (SSB) is essential to viability where it functions to regulate SSB interactome function. Here it binds to single-stranded DNA and to target proteins that comprise the interactome. The region of SSB that links these two essential protein functions is the intrinsically disordered linker. Key to linker function is the presence of three, conserved PXXP motifs that mediate binding to oligosaccharide-oligonucleotide binding folds (OB-fold) present in SSB and its interactome partners. Not surprisingly, partner OB-fold deletions eliminate SSB binding. Furthermore, single point mutations in either the PXXP motifs or, in the RecG OB-fold, obliterate SSB binding. The data also demonstrate that, and in contrast to the view currently held in the field, the C-terminal acidic tip of SSB is not required for interactome partner binding. Instead, we propose the tip has two roles. First, and consistent with the proposal of Dixon, to regulate the structure of the C-terminal domain in a biologically active conformation that prevents linkers from binding to SSB OB-folds until this interaction is required. Second, as a secondary binding domain. Finally, as OB-folds are present in SSB and many of its partners, we present the SSB interactome as the first family of OB-fold genome guardians identified in prokaryotes.

7.
Cell ; 180(4): 729-748.e26, 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-32059776

RESUMO

We undertook a comprehensive proteogenomic characterization of 95 prospectively collected endometrial carcinomas, comprising 83 endometrioid and 12 serous tumors. This analysis revealed possible new consequences of perturbations to the p53 and Wnt/ß-catenin pathways, identified a potential role for circRNAs in the epithelial-mesenchymal transition, and provided new information about proteomic markers of clinical and genomic tumor subgroups, including relationships to known druggable pathways. An extensive genome-wide acetylation survey yielded insights into regulatory mechanisms linking Wnt signaling and histone acetylation. We also characterized aspects of the tumor immune landscape, including immunogenic alterations, neoantigens, common cancer/testis antigens, and the immune microenvironment, all of which can inform immunotherapy decisions. Collectively, our multi-omic analyses provide a valuable resource for researchers and clinicians, identify new molecular associations of potential mechanistic significance in the development of endometrial cancers, and suggest novel approaches for identifying potential therapeutic targets.

9.
Cell ; 179(4): 964-983.e31, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31675502

RESUMO

To elucidate the deregulated functional modules that drive clear cell renal cell carcinoma (ccRCC), we performed comprehensive genomic, epigenomic, transcriptomic, proteomic, and phosphoproteomic characterization of treatment-naive ccRCC and paired normal adjacent tissue samples. Genomic analyses identified a distinct molecular subgroup associated with genomic instability. Integration of proteogenomic measurements uniquely identified protein dysregulation of cellular mechanisms impacted by genomic alterations, including oxidative phosphorylation-related metabolism, protein translation processes, and phospho-signaling modules. To assess the degree of immune infiltration in individual tumors, we identified microenvironment cell signatures that delineated four immune-based ccRCC subtypes characterized by distinct cellular pathways. This study reports a large-scale proteogenomic analysis of ccRCC to discern the functional impact of genomic alterations and provides evidence for rational treatment selection stemming from ccRCC pathobiology.

10.
Anesth Analg ; 129(6): 1699-1706, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31743191

RESUMO

BACKGROUND: Older people with frailty have decreased postoperative survival. Understanding how comorbidities modify the association between frailty and survival could improve risk stratification and guide development of interventions. Therefore, we evaluated whether the concurrent presence of common and high-risk comorbidities (dementia, chronic obstructive pulmonary disease [COPD], coronary artery disease [CAD], diabetes mellitus, heart failure [HF]) in conjunction with frailty might be associated with a larger decrease in postoperative survival after major elective surgery than would be expected based on the presence of the comorbidity and frailty on their own. METHODS: This cohort study used linked administrative data from Ontario, Canada to identify adults >65 years having elective noncardiac surgery from 2010 to 2015. Frailty was identified using a validated index; comorbidities were identified with validated codes. We evaluated the presence of effect modification (also called interaction) between frailty and each comorbidity on (1) the relative (or multiplicative) scale by assessing whether the risk of mortality when both frailty and the comorbidity were present was different than the product of the risks associated with each condition; and (2) the absolute risk difference (or additive) scale by assessing whether the risk of mortality when both frailty and the comorbidity were present was greater than the sum of the risks associated with each condition. RESULTS: 11,150 (9.7%) people with frailty died versus 7826 (2.8%) without frailty. After adjustment, frailty was associated with decreased survival (adjusted hazard ratio [HR] = 2.42; 95% confidence interval [CI], 2.31-2.54). On the relative (multiplicative) scale, only diabetes mellitus demonstrated significant effect modification (P value for interaction .03; reduced risk together). On the absolute risk difference (additive) scale, all comorbidities except for coronary disease demonstrated effect modification of the association of frailty with survival. Co-occurrence of dementia with frailty carried the greatest excess risk (Synergy Index [S; the excess risk from exposure to both risk factors compared to the sum of the risks from each factor in isolation] = 2.29; 95% CI, 1.32-10.80, the excess risk from exposure to both risk factors compared to the sum of the risks from each factor in isolation). CONCLUSIONS: Common comorbidities modify the association of frailty with postoperative survival; however, this effect was only apparent when analyses accounted for effect modification on the absolute risk difference, as opposed to relative scale. While the relative scale is more commonly used in biomedical research, smaller effects may be easier to detect on the risk difference scale. The concurrent presence of dementia, COPD, and HF with frailty were all associated with excess mortality on the absolute risk difference scale.

12.
Intern Med J ; 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31566857

RESUMO

BACKGROUND: Clinical trials have demonstrated that direct oral anticoagulants (DOAC) are non-inferior to vitamin K antagonist for stroke prevention in non-valvular atrial fibrillation (AF) with comparable safety outcomes; however real-world Australian data is limited. AIMS: We aim to evaluate local real-world DOAC use focusing on safety, particularly in high-risk patients. METHODS: A retrospective evaluation of 658 patients commenced or continued on DOAC between September 2013-September 2016 for non-valvular AF at Northern Hospital, a tertiary hospital in Victoria, Australia was performed. RESULTS: Factor Xa inhibitors were more commonly prescribed than direct thrombin inhibitor (83.3% vs 16.7%) for AF management. The median patient age was 75 years. The rate of clinically significant bleeding on anticoagulation was 3.13 per 100 person-years (including four deaths) with risk factors including history of bleeding (HR 3.52, 95% CI 1.22-10.17), concurrent antiplatelet therapy (HR 2.62, 95% CI: 1.11-6.20) and high falls risk (HR 2.76, 95% CI: 1.26-6.08). Patients on low dose DOAC had significantly higher bleeding risk compared to those on full dose (5.05 vs 1.82 per 100 person-years). The rate of thrombotic stroke despite anticoagulation was 1.34 per 100 person-years with risk factors including low dose anticoagulation (p = 0.034), high falls risk (p = 0.046) and previous stroke (p = 0.028). CONCLUSIONS: DOAC use in real-world Australian practice is safe and effective, consistent with international data. Low dose anticoagulation and falls risk are associated with increased bleeding and thrombotic risk demonstrating overlapping risk factors. Careful individualised patient risk assessment is still required as low dose anticoagulation is not without risks. This article is protected by copyright. All rights reserved.

13.
Anesth Analg ; 2019 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-31453872

RESUMO

BACKGROUND: Older people with frailty have decreased postoperative survival. Understanding how comorbidities modify the association between frailty and survival could improve risk stratification and guide development of interventions. Therefore, we evaluated whether the concurrent presence of common and high-risk comorbidities (dementia, chronic obstructive pulmonary disease [COPD], coronary artery disease [CAD], diabetes mellitus, heart failure [HF]) in conjunction with frailty might be associated with a larger decrease in postoperative survival after major elective surgery than would be expected based on the presence of the comorbidity and frailty on their own. METHODS: This cohort study used linked administrative data from Ontario, Canada to identify adults >65 years having elective noncardiac surgery from 2010 to 2015. Frailty was identified using a validated index; comorbidities were identified with validated codes. We evaluated the presence of effect modification (also called interaction) between frailty and each comorbidity on (1) the relative (or multiplicative) scale by assessing whether the risk of mortality when both frailty and the comorbidity were present was different than the product of the risks associated with each condition; and (2) the absolute risk difference (or additive) scale by assessing whether the risk of mortality when both frailty and the comorbidity were present was greater than the sum of the risks associated with each condition. RESULTS: 11,150 (9.7%) people with frailty died versus 7826 (2.8%) without frailty. After adjustment, frailty was associated with decreased survival (adjusted hazard ratio [HR] = 2.42; 95% confidence interval [CI], 2.31-2.54). On the relative (multiplicative) scale, only diabetes mellitus demonstrated significant effect modification (P value for interaction .03; reduced risk together). On the absolute risk difference (additive) scale, all comorbidities except for coronary disease demonstrated effect modification of the association of frailty with survival. Co-occurrence of dementia with frailty carried the greatest excess risk (Synergy Index [S; the excess risk from exposure to both risk factors compared to the sum of the risks from each factor in isolation] = 2.29; 95% CI, 1.32-10.80, the excess risk from exposure to both risk factors compared to the sum of the risks from each factor in isolation). CONCLUSIONS: Common comorbidities modify the association of frailty with postoperative survival; however, this effect was only apparent when analyses accounted for effect modification on the absolute risk difference, as opposed to relative scale. While the relative scale is more commonly used in biomedical research, smaller effects may be easier to detect on the risk difference scale. The concurrent presence of dementia, COPD, and HF with frailty were all associated with excess mortality on the absolute risk difference scale.

14.
Front Immunol ; 10: 1546, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31354711

RESUMO

The global increase in autoimmunity, together with the emerging autoimmune-related side effects of cancer immunotherapy, have furthered a need for understanding of immune tolerance and activation. Systemic lupus erythematosus (SLE) is the archetypical autoimmune disease, affecting multiple organs, and tissues. Studying SLE creates knowledge relevant not just for autoimmunity, but the immune system in general. Murine models and patient studies have provided increasing evidence for the innate immune toll like receptor-7 (TLR7) in disease initiation and progression. Here, we demonstrated that the kinase activity of the TLR7-downstream signaling molecule, interleukin-1 receptor associated kinase 4 (IRAK4), is essential for mild and severe autoimmune traits of the Sle1 and Sle1-TLR7 transgenic (Sle1Tg7) murine models, respectively. Elimination of IRAK4 signaling prevented all pathological traits associated with murine lupus, including splenomegaly with leukocyte expansion, detectable circulating antinuclear antibodies and glomerulonephritis, in both Sle1 and Sle1Tg7 mice. The expansion of germinal center B cells and increased effector memory T cell phenotypes that are typical of lupus-prone strains, were also prevented with IRAK4 kinase elimination. Analysis of renal leukocyte infiltrates confirmed our earlier findings of an expanded conventional dendritic cell (cDC) within the kidneys of nephritic mice, and this was prevented with IRAK4 kinase elimination. Analysis of TLR7 at the protein level revealed that the expression in immune cells is dependent on the TLR7-transgene itself and/or autoimmune disease factors in a cell-specific manner. Increased TLR7 protein expression in renal macrophages and cDCs correlated with disease parameters such as blood urea nitrogen (BUN) levels and the frequency of leukocytes infiltrating the kidney. These findings suggest that controlling the level of TLR7 or downstream signaling within myeloid populations may prevent chronic inflammation and severe nephritis.

15.
Thromb Res ; 179: 45-55, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31078120

RESUMO

Normal haemostasis requires maintenance of a careful equilibrium between the necessity to clot when bleeding and the retention of fluid phase at all other times. Disruption of this equilibrium can result in catastrophic outcomes, e.g. acute myocardial infarction and pulmonary embolism. However, despite the significant therapeutic advances in cardiovascular medicine over recent years, our ability to provide an accurate cardiovascular risk assessment remains an unmet need. Routine coagulation testing is not a useful reflection of haemostasis and cannot be reliably used to predict bleeding and thrombosis risks. Global coagulation assays such as viscoelastic testing, thrombin and fibrin generation have been proposed as better measures of the haemostatic function. These assays, particularly viscoelastic testing, have been increasingly used to assess bleeding risks and guide blood product replacement in trauma and massive transfusion settings. However, the role of these assays in thrombosis is less well-defined but given the complexities of the coagulation system, these global coagulation assays when used in combination may provide a better assessment of cardiovascular and thrombosis risk at an individual level. Hence, we explore the role of some of the currently available global coagulation assays - the viscoelastic, thrombin generation and fibrin generation tests - and provide a review of the literature of the current evidence for these assays specifically in the field of venous thromboembolism and cardiovascular diseases.


Assuntos
Testes de Coagulação Sanguínea/métodos , Trombose/diagnóstico , Humanos , Fatores de Risco , Trombose/sangue
16.
Polymers (Basel) ; 11(4)2019 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-30970647

RESUMO

Paper has recently found widespread applications in biomedical fields, especially as an alternative scaffolding material for cell cultures, owing to properties such as its fibrous nature, porosity and flexibility. However, paper on its own is not an optimal material for cell cultures as it lacks adhesion moieties specific to mammalian cells, and modifications such as hydrogel integration and chemical vapor deposition are necessary to make it a favorable scaffolding material. The present study focuses on modification of filter paper through electrospin-coating and dip-coating with polycaprolactone (PCL), a promising biomaterial in tissue engineering. Morphological analysis, evaluation of cell viability, alkaline phosphatase (ALP) activity and live/dead assays were conducted to study the potential of the modified paper-based scaffold. The results were compared to filter paper (FP) and electrospun PCL (ES-PCL) as reference samples. The results indicate that electrospin-coating paper is a simple and efficient way of modifying FP. It not only improves the morphology of the deposited electrospun layer through reduction of the fiber diameter by nearly 75%, but also greatly reduces the scaffold fabrication time compared to ES-PCL. The biochemical assays (Resazurin and ALP) indicate that electrospin-coated filter paper (ES-PCL/FP) provides significantly higher readings compared to all other groups. The live/dead results also show improved cell-distribution and cell-scaffold attachment all over the ES-PCL/FP.

17.
Leukemia ; 33(10): 2365-2378, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-30940905

RESUMO

Bone marrow (BM) niche responds to chemotherapy-induced cytokines secreted from acute lymphoblastic leukemia (ALL) cells and protects the residual cells from chemotherapeutics in vivo. However, the underlying molecular mechanisms for the induction of cytokines by chemotherapy remain unknown. Here, we found that chemotherapeutic drugs (e.g., Ara-C, DNR, 6-MP) induced the expression of niche-protecting cytokines (GDF15, CCL3 and CCL4) in both ALL cell lines and primary cells in vitro. The ATM and NF-κB pathways were activated after chemotherapy treatment, and the pharmacological or genetic inhibition of these pathways significantly reversed the cytokine upregulation. Besides, chemotherapy-induced NF-κB activation was dependent on ATM-TRAF6 signaling, and NF-κB transcription factor p65 directly regulated the cytokines expression. Furthermore, we found that both pharmacological and genetic perturbation of ATM and p65 significantly decreased the residual ALL cells after Ara-C treatment in ALL xenograft mouse models. Together, these results demonstrated that ATM-dependent NF-κB activation mediated the cytokines induction by chemotherapy and ALL resistance to chemotherapeutics. Inhibition of ATM-dependent NF-κB pathway can sensitize ALL to chemotherapeutics, providing a new strategy to eradicate residual chemo-resistant ALL cells.


Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/antagonistas & inibidores , NF-kappa B/antagonistas & inibidores , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos , Animais , Antineoplásicos , Linhagem Celular Tumoral , Criança , Citocinas/metabolismo , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Feminino , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Humanos , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Fator 6 Associado a Receptor de TNF/metabolismo
18.
Stem Cells Int ; 2019: 5142518, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30956670

RESUMO

We have determined the protective effects of Thymus serpyllum (TS) extract and nanoparticle-loaded TS on hydrogen peroxide-induced cell death of mesenchymal stromal cells (MSCs) in vitro. Gas chromatography-mass spectroscopy confirmed the spectrum of active components in the extract. Out of the three different extracts, the hexane extract showed significant free radical scavenging activity. Treatment of MSCs with H2O2 (hydrogen peroxide) significantly increased intracellular cell death; however, pretreatment with TS extract and nanoparticle-loaded TS (200 µg/ml) suppressed H2O2-induced elevation of Cyt-c and MMP13 and increased the survival rates of MSCs. H2O2-induced (0.1 mM) changes in cytokines were attenuated in the extract and nanoparticles by pretreatment and cotreatment at two time points (p < 0.05). H2O2 increased cell apoptosis. In contrast, treatment with nanoparticle-loaded TS suppressed the percentage of apoptosis considerably (p < 0.05). Therefore, TS may be considered as a potential candidate for enhancing the effectiveness of MSC transplantation in cell therapy.

20.
Stem Cells Int ; 2019: 9723025, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30918524

RESUMO

The present study was conducted to establish the amount of mechanical strain (uniaxial cyclic stretching) required to provide optimal tenogenic differentiation expression in human mesenchymal stromal cells (hMSCs) in vitro, in view of its potential application for tendon maintenance and regeneration. Methods. In the present study, hMSCs were subjected to 1 Hz uniaxial cyclic stretching for 6, 24, 48, and 72 hours; and were compared to unstretched cells. Changes in cell morphology were observed under light and atomic force microscopy. The tenogenic, osteogenic, adipogenic, and chondrogenic differentiation potential of hMSCs were evaluated using biochemical assays, extracellular matrix expressions, and selected mesenchyme gene expression markers; and were compared to primary tenocytes. Results. Cells subjected to loading displayed cytoskeletal coarsening, longer actin stress fiber, and higher cell stiffness as early as 6 hours. At 8% and 12% strains, an increase in collagen I, collagen III, fibronectin, and N-cadherin production was observed. Tenogenic gene expressions were highly expressed (p < 0.05) at 8% (highest) and 12%, both comparable to tenocytes. In contrast, the osteoblastic, chondrogenic, and adipogenic marker genes appeared to be downregulated. Conclusion. Our study suggests that mechanical loading at 8% strain and 1 Hz provides exclusive tenogenic differentiation; and produced comparable protein and gene expression to primary tenocytes.

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