A distal Foxp3 enhancer enables interleukin-2 dependent thymic Treg cell lineage commitment for robust immune tolerance.

Activation of the STAT5 transcription factor downstream of the Interleukin-2 receptor (IL-2R) induces expression of Foxp3, a critical step in the differentiation of regulatory T (Treg) cells. Due to the pleiotropic effects of IL-2R signaling, it is unclear how STAT5 acts directly on the Foxp3 locus to promote its expression. Here, we report that IL-2 - STAT5 signaling converged on an enhancer (CNS0) during Foxp3 induction. CNS0 facilitated the IL-2 dependent CD25+Foxp3- precursor to Treg cell transition in the thymus. Its deficiency resulted in impaired Treg cell generation in neonates, which was partially mitigated with age. While the thymic Treg cell paucity caused by CNS0 deficiency did not result in autoimmunity on its own, it exacerbated autoimmune manifestations caused by disruption of the Aire gene. Thus, CNS0 enhancer activity ensures robust Treg cell differentiation early in postnatal life and cooperatively with other tolerance mechanisms minimizes autoimmunity.

Platycodon grandiflorus polysaccharide inhibits the inflammatory response of 3D4/21 cells infected with PCV2.

Porcine circovirus type 2 (PCV2) infection cause multi-systemic inflammation in pigs. Platycodon grandiflorus polysaccharide (PGPSt) has been reported to have the effects of immune regulation and disease resistance. Nevertheless, the role and mechanism of PGPSt in the inflammatory response of 3D4/21 cells induced by PCV2 infection remain unclear. The present study aims to investigate effects of PGPSt on inflammatory response and its possible underlying mechanisms in vitro models. Cells were treated with PCV2 for 36 h to construct a cell inflammation model. The 3D4/21 cell lines were pretreated with or without PGPSt, and the changes of inflammation-related markers and the signaling pathway were detected by CCK-8, ELISA, qPCR and Western blot. The results showed that PGPSt was non-toxic to cells and protected PCV2-infected cells from inflammatory damage. PGPSt could significantly inhibit the high acetylation of histone H3 (AcH3) and histone H4 (AcH4), down-regulate HAT and up-regulate HDAC activity, and reduce the expression of pro-inflammatory enzymes iNOS and COX-2 proteins levels. Then the levels of IL-1ß, IL-6 and TNF-α were significantly inhibited, and the level of IL-10 was promoted. We also observed that PGPSt inhibited the phosphorylation of p65, p38 and Erk1/2, which subsequently inhibited nuclear translocation of NF-κB p65 to express pro-inflammatory factors. In conclusion, PGPSt can reduce the inflammatory response by regulating histone acetylation, reducing the release of inflammatory factors, reducing the expression of pro-inflammatory enzymes, and inhibiting the activation of NF-κB and MAPKs signaling pathways. This suggests that PGPSt had an anti-inflammatory effect on the inflammatory response caused by PCV2 infection, which provided theoretical data support for the research.

The surface morphology of Atractylodes macrocephala polysaccharide and its inhibitory effect on PCV2 replication.

BACKGROUND: Porcine infection with Porcine circovirus type 2 (PCV2) causes immunosuppression, which is easy to cause concurrent or secondary infection, making the disease complicated and difficult to treat, and causing huge economic losses to the pig industry. Total polysaccharide from the rhizoma of Atractylodes macrocephala Koidz. (PAMK) is outstanding in enhancing non-specific immunity and cellular immunity, and effectively improving the body's disease resistance, indicating its potential role in antiviral immunotherapy. RESULTS: PAMK had the characteristics of compact, polyporous and agglomerated morphology, but does not have triple helix conformation. PCV2 infection led to the increase in LC3-II, degradation of p62 and the increase of viral Cap protein expression and viral copy number. PAMK treatment significantly alleviated PCV2-induced autophagy and inhibited PCV2 replication. Moreover, PAMK treatment significantly attenuated the increase of PINK1 protein expression and the decrease of TOMM20 protein expression caused by PCV2 infection, alleviated Parkin recruitment from cytoplasm to mitochondria and intracellular reactive oxygen species accumulation, restored mitochondrial membrane charge, alleviated viral Cap protein expression. CONCLUSION: PAMK alleviates PCV2-induced mitophagy to suppress PCV2 replication by inhibiting the Pink 1/Parkin pathway. These findings may provide new insights into the prevention and treatment of PCV2. © 2023 Society of Chemical Industry.

Social media aids for business learning: A quantitative evaluation with the 5E instructional model.

Social media use is widely accepted in higher education, connecting students' learning with daily life. Considering the potential of social media to revolutionize the whole spectrum of teaching and learning, this study examines social media usage of business school students of different majors and their perception of social media as learning aids through a quantitative online survey guided by the 5E instructional model, with 423 valid responses from students majoring in accounting, finance, and economics. Results indicated that respondents perceived social media as influential in helping them access study-related information. It facilitated comprehensive learning, information access, information sharing, and student communication with instructors. Significant differences in perceptions of using social media as aids for business learning were found among students of different demographics, including gender, education level, and residence, but not quite for different majors. While various studies have examined the use of social media in education, scant studies focus on business school students under the lens of the 5E instructional model, especially Asians.

HLA-A*02:01 allele is associated with tanshinone-induced cutaneous drug reactions in Chinese population.

Tanshinone, a widely used Chinese patent medicine, has been confirmed to have various kinds of pharmacological effects although frequently causing cutaneous adverse drug reactions (cADRs). We aim to identify whether human leukocyte antigen (HLA) class I alleles are associated with tanshinone-induced cADRs in Han Chinese. The association study including 18 patients with tanshinone-induced cADRs, 67 tanshinone-tolerant volunteers, and two general population databases consisted of 10,689 and 169,995 healthy subjects was performed. The frequency of tanshinone-induced cADRs patients carrying HLA-A*02:01 was significantly higher when compared with the general control groups (OR = 6.25, Pc = 7.20 × 10-5; OR = 7.14, Pc = 8.00 × 10-6), and with the tolerant group (OR = 5.09, Pc = 0.024). The molecular docking assay confirmed high affinity of the ingredients of tanshinone towards HLA-A*02:01 (≤-7.5 kcal/mol). The result suggested HLA-A*02:01 may work as a promisingly predictive marker for tanshinone personalized therapy in Han Chinese.

Differential Gene Expression between Limbal Niche Progenitors and Bone Marrow Derived Mesenchymal Stem Cells.

Purpose: To compare the difference in gene expression between human limbal niche cells (LNC) and bone marrow derived mesenchymal stem cells (BMMSC). Methods: LNC were isolated by collagenase and expanded in modified embryonic stem cell medium (MESCM) on a Matrigel coated plastic plate. Cell diameters were measured with Image J software. Relative gene expression levels between LNC and BMMSC were compared using Affymetrix Human Primer View Gene Expression Array. A subset of differentially expressed genes was verified by RT-qPCR. The protein level of LAMA1 and COL4A1 was confirmed by Western blot and immunostaining. Results: The average diameter of LNC was 10.2±2.4 µm, which was significantly smaller than that of BMMSC (14 ±3.4 µm) (p<0.0001). Expression of 20,432 genes was examined by Gene Expression Array, among which expression of 349 genes in LNC was 10-fold or higher than that of BMMSC and expression of 8 genes in LNC was 100-fold or higher than that of BMMSC, while expression of 3 genes in BMMSC was 100-fold higher than that of LNC. GO analysis and pathway analysis showed that the differentially expressed genes were mainly enriched in the extracellular matrix receptor interaction pathway and Wnt signaling pathway. In addition, RT-qPCR results demonstrated that the expression of CD73, CD90, CD105, PDGFRß, Vimentin, SCF, KIT (CD117), COL14A1, LAMA2, THBS2, FZD1, BMP2 and CXCL12 genes in LNC were at least 2 folds higher than BMMSC. The protein level of LAMA1 was higher but the protein level of COL4A1 was lower in LNC than that in BMMSC. Conclusion: LNC exhibit differential gene expression from BMMSC in the extracellular matrix (ECM) receptor interaction pathway and Wnt signaling pathway, suggesting that LNC have their unique signaling pathways to support limbal stem cell niches.

Eye drops and eye gels of levofloxacin: comparison of ocular absorption characterizations and therapeutic effects in the treatment of bacterial keratitis in rabbits.

The aim was to reveal the characteristic profiles of the marketed levofloxacin eye drops (5 mg/ml) and levofloxacin eye gel (3 mg/g) from the pharmacokinetics and pharmacodynamics views of rabbits' eyes. A mild and a heavy bacterial keratitis models in rabbits were established. Different regimens of levofloxacin eye drops and eye gel, including phosphate buffer solution (the PBS group), the 4-Sol + 1-Gel group (rabbits were treated with 4 doses of levofloxacin eye drops and 1 dose levofloxacin eye gel per day), the 3-Sol + 1-Gel group (3 doses drops and 1 dose gel), the 4-Sol group (4 doses drops), the 4-Gel group (4 doses gel), the 3-Sol group (3 doses drops), and the 3-Gel group (3 doses gel), were applied to evaluate their efficacies. The ocular pharmacokinetics of levofloxacin eye drops and gel were also investigated. The results of mild infection groups showed that all treatment regimens significantly relieved the infection symptoms, and the treatment effect followed this order: 4-Gel > 4-Sol + 1-Gel > 3-Sol + 1-Gel > 4-Sol > 3-Gel > 3-Sol. In the heavy infection groups, all the treatment regimens significantly relieved the infection symptoms, and the treatment effect also followed the order with the mild infection results. All treatment regimens lowered the number of corneal colony forming units (CFU). Levofloxacin eye gel significantly increased intraocular penetration in rabbits' eyes. It can be concluded that the levofloxacin eye gel was more effective in treating bacterial keratitis than the levofloxacin eye drops in rabbit keratitis model with a proper treatment regimen such as 4-Gel.

HLA-C*12:02 is strongly associated with Xuesaitong-induced cutaneous adverse drug reactions.

Xuesaitong (XST) is mainly used to treat cardiovascular and cerebrovascular diseases, sometimes causing cutaneous adverse drug reactions (cADRs) with unknown mechanisms of pathogenicity or risk factors. We aimed to verify whether human leukocyte antigen (HLA) alleles are associated with XST-related cADRs in Han Chinese population. We carried out an association study including 12 subjects with XST-induced cADRs, 283 controls, and 28 XST-tolerant subjects. Five out of 12 patients with XST-induced cADRs carried HLA-C*12:02, and all of them received XST via intravenous drip. The carrier frequency of HLA-C*12:02 was significantly high compare to that of the control population (Pc = 4.4 × 10-4, odds ratio (OR) = 21.75, 95% CI = 5.78-81.88). Compared with that of the XST-tolerant group, the patients who received XST through intravenous drip presented a higher OR of cADRs (Pc = 0.011, OR = 27.00, 95% CI = 2.58-282.98). The results suggest that HLA-C*12:02 is a potentially predictive marker of XST-induced cADRs in Han Chinese, especially when XST is administered via intravenous drip.

Serum uric acid levels and risk of prehypertension: a meta-analysis.

Elevated serum uric acid (SUA) levels may increase the risk of prehypertension. However, the findings from these studies remain conflicting. The objective of this study was to determine the relationship between SUA levels and risk of prehypertension by conducting a meta-analysis. We conducted a comprehensive literature search of PubMed, Embase, China National Knowledge Infrastructure, VIP, and the Wangfang database without language restrictions through May 2015. Observational studies assessing the relationship between SUA levels and prevalence of prehypertension were included. Pooled adjust odds ratio (OR) and corresponding 95% confidence intervals (CI) of prehypertension were calculated for the highest vs. lowest SUA levels. Prehypertension was defined as systolic blood pressure (BP) ranging from 120 to 139 mmHg or diastolic BP ranging from 80 to 89 mmHg. Eight cross-sectional studies with a total of 21,832 prehypertensive individuals were included. Meta-analysis showed that elevated SUA levels were associated with increased risk of prehypertension (OR: 1.84; 95% CI: 1.42-2.38) comparing the highest vs. lowest level of SUA levels. Subgroup analyses showed that elevated SUA levels significantly increased the risk of prehypertension among men (OR: 1.60; 95% CI: 1.12-2.21) and women (OR: 1.59; 95% CI: 1.17-2.16). Elevated SUA levels are positively associated with the risk of prehypertension in the general population. However, more well-designed longitudinal studies are needed before a definitive conclusion can be drawn due to the cross-sectional studies included are susceptible to bias.

HLA-A*02 alleles are associated with tetanus antitoxin-induced exanthematous drug eruptions in Chinese patients.

OBJECTIVE: Tetanus antitoxin (TAT) is an effective antitetanus medicine, but may sometimes cause adverse drug reactions such as rapid-onset anaphylactic shock and late-onset cutaneous adverse drug reactions, including exanthematous drug eruptions (EDE). Human leukocyte antigen (HLA) class I alleles are strongly associated with different types of cutaneous adverse drug reactions. This study aimed to assess whether there is an association between TAT-induced EDE and HLA-A, HLA-B, and HLA-C alleles in the Chinese Han population. PATIENTS AND METHODS: We carried out an association study in 15 patients with TAT-induced EDE and two groups of general Han Chinese patients. Allele-level genotypes of the HLA-A, HLA-B, and HLA-C genes of each patient were determined using the PCR-sequence-specific oligonucleotides method. RESULTS: The carrier frequency of HLA serotype A2 was significantly higher in the TAT-induced EDE patients than in the general Han Chinese study participants from the human major histocompatibility complex database [n=283, odds ratio (OR)=6.93; P=0.0061]. Particularly, the carrier frequency of three A2 alleles, including HLA-A*02:01, HLA-A*02:06, and HLA-A*02:07, is significantly higher than that of the control group (OR=14.40; P=2.4×10). Furthermore, HLA-B*39:01 was in complete linkage disequilibrium with HLA-A*02:06 in the case patients. Consequently, the distribution of the HLA-A*02:06/-B*39:01 haplotype was also significantly different in the cases and the controls (OR=105.00; P=0.0024). CONCLUSION: The HLA-A*02:06/-B*39:01 haplotype is a potential genetic marker for the TAT-induced EDE. Furthermore, the HLA-A2 serotype, especially three alleles A*02:01, A*02:06, and A*02:07, was identified to be associated with the TAT-induced EDE in the Han Chinese population for the first time.

Water solubility differentiates the impact of tea polyphenols and rutin on the postprandial glycemic response to cooked maize starch.

Postprandial hyperglycemia is an independent risk factor for cardiovascular diseases, and the impact of tea polyphenols (TP) and rutin, representative phenolic compounds with different water solubilities, on the postprandial glycemic response to cooked normal corn starch (CCS) was investigated. Comparatively, TP (DPPH50 = 0.12 mmol L-1) are more potent than rutin (DPPH50 = 0.50 mmol L-1) in scavenging the free radicals of DPPH, but both TP and rutin inhibited the activity of porcine pancreatic α-amylase (PPA), the major enzyme in starch digestion, with an IC50 of 4.09 mmol L-1 and 2.71 mmol L-1, respectively. However, an in vivo study showed that a significant reduction in postprandial blood glucose was only observed in the presence of rutin, and TP had no effect on the glycemic response to CCS. To find out the underlying mechanism, fluorescence spectroscopy and molecular docking were carried out and they showed that, compared to TP, rutin bound to the active site of PPA with higher affinity and a lower free energy (ΔG) driven by hydrogen bonds and π-stacking, and rutin also greatly increased the viscosity of starch. Collectively, water-soluble TP have a higher antioxidant property and a lower potency to inhibit PPA compared to water-insoluble rutin, and the weaker interaction between TP and PPA, and starch as well might synergistically contribute to TP's ineffectiveness in lowering the postprandial glycemic response, and water solubility linking the molecular structures and functions of phenolic compounds might be the fundamental basis for the observed difference in their biological functions, and water solubility can also be used to enrich specific phenolic compounds for desired functions.

The work status of nurses in long-term care institutions in elderly care: A qualitative descriptive study.

AIM: To understand the work status of nurses in long-term care institutions in China for elderly care to provide a reference for further formulating management strategies and promoting the development of long-term care teams. METHODS: Using qualitative descriptive research methods, 31 nurses from three long-term care institutions were selected through purposive sampling for in-depth interviews, and a three-week participatory observation was conducted on the daily work of nurses in the above three long-term care institutions. Content analysis was used to analyse data. RESULTS: In our sample, nurses in long-term care institutions had insufficient manpower, generally had low academic qualifications, and lacked professional ability. Their work enthusiasm and initiative need to be further improved. Long-term care nurses were moderately paid, and their salary satisfaction was lower than in other trades. At the same time, the social understanding of the long-term care industry was insufficient, and the social identity of nurses in long-term care institutions was low. CONCLUSION: The development of long-term care requires the joint efforts of nurses, medical institutions, and society. By improving the system, cultivating talents and building a harmonious atmosphere, we aim to enhance the work enthusiasm of long-term care nurses and promote the stable and orderly development of the long-term care team. IMPLICATIONS FOR NURSING MANAGEMENT: Nurses in long-term care institutions are at the core of the ageing age and play a vital role in coping with the ageing problem, meeting long-term care needs, improving the quality of life of old people and reducing the cost of long-term care. The training and management of nurses in long-term care institutions and the construction of the entire long-term care system should be based on China's national conditions and actual needs.

A D-Shaped SPR-Based PCF Sensor with an Extremely High-Amplitude Sensitivity for Measuring the Refractive Index.

In this work, a new D-shaped photonic crystal fibre sensor structure based on surface plasmon resonance (SPR) is purposed for measurement of analyte refractive index (RI). In this design, a silica cylinder is polished into a D-shaped silica material structure with a flattened surface where two Au nanowires are coated. Some air holes are omitted to form the core mode region. With the implementation of gold nanowires and a core region for the exciting SPR effect with variate physical values, analyte RI can be measured with a wavelength coverage from 850 to 1350nm. The numerical simulation shows the maximum wavelength sensitivity of the purposed design achieves 19,600nm/RIU with an RI coverage from 1.37 to 1.42. Moreover, the sensor has a tremendous amplitude sensitivity and the maximum absolute value is about 2300RIU-1. Benefiting from these outstanding performance, the purposed structure can be given priority when it is applied in biomedical detecting and environmental assessment science.

Research progress into the application of Mycobacterium phlei in veterinary medicine.

Mycobacterium phlei is a gram-positive acid-fast mycobacterium from the family Mycobacteriaceae. It is a valuable resource for both natural drugs and microecological preparations. It has been widely used in the field of human medicine; however, in the field of animal husbandry and veterinary medicine, the research and application of M. phlei is still in the preliminary exploration stage. This study aims to summarize the research progress of M. phlei in the field of veterinary medicine and provide a valuable reference for future research. Key words, such as 'M. phlei', 'veterinary field', 'immune balancer', 'genome' and other relevant words to this study, were used to search through PubMed, Web of Science, SciELO, Science Direct and Google Scholar databases. The results showed that the culture conditions of M. phlei were relatively simple, but its bacterial composition and genome sequence were relatively complex, and various components in the cell wall may have immunoregulatory effects. Therefore, the inactivated preparation made from M. phlei can have various applications in the veterinary field, such as growth regulation, immune regulation, antitumour, anti-parasite and asthma treatment. The literature review indicates that M. phlei preparation is an efficient and convenient immune system balance agent. Despite the challenges associated with the use of M. phlei preparations, it has a strong potential for application in veterinary medicine.

An association study of HLA with levofloxacin-induced severe cutaneous adverse drug reactions in Han Chinese.

Levofloxacin-induced severe cutaneous adverse drug reactions (LEV-SCARs) remain unexplored. An association study of human leukocyte antigen (HLA) alleles with LEV-SCARs among 12 patients, 806 healthy subjects, and 100 levofloxacin-tolerant individuals was performed. The carrier frequencies of HLA-B∗13:01 (odds ratio [OR]: 4.50; 95% confidence interval [CI]: 1.15-17.65; p = 0.043), HLA-B∗13:02 (OR: 6.14; 95% CI: 1.73-21.76; p = 0.0072), and serotype B13 (OR: 17.73; 95% CI: 3.61-86.95; p = 4.85 × 10-5) in patients with LEV-SCARs were significantly higher than those of levofloxacin-tolerant individuals. Molecular docking analysis suggested that levofloxacin formed more stable binding models with HLA-B∗13:01 and HLA-B∗13:02 than with non-risk HLA-B∗46:01. Mass spectrometry revealed that nonapeptides bound to HLA-B∗13:02 shifted at several positions after exposure to levofloxacin. Prospective screening for serotype B13 (sensitivity: 83%, specificity: 78%) and alternative drug treatment for carriers may significantly decrease the incidence of LEV-SCARs.

Construction of a Model of Nurse Engagement in Long-Term Care Facilities: A Moderated-Mediation Model.

Aim: The aim of the study is to test a moderated mediation model that focuses on job resources mediating the relationship between organizational climate and nurse engagement in the long-term care facilities and emotional intelligence moderates this mediated relationship. Background: The shortage of nurses is a global problem, especially in the long-term care facilities. We integrated and extended past research exploring the influence of nurse engagement and constructed a model of nurse engagement in the long-term care facilities. Method: A cross-sectional survey was conducted on 494 nurses in long-term care facilities. Nurses were asked to complete a survey of nurse engagement, organizational climate, job resources, and emotional intelligence. Results: The consequence demonstrated that organizational climate increased nurse engagement directly and indirectly via job resources. In addition, emotional intelligence plays a moderation role between organizational climate and job resources. Conclusion: These phenomena revealed that a good organizational climate and job resources enable nurses to be more engaged in work. Nurse with high-emotional intelligence can take advantage of resources and improve their engagement.

Chronic Pain and Quality of Life in Maintenance Hemodialysis Patients in China: A Multicenter, Cross-Sectional Study.

PURPOSE: Patients undergoing maintenance hemodialysis (MHD) frequently experience chronic pain, which can severely affect their quality of life (QOL). The objective of this study was to evaluate the prevalence of chronic pain in MHD patients and examine the factors associated with QOL. PATIENTS AND METHODS: A cross-sectional questionnaire-based survey was conducted between October 2020 and April 2021, 1204 MHD patients from nine hemodialysis units were screened for chronic pain in Chengdu, China, and 296 MHD patients with chronic pain were enrolled in this study. We analyzed data on clinicodemographic characteristics, pain interference and severity (Brief Pain Inventory), QOL (Medical Outcomes Study 36-item Short Form Health Survey - mental component summary [MCS] and physical component summary [PCS]), pain self-efficacy (Pain Self-Efficacy Questionnaire), and social support (Social Support Rating Scale). RESULTS: The prevalence of chronic pain in MHD patients was 26.74% in this study. The most common areas of pain were lower back (63.5%), lower limbs (55.0%), and head (33.5%), 36.5% did not implement any measures to relieve it. Of the patients who did receive pain treatment or medication, 56.9% reported that the measures they took had less than half of the pain relief. MHD patients with chronic pain had poor QOL based on scores on the MCS (53 ± 16.76) and PCS (40.56 ± 13.81). Stepwise multiple regression identified age, financial strain, pain interference, social support, and pain self-efficacy as independent predictors of QOL. Pain self-efficacy was significantly associated with social support (r = 0.5, p < 0.01), MCS (r = 0.69, p < 0.01), and PCS (r = 0.8, p < 0.01). The mediating effects of pain self-efficacy were 70.31% on the relationship between social support and MCS, and 75.62% on the relationship between social support and PCS. CONCLUSION: Chronic pain is prevalent and undermanaged in Chinese MHD patients, resulting in worse QOL. Healthcare providers should focus on pain management and the impact of psychosocial factors on patient QOL. Further research should deepen our understanding of how pain self-efficacy mediates the relationship between social support and QOL.

Room temperature DMMP gas sensing based on cobalt phthalocyanine derivative/graphene quantum dot hybrid materials.

In this study, two kinds of cobalt phthalocyanine (CoPc) derivatives containing hexafluoroisopropanol (HFIP) and hexafluorbisphenol A (6FBPA) substituents have been obtained. Graphene quantum dots (GQDs) were anchored to CoPc derivatives by π-π bonding, forming hybrid materials. They were employed to detect dimethyl methylphosphonate (DMMP) gas, an ideal simulant gas for sarin nerve gas, and achieved good gas response performance at room temperature. There are strong hydrogen bonds between the two functional group molecules (HFIP and 6FBPA) and the DMMP molecule, leading to their excellent response performance to DMMP molecules. GQDs can effectively increase the electrical conductivity of hybrid materials by π-π bonding with CoPc derivatives. Therefore, the response speed of the hybrid materials to DMMP gas has been significantly improved, and the minimum detection limit is 500 ppb, while maintaining excellent repeatability, stability and selectivity. Laser-assisted irradiation was used to solve the problem of the slow recovery of CoPc derivatives. This result demonstrates that these CoPc derivative/GQD hybrid materials are expected to be the raw materials of the sarin gas sensor.

Opening the Soul Window Manually: Limbal Tissue Scaffolds with Electrospun Polycaprolactone/Gelatin Nanocomposites.

Restricted by the difficulty in fabricating scaffolds suitable for cell proliferation, the use of ex vivo expanded limbal stem cell (LSC) for LSC transplantation, an effective treatment method for patients with limb stem cell deficiency (LSCD), is hard to be widely used in clinical practice. To tackle these challenges, a novel electrospun polycaprolactone (PCL)/gelatin nanocomposite is proposed to make 3D scaffolds for limbal niche cells (LNC) proliferation in vitro, which is a milestone in the treatment of diseases such as LSCD. PCL and gelatin in different weight ratios are dissolved in a mixed solvent, and then electrospinning and cross-linking are performed to prepare a scaffold for cell proliferation. The characterizations of the nanocomposites indicate that the gelatin content has a significant effect on its micro-morphology, thermal properties, crystallinity, degradation temperature, hydrophilicity, and mechanical properties. P8G2-C (PCL: gelatin = 80: 20, cross-linked), with smooth fibers and homogeneous pores, has better hydrophilicity, mechanical properties, and flexibility, so it can support LNC as cell proliferation assays revealed. This detailed investigation presented here demonstrates the feasibility of using PCL/gelatin nanocomposites electrospun fiber membranes as a limbus tissue engineering scaffold, which undoubtedly provide a new perspective for the development of tissue engineering field.

Foxp3 enhancers synergize to maximize regulatory T cell suppressive capacity.

T reg cells bearing a diverse antigen receptor repertoire suppress pathogenic T cells and maintain immune homeostasis during their long lifespan. How their robust function is determined genetically remains elusive. Here, we investigate the regulatory space of the cis-regulatory elements of T reg lineage-specifying factor Foxp3. Foxp3 enhancers are known as distinct readers of environmental cues controlling T reg cell induction or lineage stability. However, their single deficiencies cause mild, if any, immune dysregulation, leaving the key transcriptional mechanisms determining Foxp3 expression and thereby T reg cell suppressive capacity uncertain. We examined the collective activities of Foxp3 enhancers and found that they coordinate to maximize T reg cell induction, Foxp3 expression level, or lineage stability through distinct modes and that ablation of synergistic enhancers leads to lethal autoimmunity in young mice. Thus, the induction and maintenance of a diverse, stable T reg cell repertoire rely on combinatorial Foxp3 enhancers, suggesting broad, stage-specific, synergistic activities of cell-intrinsic factors and cell-extrinsic cues in determining T reg cell suppressive capacity.