Infrared Raman spectroscopy enables noninvasive biochemical assessment of skin tissue and the thermal stability.

Raman-active modes of human skin and pork belly have been studied systematically by a near-infrared Raman spectrometer with an exciting laser of 1064 nm. The main components and quantitative determination of pork belly are extracted by fitting the Raman spectra with the normalized Raman spectra of biochemical reagents such as collagen, elastin, triolein, fibronectin, fibrin, and hyaluronic acid. It demonstrates that the main components and quantity are various at different locations of pork belly, while the main components of human skin are similar to those of pig skin. In a further step, the evolution of the heating time-dependent Raman modes of isolated pig skin has been investigated for the mechanism of burnt skin. One can find that the spatial structure and main components of skin have an excellent thermal stability in the temperature range from -120 to 200 ∘C, which is confirmed by the temperature dependent Raman spectra of isolated pig skin, microporous acellular dermal matrix (MADM) as well as their corresponding biochemical reagents (collagen, elastin, triolein, etc.). These results help understand the mechanism of the living skin burnt by fire or hot water, and supplies an alternative technology for surgeons to diagnose the depth of a burn injury in time.

Clinical significance of the detection of serum IgG4 and IgG4/IgG ratio in patients with thyroid-associated ophthalmopathy.

To evaluate the clinical significance of detecting serum IgG4 and the IgG4/IgG ratio in patients with thyroid-associated ophthalmopathy (TAO) and to explore whether high serum IgG4 levels and the IgG4/IgG ratio are associated with the severity and activity of TAO, we retrospectively assessed the records of 78 TAO patients and 32 controls collected in our hospital from July 2020 to July 2022. The TAO patients were divided into TAO inactive and TAO active phase groups according to the clinical activity score (CAS), and we evaluated the association between the serum IgG4 levels, the IgG4/IgG ratio, and the clinical data of the participants. The levels of IgG4 significantly increased in the TAO active group compared to those in the inactive and control groups (P < 0.05). Additionally, the number of patients with increased IgG4 levels (≥135 mg/dL) in the TAO active group was markedly higher than that in the inactive and control groups (P < 0.05). The IgG4/IgG ratio was also significantly enhanced in the TAO active group compared to the inactive and control groups (P < 0.05). CAS was identified as an independent factor influencing IgG4 levels in patients with TAO. The levels of serum IgG4, as well as the IgG4/IgG ratio, were significantly increased in some patients with active TAO, and they were related to the CAS, suggesting that the pathogenesis of TAO may be heterogeneous.

Engineered NF-κB siRNA-encapsulating exosomes as a modality for therapy of skin lesions.

Introduction: Despite the protection and management of skin has been paid more and more attention, effective countermeasures are still lacking for patients suffering from UV or chemotherapy with damaged skin. Recently, gene therapy by small interfering RNA (siRNA) has emerged as a new therapeutic strategy for skin lesions. However, siRNA therapy has not been applied to skin therapy due to lack of effective delivery vector. Methods: Here, we develop a synthetic biology strategy that integrates the exosomes with artificial genetic circuits to reprogram the adipose mesenchymal stem cell to express and assemble siRNAs into exosomes and facilitate in vivo delivery siRNAs for therapy of mouse models of skin lesions. Results: Particularly, siRNA enriched exosomes (si-ADMSC-EXOs) could be directly taken up by the skin cells to inhibit the expression of skin injury related genes. When mice with skin lesions were smeared with si-ADMSC-EXOs, the repair of lesioned skin became faster and the expression of inflammatory cytokines were decreased. Discussion: Overall, this study establishes a feasible therapeutic strategy for skin injury, which may offer an alternative to conventional biological therapies requiring two or more independent compounds.

Incidence of rhegmatogenous retinal detachments is increasing in Wenzhou, China.

AIM: To estimate and compare the incidence and characteristics of rhegmatogenous retinal detachments (RRDs) in the Wenzhou area in 2015 to 2019. METHODS: All newly developed RRD cases among residents of the Wenzhou area, from January 2015 to December 2019, were retrospectively retrieved from hospital records. Annual population data were extracted from the Wenzhou Statistical Yearbook. RESULTS: There were 3629 eligible cases. The average incidence of RRD was 7.79 cases per 100 000 population (95% confidence interval, 7.24-8.34), and the incidences were 7.99 and 7.56 for males and females, respectively. The annual incidence increased gradually from 7.26 cases per 100 000 in 2015 to 10.00 cases per 100 000 in 2019, with an overall increase of 37.74%. The highest rate of increase occurred in the age group from 60 to 69 years. Of 2750 eyes with axial length (AL) data, 1675 (60.91%) had an AL greater than 24 mm. CONCLUSION: A trend to increasing RRD incidence is observed in the Wenzhou area over the past 5-year period.

Hypoxia-induced mesenchymal stem cells inhibit corneal fibroblast proliferation by regulating the WWP2/Notch1 axis.

Aim: This study aimed to explore the role of hypoxic mesenchymal stem cells (MSCs) in corneal alkali burns and the underlying mechanism. Materials & methods: Rat corneal fibroblasts were incubated with IL-6, followed by treatment with hypoxic MSC supernatant. A rat corneal alkali burn model was implemented and processed with hypoxic MSCs. The associated factors were detected by corresponding methods. Results: Hypoxic MSCs reduced the Notch1 level and the proliferation of rat corneal fibroblasts. Hypoxic MSCs or WWP2 overexpression in MSCs enhanced ubiquitination of Notch1. WWP2 interacted with Notch1, and WWP2 silencing reversed the effects of the hypoxic MSCs. Hypoxic MSC treatment in vivo decreased the corneal neovascularization scores and opacity scores. Conclusion: Hypoxic MSCs inhibited inflammation and alleviated corneal injury in alkali burns via the WWP2/Notch1 axis.

Acute ocular chemical burns are ophthalmic emergencies which require immediate diagnosis and treatment. Quiescent corneal cells differentiate into active fibroblast and myofibroblast phenotypes after corneal injury. Mesenchymal stem cells (MSCs) under hypoxia treatment are applied for the treatment of acute ocular chemical burns. We aimed to explore the role of hypoxic MSCs in corneal alkali burns and the underlying mechanism. The result showed that hypoxic MSCs reduced the proliferation of rat corneal fibroblasts, implying an anti-inflammatory effect. In vivo, treatment with hypoxic MSCs decreased the corneal neovascularization scores and opacity scores, indicating a protective effect on corneal alkali burns. We concluded that hypoxic MSCs could alleviate corneal injury in alkali burns and may be a promising therapeutic option for corneal alkali burns.

miR-340-5p mediates the therapeutic effect of mesenchymal stem cells on corneal neovascularization.

BACKGROUND: Our previous study revealed that mesenchymal stem cells (MSCs) inhibited angiogenesis via miRNA-mediated repression of prospero homeobox 1 (PROX1). This study aimed to verify whether miR-340-5p participates in the therapeutic effect of MSCs on corneal neovascularization (CNV) via repressing PROX1 and epithelial membrane protein 2 (EMP2). MATERIALS AND METHODS: The rat CNV model was established by corneal alkali burn. The binding relationship between miR-340-5p and 3'-untranslational regions (3'UTRs) of EMP2 and PROX1 was confirmed using dual-luciferase reporter assay. After culturing corneal epithelial cells (CECs) using MSC supernatants, the vascular endothelial growth factor (VEGF) level in CEC supernatants and the CEC viability were detected. The role of miR-340-5p in the therapeutic effect of MSC on CNV was determined via lentivirus-mediated miR-340-5p intervention in vivo. RESULTS: The expression of miR-340-5p was reduced and EMP2 and PROX1 were increased in CNV corneal tissues. The lentivirus-mediated overexpression of miR-340-5p inhibited the expressions of EMP2 and PROX1. The dual-luciferase reporter assay confirmed that miR-340-5p could bind with the 3'UTRs of EMP2 and PROX1. miR-340-5p was enriched in MSC supernatants and the culture of CECs using MSC supernatants increased the miR-340-5p expression in CECs. After being cultured in miR-340-5p-knocking down MSC supernatants, the expressions of EMP2 and PROX1 were increased, and the VEGF level and CEC viability were restored. The in vivo experiments also indicated that the therapeutic effect of MSCs was mediated by miR-340-5p. CONCLUSIONS: miR-340-5p mediates the therapeutic effect of MSCs on CNV via binding and repressing the expressions of EMP2 and PROX1.

Morphological changes in and quantitative analysis of macular retinal microvasculature by optical coherence tomography angiography in hypertensive retinopathy.

Hypertension is a serious global health problem. Hypertensive retinopathy is generally considered to be a predictor of vascular disease elsewhere in the human body. In the past few decades, a variety of grading systems have been proposed for hypertensive retinopathy. However, these grading systems have some limitations. This study utilized optical coherence tomography angiography (OCTA) to investigate the morphological changes and macular retinal microvasculature in depth among 100 patients with hypertensive retinopathy and 66 healthy participants. Five main pathological changes were discovered in hypertensive retinopathy, as follows: focal capillary sparsity, scattered microangioma, focal macular arch ring defects, focal capillary disorder, and focal capillary nonperfusion at the levels of the superficial and deep vascular networks. In addition, we have found that the number of various pathological changes shows an increasing trend as hypertensive retinopathy progresses and may be related to renal damage. Finally, deep vessel density tended to decrease with progressive stages of hypertensive retinopathy and could be the best indicator to predict the risk of hypertensive retinopathy. Our study, therefore, proposes 3 stages of hypertensive retinopathy without macular edema according to the pathophysiology found by OCTA: stage 1 (only focal capillary sparsity), taking the place of KWB grade I; stage 2 (focal capillary sparsity and scattered microangioma), taking the place of KWB grade II; and stage 3 (focal capillary sparsity, scattered microangioma, focal capillary disorder, and nonperfusion), taking the place of KWB grade III. Hence, OCTA may be a potentially useful tool for evaluating the pathophysiology and staging of hypertensive retinopathy. Further longitudinal prospective studies are needed to confirm our findings.

Prevalence and Associations of Myopic Anisometropia in Chinese Adults.

PURPOSE: To investigate the prevalence and associations of myopic anisometropia in Chinese adults. METHODS: A total of 3,791 Chinese refractive surgery candidates with myopia (25.15±7.09 years old, Mean±SD) were recruited. All eyes underwent a standardized ophthalmological examination. Associations between myopic anisometropia and age, gender, spherical ametropia, astigmatism, and axial length (AL) were analyzed by means of the chi-squared test, nonparametric Kruskal-Wallis or Mann-Whitney test, binomial logistic regression analyses, and multivariate logistic regression analysis. RESULTS: The mean myopic anisometropic level was 0.96 D and prevalence of myopic anisometropia was 29.62% (defined as myopic anisometropia ≥1.00 D). The prevalence and severity of myopic anisometropia increased with age, larger interocular AL difference, and higher cylindrical power (all P<0.001). Myopic anisometropia showed a U-shaped correlation with spherical equivalent (SE) refractive error and V-shaped correlations with AL, J0 and J45. Myopic anisometropia was most strongly associated with interocular AL difference (P<0.001). CONCLUSIONS: Compared with previous reports, this study revealed an even higher prevalence of myopic anisometropia and showed a U-shaped correlation with SE and a V-shaped correlation with AL. These results indicate that the formation of myopic anisometropia could be related to neural control in the binocular AL growth balance. Further study is needed to clarify this presumption.

MSCs inhibits the angiogenesis of HUVECs through the miR-211/Prox1 pathway.

The aim of this study was to investigate the effect of mesenchymal stem cells (MSCs) on the angiogenesis of human umbilical vein endothelial cells (HUVECs). MSCs were subconjunctival injected into rat corneal alkali burn models. Their impacts on the degree of corneal neovascularization (CNV) and corneal opacity were evaluated at 3, 6, 9 and 12 days after injection. An in vitro experiment of MSCs affecting HUVECs angiogenesis was performed and evaluated using the tube formation assay. The results showed that both CNV and corneal opacity were decreased in rats after MSCs injection. In HUVECs, angiogenesis of cells was inhibited by miR-211 overexpression. miR-211 negatively regulated Prox1 expression. Knockdown of miR-211 blocked the decrease of Prox1 expression induced by MSCs and the inhibitory effect of MSCs on the angiogenesis of HUVECs. The critical role of miR-211 in MSCs inhibition of corneal angiogenesis was confirmed in rat experiments. We concluded that MSCs inhibited the angiogenesis of HUVEC through miR-211 mediating the down-regulation of Prox1.

AMPK promotes survival and adipogenesis of ischemia-challenged ADSCs in an autophagy-dependent manner.

Some studies have shown that transplanted fat tissues usually cannot survive for long if adipose-derived stem cells (ADSCs) are removed from the tissues in advance. It is more meaningful to explore the mechanism mediating survival and differentiation of ADSCs in the transplanted microenvironment. AMP-activated protein kinase (AMPK) has been shown to be one of the energy receptors that regulate many aspects of cellular metabolism. AMPK activation has been implicated in models of adult ischemic injury, but the mechanism and the regulating effects of AMPK on survival and adipogenesis of transplanted ADSCs are still little known. In this study, we simulated the transplanted microenvironment using oxygen-glucose deprivation (OGD) to test the survival and adipogenesis of ADSCs. We found that OGD treatment triggered significant apoptosis and promoted autophagy. Simultaneously, OGD hindered the differentiation of ADSCs into mature adipocytes. After inhibiting AMPK, the OGD-induced apoptosis rate increased but autophagy was inhibited. The adipogenesis level also decreased. To show that the effects of AMPK on apoptosis and adipogenesis were autophagy-dependent, we pre-inhibited or pre-promoted autophagy with siATG7 or rapamycin while blocking AMPK. We found that inhibiting or improving autophagy exacerbated or alleviated the role of AMPK prohibition in apoptosis and adipogenesis. Furthermore, we showed that AMPK inhibition significantly lowered ULK1 activity but promoted mTOR activity, so that to inhibit autophagy. Our study shows that AMPK plays a protective role in maintaining survival and adipogenesis of OGD-challenged ADSCs partly by positively regulating autophagy. AMPK positively regulates autophagy by inhibiting mTOR but promoting ULK1 activity in OGD condition.

Role of microRNA 146a on the healing of cornea alkali burn treated with mesenchymal stem cells.

The aim of the present study was to investigate the effect of microRNA 146a (miR146a) on promoting the repair of corneal alkali burn with bone marrow mesenchymal stem cells (MSCs). A total of 24 Sprague­Dawley female rats were divided into a normal group (Control), a normal MSC treatment group (Normal MSCs), an miR146a knockout MSC treatment group (miR146a­low MSCs) and an miR146a high­expression MSC treatment group (miR146a­high MSCs) according to the random number table. Quantitative polymerase chain reaction was used to evaluate the expression levels of miR146a. MTT assay was performed to measure the cell viability of mesenchymal stem cells (MSCs) and apoptosis was measured by flow cytometry. The expression levels of p65 nuclear factor (NF)­κB, proliferating cell nuclear antigen (PCNA) and Fas proteins were analyzed by western blotting. MSCs were tested for the secretion levels of vascular endothelial growth factor (VEGF), CD45, interferon (IFN)­Î³ and interleukin (IL)­10 by ELISA. The miR146a­high MSCs improved cell viability of MSCs and inhibited apoptosis of MSCs following alkali burn. miR146a­high MSCs decreased the expression levels of p65NF­κB and PCNA, and enhanced the expression level of Fas. Furthermore, miR146a­high MSCs improved the cornea opacity and enhanced the inhibition of neovascularization in the rats following alkali burn. miR146a­high MSCs inhibit the expression of VEGF, CD45, IFN­Î³, while enhanced the expression of IL­10. Therefore, miR146a promotes the repair of corneal alkali burn in rats treated with MSCs.

Interocular evaluation of axial length and retinal thickness in people with myopic anisometropia.

PURPOSE: To investigate the changes in axial length and retinal thickness and their relationships with myopia in highly myopic anisometropia. METHODS: A total of 87 Chinese subjects (25.28±11.98 years, mean±SD) were divided into two groups: anisometropia (n=38) and nonanisometropia (n=49). All eyes were measured for axial length, refractive status, and macular thickness (optical coherence tomography). Ocular biometric results were compared between eyes of subgroups. Linear correlation between refractive error and other biometric results was performed. RESULTS: In the anisometropic group, the inner ring macula and part of the outer ring macula (nasal and inferior quadrants) in the higher myopic eyes were significantly thinner than in the fellow eyes (P≤0.007), but the foveal thickness (minimum and average) was similar (P≥0.050) between the two eyes. However, the minimum and average foveal thicknesses were found to be significantly thicker in the highly myopic eyes than those in the emmetropic to moderate myopic eyes (P≤0.016) in the nonanisometropic group. Among the eyes ranging from emmetropia to high myopia, the refractive error was negatively correlated to the axial length of the eye (P<0.001) and the thinning of inner ring macula is consistent with the increase in both myopia and axial length. There was a negative correlation in refractive error and axial length but no correlation in parafoveal thickness between eyes of the same subjects (P<0.001) in the anisometropic group. CONCLUSIONS: In people with myopic anisometropia, the higher myopic eye has a longer axial length but a thinner parafoveal region than its fellow eye. The axial growth in the development of high myopia seems to be centrally regulated; however, the changes in parafoveal thickness are likely manipulated by local mechanisms within the eye.