Oncogene-induced matrix reorganization controls CD8+ T cell function in the soft-tissue sarcoma microenvironment.

CD8+ T cell dysfunction impedes antitumor immunity in solid cancers, but the underlying mechanisms are diverse and poorly understood. Extracellular matrix (ECM) composition has been linked to impaired T cell migration and enhanced tumor progression; however, impacts of individual ECM molecules on T cell function in the tumor microenvironment (TME) are only beginning to be elucidated. Upstream regulators of aberrant ECM deposition and organization in solid tumors are equally ill-defined. Therefore, we investigated how ECM composition modulates CD8+ T cell function in undifferentiated pleomorphic sarcoma (UPS), an immunologically active desmoplastic tumor. Using an autochthonous murine model of UPS and data from multiple human patient cohorts, we discovered a multifaceted mechanism wherein the transcriptional coactivator YAP1 promotes collagen VI (COLVI) deposition in the UPS TME. In turn, COLVI induces CD8+ T cell dysfunction and immune evasion by remodeling fibrillar collagen and inhibiting T cell autophagic flux. Unexpectedly, collagen I (COLI) opposed COLVI in this setting, promoting CD8+ T cell function and acting as a tumor suppressor. Thus, CD8+ T cell responses in sarcoma depend on oncogene-mediated ECM composition and remodeling.

The Relationship Between Muscular Strength, Jump Power, and Bone Health in Collegiate Distance Runners.

Participation in sports, especially those involving impact loading, enhance bone mineral content (BMC) and density (BMD). Additionally, participation in impact loading sports may strengthen relationships between strength or power and bone variables. The purpose of this investigation was to examine relationships between measures of muscular performance and bone variables in Division I endurance athletes (29 males, 31 females, 19.6 ± 1.4 years). Dual-energy x-ray absorptiometry (DXA) scans were analyzed at the anterior-posterior (AP) and lateral (LAT) spine, femoral neck (FN), total hip (TH), whole body (WB), and ultra-distal forearm (UD) for BMC and BMD measures. WB scans provided information for bone-free lean mass (BFLM). Performance measures included absolute, and relative (to body weight), grip strength (GS) and absolute lower body power (LBP) derived from a vertical jump. Pearson correlation coefficients were determined between bone variables and muscular performance measures. Hierarchical multiple regression was used to quantify the variance explained in bone variables. Male runners showed strong relationships between absolute and relative GS and numerous bone variables. Female runner had significant relationships between absolute jump power and numerous bone variables. Sex, GS, and LBP explained 41-76% of BMC at the various bone sites and 12-30% of BMD. Results indicate that in collegiate men, greater strength is related to higher BMC and BMD, however this was not the case for women. In female collegiate distance runners, higher jump power was related to greater BMC and BMD.

Collagen VI deposition mediates stromal T cell trapping through inhibition of T cell motility in the prostate tumor microenvironment.

The tumor extracellular matrix (ECM) is a barrier to anti-tumor immunity in solid tumors by disrupting T cell-tumor cell interaction underlying the need for elucidating mechanisms by which specific ECM proteins impact T cell motility and activity within the desmoplastic stroma of solid tumors. Here, we show that Collagen VI (Col VI) deposition correlates with stromal T cell density in human prostate cancer specimens. Furthermore, motility of CD4+ T cells is completely ablated on purified Col VI surfaces when compared with Fibronectin and Collagen I. Importantly, T cells adhered to Col VI surfaces displayed reduced cell spreading and fibrillar actin, indicating a reduction in traction force generation accompanied by a decrease in integrin ß1 clustering. We found that CD4+ T cells largely lack expression of integrin α1 in the prostate tumor microenvironment and that blockade of α1ß1 integrin heterodimers inhibited CD8+ T cell motility on prostate fibroblast-derived matrix, while re-expression of ITGA1 improved motility. Taken together, we show that the Col VI-rich microenvironment in prostate cancer reduces the motility of CD4+ T cells lacking integrin α1, leading to their accumulation in the stroma, thus putatively inhibiting anti-tumor T cell responses.

Study protocol for The GOAL Trial: comprehensive geriatric assessment for frail older people with chronic kidney disease to increase attainment of patient-identified goals-a cluster randomised controlled trial.

BACKGROUND: An increasing number of older people are living with chronic kidney disease (CKD). Many have complex healthcare needs and are at risk of deteriorating health and functional status, which can adversely affect their quality of life. Comprehensive geriatric assessment (CGA) is an effective intervention to improve survival and independence of older people, but its clinical utility and cost-effectiveness in frail older people living with CKD is unknown. METHODS: The GOAL Trial is a pragmatic, multi-centre, open-label, superiority, cluster randomised controlled trial developed by consumers, clinicians, and researchers. It has a two-arm design, CGA compared with standard care, with 1:1 allocation of a total of 16 clusters. Within each cluster, study participants ≥ 65 years of age (or ≥ 55 years if Aboriginal or Torres Strait Islander (First Nations Australians)) with CKD stage 3-5/5D who are frail, measured by a Frailty Index (FI) of > 0.25, are recruited. Participants in intervention clusters receive a CGA by a geriatrician to identify medical, social, and functional needs, optimise medication prescribing, and arrange multidisciplinary referral if required. Those in standard care clusters receive usual care. The primary outcome is attainment of self-identified goals assessed by standardised Goal Attainment Scaling (GAS) at 3 months. Secondary outcomes include GAS at 6 and 12 months, quality of life (EQ-5D-5L), frailty (Frailty Index - Short Form), transfer to residential aged care facilities, cost-effectiveness, and safety (cause-specific hospitalisations, mortality). A process evaluation will be conducted in parallel with the trial including whether the intervention was delivered as intended, any issue or local barriers to intervention delivery, and perceptions of the intervention by participants. The trial has 90% power to detect a clinically meaningful mean difference in GAS of 10 units. DISCUSSION: This trial addresses patient-prioritised outcomes. It will be conducted, disseminated and implemented by clinicians and researchers in partnership with consumers. If CGA is found to have clinical and cost-effectiveness for frail older people with CKD, the intervention framework could be embedded into routine clinical practice. The implementation of the trial's findings will be supported by presentations at conferences and forums with clinicians and consumers at specifically convened workshops, to enable rapid adoption into practice and policy for both nephrology and geriatric disciplines. It has potential to materially advance patient-centred care and improve clinical and patient-reported outcomes (including quality of life) for frail older people living with CKD. TRIAL REGISTRATION: ClinicalTrials.gov NCT04538157. Registered on 3 September 2020.

A 2-Year Longitudinal Study of Bone Mineral Density in Collegiate Distance Runners.

ABSTRACT: Brimacomb, OE, Martinez, MP, McCormack, WP, and Almstedt, HC. A 2-year longitudinal study of bone mineral density in collegiate distance runners. J Strength Cond Res 37(8): 1654-1659, 2023-The purpose of this investigation was to examine changes in bone mineral density (BMD) of male and female collegiate distance runners over 2 years. Bone mineral density of 29 collegiate distance runners (16 men and 13 women) were measured 5 times over 24 months using dual-energy x-ray absorptiometry (DXA) at the anterior-posterior (AP) and lateral (LAT) spine, femoral neck (FN), total hip (TH), whole body (WB), and ultradistal (UD) forearm. Repeated-measures multivariate analysis of covariance, with bone-free lean mass (BFLM) as covariate, was used to compare mean BMD values. Adjusted for BFLM, there were no significant differences ( p > 0.05) in BMD at any site between sexes. There were no significant differences at the AP or LAT spine, FN, or WB between visit 1 and 5 for either sex. There was a significant increase in BMD ( p = 0.044) at the UD forearm over 2 years in males. However, 56% of the men ( n = 9) had a Z-score < -1.0 at the UD forearm. Seven of 11 women had Z-scores < -1.0 at the LAT spine and 4 of 13 had Z-scores < -1.0 at the AP spine. There were no significant changes in BMD at any site over the 2-year time frame, except a significant increase in BMD at the nondominant forearm in men. The spine appears to be an area of concern for women in this study when examining Z-score results. Coaches and medical staff need to continually educate collegiate endurance athletes about the importance of achieving and maintaining BMD through their college years.

Nanoparticle-based modulation of CD4+ T cell effector and helper functions enhances adoptive immunotherapy.

Helper (CD4+) T cells perform direct therapeutic functions and augment responses of cells such as cytotoxic (CD8+) T cells against a wide variety of diseases and pathogens. Nevertheless, inefficient synthetic technologies for expansion of antigen-specific CD4+ T cells hinders consistency and scalability of CD4+ T cell-based therapies, and complicates mechanistic studies. Here we describe a nanoparticle platform for ex vivo CD4+ T cell culture that mimics antigen presenting cells (APC) through display of major histocompatibility class II (MHC II) molecules. When combined with soluble co-stimulation signals, MHC II artificial APCs (aAPCs) expand cognate murine CD4+ T cells, including rare endogenous subsets, to induce potent effector functions in vitro and in vivo. Moreover, MHC II aAPCs provide help signals that enhance antitumor function of aAPC-activated CD8+ T cells in a mouse tumor model. Lastly, human leukocyte antigen class II-based aAPCs expand rare subsets of functional, antigen-specific human CD4+ T cells. Overall, MHC II aAPCs provide a promising approach for harnessing targeted CD4+ T cell responses.

Postoperative outcomes after bariatric surgery in patients on chronic dialysis: A systematic review and meta-analysis.

BACKGROUND: Obesity is a barrier to kidney transplantation for patients with kidney failure. Consequently, bariatric surgery is often considered as a bridge to transplantation, even though its risks and benefits are poorly characterised in the dialysis population. METHODS: Systematic searches of observational studies indexed in Embase, MEDLINE and CENTRAL till April 2020 were performed to identify relevant studies. Risk of bias was assessed by the Newcastle Ottawa Scale and quality of evidence was summarised in accordance with GRADE methodology. Random effects meta-analyses were performed to obtain summary odds ratios for postoperative outcomes. RESULTS: Four cohort studies involving 4196 chronic dialysis and 732,204 non-dialysis patients undergoing bariatric surgery were included. Sleeve gastrectomy (61%), and Roux-en-Y gastric bypass (29%) were the most common procedures performed. Absolute rates of adverse events were low, but the odds of postoperative mortality (0.4-0.5% vs. 0.1%; odds ratio [OR] 4.7, 95%CI 2.2-9.9), and myocardial infarction (0.0-0.5% vs. 0.1%, OR 3.4, 95% CI 2.0-5.9) were higher in dialysis compared to non-dialysis patients. Patients on dialysis also had more than 2-fold increased odds of returning to theatre and having a readmission. Rates of kidney transplant wait-listing among dialysis patients was 59%, with 28% of all patients eventually receiving a kidney transplant. CONCLUSION: Patients receiving chronic dialysis have substantially increased odds of postoperative mortality and myocardial infarction following bariatric surgery compared with patient who do not have kidney failure. It is uncertain whether bariatric surgery improves the likelihood of kidney transplantation, with mid- to long-term outcomes being poorly described.

Disruption of STAT5A and NMI signaling axis leads to ISG20-driven metastatic mammary tumors.

Molecular dynamics of developmental processes are repurposed by cancer cells to support cancer initiation and progression. Disruption of the delicate balance between cellular differentiation and plasticity during mammary development leads to breast cancer initiation and metastatic progression. STAT5A is essential for differentiation of secretory mammary alveolar epithelium. Active STAT5A characterizes breast cancer patients for favorable prognosis. N-Myc and STAT Interactor protein (NMI) was initially discovered as a protein that interacts with various STATs; however, the relevance of these interactions to normal mammary development and cancer was not known. We observe that NMI protein is expressed in the mammary ductal epithelium at the onset of puberty and is induced in pregnancy. NMI protein is decreased in 70% of patient specimens with metastatic breast cancer compared to primary tumors. Here we present our finding that NMI and STAT5A cooperatively mediate normal mammary development. Loss of NMI in vivo caused a decrease in STAT5A activity in normal mammary epithelial as well as breast cancer cells. Analysis of STAT5A mammary specific controlled genetic program in the context of NMI knockout revealed ISG20 (interferon stimulated exonuclease gene 20, a protein involved in rRNA biogenesis) as an unfailing negatively regulated target. Role of ISG20 has never been described in metastatic process of mammary tumors. We observed that overexpression of ISG20 is increased in metastases compared to matched primary breast tumor tissues. Our observations reveal that NMI-STAT5A mediated signaling keeps a check on ISG20 expression via miR-17-92 cluster. We show that uncontrolled ISG20 expression drives tumor progression and metastasis.

Bone mineral density and hip structure changes over one-year in collegiate distance runners and non-athlete controls.

Modification of bone is continuous throughout life and influenced by many factors, including physical activity. This study investigated changes in areal bone mineral density (aBMD) and hip structure among male and female collegiate distance runners and non-athlete controls over 12 months. Using dual-energy x-ray absorptiometry (DXA) and hip structure analysis (HSA) software, aBMD at the posterior-anterior (PA) and lateral spine, femoral neck, total hip (TH), whole body (WB), and bone geometry at the narrow neck (NN) of the femur was measured three times over 12 months. HSA included cross-sectional area (CSA), cross-sectional moment of inertia (CSMI), and Z-section modulus (Z). Male runners had significantly higher aBMD at TH and WB and greater CSA, CSMI, and Z than male controls at the end of 12 months. Female controls had higher aBMD at the PA spine than female runners at the end of 12 months. Male runners had significant increases in aBMD at the PA (p = 0.003) and lateral spine (p = 0.002), and TH (p = 0.002), female runners had significant decreases in aBMD at TH (p = 0.015) and WB (p = 0.002), male controls had significant increases in aBMD at the PA spine (p < 0.001) and WB (p < 0.001), and female controls had significant decreases in aBMD at lateral spine and TH (p = 0.008) over the year. When applying covariates of bone-free lean mass and vitamin D, male distance runners demonstrated significant improvement in CSA (3.602 ± 0.139 vs. 3.675 ± 0.122 cm2, p = 0.05), CSMI (3.324 ± 0.200 to 3.467 ± 0.212 cm4, p < 0.05), and Z (1.81 ± 0.08 to 1.87 ± 0.08 cm3, p = 0.05) during the study. No other changes in hip structure occurred over the year. Distance running may be beneficial to aBMD and hip structure in college-age males but not females. Further research is needed on potential influences of weight-bearing activity, energy availability, and hormonal status on aBMD and hip structure in males and females.

Hypoxia re-programs 2'-O-Me modifications on ribosomal RNA.

Hypoxia is one of the critical stressors encountered by various cells of the human body under diverse pathophysiologic conditions including cancer and has profound impacts on several metabolic and physiologic processes. Hypoxia prompts internal ribosome entry site (IRES)-mediated translation of key genes, such as VEGF, that are vital for tumor progression. Here, we describe that hypoxia remarkably upregulates RNA Polymerase I activity. We discovered that in hypoxia, rRNA shows a different methylation pattern compared to normoxia. Heterogeneity in ribosomes due to the diversity of ribosomal RNA and protein composition has been postulated to generate "specialized ribosomes" that differentially regulate translation. We find that in hypoxia, a sub-set of differentially methylated ribosomes recognizes the VEGF-C IRES, suggesting that ribosomal heterogeneity allows for altered ribosomal functions in hypoxia.

Intensity of resistance training via self-reported history is critical in properly characterizing musculoskeletal health.

BACKGROUND: Intensity of resistance training history might be omitted or poorly ascertained in prescreening or data questionnaires involving musculoskeletal health. Failure to identify history of high-versus low-intensity training may overlook higher effect sizes with higher intensities and therefore diminish the precision of statistical analysis with resistance training as a covariate and bias the confirmation of baseline homogeneity for experimental group designation. The purpose was to determine the degree to which a single question assessing participant history of resistance training intensity predicted differences in musculoskeletal health. METHODS: In the first research aim, participants were separated into groups with a history (RT) and no history (NRT) of resistance training. The second research aim evaluated the history of resistance training intensity on muscular strength, lean mass, and bone mineral density (BMD), RT participants were reassigned into a low- (LIRT) or high-intensity resistance training group (HIRT). 83 males and 87 females (19.3 ± 0.6 yrs., 171.1 ± 9.9 cm, 67.1 ± 10.5 kg, 22.9 ± 2.8 BMI, 26.2 ± 7.2% body fat) completed handgrip dynamometry (HG) and dual-energy x-ray absorptiometry scans (DXA) for BMD and bone mineral-free lean mass (BFLM). RESULTS: A 3-group method (NRT, LIRT, HIRT) reduced type-I error compared with the 2-group method (NRT, RT) in characterizing the likely effects of one's history of resistance training. For the second aim, HIRT had significantly (p < 0.05) greater HG strength (76.2 ± 2.2 kg) and arm BFLM (6.10 ± 0.16 kg) than NRT (67.5 ± 1.3 kg; 4.96 ± 0.09 kg) and LIRT (69.7 ± 2.0 kg; 5.42 ± 0.14 kg) while also showing significantly lower muscle quality (HG/BFLM) than NRT (13.9 ± 0.2 vs. 12.9 ± 0.3). HIRT had greater BMD at all sites compared to NRT (whole body = 1.068 ± 0.008 vs. 1.120 ± 0.014; AP spine = 1.013 ± 0.011 vs. 1.059 ± 0.019; lateral spine = 0.785 ± 0.009 vs. 0.846 ± 0.016; femoral neck = 0.915 ± 0.013 vs. 0.970 ± 0.022; total hip = 1.016 ± 0.012 vs. 1.068 ± 0.021 g/cm2) while LIRT revealed no significant skeletal differences to NRT. CONCLUSIONS: Retrospective identification of high-intensity history of resistance training appears critical in characterizing musculoskeletal health and can be ascertained easily in as little as a single, standalone question. Both retrospective-questionnaire style investigations and pre-screening for potential participation in prospective research studies should include participant history of resistance training intensity.

Hydrogel Network Dynamics Regulate Vascular Morphogenesis.

Matrix dynamics influence how individual cells develop into complex multicellular tissues. Here, we develop hydrogels with identical polymer components but different crosslinking capacities to enable the investigation of mechanisms underlying vascular morphogenesis. We show that dynamic (D) hydrogels increase the contractility of human endothelial colony-forming cells (hECFCs), promote the clustering of integrin ß1, and promote the recruitment of vinculin, leading to the activation of focal adhesion kinase (FAK) and metalloproteinase expression. This leads to the robust assembly of vasculature and the deposition of new basement membrane. We also show that non-dynamic (N) hydrogels do not promote FAK signaling and that stiff D- and N-hydrogels are constrained for vascular morphogenesis. Furthermore, D-hydrogels promote hECFC microvessel formation and angiogenesis in vivo. Our results indicate that cell contractility mediates integrin signaling via inside-out signaling and emphasizes the importance of matrix dynamics in vascular tissue formation, thus informing future studies of vascularization and tissue engineering applications.

Indicators of Sarcopenia: Sex Differences in Competitive Runners Prior to Peak Muscle Mass.

Strength, muscle mass, and muscle quality have been observed to be compromised in low body-mass index individuals such as competitive runners, increasing their risk for sarcopenia. The purpose was to compare indices of sarcopenia in young runners to age, height, body-mass, and body-mass index-matched non-runners. Handgrip strength and arm composition from dual-energy x-ray absorptiometry (baseline-T1, T2=5.3±1.4, T3=11.5±0.7 months later) were assessed in 40 non-runners and 40 runners (19.3±0.7 vs. 19.2±1.1 years, 170.7±10.3 vs. 171.1±9.1 cm, 60.2±7.4 vs. 60.2±7.9 kg, 20.6±0.9 vs. 20.5±1.5 kg m-2). The unitless variable of muscle quality, was defined as the sum of right and left maximal handgrip (in kg) divided by the sum of bone-free lean mass of both arms (in kg). Female runners displayed the highest muscle quality (T1=15.3±1.7; T3=15.7±2.0) compared to male runners (T1=13.7±1.4, p < 0.001; T3=14.2±1.6, p < 0.001) and male non-runners (T1=12.4±1.8, p=0.001; T3=13.2±1.6, p < 0.001), while female non-runners (T1=14.6±2.5, p=0.154; T3=15.1 ±2.2, p=0.124) showed higher muscle quality than male non-runners. Higher muscle quality in low-body-mass index females persists over one-year during young-adulthood and while running contributes to whole-body muscle mass accrual, it does not appear to be significantly associated with improvements in the most commonly used upper-body diagnostic indicator of sarcopenia.

Nutritional Intake and Energy Availability of Collegiate Distance Runners.

Objective: Research investigating the dietary habits of distance runners has presented varying results. Proper dietary intake appears to enhance distance running performance and low dietary intake may impact health. The purpose of this investigation was to perform a comprehensive evaluation of nutrient intake of collegiate distance runners with comparison to recommendations for athletes.Methods: Twenty-one men (Age: 19.6 ± 1.2 years; height: 177.1 ± 5.7 cm; body mass: 65.7 ± 4.6 kg; body fat: 15.5 ± 2.2%) and 20 women (Age: 20.2 ± 1.7 years; height: 162.9 ± 6.6 cm; body mass: 53.7 ± 6.5 kg; body fat: 23.3 ± 3.6%) volunteered to participate in the investigation. Energy intake was derived from the Block Food Frequency Questionnaire. Energy availability was calculated by subtracting exercising energy expenditure from daily energy intake, divided by bone free lean mass and fat-free mass. Macronutrient and micronutrient consumption were compared with the appropriate dietary reference intake values, U.S. Dietary Guidelines, or standards recommended for endurance athletes.Results: Dietary intake for the men was 2,741.0 ± 815.2kilocalories and for the women was 1,927.7 ± 638.2kilocalories. A majority of the runners (73%) consumed less than recommended levels of carbohydrates. All men and 75% of women met or exceeded the recommended daily protein intake. Fifty percent of women and 24% of men did not meet the recommended daily allowance for calcium. Ninety-five percent of the runners did not meet the RDA for vitamin D. All the men and 75% of the women met the RDA for iron intake, with 24 of the runners taking an iron supplement. Eight men and 10 women did not meet the recommended intake for potassium.Conclusion: The dietary intake in this group of distance runners is below that necessary for the level of energy expended in their training. Carbohydrate intake is below the recommended amount for endurance athletes, and the calcium and vitamin D intake may not be favorable for bone health in this group of distance runners.

Oral contraceptive use, bone mineral density, and bone turnover markers over 12 months in college-aged females.

INTRODUCTION: The purpose of this study was to compare bone mineral density (BMD) and bone turnover markers between combined oral contraceptive (COC) and non-COC users over 12 months. MATERIALS AND METHODS: COC users (n = 34, age = 19.2 ± 0.5) and non-COC users (n = 28, age = 19.3 ± 0.6) provided serum at baseline, 6 months, and 12 months. C-terminal telopepetides (CTX) and pro-collagen type 1 N-terminal propeptides (P1NP) were determined using ELISA. BMD was measured at the three time points using dual-energy x-ray absorptiometry (DXA). RESULTS: COC users had greater CTX than non-COC users at baseline (18.6 ± 8.2 vs. 13.8 ± 5.3 ng/mL, P = 0.021) and 6 months (20.4 ± 10.3 vs. 14.2 ± 8.5 ng/mL, P = 0.018). Controlling for lean mass, groups were similar in BMD. Over 12 months, non-COC users maintained BMD at the spine, while the COC users declined 2.2% in lateral spine BMD (0.773 ± 0.014 to 0.756 ± 0.014 g/cm2, P = 0.03) and 0.7% in anterior-posterior spine BMD (1.005 ± 0.015 to 0.998 ± 0.015 g/cm2, P = 0.069). Non-COC users increased in BMD of the whole body over 12 months (P < 0.001) while COC users had no change. Women who began COCs within 4 years after menarche had lower BMD at the hip and whole body. Women taking very low dose COCs (20 mcg ethinyl estradiol, EE) significantly declined in CTX, P1NP, and lateral spine BMD in comparison to participants using low dose COCs (30/35 mcg EE). CONCLUSION: College-aged women who did not use COCs increased BMD of the whole body, while COC users had elevated bone turnover, declines in spinal BMD, and lack of bone acquisition of the whole body over 12 months. Young females who initiate COC use early after menarche may experience skeletal detriments.

Collagen fiber structure guides 3D motility of cytotoxic T lymphocytes.

Lymphocyte motility is governed by a complex array of mechanisms, and highly dependent on external microenvironmental cues. Tertiary lymphoid sites in particular have unique physical structure such as collagen fiber alignment, due to matrix deposition and remodeling. Three dimensional studies of human lymphocytes in such environments are lacking. We hypothesized that aligned collagenous environment modulates CD8+ T cells motility. We encapsulated activated CD8+ T cells in collagen hydrogels of distinct fiber alignment, a characteristic of tumor microenvironments. We found that human CD8+ T cells move faster and more persistently in aligned collagen fibers compared with nonaligned collagen fibers. Moreover, CD8+ T cells move along the axis of collagen alignment. We showed that myosin light chain kinase (MLCK) inhibition could nullify the effect of aligned collagen on CD8+ T cell motility patterns by decreasing T cell turning in unaligned collagen fiber gels. Finally, as an example of a tertiary lymphoid site, we found that xenograft prostate tumors exhibit highly aligned collagen fibers. We observed CD8+ T cells alongside aligned collagen fibers, and found that they are mostly concentrated in the periphery of tumors. Overall, using an in vitro controlled hydrogel system, we show that collagen fiber organization modulates CD8+ T cells movement via MLCK activation thus providing basis for future studies into relevant therapeutics.

Bone mineral density, energy availability, and dietary restraint in collegiate cross-country runners and non-running controls.

PURPOSE: Weight-bearing activities such as running have been shown to be osteogenic. However, investigations have also shown that running may lead to site-specific deficiencies in bone mineral density (BMD) as well as overall low BMD. The purpose of this investigation was to evaluate and compare the BMD of female and male collegiate cross-country runners with non-running controls. In addition, energy availability and disordered eating attitudes and behaviors were assessed. METHODS: BMD of 60 collegiate cross-country runners and 47 BMI and age-matched non-running controls were measured via DXA scans. Participants completed a Block 2014 Food Frequency Questionnaire and Eating Disorder Examination Questionnaire. RESULTS: Controlling for fat-free mass (FFM), male runners showed greater BMD at the femoral neck (0.934 ± 0.029 vs. 0.866 ± 0.028 g cm2, p < 0.05), total hip (1.119 ± 0.023 vs. 1.038 ± 0.021 g cm2, p < 0.05), and whole body (1.119 ± 0.023 vs. 1.038 ± 0.021 g cm2, p < 0.05) than male controls. The female runners had greater whole-body BMD than female controls (1.143 ± 0.018 vs. 1.087 ± 0.022 g cm2, p < 0.05). Runners scored significantly higher than controls in dietary restraint (1.134 ± 1.24 vs. 0.451 ± 0.75, p < 0.05), male runners were significantly higher than male controls in eating concern (1.344 ± 1.08 vs. 0.113 ± 0.27, p < 0.05) and female runners were significantly higher than male runners in shape concern (1.056 ± 1.27 vs. 0.242 ± 0.31, p < 0.05). Forty-two percent of the male runners and 29% of female runners had an energy availability of less than 30 kcals kg-1FFM. CONCLUSION: It appears that distance running has beneficial effects on whole-body BMD and site-specific areas. Further research is warranted to further clarify the health effects of eating behaviors and EA of distance runners.

Engineering an Artificial T-Cell Stimulating Matrix for Immunotherapy.

T cell therapies require the removal and culture of T cells ex vivo to expand several thousand-fold. However, these cells often lose the phenotype and cytotoxic functionality for mediating effective therapeutic responses. The extracellular matrix (ECM) has been used to preserve and augment cell phenotype; however, it has not been applied to cellular immunotherapies. Here, a hyaluronic acid (HA)-based hydrogel is engineered to present the two stimulatory signals required for T-cell activation-termed an artificial T-cell stimulating matrix (aTM). It is found that biophysical properties of the aTM-stimulatory ligand density, stiffness, and ECM proteins-potentiate T cell signaling and skew phenotype of both murine and human T cells. Importantly, the combination of the ECM environment and mechanically sensitive TCR signaling from the aTM results in a rapid and robust expansion of rare, antigen-specific CD8+ T cells. Adoptive transfer of these tumor-specific cells significantly suppresses tumor growth and improves animal survival compared with T cells stimulated by traditional methods. Beyond immediate immunotherapeutic applications, demonstrating the environment influences the cellular therapeutic product delineates the importance of the ECM and provides a case study of how to engineer ECM-mimetic materials for therapeutic immune stimulation in the future.

Hypoxia and matrix viscoelasticity sequentially regulate endothelial progenitor cluster-based vasculogenesis.

Vascular morphogenesis is the formation of endothelial lumenized networks. Cluster-based vasculogenesis of endothelial progenitor cells (EPCs) has been observed in animal models, but the underlying mechanism is unknown. Here, using O2-controllabe hydrogels, we unveil the mechanism by which hypoxia, co-jointly with matrix viscoelasticity, induces EPC vasculogenesis. When EPCs are subjected to a 3D hypoxic gradient ranging from <2 to 5%, they rapidly produce reactive oxygen species that up-regulate proteases, most notably MMP-1, which degrade the surrounding extracellular matrix. EPC clusters form and expand as the matrix degrades. Cell-cell interactions, including those mediated by VE-cadherin, integrin-ß2, and ICAM-1, stabilize the clusters. Subsequently, EPC sprouting into the stiffer, intact matrix leads to vascular network formation. In vivo examination further corroborated hypoxia-driven clustering of EPCs. Overall, this is the first description of how hypoxia mediates cluster-based vasculogenesis, advancing our understanding toward regulating vascular development as well as postnatal vasculogenesis in regeneration and tumorigenesis.

Heavy Episodic Drinking Is Associated With Poorer Bone Health in Adolescent and Young Adult Women.

OBJECTIVE: Osteoporosis is a costly bone disease characterized by low bone mineral density (BMD) that primarily affects postmenopausal women. One factor that may lead to osteoporosis is a failure to reach peak bone mass (PBM) in early adulthood. In older adults and animal models, heavy episodic drinking (HED) has been found to predict failure to reach PBM. However, this relationship has yet to be investigated in adolescent human females. METHOD: Female college students (N = 87; 60% White) reported age at menarche, hormonal contraceptive use, physical activity, smoking habits, and HED history via an online survey and then received a dual energy x-ray absorptiometry bone scan to assess both lean body mass and BMD at the lumbar spine. RESULTS: Frequent HED (having four or more drinks within 2 hours on 115 or more occasions since the start of high school, which is approximately equal to 1.6 episodes per month over this period) was associated with decreased vertebral BMD even when variables most commonly associated with bone health (lean body mass, physical activity, age at menarche, smoking, and oral contraception use) were controlled for. However, early HED initiation (beginning HED at age 15 years or younger) was not significantly related to BMD. CONCLUSIONS: This is the first study to assess the impacts of early HED initiation and frequent HED during adolescence on the bone health of young women. Results suggest frequency of HED before reaching PBM, but not age at initiation, may be negatively related to skeletal health during young adulthood. These findings encourage research into the association between HED and BMD in late adolescence.