Glycosaminoglycan Synthesis by Human Keratinocytes: Cell Growth and Medium Calcium Effects

The influences of cell density, differentiation, and medium calcium levels on glycosaminoglycan biosynthesis were evaluated in cultured human epidermal keratinocytes. Following metabolic labeling with [35S]-sulfate and [3H]-glucosamine under steady state conditions in “high” medium calcium (> 1.0 mMol), the majority of sulfated glycosaminoglycans remained associated with the cell layers, whereas hyaluronic acid, which was present in smaller amounts than the sulfated products, was about equally distributed between the medium and the cell layers. Of the sulfated glycosaminoglycans, heparan sulfate and chondroitin 4/6-sulfate were the major species and were present in roughly comparable amounts, whereas dermatan sulfate was quantitatively the lesser of the products. The effects of “low” medium calcium (0.3 and 0.025 mM) were complex, although a consistent decrease in the incorporation of the [3H]-glucosamine precursor was found at high cell density, probably reflecting a decrease in its intracellular specific activity. In “high” calcium cultures, there was a strong inverse correlation (r = -0.92) between keratinocyte cell number and cellular production of sulfated glycosaminoglycans, whereas no such relationship was evident in cultures grown in “low” calcium medium at comparable cell density. Because keratinocyte differentiation is inhibited in the low calcium conditions, the results suggest that the decrease in production of sulfated glycosaminoglycans by confluent keratinocytes may actually correlate with differentiation rather than with cell number

Staphylococcus aureus Biofilm and Planktonic cultures differentially impact gene expression, mapk phosphorylation, and cytokine production in human keratinocytes

<p>Abstract</p> <p>Background</p> <p>Many chronic diseases, such as non-healing wounds are characterized by prolonged inflammation and respond poorly to conventional treatment. Bacterial biofilms are a major impediment to wound healing. Persistent infection of the skin allows the formation of complex bacterial communities termed biofilm. Bacteria living in biofilms are phenotypically distinct from their planktonic counterparts and are orders of magnitude more resistant to antibiotics, host immune response, and environmental stress. <it>Staphylococcus aureus </it>is prevalent in cutaneous infections such as chronic wounds and is an important human pathogen.</p> <p>Results</p> <p>The impact of <it>S. aureus </it>soluble products in biofilm-conditioned medium (BCM) or in planktonic-conditioned medium (PCM) on human keratinocytes was investigated. Proteomic analysis of BCM and PCM revealed differential protein compositions with PCM containing several enzymes involved in glycolysis. Global gene expression of keratinocytes exposed to biofilm and planktonic <it>S. aureus </it>was analyzed after four hours of exposure. Gene ontology terms associated with responses to bacteria, inflammation, apoptosis, chemotaxis, and signal transduction were enriched in BCM treated keratinocytes. Several transcripts encoding cytokines were also upregulated by BCM after four hours. ELISA analysis of cytokines confirmed microarray results at four hours and revealed that after 24 hours of exposure, <it>S. aureus </it>biofilm induced sustained low level cytokine production compared to near exponential increases of cytokines in planktonic treated keratinocytes. The reduction in cytokines produced by keratinocytes exposed to biofilm was accompanied by suppressed phosphorylation of MAPKs. Chemical inhibition of MAPKs did not drastically reduce cytokine production in BCM-treated keratinocytes suggesting that the majority of cytokine production is mediated through MAPK-independent mechanisms.</p> <p>Conclusions</p> <p>Collectively the results indicate that <it>S. aureus </it>biofilms induce a distinct inflammatory response compared to their planktonic counterparts. The differential gene expression and production of inflammatory cytokines by biofilm and planktonic cultures in keratinocytes could have implications for the formation and persistence of chronic wounds. The formation of a biofilm should be considered in any study investigating host response to bacteria.</p

The Association between Language Use and Food Insecurity among Hispanic Adults Residing in the United States Depends on Nativity

Abstract Objective: To examine the association between language use – predominantly English, English and Spanish equally, and predominantly Spanish – and food insecurity among Hispanic adults residing in the United States, 1999-2018. Design: Pooled cross-sectional study design. Setting: United States. Participants: 15,073 Hispanic adults. Results: Compared to Hispanic adults who predominantly spoke English and after adjusting for age, sex, family income-to-poverty ratio, education level, and employment status, Hispanic adults who spoke English and Spanish equally (OR=1.28, 95%CI=1.05-1.56) or predominantly Spanish (OR=1.25, 95%CI=1.04-1.49) had higher odds of food insecurity. After stratifying by country of birth, language use was associated with higher odds of food insecurity only for Hispanic adults born outside of the United States, but not for Hispanic adults born in the United States. Hispanic adults born outside of the United States who spoke English and Spanish equally (OR=1.27, 95%CI=1.04-1.55) or spoke predominantly Spanish (OR=1.24, 95%CI=1.04-1.48) had higher odds of food insecurity when compared to those who predominantly spoke English. Conclusion: Foreign-born Hispanic adults who speak predominantly Spanish, or English and Spanish equally, have higher odds of food insecurity. Food and nutrition assistance programs that serve Hispanic immigrants should make sure to provide linguistically- and culturally appropriate services to this population

Lessons learned for social and behavior change programming from the USAID Zika response

Breakthrough RESEARCH documented the strengths, weaknesses, gaps, and challenges in social and behavior change (SBC) efforts to combat the Zika outbreak to inform future public health emergency programming. What were the successes, challenges, and gaps in designing, implementing, and adapting SBC programming in the USAID Zika response? What were the successes, challenges, and gaps in generating and using data and evidence in SBC programming in the USAID Zika response? What do the successes, challenges, and gaps of the USAID Zika response’s SBC programming imply for future health emergency responses? Eight recommendations are offered as a reslt of these research queries

A case study in leveraging strategic partnerships through trust-based philanthropy

This practice note highlights a case study of leveraging strategic partnerships through trust-based philanthropy, a set of practices rooted in values, relationship building, mutual learning, and equity. It describes the motivations, planning, and execution of a symposium organized by, and held for, a Foundation and four of its grantees. The symposium led to the development of sustained pathways between and among the partners, resulting in productive collaborations and shared projects. This case study is shared to illustrate the argument that it is the responsibility of funders, and certainly in their self-interest, to eliminate competition between organizations to whom they provide financial resources and support. By facilitating trust and collaboration, funders are uniquely positioned to foster collective, higher-impact work. © 2024 The Authors. Journal of Philanthropy and Marketing published by John Wiley & Sons Ltd

Aging and health among migrants in a European perspective

Kristiansen M, Razum O, Tezcan-Güntekin H, Krasnik A. Aging and health among migrants in a European perspective. Public Health Reviews. 2016;37(1): 20