A Modular Cataract Surgery Training Model Incorporating Human Factors and a Pedagogical Theory.

Synopsis: High volume cataract lists are cost-effective, reduce waiting times, and facilitate surgical teaching. We propose a stepwise training model that incorporates human factor principles and a reflective pedagogical approach, which has not been documented previously. Background/Aims: Surgical training in ophthalmology is effective when a modular approach is utilised. High volume lists further enhance training by increasing exposure to a newer way of learning and working. We evaluated the efficiency and safety of trainee-assisted cataract surgery across a single NHS eye unit and an independent sector (IS) provider. Methods: We examined results from audits of surgical efficiency and safety in trainee-assisted high-volume lists, including a single-centre comparative evaluation of consultant-only and trainee lists. The quantitative and qualitative information gained from these projects helped us to implement a modular, structured training programme that utilises a reflective cycle of pedagogy, suitable for any grade of trainee. Results: Our projects included an audit following cataract surgery performed by a surgical trainee over a 5-month period, which showed excellent post-op refractive results and no cases of intra-operative and post-operative complications. A single-centre observational study demonstrated comparable surgical throughput and safety results for trainee and solo consultant high volume lists. Systemic and ocular complication rates were reported to be similar for low and medium risk cataract surgery among trainee supervised IS and NHS lists. Conclusion: Cataract surgery outcomes and patient feedback support the effectiveness of the surgical training model. Combining Gibbs' reflective cycle of critical reflection with the International Council of Ophthalmology's principles helped us to develop the QM Model of modular teaching for cataract surgery, which we believe is suitable for utilisation in all surgical centres in the NHS and IS settings, for both low volume and high-volume surgical lists regardless of trainee experience.

What Is Already Known on This Topic High volume lists are increasingly popular for cataract surgery; however, trainee exposure to high flow cataract surgery lists is limited. What This Study Adds A modular approach to training via high volume training lists is possible.Origination and implementation of a stepwise cataract surgery training model that incorporates human factors and a pedagogical learning approach within high volume lists in the independent sector and NHS setting. How This Study Might Affect Research, Practice, or Policy Promote the widespread adoption of the QM model which integrates modular-based experiential learning approaches for surgical training in both NHS and independent sector settings, applicable to low and high volume surgical lists, irrespective of trainee experience.

Endogenous Bone Marrow-Derived Stem Cell Mobilization and Homing for In Situ Tissue Regeneration.

In mammals, post-injury repair and regenerative events rely predominantly on stem cell function. Stem cell transplantation has achieved considerable success in animals but remains unfavorable for humans because of the unavoidable drawbacks. Nevertheless, substantial evidence suggests the regenerative potential of endogenous stem cells can be improved for functional and structural recovery of tissue damage or in disease conditions. Endogenous stem cells are mostly quiescent under steady-state conditions and reside in their niche. Once faced with tissue injury, physiological and molecular changes within the niche or from distant tissues activate the migration, proliferation, and differentiation of stem cells, contributing to tissue repair. Tissue regeneration is augmented by artificially amplifying the factors that promote stem cell mobilization or enhance the homing of endogenous stem cells. This cell-free strategy, known as "in situ tissue regeneration," represents a safer and more efficient means to conduct tissue regeneration. Bone marrow (BM) is considered the central niche and main reservoir of many types of stem cells. These stem cells hold great therapeutic potential for the regeneration of multiple injured tissues. Herein, we review recent strategies for promoting in situ tissue regeneration through BM-derived stem cell mobilization or homing in animal models as well as in human trials. With the advancement in biomaterial engineering, chemoattractant signals combined with functionalized bioscaffolds have accomplished sustained activation of endogenous BM-derived stem cells that can be used as an attractive strategy for efficient in situ tissue regeneration.

Fascia Promotes Adipose Tissue Regeneration by Improving Early Macrophage Infiltration after Fat Grafting in a Mouse Model.

BACKGROUND: Low early macrophage fat graft infiltration (within a week of surgery) hinders tissue regeneration, suggesting that macrophages play a vital role in early angiogenesis and adipogenesis. However, the source of macrophages during this period is unclear. METHOD: C57BL/6 mice were split into fascial removal (FR) group and control groups (CG). Mice had a piece of back fascia removed in the FR group, which was immediately replaced in the CG, and inguinal fat injected into the transplantation site of both groups. Separately, fascia was harvested from green fluorescent protein-expressing mice and transplanted into C57BL/6 mice for tracing macrophage infiltration after fat grafting. RESULTS: The number of capillaries in the FR group was lower than that in the CG at days 3 ( P < 0.01) and 7 ( P < 0.05). Moreover, the number of small adipocytes in the FR group was lower than in the CG on days 3, 7, and 14 (all P < 0.05), and the relative expression of several adipogenic proteins was significantly lower in the FR group than in the CG on days 14 and 30. The timeline of macrophage infiltration was consistent with angiogenesis and adipogenesis. The number of macrophages in the FR group was significantly lower than in the CG at days 3 and 7 ( P < 0.05), and there were more fascia-derived macrophages than circulation-derived macrophages infiltrated into fat grafts within 7 days. Finally, the graft retention was lower in the FR group than the CG at day 90 ( P < 0.05). CONCLUSION: In the early stage after fat grafting, fascial macrophage infiltration initiates tissue regeneration, thereby improving graft retention by promoting angiogenesis and adipogenesis. CLINICAL RELEVANCE STATEMENT: In the clinic, injecting fat close to the fascia may increase fat retention. Fascia is widespread and self-regenerating, which may be a promising alternative source of local macrophages, with implications for tissue-engineering therapies such as correction of soft-tissue defects and breast reconstruction.

Early Angiogenesis-Dependent CXCL12 Attracts Adipose-Derived Stem Cells to Promote the Repair of Fat Grafting in a Mouse Model.

BACKGROUND: The unpredictable and unstable tissue retention rate of autologous fat grafting remains an obstacle faced by plastic surgeons. The authors' previous study using a fat grafting mouse model with donor sites showed that adipose-derived stem cell (ASC) infiltration in the recipient site was delayed, leading to poor regeneration and lower retention. Thus, the mechanism behind the differential infiltration of ASCs needed to be explored. METHODS: First, the authors locally injected C-X-C chemokine ligand 12 (CXCL12) or C-X-C motif chemokine receptor 4 (CXCR4) inhibitor AMD3100 in the recipient or donor site, respectively (CXCL12 + AMD3100 - , CXCL12 - AMD3100 + , and CXCL12 + AMD3100 + groups). The authors compared the migration of ASCs, adipose regeneration, and long-term retention. Next, the authors explored the role of angiogenesis using a normal/ischemic mice model in which the authors test the expression of CXCL12/CXCR4, migration of ASCs, and adipose regeneration. RESULTS: Blocking CXCL12 in the donor site using AMD3100 (CXCL12 - AMD3100 + and CXCL12+AMD3100+ groups) could accelerate ASC infiltration and promote adipose regeneration and long-term retention ( P < 0.05) compared with the other groups. CXCL12 and its receptor CXCR4 were more highly expressed in normal than in ischemic adipose tissue; consistently, there were more ASCs infiltrating normal than ischemic adipose tissue early after surgery ( P < 0.05). CONCLUSION: Early angiogenesis is essential for CXCL12 in promoting ASC infiltration, improving adipose tissue repair in the recipient site, and potentiating the long-term fat retention rate. CLINICAL RELEVANCE STATEMENT: The authors provide a proof-of-concept way to improve the outcomes of fat grafting by locally injecting AMD3100, also known as plerixafor, to the donor site.

The Danger of Laser Pointer-Induced Retinal Damage in Children: A Large United Kingdom Case Series and Survey of Public Awareness.

PURPOSE: To explore the clinical features of laser pointer-related retinal injuries among children and gain insight into the general public awareness around laser pointer use. METHODS: This was a retrospective case series of 9 children (12 eyes) with laser pointer-related retinal injury from a United Kingdom tertiary ophthalmology unit and a prospective survey of laser pointer use and awareness among children and parents presenting to the hospital eye service for other eye conditions. RESULTS: Within the case series, 67% of patients were asymptomatic on presentation. A mean follow-up of 25.6 months showed that structural changes persisted in all cases, and in one case, there was progression in the macular lesion size. One case presented with secondary choroidal neovascular membrane, requiring intravitreal anti-vascular endothelial growth factor injections. A survey showed that 9% of children admitted to having played with laser pointers and 13% of parents were aware of their children playing with laser pointers. Only one-third of children and parents were aware of laws regulating laser pointers. Most parents (96%) agreed that there needs to be increased awareness regarding laser pointers' effect on vision. CONCLUSIONS: This study has highlighted that although children may be asymptomatic at presentation, there is usually permanent structural damage to the macula, and complications such as secondary choroidal neovascular membrane can develop years later. The survey found a relatively high incidence of laser pointer use with little awareness of the regulation laws. There is an urgent need to establish more robust measures to improve public awareness and regulations around laser pointers. [J Pediatr Ophthalmol Strabismus. 2023;60(1):52-59.].

Density-Based High-Quality Fat: Characterization and Correlation with Different Body Fat Ratio.

BACKGROUND: Lipoaspirate can be divided into high-quality fat and low-quality fat using Coleman's centrifugation by adding 0.935 g/ml marker float; the ratio obtained by different individuals is different. OBJECTIVES: This study aimed to examine the HQF obtained from different individuals and establish the relationship between individual body data and HQF. METHODS: We used Coleman's centrifugation method (1200 g, 3 min) with 0.935 g/ml density float to process lipoaspirate and collect HQF from different individuals for the analysis of fat characteristics and in vivo grafting. RESULTS: The HQF obtained from different individuals had similar stromal vascular fraction cell numbers and extracellular matrix content. In animal experiments at different time points (especially 12 weeks), the appearance, retention rate, hematoxylin and eosin staining, and immunohistochemistry results of HQF grafts were similar, while being different from those of Coleman fat. The HQF obtained from individuals with higher body fat ratio was less than those with lower body fat ratio. Following the establishment of the relationship between high-quality fat percentage and the body fat ratio of the donors, we proposed an innovative calculation formula model for the required lipoaspirate. CONCLUSIONS: HQF obtained from different individuals has similar fat characteristics, transplantation process, and outcome. The HQF percentage obtained from different individuals is negatively correlated with the body fat ratio. The amount of liposuction can be predicted using the proposed formula and improve the predictability of fat transplantation. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Alternatively activated macrophages at the recipient site improve fat graft retention by promoting angiogenesis and adipogenesis.

The inflammatory response mediated by macrophages plays a role in tissue repair. Macrophages preferentially infiltrate the donor site and subsequently, infiltrate the recipient site after fat grafting. This study aimed to trace host-derived macrophages and to evaluate the effects of macrophage infiltration at the recipient site during the early stage on long-term fat graft retention. In our novel mouse model, all mice underwent simulated liposuction and were divided into 2 groups. The fat procurement plus grafting (Pro-Grafting) group was engrafted with prepared fat (0.3 ml). The pro-Grafting+M2 group was engrafted with prepared fat (0.3 ml) mixed with 1.0 × 106 GFP+M0 macrophages, and then, 2 ng IL-4 was injected into the grafts on Day 3. In addition, 1.0 × 106 GFP+M0 macrophages were injected into the tail vein for tracing in the Pro-Grafting group. As a result, GFP+macrophages first infiltrated the donor site and subsequently infiltrated the recipient site in the Pro-Grafting group. The long-term retention rate was higher in the Pro-Grafting+M2 group (52% ± 6.5%) than in the Pro-Grafting group (40% ± 3.5%). CD34+ and CD31+ areas were observed earlier, and expression of the adipogenic proteins PPAR-γ, C/EBP and AP2 was higher in the Pro-Grafting+M2 group than in the Pro-Grafting group. The host macrophages preferentially infiltrate the donor site, and then, infiltrate the recipient site after fat grafting. At the early stage, an increase in macrophages at the recipient site may promote vascularization and regeneration, and thereby improve the fat graft retention rate.

Tumor protein D52 promotes breast cancer proliferation and migration via the long non-coding RNA NEAT1/microRNA-218-5p axis.

BACKGROUND: Breast cancer is an aggressive disease with high morbidity and mortality rates among women globally. Tumor protein D52 (TPD52) is an oncogene in breast cancer; however, its physiological function remains elusive. This study set out to obtain a deeper understanding of the functions of TPD52 in the pathophysiology of breast cancer by exploring its effects on breast cancer cell proliferation and migration. METHODS: Bioinformatics analysis was performed to predict the bonding of TPD52 and nuclear paraspeckle assembly transcript 1 (NEAT1) with miR-218-5p. The bonding of TPD52 and NEAT1 with miR-218-5p were verified by luciferase reporter assays. The mRNA expression of TPD52, miR-218-5p or NEAT1 were tested by Rt-qPCR and the protein expression of TPD52 was tested by western blot. Colony formation and EdU assays were carried out to evaluate cell proliferation. Wound healing and Transwell assays were used to evaluate migration. RESULTS: In this study, TPD52 was upregulated in breast cancer cells, and silencing of TPD52 repressed the proliferation and migration of breast cancer cells in vitro and in vivo. Further, microRNA (miR)-218-5p reduced the expression level of TPD52, while overexpression of TPD52 attenuated the effects of miR-218-5p mimics on breast cancer cell proliferation and migration. Also, NEAT1 acted as a competitive endogenous sponge of miR-218-5p to downregulate free miR-218-5p levels. It was further observed that TPD52 overexpression recovered the inhibition of breast cancer cell growth and migration caused by NEAT1 downregulation. These results confirmed the functions of NEAT1 in breast cancer and supported the mechanism of the NEAT1/miR-218-5p/TPD52 axis. CONCLUSIONS: Our findings highlight the important role of the NEAT1/miR-218-5p/TPD52 axis in breast cancer cell proliferation and migration. This axis may be a potential therapeutic target for breast cancer.

The Association between Foveal Floor Measurements and Macular Hole Size.

PURPOSE: Determining which factors influence idiopathic macular hole (MH) size is important because it is a major prognostic indicator of treatment success. Foveal pit morphologic features are highly symmetrical within individuals and may influence idiopathic MH size. Using a series of patients with unilateral idiopathic MHs, we examined the foveal floor size of the fellow eye to evaluate its relationship with idiopathic MH size and postoperative outcomes. DESIGN: Retrospective observational study. PARTICIPANTS: Two hundred forty-one participants with a unilateral idiopathic MH treated with surgery and a fellow eye with no ocular pathologic features. METHODS: Both eyes underwent spectral-domain (SD) OCT imaging at the time of surgery. Minimum linear diameter (MLD) and base diameter (BD) defined idiopathic MH size. Foveal floor width (FFW) and minimal foveal thickness defined foveal pit morphologic features of the fellow eye. MAIN OUTCOME MEASURES: Baseline characteristics, SD OCT measurements, and preoperative variables were compared to determine their relationship with idiopathic MH size and postoperative visual acuity (VA) in logarithm of the minimum angle of resolution units. RESULTS: Foveal floor width was correlated with MLD (r = 0.36; P ≤ 0.001) and BD (r = 0.30; P ≤ 0.001), but not postoperative VA. Minimum linear diameter correlated with preoperative VA (r = 0.49; P ≤ 0.0001) and postoperative VA (r = 0.54; P ≤ 0.0001). A 2-stage regression model was developed to predict postoperative VA (r2 = 0.28): preoperative VA (ß = 0.36; P = 0.002) explained 13% of variability and MLD (ß = 0.29; P = 0.002), and idiopathic MH duration (ß = 0.23; P = 0.004) explained a further 16%. CONCLUSIONS: Foveal floor width of the fellow eye in patients with a unilateral idiopathic MH was correlated significantly with idiopathic MH size and may explain some of the variability in idiopathic MH size observed between individuals. However, FFW could not predict postoperative vision.

Effects of whole globe enucleation versus in situ corneoscleral excision on donor cornea tissue quality: a systematic review protocol.

OBJECTIVE: The objective of this review is to systemically compare the effects of whole globe enucleation versus in situ corneoscleral excision on donor cornea tissue quality. INTRODUCTION: Corneal transplantation serves as a sight-restoring surgery for corneal diseases, but the treatment is limited by the persistent shortage of donor corneas globally. Whole globe enucleation and in situ corneoscleral excision are the two methods for eye retrieval. Although studies have reported a higher acceptance rate for corneal donation among donors' relatives with in situ corneoscleral excision than whole globe enucleation, there are concerns regarding the impact on donor cornea tissue quality with in situ corneoscleral excision. Currently, there is limited high-quality evidence comparing the two methods. INCLUSION CRITERIA: We will consider prospective and retrospective comparative studies that examine the effects of whole globe enucleation and in situ corneoscleral excision on donor cornea tissue quality. There will be no restrictions on the recipients' characteristics, including age, sex, ocular comorbidities, or potential visual acuity after corneal transplantation. METHODS: Electronic databases, including (but not limited to) MEDLINE, Embase, Cochrane CENTRAL, ClinicalTrials,gov, and ISRCTN registry will be searched, with no restriction to the language used or date of publication. Retrieval of full-text studies, assessment of methodological quality, and data extraction will be performed independently by two reviewers. A meta-analysis, using fixed or random effects, will be performed for the included randomized controlled trials when there are sufficient similarities in the reporting of outcome measures. If meta-analysis is not possible, the pre-specified outcomes will be narratively synthesized. SYSTEMATIC REVIEW REGISTRATION NUMBER: PROSPERO (CRD42020210575).

Clinical evaluation of vitamin D status and its relationship with disease activity and changes of intestinal immune function in patients with Crohn's disease in the Chinese population.

BACKGROUND: High prevalence of vitamin D deficiency has been found among Crohn's disease (CD) patients. Vitamin D probably participates in the pathogenesis of CD, but this idea remains controversial. This study was to investigate the levels of vitamin D in CD patients and analyze the relationship between vitamin D and intestinal inflammation. METHODS: Vitamin D levels were measured by chemiluminescence immunoassay in 198 CD patients (96 in active, 102 in remission) and 100 healthy controls. The correlation between vitamin D levels and clinical parameters was analysed. The expression of intestinal tight junction (TJ) proteins in CD patients was measured by immunofluorescence staining. Treg and Th17 percentages in the peripheral blood were determined by flow cytometry. RESULTS: CD patients exhibited significantly lower 25(OH)D levels than healthy controls, especially in active CD patients. Serum 25(OH)D levels in CD patients were negatively correlated with the CD activity index (CDAI), the simple endoscopic score for CD (SES-CD), and inflammatory markers, including erythrocyte sedimentation rate (ESR), platelet (PLT) count and faecal calprotectin (FC) levels. Moreover, in patients with vitamin D deficiency, the expression of TJ proteins (Occludin, claudin-1, ZO-1 and JAM-1) in the intestinal mucosa was reduced, and Treg cells in the peripheral blood were decreased, while Th17 cells were increased compared to those with vitamin D sufficiency and controls. CONCLUSIONS: Vitamin D deficiency in CD patients is common. Vitamin D is associated with disease activity and intestinal inflammation, which may affect the Treg/Th17 balance and the expression of gut TJ proteins.

The effects of macrophage-mediated inflammatory response to the donor site on long-term retention of a fat graft in the recipient site in a mice model.

Inflammatory responses mediated by macrophages play a role in tissue repair. However, it is unclear whether the repair in the donor site after liposuction would have any effects on fat graft retention in the recipient site. This study is designed to evaluate the effects of a macrophage-mediated inflammatory response in donor sites on long-term retention of fat grafting. In this study, mice were randomly divided into two groups. One underwent simulated liposuction, called the fat procurement plus grafting (Pro-Grafting) group, and the other underwent sham surgery, called the fat grafting only (Grafting Only) group. The prepared fat (0.3 ml each) was engrafted and cellular events over a 90-day period were assessed. We found macrophages were infiltrated into adipose tissue at the recipient site in the Grafting Only group within 7 days and the repair essentially completed within 30 days. By contrast, few macrophages infiltrated the recipient site in the Pro-Grafting group within 7 days and the entire remodeling process took 30 days longer in the Pro-Grafting than the Grafting Only group. Moreover, C-reactive protein levels were immediately upregulated after surgery, and the inflammatory factors' expression was higher at the donor rather than the recipient site. However, the repair processes and the long-term retention rate became normal when the adipose tissue was grafted after the donor site did not require macrophages for repair. Therefore, we suggest higher inflammatory factors promote macrophage infiltration and the adipose tissue regeneration process at the donor site. This process is delayed at the recipient site, which may affect long-term retention of fat grafts.

Identification of High-Quality Fat Based on Precision Centrifugation in Lipoaspirates Using Marker Floats.

BACKGROUND: Centrifugation creates "graded densities" of fat with varying cellular and biological compositions that influence graft retention. This study aimed to find an accurate method to identify fat fractions that are suitable for implantation. METHODS: Five marker floats (0.925, 0.930, 0.935, 0.940, and 0.945 g/ml) were added to human lipoaspirates that were then centrifuged at 1200 g for 3 minutes to grade the density of centrifuged lipoaspirates. After centrifugation, four fat fractions divided by floats were collected for fat characteristics analysis and in vivo grafting, with Coleman fat as a control. RESULTS: Fat characteristics varied significantly between the centrifuged fat fractions divided by the 0.935-g/ml marker float. Compared with low-quality fat (<0.935 g/ml), high-quality fat (>0.935 g/ml) contains more stromal vascular fraction, adipose-derived stem cells, and extracellular matrix content. Furthermore, adipocytes were found to be significantly smaller in high-quality fat than in low-quality fat, and high-quality fat persisted at a greater volume compared with low-quality fat in vivo at week 12. CONCLUSIONS: High-quality fat contains more stromal vascular fraction cells, extracellular matrix content, and small adipocytes, leading to the highest implant volume retention, whereas low-quality fat contains more fragile large adipocytes, leading to the least volume retention. Marker floats can be used to grade the density of lipoaspirates, with fat greater than 0.935 g/ml recommended as a suitable alternative for implantation. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.

Effectiveness and safety of accelerated (9 mW/cm2) corneal collagen cross-linking for progressive keratoconus: a 24-month follow-up.

OBJECTIVES: To examine the effectiveness and safety of accelerated corneal collagen cross-linking (CXL) for keratoconus over a 24-month period and to explore potential prognostic factors for post-treatment visual outcome and progression. METHODS: A retrospective, non-comparative, interventional case series. All patients who underwent accelerated epithelium-off CXL, using 9 mW/cm2 ultraviolet-A irradiation for 10 min, for progressive keratoconus in Sunderland Eye Infirmary, UK, between May 2014 and July 2016 were included. All patients completed 24 months' post-CXL follow-up. Significant post-CXL progression of keratoconus was defined as >1 D increase in Kmax from preoperative to 24-month visit. RESULTS: Fifty-two eyes of 48 patients were included. At 24-month post-CXL, there was a significant improvement in corrected-distance visual acuity (CDVA; -0.05 LogMAR; p = 0.026), Kmax (-1.68 D; p < 0.001), K1 (-0.64 D; p = 0.002) and Kmean (-0.50 D; p = 0.009). The proportion of eyes with CDVA ≥ 0.3 LogMAR significantly improved from 43 (82.7%) eyes preoperatively to 50 (96.2%) eyes at 24 months (p = 0.026). Corneal haze (12, 23.1%) was the only postoperative complication and no adverse event was noted. Final CDVA was associated with lower CDVA (p = 0.002) and greater Kmax (p = 0.018) at baseline. Post-CXL progression of keratoconus was associated with greater preoperative Kmax (p = 0.12) and Kmean (p = 0.11), though statistical significances were not achieved. CONCLUSIONS: Accelerated CXL (9 mW/cm2) serves as an effective and safe treatment for halting the progression of keratoconus and stabilising the vision over a 24-month period. Our observation suggests that accelerated CXL might be more effective in stabilising keratoconus of milder severity; however further larger studies are required to elucidate this finding.

Sphingosine kinase 2 cooperating with Fyn promotes kidney fibroblast activation and fibrosis via STAT3 and AKT.

Sphingosine kinases (Sphks) are the rate-limiting enzymes in the conversion of sphingosine to biologically active sphingosine-1-phosphate. The present study aimed to determine the role of Sphk2 and its downstream targets in renal fibroblast activation and interstitial fibrosis. In the kidney interstitium of patients with renal fibrosis, Sphk2high-expressing cells (mainly interstitial fibroblasts) were significantly elevated and highly correlated with disease progression in patients. In a murine model of renal interstitial fibrosis, Sphk2 was upregulated in the kidney of wild-type mice in response to disease progression. Importantly, Sphk2-knockout (KO) mice exhibited significantly lower levels of extracellular matrix (ECM) production and a suppressed inflammatory response in the kidney tissues, compared to those in their wild-type counterparts, whereas the expression of TGF-ß1 was unaffected. TGF-ß1 effectively upregulated Sphk2 expression in the renal interstitial fibroblast line, NRK-49F, independent of canonical Smad signaling activation. Furthermore, siRNA-mediated Sphk2 knockdown or suppression of Sphk2 activity by ABC294640 exposure effectively attenuated AKT and STAT3 activation and ECM production, but had no effects on Smad2 and Smad3 activation. Sphk2 phosphorylated Fyn to activate downstream STAT3 and AKT, thereby promoting ECM synthesis. Therefore, our findings indicate that targeting Sphk2-Fyn-STAT3/AKT signaling pathway may be a novel therapeutic approach for renal fibrosis.

1,25-Dihydroxyvitamin D Protects Intestinal Epithelial Barrier by Regulating the Myosin Light Chain Kinase Signaling Pathway.

BACKGROUND: The myosin light chain kinase (MLCK) pathway controls intestinal epithelial barrier permeability by regulating the tight junction. 1,25-dihydroxyvitamin D (1,25(OH)2D3)-vitamin D receptor (VDR) signaling protects the epithelial barrier, but the molecular mechanism is incompletely understood. METHODS: MLCK activation and barrier permeability were studied using monolayers of HCT116, Caco-2, and SW480 cells treated with tissue necrosis factor α with or without 1,25(OH)2D3. The MLCK pathway was analyzed in normal and inflamed colonic biopsies from patients with ulcerative colitis. Colonic mucosal barrier permeability and MLCK activation were also investigated using trinitrobenzene sulfonic acid-induced colitis models in vitamin D analog paricalcitol-treated wild-type mice and mice carrying VDR deletion in colonic epithelial cells. RESULTS: Tissue necrosis factor α increased cell monolayer permeability and induced long isoform of MLCK expression and myosin II regulatory light chain (MLC) phosphorylation, and 1,25(OH)2D3 blocked tissue necrosis factor α-induced increases in monolayer permeability and MLCK-MLC pathway activation by a VDR-dependent fashion. 1,25(OH)2D3 directly suppressed long MLCK expression by attenuating NF-κB activation, and chromatin immunoprecipitation assays confirmed that 1,25(OH)2D3 disrupted p65 binding to 3 κB sites in long MLCK gene promoter. In human ulcerative colitis biopsies, VDR reduction was associated with increases in long MLCK expression and MLC phosphorylation. In trinitrobenzene sulfonic acid colitis models, paricalcitol ameliorated colitis, attenuated the increase in mucosal barrier permeability, and inhibited long MLCK induction and MLC phosphorylation. In contrast, mice with colonic epithelial VDR deletion exhibited more robust increases in mucosal barrier permeability and MLCK activation compared with wild-type mice. CONCLUSIONS: These data demonstrate that 1,25(OH)2D3-VDR signaling preserves the mucosal barrier integrity by abrogating MLCK-dependent tight junction dysregulation during colonic inflammation.

Critical roles of intestinal epithelial vitamin D receptor signaling in controlling gut mucosal inflammation.

Although vitamin D receptor (VDR) is highly expressed in the intestine, the role of VDR signaling in the gut is not fully understood. Our recent studies unveil a regulatory circuit that centers gut epithelial VDR as a key molecule in the control of mucosal inflammation and colitis development. On the one hand, intestinal epithelial VDR signaling protects the integrity of the mucosal barrier by inhibiting inflammation-induced epithelial cell apoptosis. This barrier-protecting, anti-colitic activity is independent of the non-epithelial immune VDR actions. A healthy and intact mucosal barrier prevents bacterial invasion and thus reduces mucosal inflammation. On the other hand, inflammation in turn down-regulates epithelial VDR expression by inducing VDR-targeting microRNA-346, thus compromising mucosal barrier functions. Consistently, colonic epithelial VDR levels are markedly reduced in patients with inflammatory bowel diseases or in experimental colitis models, whereas vitamin D analog therapy that ameliorates colitis up-regulates epithelial VDR. Thus, gut epithelial VDR signaling appears to play an essential role in controlling mucosal inflammation and thus could be a useful therapeutic target in the management of inflammatory bowel diseases. This article is part of a special issue entitled '17th Vitamin D Workshop' .

MicroRNA-346 mediates tumor necrosis factor α-induced downregulation of gut epithelial vitamin D receptor in inflammatory bowel diseases.

BACKGROUND: We recently reported that the gut epithelial vitamin D receptor (VDR) signaling inhibits colitis through inhibition of intestinal epithelial cell apoptosis, and the level of colonic epithelial VDR is markedly reduced in patients with inflammatory bowel diseases (IBD). VDR downregulation promotes colitis, but the mechanism underlying VDR downregulation in IBD is unknown. METHODS: VDR expression was analyzed in colon cancer cells under proinflammatory cytokine treatment. VDR as a target of miR-346 was confirmed using colon cancer cell culture. The relationship among inflammation, miR-346, and VDR was assessed in human IBD biopsies and experimental colitis models. RESULTS: We showed that tumor necrosis factor α (TNF-α) suppresses VDR expression while simultaneously upregulating miR-346 in human colon cancer cells. Further studies demonstrated that miR-346 inhibits VDR by a specific target sequence in the 3' untranslated region of the human VDR transcript, and blockade of miR-346 with a hairpin inhibitor abrogates the ability of TNF-α to inhibit VDR, confirming that TNF-α downregulates VDR by inducing miR-346. Consistently, in human IBD biopsies, the reduction of epithelial VDR is associated with increased immune cell infiltration and elevation of TNF-α and miR-346. In an experimental model of colitis, mucosal VDR expression is reduced over time with the progression of colitis, inversely correlated with the induction of TNF-α and miR-346 in the mucosa. CONCLUSIONS: These data suggest that during mucosal inflammation TNF-α induces miR-346, which downregulates epithelial VDR. Mucosal VDR reduction in turn compromises the integrity of the mucosal epithelial barrier, further driving mucosal inflammation and colitis development.

Severe vitamin D-deficiency and increased bone turnover in patients with hepatitis B from northeastern China.

INTRODUCTION: Vitamin D plays a key role in maintaining calcium homeostasis and skeletal health. The liver is critically involved in vitamin D metabolism, as 25-hydroxyvitamin D3 (25(OH)D3) is synthesized in the liver. Therefore liver dysfunction may lead to vitamin D deficiency and bone problems. The aim of this study was to examine vitamin D status and bone turnover markers in hepatitis B patients from northeastern China. METHODS: We recruited 39 patients with hepatitis B (23 noncirrhotic and 16 cirrhotic) and 48 healthy controls in Shenyang, a metropolitan city in northeastern China, and measured serum 25(OH)D3 levels and serum and urinary bone turnover markers in these subjects. RESULTS: Serum 25(OH)D3 levels in the patients with or without cirrhosis were markedly lower compared to the nonhepatitis controls (19.2 ± 1.2 and 18.5 ± 1.3 vs. 31.6 ± 1.3 nmol/L control), whereas serum and urinary bone turnover markers (alkaline phosphatase, C-terminal telopeptide of type I collagen, and pyridinoline) were significantly higher in these patients than in the controls. Moreover, serum levels of osteoprotegerin, a bone mass-regulating protein, were substantially reduced in the patients, with the lowest seen in patients with cirrhosis (2.7 ± 1.1 and 1.4 ± 0.4 vs. 3.4 ± 0.7 pg/mL control). Serum 25(OH)D3 levels below 30 nmol/L were positively correlated with serum osteoprotegerin levels in this cohort. CONCLUSIONS: Severe vitamin D deficiency is very common in hepatitis B patients in northeastern China, which negatively impacts their bone health. These data strongly suggest a need to treat these patients with vitamin D supplementation to protect their bone health.