Age-Related Loss of Innate Immune Antimicrobial Function of Dermal Fat Is Mediated by Transforming Growth Factor Beta.

Dermal fibroblasts (dFBs) resist infection by locally differentiating into adipocytes and producing cathelicidin antimicrobial peptide in response to Staphylococcus aureus (S. aureus). Here, we show that neonatal skin was enriched with adipogenic dFBs and immature dermal fat that highly expressed cathelicidin. The pool of adipogenic and antimicrobial dFBs declined after birth, leading to an age-dependent loss of dermal fat and a decrease in adipogenesis and cathelidicin production in response to infection. Transforming growth factor beta (TGF-ß), which acted on uncommitted embryonic and adult dFBs and inhibited their adipogenic and antimicrobial function, was identified as a key upstream regulator of this process. Furthermore, inhibition of the TGF-ß receptor restored the adipogenic and antimicrobial function of dFBs in culture and increased resistance of adult mice to S. aureus infection. These results provide insight into changes that occur in the skin innate immune system between the perinatal and adult periods of life.

Obesity alters pathology and treatment response in inflammatory disease.

Decades of work have elucidated cytokine signalling and transcriptional pathways that control T cell differentiation and have led the way to targeted biologic therapies that are effective in a range of autoimmune, allergic and inflammatory diseases. Recent evidence indicates that obesity and metabolic disease can also influence the immune system1-7, although the mechanisms and effects on immunotherapy outcomes remain largely unknown. Here, using two models of atopic dermatitis, we show that lean and obese mice mount markedly different immune responses. Obesity converted the classical type 2 T helper (TH2)-predominant disease associated with atopic dermatitis to a more severe disease with prominent TH17 inflammation. We also observed divergent responses to biologic therapies targeting TH2 cytokines, which robustly protected lean mice but exacerbated disease in obese mice. Single-cell RNA sequencing coupled with genome-wide binding analyses revealed decreased activity of nuclear receptor peroxisome proliferator-activated receptor-γ (PPARγ) in TH2 cells from obese mice relative to lean mice. Conditional ablation of PPARγ in T cells revealed that PPARγ is required to focus the in vivo TH response towards a TH2-predominant state and prevent aberrant non-TH2 inflammation. Treatment of obese mice with a small-molecule PPARγ agonist limited development of TH17 pathology and unlocked therapeutic responsiveness to targeted anti-TH2 biologic therapies. These studies reveal the effects of obesity on immunological disease and suggest a precision medicine approach to target the immune dysregulation caused by obesity.

Antimicrobial peptide-producing dermal preadipocytes defend against Candida albicans skin infection via the FGFR-MEK-ERK pathway.

Dermal fibroblasts (dFBs) defend against deep bacterial skin infections by differentiating into preadipocytes (pAds) that produce the antimicrobial peptide cathelicidin; this differentiation is known as the dermal reactive adipogenesis response. However, the role of dFBs in fungal infection remains unknown. Here, we found that cathelicidin-producing pAds were present in high numbers in skin lesions from patients with cutaneous Candida granulomas. Second, we showed that dermal Candida albicans (C. albicans) infection in mice robustly triggered the dermal reactive adipogenesis response and induced cathelicidin expression, and inhibition of adipogenesis with pharmacological inhibitors of peroxisome proliferator-activated receptor γ (PPARγ) impaired skin resistance to C. albicans. In vitro, C. albicans products induced cathelicidin expression in pAds, and differentiating pAds markedly suppressed the growth of C. albicans by producing cathelicidin. Finally, we showed that C. albicans induced an antimicrobial response in pAds through the FGFR-MEK-ERK pathway. Together, our data reveal a previously unknown role of dFBs in the defense against skin infection caused by C. albicans.

Antimicrobial Peptide LL37 and MAVS Signaling Drive Interferon-ß Production by Epidermal Keratinocytes during Skin Injury.

Type 1 interferons (IFNs) promote inflammation in the skin but the mechanisms responsible for inducing these cytokines are not well understood. We found that IFN-ß was abundantly produced by epidermal keratinocytes (KCs) in psoriasis and during wound repair. KC IFN-ß production depended on stimulation of mitochondrial antiviral-signaling protein (MAVS) by the antimicrobial peptide LL37 and double stranded-RNA released from necrotic cells. MAVS activated downstream TBK1 (TANK-Binding Kinase 1)-AKT (AKT serine/threonine kinase 1)-IRF3 (interferon regulatory factor 3) signaling cascade leading to IFN-ß production and then promoted maturation of dendritic cells. In mice, the production of epidermal IFN-ß by LL37 required MAVS, and human wounded and/or psoriatic skin showed activation of MAVS-associated IRF3 and induction of MAVS and IFN-ß gene signatures. These findings show that KCs are an important source of IFN-ß and MAVS is critical to this function, and demonstrates how the epidermis triggers unwanted skin inflammation under disease conditions.

Dermal extracellular matrix molecules in skin development, homeostasis, wound regeneration and diseases.

The extracellular matrix (ECM) is a dynamic structure that surrounds and anchors cellular components in tissues. In addition to functioning as a structural scaffold for cellular components, ECMs also regulate diverse biological functions, including cell adhesion, proliferation, differentiation, migration, cell-cell interactions, and intracellular signaling events. Dermal fibroblasts (dFBs), the major cellular source of skin ECM, develop from a common embryonic precursor to the highly heterogeneous subpopulations during development and adulthood. Upon injury, dFBs migrate into wound granulation tissue and transdifferentiate into myofibroblasts, which play a critical role in wound contraction and dermal ECM regeneration and deposition. In this review, we describe the plasticity of dFBs during development and wound healing and how various dFB-derived ECM molecules, including collagen, proteoglycans, glycosaminoglycans, fibrillins and matricellular proteins are expressed and regulated, and in turn how these ECM molecules play a role in regulating the function of dFBs and immune cells. Finally, we describe how dysregulation of ECM matrix is associated the pathogenesis of wound healing related skin diseases, including chronic wounds and keloid.

Feasibility of an oral health promotion program among older people in geriatric care facilities, Shanghai, China: a pre/post-implementation study.

BACKGROUND: The oral health of older people is closely related to their overall health. Timely and effective intervention in oral issues is necessary to maintain their overall health. This study aimed to evaluate the feasibility and effectiveness of an Oral Health Promotion Program (OHPP) in Geriatric Care Facilities (GCFs). METHODS: The OHPP was implemented in two GCFs and evaluated using a pre/post-design. Questionnaires on self-efficacy and attitude for providing oral care were sent to 42 nurse participants before and three months after the implementation of the OHPP. Outcomes of 295 patient participants were assessed at four time points (T1-baseline, T2-one month, T3-two months, and T4-three months post-implementation) including Activities of Daily Living (ADL), Mini-Mental State Examination (MMSE), and Oral Health Assessment Tool (OHAT). RESULTS: The oral health and daily activity ability of patient participants showed an improving trend at four time points pre/post-implementation of the OHPP. The proportion of patients with healthy mouths (OHAT: 0-3 points) increased from 29.8 to 67.8% and their scores of OHAT and ADL were significantly better at T4 compared to T1, T2, and T3 (p < 0.001). Self-efficacy (SE-PMC: T1 = 18.93 ± 3.18, T4 = 28.83 ± 6.56, p < 0.001) and attitude (A-PMC: T1 = 18.78 ± 3.09, T4 = 28.20 ± 6.03, p < 0.001) for oral care among nurse participants improved after the implementation of the OHPP. CONCLUSIONS: This study highlights the feasibility of implementing OHPP within GCFs, potentially enhancing the oral health and daily living activities of older individuals. Integrating the OHPP into routine care in geriatric settings is not only practical but also widely acceptable, offering a proactive approach to address oral health disparities among older residents. Stakeholders can maximize the impact of the OHPP by fostering collaboration among healthcare professionals, administrators, and residents, ultimately improving oral health outcomes and overall quality of life of older residents. TRIAL REGISTRATION: ChiCTR2000035236 (registration date: 04/08/2020).

Coordinated Patient Care via Mobile Phone-Based Telemedicine in Secondary Stroke Prevention: A Propensity Score-Matched Cohort Study.

BACKGROUND: To prevent recurrent stroke, patients need to follow evidence-based practices following discharge; however, adherence to these practices is suboptimal. PURPOSE: To evaluate whether a smartphone mobile application can improve medication adherence and stroke awareness in secondary stroke prevention. METHODS: A retrospective study design was used. Patients with ischemic stroke registered in a database between August 2018 and January 2019 were enrolled. Propensity score matching was used to match patients managed with the mobile application compared with regular practice in a 1:2 ratio. RESULTS: Sixty-five patients were paired with 123 controls. Three-month medication adherence was 93.8% in the application group versus 82.9% in the control group ( P = .036). Patients in the application group were more likely to know stroke warning signs ( P = .003) and when to call an ambulance for stroke symptoms (87.7% vs 72.4%, P = .016). CONCLUSIONS: Using a mobile application may increase medication adherence and stroke awareness in secondary stroke prevention.

Factors associated with nurses' attitudes for providing oral care in geriatric care facilities: a cross-sectional study.

BACKGROUND: The world's population is getting older. This issue is accompanied by a rise in the number of older people suffering from dementia and disability, for whom oral hygiene care is challenging. Nurses' attitudes toward providing oral care (POC) are critical for the elderly, while few studies have investigated the determinant factors of nurses' attitudes by identifying the current work pressure, resilience and self-efficacy in geriatric care facilities (GCFs). It is of great significance to explore the nurses' attitudes toward POC and associated influencing factors related to psychological aspects including resilience, self-efficacy, and stress from the workplace. METHODS: Attitudes for Providing Mouth Care (A-PMC) in Chinese version were used in this cross-sectional study with 160 nurses in 2 GCFs. Data were collected using online questionnaires and analyzed by multiple linear regression analysis. Statistically significant values were considered at p < 0.05. RESULTS: A total of 160 nurses participated in this study, with an average age of 32.86 ± 7.43. The mean score for the A-PMC was 2.81 ± 0.47. The score of A-PMC was negatively correlated with work pressure (r=-0.332, p < 0.01), and positively correlated with resilience (r = 0.735, p < 0.01) and self-efficacy (r = 0.425, p < 0.01) respectively. Multiple linear regression analyses identified that the potential influencing factors of A-PMC were education background, work hours every shift, self-efficacy, work pressure and resilience. CONCLUSIONS: The study results indicate nurses' attitudes regarding PMC were at a low level, which is influenced by many factors. To improve nurses' attitudes toward PMC and the oral hygiene (OH) of the elderly in GCFs, it is necessary to increase nurses' education and training, establish a reasonable and effective incentive mechanism to improve nurses' work motivation and other intervention measures to reduce work pressure.

Development and psychometric testing of burn inpatient nursing dependency assessment scale.

AIMS: The aim was to develop and psychometrically test the burn inpatient nursing dependency assessment scale (BINDAS). DESIGN: This was a scale development study. METHODS: This study was conducted in four phases from November 2019 to November 2021. Items were generated and the initial scale was constructed in phase 1. The preliminary evaluation of items was conducted through expert reviews and a pilot study in phase 2. The scale, including item quality, reliability and validity, was validated with 420 individuals in phase 3. The translation of the scale from Chinese to English was performed in phase 4. RESULTS: Content validity was satisfactory. Thirteen items were retained after item analysis, and three factors accounting for 73% of the total item variance were extracted through exploratory and confirmatory factor analyses. Predictive validity with nursing time spent with patients during 24 h was also estimated, with r = .66 (p < .01). Receiver operating characteristic analysis was conducted, and an area under the curve of the scale of 0.94 was obtained. Concurrent validity with Barthel index was estimated, with r = -.71 (p < .01). Cronbach's alpha coefficient for scale was .93, and the correlation between raters for total scores was .95. CONCLUSION: Burn inpatient nursing dependency assessment scale is a psychometrically valid and reliable measurement instrument as well as objective other-rating scale with 12 items for scoring on a four-point scale (0, 1, 2 or 3) and 1 item for scoring on a two-point scale (0 or 2). BINDAS with 13 items was developed in this study. Nurses can give each patient a total score of 0-38. A high score indicates high nursing dependency. The 13-item scale consists of three factors: basic care need, physiological index, and psychology and adaptation. IMPACT: This scale demonstrated satisfactory psychometric properties and can be used to evaluate patient dependency on nurses in burn units and optimize an individual's care plan to achieve efficient staff allocation.

Identification of Lineage-Specific Transcription Factors That Prevent Activation of Hepatic Stellate Cells and Promote Fibrosis Resolution.

BACKGROUND & AIMS: Development of liver fibrosis is associated with activation of quiescent hepatic stellate cells (HSCs) into collagen type I-producing myofibroblasts (activated HSCs). Cessation of liver injury often results in fibrosis resolution and inactivation of activated HSCs/myofibroblasts into a quiescent-like state (inactivated HSCs). We aimed to identify molecular features of phenotypes of HSCs from mice and humans. METHODS: We performed studies with LratCre, Ets1-floxed, Nf1-floxed, Pparγ-floxed, Gata6-floxed, Rag2-/-γc-/-, and C57/Bl6 (control) mice. Some mice were given carbon tetrachloride (CCl4) to induce liver fibrosis, with or without a peroxisome proliferator-activated receptor-γ (PPARγ) agonist. Livers from mice were analyzed by immunohistochemistry. Quiescent, activated, and inactivated HSCs were isolated from livers of Col1α1YFP mice and analyzed by chromatin immunoprecipitation and sequencing. Human HSCs were isolated from livers denied for transplantation. We compared changes in gene expression patterns and epigenetic modifications (histone H3 lysine 4 dimethylation and histone H3 lysine 27 acetylation) in primary mouse and human HSCs. Transcription factors were knocked down with small hairpin RNAs in mouse HSCs. RESULTS: Motif enrichment identified E26 transcription-specific transcription factors (ETS) 1, ETS2, GATA4, GATA6, interferon regulatory factor (IRF) 1, and IRF2 transcription factors as regulators of the mouse and human HSC lineage. Small hairpin RNA-knockdown of these transcription factors resulted in increased expression of genes that promote fibrogenesis and inflammation, and loss of HSC phenotype. Disruption of Gata6 or Ets1, or Nf1 or Pparγ (which are regulated by ETS1), increased the severity of CCl4-induced liver fibrosis in mice compared to control mice. Only mice with disruption of Gata6 or Pparγ had defects in fibrosis resolution after CCl4 administration was stopped, associated with persistent activation of HSCs. Administration of a PPARγ agonist accelerated regression of liver fibrosis after CCl4 administration in control mice but not in mice with disruption of Pparγ. CONCLUSIONS: Phenotypes of HSCs from humans and mice are regulated by transcription factors, including ETS1, ETS2, GATA4, GATA6, IRF1, and IRF2. Activated mouse and human HSCs can revert to a quiescent-like, inactivated phenotype. We found GATA6 and PPARγ to be required for inactivation of human HSCs and regression of liver fibrosis in mice.

Retinoids Enhance the Expression of Cathelicidin Antimicrobial Peptide during Reactive Dermal Adipogenesis.

A subset of dermal fibroblasts undergo rapid differentiation into adipocytes in response to infection and acutely produce the cathelicidin antimicrobial peptide gene Camp Vitamin A and other retinoids inhibit adipogenesis yet can show benefit to skin disorders, such as cystic acne, that are exacerbated by bacteria. We observed that retinoids potently increase and sustain the expression of Camp in preadipocytes undergoing adipogenesis despite inhibition of markers of adipogenesis, such as Adipoq, Fabp4, and Rstn Retinoids increase cathelicidin in both mouse and human preadipocytes, but this enhancement of antimicrobial peptide expression did not occur in keratinocytes or a sebocyte cell line. Preadipocytes undergoing adipogenesis more effectively inhibited growth of Staphylococcus aureus when exposed to retinoic acid. Whole transcriptome analysis identified hypoxia-inducible factor 1-α (HIF-1α) as a mechanism through which retinoids mediate this response. These observations uncouple the lipid accumulation element of adipogenesis from the innate immune response and uncover a mechanism, to our knowledge previously unsuspected, that may explain therapeutic benefits of retinoids in some skin disorders.

Silver-Catalyzed Nucleophilic Addition of ß-Dicarbonyls to Isocyano Group: Facile Access to Indolin-3-ol Derivatives.

A domino silver-catalyzed intermolecularly nucleophilic addition of ß-dicarbonyls to the isocyano group and cyclization of the imidoyl silver sequence was developed for the direct and efficient synthesis of indolin-3-ol derivatives. This domino transformation tolerates a range of readily available o-acyl arylisocyanides and 1,3-dicarbonyls under an operationally simple procedure. Triple roles of silver carbonate are demonstrated in this reaction: (1) activation of isocyano group, (2) formation of enolate, and (3) promotion the nucleophilic reactivity of imidoyl intermediate.

LncRNA TUG1 promoted viability and associated with gemcitabine resistant in pancreatic ductal adenocarcinoma.

OBJECTIVE: To investigate the underlying mechanism of lncRNA TUG1 in pancreatic ductal adenocarcinoma (PDAC). METHODS: The expression of TUG1 was defined by qRT-PCR. The apoptotic cells were detected by flow cytometry assay. The cell migration and invasion were measured by scratch assay and Transwell assay. The level of ERK pathway was detected using Western blot. RESULTS: Compared with normal tissues and cells, the expression of TUG1 was up-regulated in pancreatic cancer tissue and cells. Meanwhile, knockdown of TUG1 could promote PDAC cells apoptosis and inhibit PDAC cells viability, migration and invasion. In addition, overexpression of TUG1 enhanced the gemcitabine chemoresistance of PDAC cells. Surprisingly, gemcitabine combined with SCH772984 (a suppressor of ERK pathway) could reverse the drug resistance resulted from overexpression of TUG1. CONCLUSION: TUG1 promoted the viability of PDAC cells and enhanced its resistance of gemcitabine.

Molecular cartography of the human skin surface in 3D.

The human skin is an organ with a surface area of 1.5-2 m(2) that provides our interface with the environment. The molecular composition of this organ is derived from host cells, microbiota, and external molecules. The chemical makeup of the skin surface is largely undefined. Here we advance the technologies needed to explore the topographical distribution of skin molecules, using 3D mapping of mass spectrometry data and microbial 16S rRNA amplicon sequences. Our 3D maps reveal that the molecular composition of skin has diverse distributions and that the composition is defined not only by skin cells and microbes but also by our daily routines, including the application of hygiene products. The technological development of these maps lays a foundation for studying the spatial relationships of human skin with hygiene, the microbiota, and environment, with potential for developing predictive models of skin phenotypes tailored to individual health.

Non-coding Double-stranded RNA and Antimicrobial Peptide LL-37 Induce Growth Factor Expression from Keratinocytes and Endothelial Cells.

A critical function for skin is that when damaged it must simultaneously identify the nature of the injury, repair barrier function, and limit the intrusion of pathogenic organisms. These needs are carried out through the detection of damage-associated molecular patterns (DAMPs) and a response that includes secretion of cytokines, chemokines, growth factors, and antimicrobial peptides (AMPs). In this study, we analyzed how non-coding double-stranded RNA (dsRNAs) act as a DAMP in the skin and how the human cathelicidin AMP LL-37 might influence growth factor production in response to this DAMP. dsRNA alone significantly increased the expression of multiple growth factors in keratinocytes, endothelial cells, and fibroblasts. Furthermore, RNA sequencing transcriptome analysis found that multiple growth factors increase when cells are exposed to both LL-37 and dsRNA, a condition that mimics normal wounding. Quantitative PCR and/or ELISA validated that growth factors expressed by keratinocytes in these conditions included, but were not limited to, basic fibroblast growth factor (FGF2), heparin-binding EGF-like growth factor (HBEGF), vascular endothelial growth factor C (VEGFC), betacellulin (BTC), EGF, epiregulin (EREG), and other members of the transforming growth factor ß superfamily. These results identify a novel role for DAMPs and AMPs in the stimulation of repair and highlight the complex interactions involved in the wound environment.

Resveratrol supplement inhibited the NF-κB inflammation pathway through activating AMPKα-SIRT1 pathway in mice with fatty liver.

Nonalcoholic fatty liver disease (NAFLD) is characterized by high levels of nonesterified fatty acids (NEFA), inflammation, and hepatic steatosis. Inflammation plays a crucial role in the development of fatty liver. Resveratrol (RSV) supplement could improve inflammatory response and hepatic steatosis, whereas the underlying mechanism was not well understood. In this study, mice fed with high-fat diet (HFD) exhibited severe hepatic injury and high blood concentrations of the inflammatory cytokines TNF-α, IL-6, and IL-1ß. Hepatic NF-κB inflammatory pathway was over-induced in HFD mice. In vitro, NEFA treatment further increased NF-κB pathway activation in mice hepatocytes, which then promoted the synthesis of inflammatory cytokines. Interestingly, RSV treatment significantly inhibited overactivation of NF-κB pathway and improved hepatic steatosis. Furthermore, RSV further increased the AMP-activated protein kinaseα (AMPKα) phosphorylation and sirtuin1 (SIRT1) protein levels to inhibit overactivation of NF-κB pathway induced by HFD or high levels of NEFA. AMPKα or SIRT1 inhibition significantly decreased the improvement effect of RSV on the NF-κB pathway induced by high levels of NEFA. Taken together, these findings indicate that RSV supplement decreases the inflammatory level and improves hepatic steatosis through activating AMPKα-SIRT1 pathway. Therefore, these data suggested an important clinical application of RSV in preventing NAFLD in humans.

Ctip2 is a dynamic regulator of epidermal proliferation and differentiation by integrating EGFR and Notch signaling.

Epidermal morphogenesis results from a delicate balance between keratinocyte proliferation and differentiation, and this balance is perturbed upon deletion of transcription factor Ctip2. Here we demonstrate that Ctip2, in a cell autonomous manner, controls keratinocyte proliferation and cytoskeletal organization, and regulates the onset and maintenance of differentiation in keratinocytes in culture. Ctip2 integrates keratinocyte proliferation and the switch to differentiation by directly and positively regulating EGFR transcription in proliferating cells and Notch1 transcription in differentiating cells. In proliferative cells, the EGFR promoter is occupied by Ctip2, whereas Ctip2 is only recruited to the Notch1 promoter under differentiating conditions. Activation of EGFR signaling downregulates Ctip2 at the transcript level, whereas high calcium signaling triggers SUMOylation, ubiquitination and proteasomal degradation of Ctip2 at the protein level. Together, our findings demonstrate a novel mechanism(s) of Ctip2-mediated, coordinated control of epidermal proliferation and terminal differentiation, and identify a pathway of negative feedback regulation of Ctip2 during epidermal development.

TGFß-mediated inhibition of hypodermal adipocyte progenitor differentiation promotes wound-induced skin fibrosis.

Aberrant activation of dermal fibroblasts during wound healing often leads to debilitating fibrotic changes in the skin, such as scleroderma and keloids. However, the underlying cellular and molecular mechanisms remain elusive. Here, we established a wound-induced skin fibrosis (WISF) mouse model in mature adult mice, characterised by excessive deposition of collagen bundles, loss of dermal adipocytes, and enrichment of DPP4+Ly6A+THY1+ hypodermal interstitial adipocyte progenitors (HI-APs) and pericytes, resembling human fibrotic skin diseases. This WISF model exhibited an age-dependent gain of fibrotic characteristics, contrasting with the wound-induced hair neogenesis observed in younger mice. Through comprehensive analyses of the WISF, we delineated a trajectory of fibroblast differentiation that originates from HI-APs. These progenitors highly expressed several extracellular matrix (ECM) genes and exhibited a TGFß pathway signature. TGFß was identified as the key signal to inhibit the adipogenic potential and maintain the fibrogenic potential of dermal APs. Additionally, administering a TGFß receptor inhibitor to wound scar reduced the abundance of ECM-producing APs. Finally, analysis of human scleroderma skin tissues revealed a negative correlation between the expression of AP-, ECM-, and TGFß pathway-related genes and PPARG. Overall, this study establishes a wound-induced skin fibrosis mouse model and demonstrates that TGFß-mediated blockage of HI-AP differentiation is crucial for driving fibrotic pathology. Targeting HI-APs and adipogenesis may provide novel avenues for developing disease-modifying therapies for fibrotic skin diseases.