alpha II-spectrin and beta II-spectrin do not affect TGF beta 1-induced myofibroblast differentiation

Mechanosensing of fibroblasts plays a key role in the development of fibrosis. So far, no effective treatments are available to treat this devastating disorder. Spectrins regulate cell morphology and are potential mechanosensors in a variety of non-erythroid cells, but little is known about the role of spectrins in fibroblasts. We investigate whether II- and II-spectrin are required for the phenotypic properties of adult human dermal (myo)fibroblasts. Knockdown of II- or II-spectrin in fibroblasts did not affect cell adhesion, cell size and YAP nuclear/cytosolic localization. We further investigated whether II- and II-spectrin play a role in the phenotypical switch from fibroblasts to myofibroblasts under the influence of the pro-fibrotic cytokine TGF1. Knockdown of spectrins did not affect myofibroblast formation, nor did we observe changes in the organization of SMA stress fibers. Focal adhesion assembly was unaffected by spectrin deficiency, as was collagen type I mRNA expression and protein deposition. Wound closure was unaffected as well, showing that important functional properties of myofibroblasts are unchanged without II- or II-spectrin. In fact, fibroblasts stimulated with TGF1 demonstrated significantly lower endogenous mRNA levels of II- and II-spectrin. Taken together, despite the diverse roles of spectrins in a variety of other cells, II- and II-spectrin do not regulate cell adhesion, cell size and YAP localization in human dermal fibroblasts and are not required for the dermal myofibroblast phenotypical switch

Substrate Elastic Modulus Regulates the Morphology, Focal Adhesions, and alpha-Smooth Muscle Actin Expression of Retinal Muller Cells

PURPOSE. The stiffness of the extracellular matrix has been shown to regulate cell adhesion, migration, and transdifferentiation in fibrotic processes. Retinal Muller cells have been shown to be mechanosensitive; they are involved in fibrotic vitreoretinal diseases. Since fibrosis increases the rigidity of the extracellular matrix, our aim was to develop an in vitro model for studying Muller cell morphology and differentiation state in relation to matrix stiffness. METHODS. A spontaneously immortalized human Muller cell line (MIO-M1) was cultured on type I collagen-coated polyacrylamide gels with Young's moduli ranging from 2 to 92 kPa. Cell surface area, focal adhesion, and the expression and morphology of alpha-smooth muscle actin induced by transforming growth factor beta (TGF-beta [10 ng/mL for 48 hours]) were analyzed by immunocytology. The images were documented by using fluorescence microscopy and confocal scanning laser microscopy. RESULTS. MIO-M1 cells cultured on stiff substrates exhibited a significant increase in cell surface area, stress fiber, and mature focal adhesion formation. Furthermore, Muller cells treated with TGF-beta 1 and TGF-beta 2 and cultured on stiff substrates showed an increased incorporation of alpha-smooth muscle actin into stress fibers when compared to those grown on soft surfaces. CONCLUSIONS. Compliance of the surrounding matrix seems to influence the morphology and contraction of retinal Muller cells in fibrotic conditions. Development of an in vitro model simulating both the normally compliant retinal tissue and the rigid retinal fibrotic tissue helps fill the gap between the results of petri-dish cell culture with rigid surfaces and in vivo findings

Sex-Based Differences in Treatment with Immune Checkpoint Inhibition and Targeted Therapy for Advanced Melanoma:A Nationwide Cohort Study

SIMPLE SUMMARY: Melanoma is a malignant form of skin cancer. The overall survival of patients with advanced stages of disease were initially low. Fortunately, in recent years systemic treatment with immunotherapy has prolonged survival. We set out to answer the question whether men and women with advanced melanoma differ in prognostic factors, tumor-response to immunotherapy, and treatment-related adverse events. All patients in the Netherlands were registered between July 2013 and July 2018. We showed that although clinical and tumor characteristics differ, the safety profile of immunotherapy is comparable. Furthermore, overall, a 10% survival advantage for women was seen. Following immunotherapy there was no survival difference. ABSTRACT: Recent meta-analyses show conflicting data on sex-dependent benefit following systemic treatment for advanced melanoma patients. We examined the nationwide Dutch Melanoma Treatment Registry (July 2013–July 2018), assessing sex-dependent differences in advanced melanoma patients (stage IIIC/IV) with respect to clinical characteristics, mutational profiles, treatments initiated, grade 3–4 adverse events (AEs), treatment responses, and mortality. We included 3985 patients, 2363 men (59%) and showed that although men and women with advanced melanoma differ in clinical and tumor characteristics, the safety profile of immune checkpoint inhibition (ICI) is comparable. The data suggest a 10% survival advantage for women, mainly seen in patients ≥60 years of age and patients with BRAF V600 mutant melanoma. Following ICI there was no survival difference

Safety and Efficacy of Checkpoint Inhibition in Patients With Melanoma and Preexisting Autoimmune Disease:A Cohort Study

BACKGROUND: Because immune checkpoint inhibition (ICI) can cause immune-related adverse events (irAEs) mimicking immunologic diseases, patients with preexisting autoimmune disease (AID) have been excluded from clinical trials. OBJECTIVE: To evaluate the safety and efficacy of ICI in patients with advanced melanoma with and without AID. DESIGN: Nationwide cohort study. SETTING: The Netherlands. PATIENTS: 4367 patients with advanced melanoma enrolled in the Dutch Melanoma Treatment Registry (DMTR) between July 2013 and July 2018 and followed through February 2019. MEASUREMENTS: Patient, clinical, and treatment characteristics; irAEs of grade 3 or higher; treatment response; and survival. RESULTS: A total of 415 patients (9.5%) had AID, categorized as rheumatologic AID (n = 227), endocrine AID (n = 143), inflammatory bowel disease (IBD) (n = 55), or "other" (n = 8). Of these, 228 patients (55%) were treated with ICI (vs. 2546 [58%] without AID); 87 were treated with anti-cytotoxic T lymphocyte-associated protein 4 (CTLA-4), 187 with anti-programmed cell death 1 (PD-1), and 34 with the combination. The incidences of irAEs of grade 3 or higher in patients with AID were 30% (95% CI, 21% to 41%) with anti-CTLA-4, 17% (CI, 12% to 23%) with anti-PD-1, and 44% (CI, 27% to 62%) with combination therapy; for patients without AID, the incidences were 30% (CI, 27% to 33%) (n = 916), 13% (CI, 12% to 15%) (n = 1540), and 48% (CI, 43% to 53%) (n = 388), respectively. Patients with AID more often discontinued anti-PD-1 treatment because of toxicity than patients without AID (17% [CI, 12% to 23%] vs. 9% [CI, 8% to 11%]). Patients with IBD were more prone to anti-PD-1-induced colitis (6 / 31 = 19% [CI, 7% to 37%]) than patients with other AIDs (3% [CI, 0% to 6%]) and patients without AID (2% [CI, 2% to 3%]). The objective response rate was similar in patients with versus without AID who were treated with anti-CTLA-4 (10% [CI, 5% to 19%] vs. 16% [CI, 14% to 19%]), anti-PD-1 (40% [CI, 33% to 47%] vs. 44% [CI, 41% to 46%]), or the combination (39% [CI, 20% to 59%] vs. 43% [CI, 38% to 49%]). Survival did not differ between patients with and those without AID (median, 13 months [CI, 10 to 16 months] vs. 14 months [CI, 13 to 15 months]). LIMITATION: Information was limited on AID severity and immunosuppressive treatment. CONCLUSION: Response to ICI with anti-CTLA-4, anti-PD-1, or their combination for advanced melanoma and overall incidence of any irAEs of grade 3 or higher were similar in patients with and without preexisting AID. However, severe colitis and toxicity requiring early discontinuation of treatment occurred more frequently among patients with preexisting IBD, warranting close follow-up. PRIMARY FUNDING SOURCE: The Netherlands Organization for Health Research and Development

Systems medicine and integrated care to combat chronic noncommunicable diseases

We propose an innovative, integrated, cost-effective health system to combat major non-communicable diseases (NCDs), including cardiovascular, chronic respiratory, metabolic, rheumatologic and neurologic disorders and cancers, which together are the predominant health problem of the 21st century. This proposed holistic strategy involves comprehensive patient-centered integrated care and multi-scale, multi-modal and multi-level systems approaches to tackle NCDs as a common group of diseases. Rather than studying each disease individually, it will take into account their intertwined gene-environment, socio-economic interactions and co-morbidities that lead to individual-specific complex phenotypes. It will implement a road map for predictive, preventive, personalized and participatory (P4) medicine based on a robust and extensive knowledge management infrastructure that contains individual patient information. It will be supported by strategic partnerships involving all stakeholders, including general practitioners associated with patient-centered care. This systems medicine strategy, which will take a holistic approach to disease, is designed to allow the results to be used globally, taking into account the needs and specificities of local economies and health systems

3,4-Dihydroxy-L-Phenylalanine as a Novel Covalent Linker of Extracellular Matrix Proteins to Polyacrylamide Hydrogels with a Tunable Stiffness

Cells acquire mechanical information from their surrounding and convert this into biochemical activity. The concept and mechanism behind this cellular mechanosensing and mechanotransduction are often studied by means of two-dimensional hydrogels. Polyacrylamide hydrogels (PAAMs) offer chemical, mechanical, and optical advantages but due to their inert surface do not allow protein and cell adherence. Several cross-linkers have been used to functionalize the surface of PAAMs with extracellular matrix (ECM) proteins to enable cell culture. However, the most commonly used cross-linkers are either unstable, expensive, or laborious and often show heterogeneous coating or require PAAM modification. Here, we introduce 3,4-dihydroxy-l-phenylalanine (L-DOPA) as a novel cross-linker that can functionalize PAAMs with ECM without the above-mentioned disadvantages. A homogenous collagen type I and fibronectin coating was observed after L-DOPA functionalization. Fibroblasts responded to differences in PAAMs' stiffness; morphology, cell area, and protein localization were all affected as expected, in accordance with literature where other cross-linkers were used. In conclusion, L-DOPA can be used as a crosslinker between PAAMs and ECM and represents a novel, straightforward, nonlaborious, and robust method to functionalize PAAMs for cell culture to study cell mechanosensing

Induction of resistance to the multitargeted antifolate Pemetrexed (ALIMTA) in WiDr human colon cancer cells is associated with thymidylate synthase overexpression

Pemetrexed (ALIMTA, MTA) is a novel thymidylate synthase (TS) inhibitor and has shown activity against colon cancer, mesothelioma and nonsmall-cell lung cancer. We induced resistance to Pemetrexed in the human colon cancer cell line WiDr by using a continuous exposure to stepwise increasing Pemetrexed concentrations (up to 20 microM) as well as a more clinically relevant schedule with intermittent exposure (up to 50 microM) for 4 hr every 7 days, resulting in WiDr variants WiDr-cPEM and WiDr-4PEM, respectively. However, using the same conditions, it was not possible to induce resistance in the WiDr/F cell line, a variant adapted to growth under low folate conditions. Mechanisms of resistance to Pemetrexed were determined at the level of TS, folylpolyglutamate synthetase (FPGS) and reduced folate carrier (RFC). WiDr-4PEM and WiDr-cPEM showed cross-resistance to the polyglutamatable TS inhibitor Raltitrexed (6- and 19-fold, respectively) and the nonpolyglutamatable TS-inhibitor Thymitaq (6- and 42-fold, respectively) but not to 5-fluorouracil. The ratios of TS mRNA:beta actin mRNA in WiDr-4PEM and WiDr-cPEM were 5-fold (P=0.01) and 18-fold (P=0.04) higher, respectively, compared to WiDr (ratio: 0.012). In addition, TS protein expression in the resistant WiDr variants was elevated 3-fold compared to WiDr, while the catalytic activity of TS with 1 microM dUMP increased from 30 pmol/hr/10(6) cells in WiDr cells to 2201 and 7663 pmol/hr/10(6) cells in WiDr-4PEM and WiDr-cPEM, respectively. The activity of FPGS was moderately decreased, but not significantly different in all WiDr variants. Finally, no evidence was found that decreased catalytic activity of RFC was responsible for the obtained Pemetrexed resistance. Altogether, these results indicate that resistance to Pemetrexed in the colon cancer cell line WiDr was solely due to upregulation of TS of which all related parameters (mRNA and protein expression and TS activity) were increased, rather than alterations in FPGS or RFC activity

Ascorbic acid promotes a TGFβ1-induced myofibroblast phenotype switch

l-Ascorbic acid (AA), generally known as vitamin C, is a crucial cofactor for a variety of enzymes, including prolyl-3-hydroxylase (P3H), prolyl-4-hydroxylase (P4H), and lysyl hydroxylase (LH)-mediated collagen maturation. Here, we investigated whether AA has additional functions in the regulation of the myofibroblast phenotype, besides its function in collagen biosynthesis. We found that AA positively influences TGFβ1-induced expression of COL1A1, ACTA2, and COL4A1 Moreover, we demonstrated that AA promotes αSMA stress fiber formation as well as the synthesis and deposition of collagens type I and IV Additionally, AA amplified the contractile phenotype of the myofibroblasts, as seen by increased contraction of a 3D collagen lattice. Moreover, AA increased the expression of several TGFβ1-induced genes, including DDR1 and CCN2 Finally, we demonstrated that the mechanism of AA action seems independent of Smad2/3 signaling