Clinical significance of CTGF and Cry61 protein in extraocular muscles of strabismic patients.

PURPOSE: To investigate the relationship between clinical features and protein amounts of Cysteine-rich 61 (Cyr61/CCN1) and connective tissue growth factor (CTGF/CCN2), which are vital components and regulators of the extracellular matrix in resected muscles from strabismus surgery. METHODS: Strabismus patients who were diagnosed with horizontal concomitant strabismus or inferior oblique overaction (IOOA) and required extraocular muscles (EOMs) resection to correct eye position were included in this study. The protein amounts were measured by enzyme-linked immunosorbent assay (ELISA) in resected EOMs. Multivariable linear regression was used to investigate the associations, adjusting for gender, age (continuous), amblyopia, and disease duration. RESULTS: A total of 141 muscles (including 38 lateral, 81 medial rectus, and 22 inferior oblique muscles) from 128 patients were collected in this study. The amount of Cry61 and CTGF per millimeter was significantly negatively associated with deviation angle in intermittent exotropia patients (Cry61: ß, - 1.44; 95%CI, - 2.79 to - 0.10, p = 0.035; CTGF: ß, - 3.14; 95%CI, - 5.06 to - 1.22, p = 0.002). The same relationship was also detected in the partially accommodative and non-accommodative esotropia patients, although it was not statistically significant (Cry61: ß, - 2.40; 95%CI, - 5.05 to 0.24; p = 0.073; CTGF: ß, - 3.47; 95%CI, - 9.18 to 2.87; p = 0.269). The amount of Cry61 and CTGF per millimeter showed significant associations with the degree of IOOA (p < 0.05). CONCLUSIONS: Taken together, our results demonstrated a significant relationship between deviation angle and protein amount of Cry61 and CTGF and implied that Cry61 and CTGF may play important roles in modulation of EOM contractility, which provide new insights into strabismus pathogenesis.

Socioeconomic disparities in the global burden of glaucoma: an analysis of trends from 1990 to 2016.

PURPOSE: To assess the global burden of glaucoma by year, age, sex, regions, socioeconomic development, and mean years of schooling (MYS) by using disability-adjusted life year (DALY), then to explore the health inequality with socioeconomic status in glaucoma. METHODS: Global, national, and regional DALY data of glaucoma by year, age, and sex were extracted from the Global Health Data Exchange. Human development index (HDI) and national MYS in 2015 were obtained from the Human Development Report (HDR) 2016. Mann-Whitney U test was performed to explore the sexual difference in global DALYs. Kruskal-Wallis tests were performed to explore the difference of age-standardized DALY rates across WHO regions and HDI-related country groups. Linear regression analyses were performed to explore the association between age-standardized DALY rates with HDI and MYS. Health-related Gini coefficients and concentration indexes were calculated to evaluate the trends in health inequality of glaucoma since 1990. RESULTS: DALY numbers, crude DALY rates, and age-standardized DALY rates increased by 118.0%, 55.22%, and 12.12%, respectively, since 1990. Global DALY numbers and crude DALY rates increased with age, and Mann-Whitney U test revealed no significant sex difference in global DALY numbers (P = 0.807) and global crude DALYs rates (P = 0.976) for each age group in 2016. Africa and Eastern Mediterranean had higher age-standardized DALY rates than the global one in 2016. Kruskal-Wallis test indicated significant difference in age-standardized DALY rates across WHO regions (χ2 = 94.227, P < 0.001). Linear regression analysis indicated that HDI (adjusted R2 = 0.079; F = 16.722, P < 0.001) and MYS (adjusted R2 = 0.108; F = 23.048, P < 0.001) had a significant effect on age-standardized DALY rates. Gini coefficients rose from 0.290 in 1990 to 0.292 in 2015 with a peak value 0.299 in 2005, concentration index declined from 1990 (- 0.099) to 2000 (- 0.077) with reaching a low peak value, then rapidly increased to - 0.097 in 2015. CONCLUSIONS: With population growth and aging, global burden of glaucoma is increasing and older age, lower socioeconomic status, and lower MYS are associated with higher glaucoma burden. Our results help to gain a better understanding of glaucoma and guide future health policies tailored for public.

Scanning and transmission electron microscopy study of anterior lens epithelium in presenile cataract.

PURPOSE: To study the structure of lens epithelial cells (LECs) in the anterior lens epithelium of presenile cataract and to further explore the possible reasons for presenile cataract development. METHODS: The anterior lens capsules (aLCs) of patients with presenile cataracts and patients with ordinary age-related cataracts were obtained from routine cataract surgery, and the 5-5.5 mm circles of the central aLC were cut in half and prepared for transmission electron microscopy (TEM) and scanning electron microscopy (SEM). RESULTS: The most obvious structural changes in the LECs observed in both cataract groups by TEM were uneven thickness of the anterior lens epithelium, vacuolated cytoplasm and elongated nuclei. SEM showed abnormal structural changes in the LECs, with swollen cells and spheres on the anterior lens epithelium observed in both groups and holes formed by the LECs stretching observed only in the presenile cataract patients. The degeneration of the anterior lens epithelium and the structural changes in the LECs were observed more prominently in presenile cataract patients. CONCLUSIONS: Abnormal and prominently affected structural features of LECs were observed in the presenile compared to age-related cataract patients by TEM and SEM. We suppose that ultrastructural pathological changes in the anterior lens epithelial cells are one of the important reasons for the development of presenile and age-related cataract.

Atrophic and hypertrophic photoaging: Clinical, histologic, and molecular features of 2 distinct phenotypes of photoaged skin.

BACKGROUND: Exposure to the sun causes premature skin aging, known as photoaging. Clinical features of photoaging vary widely among individuals. In one form, skin appears thin with telangiectasia, and in another form, skin appears thickened with coarse wrinkles. Etiologic, clinical, and therapeutic distinctions among different forms of photoaging remain largely unknown. OBJECTIVE: To characterize the clinical, histologic, and molecular features of hypertrophic and atrophic photoaging. METHODS: In total, 53 individuals were clinically classified as having primarily atrophic or hypertrophic photoaging or neither (controls). Participants' demographic and sun exposure-related lifestyle data were captured by questionnaire. Fifteen clinical features of participants were qualitatively or quantitively scored. Facial biopsies were analyzed for gene expression and histologic characteristics. RESULTS: Actinic and seborrheic keratosis, telangiectasia, and prior incidence of skin cancers were statistically significantly greater and photoaging scale severity, coarse wrinkles, thickness, and sallowness were significantly reduced in atrophic versus hypertrophic groups. Histology also revealed significantly less elastotic material in atrophic photoaging. Gene expression of matrix metalloproteinases and collagens did not differ between the 2 forms of photoaging. LIMITATIONS: The study was not designed to identify other possible subtypes of photoaging. CONCLUSION: Systematic, categorical, and quantitative clinical and histologic assessments distinguish atrophic and hypertrophic photoaging.

The impact of GJA8 SNPs on susceptibility to age-related cataract.

The gap junction protein alpha 8 (GJA8) gene has been widely studied in human congenital cataracts. However, little is known about its relationship with age-related cataract (ARC). In this study, three GJA8-tagged single nucleotide polymorphisms related to an increased ARC risk were identified: rs2132397 for general ARC under both dominant and additive models; rs7541950 for general ARC under both recessive and additive models; and rs6657114 for cortical cataract under the recessive model. To uncover the underlying mechanisms, this study also sought to explore whether GJA8 is involved in the autophagy process in human lens epithelial cells. The results showed that GJA8 may participate in autophagy to maintain the intracellular environment, which may be a novel mechanism for cataract formation induced by GJA8. In conclusion, this study identified the genetic susceptibility of GJA8 polymorphisms on ARC and provides new clues for fully understanding the pathological mechanism of GJA8 variants in affecting lens opacity.

Role of Rapamycin and 3-MA in oxidative damage of HLECs caused by two doses of UVB radiation.

Background: This study compared the role of autophagy regulators Rapamycin and 3-MA in oxidative damage and apoptosis of human lens epithelial cells (HLECs) caused by two doses of Ultraviolet Radiation B (UVB). Methods: HLECs were irradiated with UVB, and two doses of UVB damage models were constructed. After treatment with autophagy regulators, cell damage tests such as CCK-8, LDH activity, and Ros detection were performed. Western blotting was used to detect the levels of autophagy-related proteins and apoptosis-related proteins. Quantitative real-time PCR (RT-qPCR) was used to detect the mRNA leve of secondary antioxidant enzymes.Flow cytometry was used to examine cell viability and apoptosis. Finally, the proportion of autophagy and apoptosis was observed by electron microscope. Results: Autophagy inhibitor 3-MA promoted oxidative damage and apoptosis of HLECs at low doses of UVB (5 mJ/cm2), which corresponds to 1.3 â€‹h of exposure to sunlight in human eyes. Under the high dose of UVB (50mJ/cm2), which is equivalent to 13 â€‹h of exposure to sunlight in human eyes, the autophagy inducer Rapamycin caused more extensive oxidative damage and apoptosis of HLECs. 3-MA was able to reduce this damage, indicating that moderate autophagy is necessary for HLECs to cope with mild oxidative stress. For high dose UVB-induced oxidative stress, the use of 3-MA inhibiting autophagy is more beneficial to reduce cell damage and apoptosis. The mechanisms include degradation of damaged organelles, regulation of the expression of antioxidant enzymes HO-1, NQO1, GCS and regulation of apoptosis-related proteins. Conclusions: Autophagy played different roles in HLECs oxidative stress induced by two doses of UVB. It provides new ideas for reducing oxidative damage and apoptosis of HLECs to prevent or delay the progression of age-related cataract (ARC).

Glycolysis Aids in Human Lens Epithelial Cells' Adaptation to Hypoxia.

Hypoxic environments are known to trigger pathological damage in multiple cellular subtypes. Interestingly, the lens is a naturally hypoxic tissue, with glycolysis serving as its main source of energy. Hypoxia is essential for maintaining the long-term transparency of the lens in addition to avoiding nuclear cataracts. Herein, we explore the complex mechanisms by which lens epithelial cells adapt to hypoxic conditions while maintaining their normal growth and metabolic activity. Our data show that the glycolysis pathway is significantly upregulated during human lens epithelial (HLE) cells exposure to hypoxia. The inhibition of glycolysis under hypoxic conditions incited endoplasmic reticulum (ER) stress and reactive oxygen species (ROS) production in HLE cells, leading to cellular apoptosis. After ATP was replenished, the damage to the cells was not completely recovered, and ER stress, ROS production, and cell apoptosis still occurred. These results suggest that glycolysis not only performs energy metabolism in the process of HLE cells adapting to hypoxia, but also helps them continuously resist cell apoptosis caused by ER stress and ROS production. Furthermore, our proteomic atlas provides possible rescue mechanisms for cellular damage caused by hypoxia.

Skin aging from the perspective of dermal fibroblasts: the interplay between the adaptation to the extracellular matrix microenvironment and cell autonomous processes.

This article summarizes important molecular mechanisms that drive aging in human skin from the perspective of dermal fibroblasts. The dermis comprises the bulk of the skin and is largely composed of a collagen-rich extracellular matrix (ECM). The dermal ECM provides mechanical strength, resiliency, and an environment that supports the functions of ibroblasts and other types of dermal cells. Fibroblasts produce the dermal ECM and maintain its homeostasis. Fibroblasts attach to the ECM and this attachment controls their morphology and function. During aging, the ECM undergoes gradual degradation that is nitiated by matrix metalloproteinases (MMPs). This degradation alters mechanical forces within the dermal ECM and disrupts he interactions between fibroblasts and the ECM thereby generating an aged fibroblast phenotype. This aged fibroblast phenotype is characterized by collapsed morphology, altered mechanosignaling, induction of CCN1, and activation of transcription factor AP-1, with consequent upregulation of target genes including MMPs and pro-inflammatory mediators. The TGF-beta pathway coordinately regulates ECM production and turnover. Altered mechanical forces, due to ECM fragmentation, down-regulate the type II TGF-beta receptor, thereby reducing ECM production and further increasing ECM breakdown. Thus, dermal aging involves a feed-forward process that reinforces the aged dermal fibroblast phenotype and promotes age-related dermal ECM deterioration. As discussed in the article, the expression of the aged dermal fibroblast phenotype involves both adaptive and cell-autonomous mechanisms.

Direct quantitative comparison of molecular responses in photodamaged human skin to fractionated and fully ablative carbon dioxide laser resurfacing.

BACKGROUND: Fractionated ablative laser resurfacing has become a widely used treatment modality. Its clinical results are often found to approach those of traditional fully ablative laser resurfacing. OBJECTIVE: To directly compare the molecular changes that result from fractionated and fully ablative carbon dioxide (CO(2)) laser resurfacing in photodamaged human skin. METHODS AND MATERIALS: Photodamaged skin of 34 adult volunteers was focally treated at distinct sites with a fully ablative CO(2) laser and a fractionated CO(2) laser. Serial skin samples were obtained at baseline and several time points after treatment. Real-time reverse transcriptase polymerase chain reaction technology and immunohistochemistry were used to quantify molecular responses to each type of laser treatment. RESULTS: Fully ablative and fractionated CO(2) laser resurfacing induced significant dermal remodeling and collagen induction. After a single treatment, fractionated ablative laser resurfacing resulted in collagen induction that was approximately 40% to 50% as pronounced as that induced by fully ablative laser resurfacing. CONCLUSIONS: The fundamental cutaneous responses that result from fully ablative and fractionated carbon dioxide laser resurfacing are similar but differ in magnitude and duration, with the fully ablative procedure inducing relatively greater changes including more pronounced collagen induction. However, the molecular data reported here provide substantial support for fractionated ablative resurfacing as an effective treatment modality for improving skin texture.

Novel Mutations Identified in the Chinese Han Population with Keratoconus by Next-Generation Sequencing.

AIM: To identify novel mutations in keratoconus (KC) susceptibility genes in the Chinese Han population. METHODS: A total of fifty-two patients with primary KC were recruited. Blood samples were collected, and genomic DNA was isolated from peripheral blood leukocytes. The entire coding region, intron-exon junctions, and promoter regions of sixteen known KC susceptibility genes were screened with next-generation sequencing technology. All identified variants were further confirmed using the Sanger sequencing technology. The Sorting Intolerant from Tolerant (SIFT), MutationTaster, and PolyPhen 2 programs were used to predict the effect of amino acid substitution on protein. RESULTS: After removing twelve known SNPs (single nucleotide polymorphisms) and three variants predicted to be harmless, nine novel mutations were identified in eight of the fifty-two patients, including c.455C > T:p.P152L in FNDC3B; c.3636_3637del:p.R1212fs in COL4A4; c.5015G > T:p.R1672L, c.3798dupA:p.P1267fs, and c.28G > A:p.A10T in MPDZ; c.1940C > T:p.P647L in DOCK9; c.127_128insGGC:p.Q43delinsRQ in POLG; c.3019G > A:p.V1007I in IPO5; and c.624 + 7- > A in TGFBI. All nine mutations in the patients with KC were heterozygote. CONCLUSION: This study enlarged the gene profile of KC and should be further confirmed by well-powered, genome-wide association studies (GWAS) of Han Chinese patients.

Incidence of endophthalmitis after phacoemulsification cataract surgery: a Meta-analysis.

AIM: To evaluate the overall endophthalmitis incidence and the effectiveness of potential prophylaxis measures following phacoemulsification cataract surgery (PCS). METHODS: The PubMed and Web of Science databases were searched from inception to April 30th, 2021. We included studies that reported on the incidence of endophthalmitis following PCS. The quality of the included studies was critically evaluated with the Newcastle-Ottawa quality assessment scale. The random effect or the fixed-effects model was used to evaluated the pooled incidence based on the heterogeneity. The publication bias was assessed by Egger's linear regression and Begg's rank correlation tests. RESULTS: A total of 39 studies containing 5 878 114 eyes were included and critically appraised in the Meta-analysis. For overall incidence of endophthalmitis after PCS, the Meta-analysis yielded a pooled estimate of 0.092% (95%CI: 0.083%-0.101%). The incidence appeared to decrease with time (before 2000: 0.097%, 95%CI: 0.060%-0.135%; 2000 to 2010: 0.089%, 95%CI: 0.076%-0.101%; after 2010: 0.063%, 95%CI: 0.050%-0.077%). Compared with typical povidone-iodine solution (0.178%, 95%CI: 0.071%-0.285%) and antibiotics subconjunctival injections (0.047%, 95%CI: 0.001%-0.095%), the use of intracameral antibiotics significantly reduced the incidence of endophthalmitis after PCS (0.045%, 95%CI: 0.034%-0.055%, RR: 7.942, 95%CI: 4.510-13.985). CONCLUSION: Due to the advancement of phacoemulsification technology and the widespread use of intracameral antibiotics, the incidence of endophthalmitis following PCS shows a decreasing trend over time. The use of intracameral antibiotics administration will significantly reduce the risk of endophthalmitis.

TP53INP2 Contributes to TGF-ß2-Induced Autophagy during the Epithelial-Mesenchymal Transition in Posterior Capsular Opacification Development.

BACKGROUND: Posterior capsule opacification (PCO) is the most common complication after cataract surgery, in which increased levels of transforming growth factor-beta 2 (TGF-ß2) accelerate PCO formation; however, the pathological mechanisms are not fully understood. This study aims to explore the regulation mechanism of TGF-ß2 in PCO formation via its autophagic functions. METHODS: The autophagic effect of TGF-ß2 was detected by transmission electron microscopy (TEM), Western blotting, and immunofluorescence analysis. The association between autophagy and the epithelial-mesenchymal transition (EMT) was evaluated by qPCR and Western blotting. The transcriptome analysis was used to uncover the molecular mechanism of TGF-ß2-induced PCO formation. RESULTS: TGF-ß2 specifically promotes autophagy flux in human lens epithelial cells. The activation of autophagy by rapamycin can promote EMT marker synthesis and improve cell migration. However, the inhibition of autophagy by 3-MA attenuates EMT. To uncover the molecular mechanisms, we performed RNA sequencing and found that TGF-ß2 elevated tumor protein p53-inducible nuclear protein2 (TP53INP2) expression, which was accompanied by a nuclear-to-cytoplasm translocation. Moreover, the knockdown of TP53INP2 blocked the TGF-ß2-induced autophagy and EMT processes, revealing that TP53INP2 plays an important role in TGF-ß2-induced autophagy during EMT. CONCLUSIONS: Taken together, the results of this study suggested that TP53INP2 was a novel regulator of PCO development by TGF-ß2, and notably, TP53INP2, may be a potential target for the pharmacological treatment of PCO.

Rejuvenation of Aged Human Skin by Injection of Cross-linked Hyaluronic Acid.

BACKGROUND: Dermal injection of chemically cross-linked hyaluronic acid (CL-HA) is a common procedure to smooth wrinkles and add fullness to the face. Due to its physical properties, CL-HA both fills space and exerts mechanical forces within the dermis. Dermal fibroblasts produce the collagen-rich extracellular matrix (ECM), which comprises the bulk of skin. Attachment to the ECM allows fibroblasts to achieve a stretched, morphology, which confers a functional phenotype that maintains collagen production. In aged/photoaged skin, collagen fibril fragmentation impairs fibroblast attachment, resulting in a collapsed morphology and reduced collagen production. This article describes investigations of the impact of CL-HA injection on fibroblast morphology and function in the aged/photoaged human skin. METHODS: Fifty-three subjects, age 70 years or older, received a single injection of saline (vehicle control) and CL-HA (0.5 ml each) in separate adjacent skin sites on photodamaged forearm or sun-protected buttock skin. Full-thickness punch biopsies were obtained from injected skin sites at various times and analyzed for molecular and cellular changes. RESULTS: Injected CL-HA forms discreet pockets that localize to areas of the dermis that contain fragmented, loosely organized collagen fibrils. These CL-HA pockets fill space and apply mechanical forces on adjacent ECM that induce stretching of fibroblasts. This stretching is associated with increased collagen gene expression and deposition of mature collagen fibril bundles, which resemble those observed in young skin. CONCLUSIONS: CL-HA injected into aged/photoaged human dermis acts by both filling space and inducing production of collagen by dermal fibroblasts. Deposition of mature collagen, which remains in the skin for decades, likely confers long-term benefits. Reduced collagen production in aged/photoaged skin is an adaptive response of fibroblasts to ECM fragmentation, rather than inherent cellular aging mechanisms.

Ultrastructural and immunofluorescence analysis of anterior lens capsules in autosomal recessive Alport syndrome.

Background: To first report and study the ultrastructural and immunofluorescence abnormalities of the lens anterior capsules in a patient with autosomal recessive Alport syndrome.Methods: Two anterior lens capsules were collected in femtosecond laser-assisted cataract surgeries from a 29-year-old male patient with bilateral lenticonus caused by autosomal recessive Alport syndrome. The left capsule was examined by transmission electron microscopy and the right capsule was serial sectioned and stained with antibodies against the α2, α3, and α4 chains of type Ⅳ collagen. Anterior lens capsules of another two uncomplicated age-related cataract patients were collected and treated in the same way as the control.Results: The novel findings are that the mitochondria in lens epithelial cells in autosomal recessive Alport syndrome patients increased, twisted, and exhibited high electron density. Characteristic ultrastructure changes of capsule thinning, vertical dehiscence, and irregular-shaped lens epithelial cells were also observed in the left anterior lens capsule. Normal reactivity against the α2 chain and decreased reactivity against the α3 and α4 chains were observed in the right anterior lens capsule.Conclusions: The homozygous c.4599 T > G mutation of COL4A4 not only affects the formation of type Ⅳ collagen networks in the extracellular matrix, but also affects the morphology and survival of the lens epithelial cells in the patient with autosomal recessive Alport syndrome. This study is the first report of the ultrastructural and immunofluorescence changes of anterior lens capsules in autosomal recessive Alport syndrome.

Alterations in extracellular matrix composition during aging and photoaging of the skin.

Human skin is composed of the cell-rich epidermis, the extracellular matrix (ECM) rich dermis, and the hypodermis. Within the dermis, a dense network of ECM proteins provides structural support to the skin and regulates a wide variety of signaling pathways which govern cell proliferation and other critical processes. Both intrinsic aging, which occurs steadily over time, and extrinsic aging (photoaging), which occurs as a result of external insults such as solar radiation, cause alterations to the dermal ECM. In this study, we utilized both quantitative and global proteomics, alongside single harmonic generation (SHG) and two-photon autofluorescence (TPAF) imaging, to assess changes in dermal composition during intrinsic and extrinsic aging. We find that both intrinsic and extrinsic aging result in significant decreases in ECM-supporting proteoglycans and structural ECM integrity, evidenced by decreasing collagen abundance and increasing fibril fragmentation. Intrinsic aging also produces changes distinct from those produced by photoaging, including reductions in elastic fiber and crosslinking enzyme abundance. In contrast, photoaging is primarily defined by increases in elastic fiber-associated protein and pro-inflammatory proteases. Changes associated with photoaging are evident even in young (mid 20s) sun-exposed forearm skin, indicating that proteomic evidence of photoaging is present decades prior to clinical signs of photoaging. GO term enrichment revealed that both intrinsic aging and photoaging share common features of chronic inflammation. The proteomic data has been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the data set identifier PXD015982.

Three novel variants identified within ECM-related genes in Chinese Han keratoconus patients.

As the primary indication for corneal transplantation, the pathogenesis of keratoconus remains elusive. Aiming to identify whether any mutation from extracellular-matrix (ECM)-related genes contributes to the patients with sporadic cases of keratoconus (KC) from Chinese Han population, one hundred and fifty-three participants in total were enrolled in our study, including fifty-three KC patients and one hundred healthy controls. Mutational analysis of three ECM-related genes (LOX, COL5A1 and TIMP3) with next-generation sequencing and Sanger sequencing was performed. To further confirm the function of three ECM-related genes in the pathogenesis of keratoconus, we performed Real-time Quantitative PCR in vitro. Results showed that three new sequence variants (c.95 G > A in LOX, c.1372 C > T in COL5A1 and c.476 C > T in TIMP3) were identified in aforementioned ECM-related genes in KC patients without being detected among the healthy controls. According to the results of QPCR, we found that the expression levels of LOX and TIMP3 were decreased in the KC patients, while COL5A1 showed no significant difference of expression. This is the first time to screen so many ECM-related genes in Chinese keratoconus patients using next-generation sequencing. We find numerous underlying causal variants, enlarging lots of mutation spectrums and thus providing new sites for other investigators to replicate and for further research.

CD26 Identifies a Subpopulation of Fibroblasts that Produce the Majority of Collagen during Wound Healing in Human Skin.

Fibroblasts produce collagens and other proteins that form the bulk of the extracellular matrix (ECM) in connective tissues. Emerging data point to functional heterogeneity of fibroblasts. However, the lack of subtype-specific markers hinders our understanding of the different roles of fibroblasts in ECM biology, wound healing, diseases, and aging. We have investigated the utility of the cell surface protein CD26 to identify functionally distinct fibroblast subpopulations in human skin. Using flow cytometry and immunohistology, we found that CD26, in combination with the cell surface glycoprotein CD90, identifies a distinct subpopulation of cells, which express relatively high levels of COL1A1, a hallmark of fibroblasts. Importantly, the population of CD26+ fibroblasts is selectively increased after wounding of human skin. These cells account for the majority of COL1A1 expression during the ECM remodeling phase of healing. The proportion of CD26+ fibroblasts in the skin of young and aged individuals is similar, indicating that the loss of collagen production during aging does not involve selective reduction of CD26+ fibroblasts. In culture, the majority of freshly isolated CD26- fibroblasts gain expression of CD26+. Taken together, these data provide a foundation for targeting CD26+ fibroblasts to modulate wound healing in human skin.

Cytoprotective role of humanin in lens epithelial cell oxidative stress­induced injury.

Oxidative stress-induced injury and apoptosis of human lens epithelial cells (HLECs) are early events in the development of age­related cataracts (ARCs). Humanin (HN) is a mitochondrial­related peptide that serves a cytoprotective role in various cell types and animal models. Following HN knockdown or overexpression, the level of reactive oxygen species (ROS), mitochondrial membrane potential and mitochondrial DNA copy number, cell viability, LDH activity and apoptosis of HLECs under oxidative stress were detected, and apoptosis and autophagy were detected via transmission electron microscopy. The results suggested that HN may be involved in the response of HLECs to oxidative stress, and that HN expression was significantly upregulated under oxidative stress conditions. Furthermore, exogenous HN reduced intracellular ROS content and mitochondrial damage, and enhanced mitochondrial biosynthesis; however, this protection was lost in an endogenous HN knockdown cell model. In addition, to the best of our knowledge, the present study was the first to identify that HN increased mitochondrial autophagy, which was involved in reducing ROS production under oxidative stress. The present study indicated a potential mechanism underlying the anti­oxidative damage and apoptotic effects of HN under oxidative stress. In conclusion, HN may be a potential therapeutic target for ARCs as it has a significant cellular protective effect on HLECs under oxidative stress; therefore, further study is required to investigate its role in the occurrence and development of ARCs.

Association of IGF1R polymorphisms (rs1546713) with susceptibility to age-related cataract in a Han Chinese population.

AIM: To explore the susceptible association between the insulin-like growth factor-1 receptor (IGF1R) single nucleotide polymorphism (SNP) and age-related cataract (ARC), and investigate the underlying mechanisms in human lens epithelium (HLE) cells. METHODS: Totally 1190 unrelated participants, comprising 690 ARC patients and 500 healthy individuals in Han Chinese population were recruited and genotyped for target SNP. The χ 2-test was used to detect genotypic distribution between the patient and control groups and the logistic regression was performed to adjust the age and gender. Meanwhile, different biological experimental methods, such as cell counting kit 8 (CCK-8) assay, flow cytometry, quantitative real time polymerase chain reaction (Q-PCR) and Western blot, were used to detect cell viability, cell cycle progression and apoptosis in HLE cells or IGF1R knockdown HLE cells. RESULTS: The rs1546713 in IGF1R gene was identified (P=0.046, OR: 1.606, 95%CI: 1.245-2.071), which shown a significant relevance with ARC risk under the dominant model. The results demonstrated that IGF1R knockdown inhibited cell proliferation by inducing cell cycle arrested at S phase and promoting apoptosis. Mechanistically, the cell cycle blocked at S phase was linked with the alterations of cyclin A, cyclin B, cyclin E and P21. The pro-apoptosis function of IGF1R may related with stimulating the activation of Caspase-3 and altering the expression levels of apoptotic proteins, including Bcl-2, Bax and Caspase-3. CONCLUSION: This study first report that IGF1R polymorphisms may affect susceptibility to ARCs in Han Chinese population and provide new clues to understand the pathogenic mechanism of ARCs. Notably, IGF1R is likely a potential target for ARC prevention and treatment.

Early auditory experience-induced composition/ratio changes of N-methyl-D-aspartate receptor subunit expression and effects of D-2-amino-5-phosphonovaleric acid chronic blockade in rat auditory cortex.

Auditory function can be affected by many factors, including environment and experience. In this study, we investigated whether early auditory experience mediates the regulation of the composition/ratio changes of the N-methyl-D-aspartic acid (NMDA) receptor subunits during development of the rat auditory cortex. We found that early sound exposure can increase expression of the NMDA receptor subunits and increase the composition/ratios of NMDA receptor subunits during the postnatal critical period. D-2-amino-5-phosphonovaleric acid (D-APV) could block and reverse the auditory experience-mediated changes, and there were marked reductions in expression levels and the composition/ratios of NMDA receptor subunits. These results indicate that the experience-dependent plasticity of the auditory cortex in the critical period during postnatal development has a marked influence on NMDA receptor expression in the rat and that changes in NMDA receptor subunit composition/ratios might mediate the early auditory experience-dependent plasticity crucial to auditory function.