Diallyl disulfide synergizes with melphalan to increase apoptosis and DNA damage through elevation of reactive oxygen species in multiple myeloma cells.

Diallyl disulfide (DADS), one of the main components of garlic, is well known to have anticancer effects on multiple cancers. However, its efficacy in treating multiple myeloma (MM) is yet to be determined. We explored the effects of DADS on MM cells and investigated the synergistic effects of DADS when combined with five anti-MM drugs, including melphalan, bortezomib, carfilzomib, doxorubicin, and lenalidomide. We analyzed cell viability, cell apoptosis, and DNA damage to determine the efficacy of DADS and the drug combinations. Our findings revealed that DADS induces apoptosis in MM cells through the mitochondria-dependent pathway and increases the levels of γ-H2AX, a DNA damage marker. Combination index (CI) measurements indicated that the combination of DADS with melphalan has a significant synergistic effect on MM cells. This was further confirmed by the increases in apoptotic cells and DNA damage in MM cells treated with the two drug combinations compared with those cells treated with a single drug alone. The synergy between DADS and melphalan was also observed in primary MM cells. Furthermore, mechanistic investigations showed that DADS decreases reduced glutathione (GSH) levels and increases reactive oxygen species (ROS) production in MM cells. The addition of GSH is effective in neutralizing DADS cytotoxicity and inhibiting the synergy between DADS and melphalan in MM cells. Taken together, our study highlights the effectiveness of DADS in treating MM cells and the promising therapeutic potential of combining DADS and melphalan for MM treatment.

Bortezomib elevates intracellular free Fe2+ by enhancing NCOA4-mediated ferritinophagy and synergizes with RSL-3 to inhibit multiple myeloma cells.

Iron contributes to tumor initiation and progression; however, excessive intracellular free Fe2+ can be toxic to cancer cells. Our findings confirmed that multiple myeloma (MM) cells exhibited elevated intracellular iron levels and increased ferritin, a key protein for iron storage, compared with normal cells. Interestingly, Bortezomib (BTZ) was found to trigger ferritin degradation, increase free intracellular Fe2+, and promote ferroptosis in MM cells. Subsequent mechanistic investigation revealed that BTZ effectively increased NCOA4 levels by preventing proteasomal degradation in MM cells. When we knocked down NCOA4 or blocked autophagy using chloroquine, BTZ-induced ferritin degradation and the increase in intracellular free Fe2+ were significantly reduced in MM cells, confirming the role of BTZ in enhancing ferritinophagy. Furthermore, the combination of BTZ with RSL-3, a specific inhibitor of GPX4 and inducer of ferroptosis, synergistically promoted ferroptosis in MM cell lines and increased cell death in both MM cell lines and primary MM cells. The induction of ferroptosis inhibitor liproxstatin-1 successfully counteracted the synergistic effect of BTZ and RSL-3 in MM cells. Altogether, our findings reveal that BTZ elevates intracellular free Fe2+ by enhancing NCOA4-mediated ferritinophagy and synergizes with RSL-3 by increasing ferroptosisin MM cells.

Microfluidic Study on the Effect of Single Pore-Throat Geometry on Spontaneous Imbibition.

Spontaneous imbibition is a naturally occurring phenomenon in porous media that plays an important role in various processes. Particularly during the oil recovery process, imbibition efficiency could be significantly affected by the physical properties of the reservoir rock, such as pore-throat structure. However, the effect of the pore-throat structure on the imbibition process has rarely been investigated quantitatively. Therefore, in this study, spontaneous imbibition was examined quantitatively using microfluidic devices with different single pore-throat geometries. Three key geometric parameters were examined, namely, pore-throat ratio, coordination number, and tortuosity. The pore-to-throat ratio of a single pore-to-throat structure under investigation ranges from 3 to 50. Designated coordination numbers range from 2 to 6. Tortuosity values for meandering channels range from 1 to 2. Imbibition process was mimicked using microfluidic devices with varying pore-throat geometries. The results showed that average imbibition velocity exhibited an initial increase followed by a subsequent decline with the increase in the pore-throat ratio. As the coordination number increased, imbibition velocity decreased as the coordination number increased, and the influence of the pore-throat ratio diminished as the coordination number increased. Imbibition velocity decreased as the tortuosity increased. Meniscus movements were investigated for different pore-throat structures. Statistical analysis was also conducted to determine the dominant factor governing the imbibition behavior. It was found that pore-throat ratio, tortuosity, and coordination number exerted a decreasing impact on the imbibition velocity. Wetting phase saturation was examined over time using a single pore-throat geometry device with varying pore-throat ratios. Four distinct types of imbibition behaviors were identified and characterized. In conclusion, this work examined the imbibition behaviors within specified pore-throat geometries, which could contribute to a comprehensive understanding of the imbibition behavior in realistic porous media.

Risk factors for neonatal hypoglycemia: a meta-analysis.

OBJECTIVE: This Study aims to investigate the risk factors of hypoglycemia in neonates through meta-analysis. METHOD: PubMed, Embase, Cochrane library, and Web of science databases were searched for case-control studies on risk factors for neonatal hypoglycemia. The search was done up to 1st October 2023 and Stata 15.0 was used for data analysis. RESULTS: A total of 12 published studies were included, including 991 neonates in the hypoglycemic group and 4388 neonates in the non-hypoglycemic group. Meta-analysis results suggested caesarean section [OR = 1.90 95%CI (1.23, 2.92)], small gestational age[OR = 2.88, 95%CI (1.59, 5.20)], gestational diabetes [OR = 1.65, 95%CI (1.11, 2.46)], gestational hypertension[OR = 2,79, 95%CI (1.78, 4.35)] and respiratory distress syndrome[OR = 5.33, 95%CI (2.22, 12.84)] were risk factors for neonatal hypoglycemia. CONCLUSION: Based on the current study, we found that caesarean section, small gestational age, gestational diabetes, gestational hypertension, respiratory distress syndrome are risk factors for neonatal hypoglycemia. PROSPERO REGISTRATION NUMBER: CRD42023472974.

Peripheral T-cell lymphoma invasion of the liver: The underappreciated hypoechoic periportal cuffing on ultrasound-A case report and literature review.

Liver involvement in lymphoma often manifests as nonoccupying diffuse infiltration, posing challenges in distinguishing it from primary liver disorder. Herein, we present the case of a 21-year-old female who underwent two separate diagnoses within a nine-month interval before being ultimately diagnosed with peripheral T-cell lymphoma, not otherwise specified. Our review of this case identified an ultrasound imaging feature, the hypoechoic periportal cuffing. When combined with associated increased lymphocyte count and liver enlargement, it can serve as a noninvasive suggestion for malignant disorders, in particular hemic and lymphatic diseases.

RBM15 silencing promotes ferroptosis by regulating the TGF-ß/Smad2 pathway in lung cancer.

OBJECTIVE: We assessed the function and mechanism of RNA binding motif protein 15 (RBM15) silencing in lung cancer development. METHODS: The effects of RBM15 knockdown on A549 and H1299 cells were evaluated by MTT, EdU, wound healing, and transwell assay. We then detected the functions of RBM15 silencing on lipid peroxidation, labile iron pool (LIP), ferrous iron (Fe2+ ), and ferroptosis-related genes. RNA sequencing was performed after RBM15 knockout in lung cancer cells, followed by differentially expressed genes (DEGs), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed. Finally, the expression of RBM15 and pathway-related genes was determined by western blot. RESULTS: RBM15 was highly expressed in lung cancer cells. RBM15 silencing reduced the viability, inhibited cell proliferation, invasion, and migration, and suppressed tumor growth in the xenograft mouse model. Knockout of RBM15 regulated ferroptosis-related gene expression. LIP, Fe2+ , and lipid peroxidation were distinctly increased by the knockout of RBM15. RNA-seq sequencing revealed that there are 367 up-regulated and 368 down-regulated DEGs, which were enriched in molecular functions, biological processes, and cellular components. RBM15 silencing reduced the expression of TGF-ß/Smad2, and TGF-ß activator (SRI-011381) reversed the inhibitory effect of RBM15 silencing on tumor cell growth. CONCLUSION: We demonstrated that RBM15 silencing promoted ferroptosis in lung cancer cells by TGF-ß/Smad2 pathway, thereby inhibiting lung cancer cell growth, which may provide new light for lung cancer treatment.

Exploring TCGA database for identification of potential prognostic genes in stomach adenocarcinoma.

BACKGROUND: Stomach adenocarcinoma (STAD) is the fifth most prevalent cancer in the world and ranks third among cancer-related deaths worldwide. The tumour microenvironment (TME) plays an important role in tumorigenesis, development, and metastasis. Hence, we calculated the immune and stromal scores to find the potential prognosis-related genes in STAD using bioinformatics analysis. METHODS: The ESTIMATE algorithm was used to calculate the immune/stromal scores of the STAD samples. Functional enrichment analysis, protein-protein interaction (PPI) network analysis, and overall survival analysis were then performed on differential genes. And we validated these genes using data from the Gene Expression Omnibus database. Finally, we used the Human Protein Atlas (HPA) databases to verify these genes at the protein levels by IHC. RESULTS: Data analysis revealed correlation between stromal/immune scores and the TNM staging system. The top 10 core genes extracted from the PPI network, and primarily involved in immune responses, extracellular matrix, and cell adhesion. There are 31 genes have been validated with poor prognosis and 16 genes were upregulated in tumour tissues compared with normal tissues at the protein level. CONCLUSIONS: In summary, we identified genes associated with the tumour microenvironment with prognostic implications in STAD, which may become potential therapeutic markers leading to better clinical outcomes.

miRNA-365b promotes hepatocellular carcinoma cell migration and invasion by downregulating SGTB.

Aim: miR-365b, a miRNA at chromosomal breakpoint, was often amplified and upregulated in human hepatocellular carcinoma (HCC). However, the role of miR-365b dysregulation remains unclear. Materials & methods: miR-365b function assays and its target gene analyses were performed. Results: We revealed that miR-365b promoted HCC cell motility and spreading. Furthermore, SGTB was found to be a downstream target of miR-365b, and knockdown of the SGTB gene could mimic the effect of miR-365b in hastening HCC cell migration and invasion. Conclusion: These results imply that miR-365b plays a tumor-promoting role in HCC by suppressing SGTB expression, offering novel potential targets for the treatment of HCC.

Remodeling the Th1 polarized systemic environment contributes to neurogenesis and cognitive function via the Wnt7a pathway in neonatal mice.

Neonatal Bacillus Calmette-Guérin (BCG) vaccination results in a positive effect on hippocampal neurogenesis and cognition. Serum cytokines are considered to be the chief culprit. In this study, serum from BCG-treated mice was identified as Th1 polarized serum. The serum showed an increased ratio of IFN-γ to IL-4 and decreased levels of TNF-α and IL-6. After Th1 polarized serum was injected intraperitoneally into postnatal mice, the levels of cytokines and ratio of IFN-γ to IL-4 in the serum and hippocampus of postnatal mice showed a similar alteration as those in Th1 polarized serum. This result indicated that the immune homeostatic milieu in postnatal mice was broken and the Th1 polarized systemic environment in the BCG-serum group was remodeled. The BCG-serum group displayed more BrdU+/DCX+ cells, BrdU+/NeuN+ cells, Nestin+ cells and better cognitive abilities. In neural stem cells, the Wnt7a/ß-catenin signaling pathway was activated and exposure to the Wnt7a antagonist Dickkopf-1 inhibited BCG-serum-induced Wnt7a/ß-catenin signaling, neurogenesis and cognitive function. Additionally, BCG-serum was associated with elevations in hippocampal brain-derived neurotrophic factor (BDNF) levels, and BDNF expression in the BCG-serum group was offset by Dickkopf-1 treatment. By rebalancing the Th1 polarized systemic environment in neonatal mice, it is possible that treatment with BCG-serum promotes hippocampal neurogenesis and improves cognitive functions, which are associated with Wnt7a/ß-catenin-BDNF signaling.

The Role of Water in the Catalyst-Free Aldol Reaction of Water-Insoluble N-Methyl-2,4-thiazolidinedione with N-Methylisatin from QM/MM Monte Carlo Simulations.

The role of water in the uncatalyzed aldol reaction of N-methyl-2,4-thiazolidinedione with N-methylisatin is investigated through Monte Carlo statistical mechanics simulations that utilize free energy perturbation theory and the mixed quantum mechanics and molecular mechanics (QM/MM) model with PDDG/PM3 for the QM method in "on-water" and DMSO environments. There are several conceivable orientations between thiazolidinedione and isatin in the process of C-C bond formation. However, the formation of the C-C bond takes place between the re face of isatin and the si face of (E)-enol of the thiazolidinedione to form the preferred anti-type product, which results from enhanced hydrogen-bonding interactions between water molecules and the oxygen atoms undergoing bond breakage and bond formation during the reaction. Novel insights into the effect of water on the aldol reaction are presented herein.

High expression of COX5B is associated with poor prognosis in breast cancer.

BACKGROUND: Cytochrome c oxidase subunit VB (COX5B), a subunit of mammalian COX, takes roles in COX assembling and functions. Online database predicts high COX5B transcription may be associated with worse disease-free survival (DFS). However, the clinical implications of COX5B in breast cancer remain unclear. METHODS: We carried out immunohistochemistry on tissue microarrays of 244 patients with invasive ductal breast carcinoma to detected COX5B expression. RESULTS: Our results suggest that COX5B protein level might be associated with tumor size. COX5B overexpression indicated a worse DFS (p < 0.05) in breast cancer. Furthermore, high COX5B expression may act as an independent factor for worse DFS in breast cancer. CONCLUSIONS: Cumulatively, our findings suggest that COX5B might serve as an important prognostic factor for breast cancer.

Loss of TIM50 suppresses proliferation and induces apoptosis in breast cancer.

TIM50 is an essential component of TIM23 complex and involved in protein translocating into the inner mitochondrial membrane. Here, we found that TIM50 was increased in breast cancer cells by SILAC. However, its biological functions and molecular mechanisms in breast cancer are poorly understood. To gain insight into the functions of TIM50 in breast cancer, we constructed two stably transfected cell lines and examined TIM50 expression in tissue samples. Our data showed that TIM50 expression was increased in breast cancer. The stable suppression of TIM50 expression through lentivirus-mediated shRNA was shown to inhibit the abilities of cancer cell proliferation and induce apoptosis. What is more, depletion of TIM50 could decrease mitochondrial membrane potential, which may be associated with cell viability. Taken together, our findings reveal a new role for TIM50 in regulating cell proliferation and apoptosis through decreasing mitochondrial membrane potential in breast cancer cell and suggest that TIM50 might be a potential target for controlling breast cancer progression.

Dyadic coping, resilience, and posttraumatic growth in spinal cord injury patients and their spouses: An actor-partner interdependence mediation model analysis.

OBJECTIVE: Despite the recognized importance of posttraumatic growth (PTG) in the recovery process, the mechanisms that promote PTG in spinal cord injury (SCI) patients and their spouses, especially the roles of dyadic coping (DC) and resilience, have not been fully explored. This study aimed to assess the PTG of patients with SCI and their spouses and to investigate the interrelationships among DC, resilience, and PTG within the dyadic context. METHOD: A total of 154 SCI patient-spouse dyads were recruited from a rehabilitation hospital in China. All participants completed questionnaires about DC, resilience, and PTG. Our study was based on the actor-partner interdependence mediation model (APIMeM). RESULTS: SCI patients and their spouses experienced comparable PTG level, M(patients) = 56.05 ± 14.09, M(spouses) = 54.74 ± 15.31. In the APIMeM, the patients' and their spouses' DC exerted actor effects on their own resilience, ß(patients) = .418, p < .001; ß(spouses) = .409, p < .01, and their own resilience also exerted actor effects on their own PTG, ß(patients) = .416, p < .001; ß(spouses) = .431, p < .001. The mediating effects of resilience on the impact of patients' and spouses' own DC on their own PTG were confirmed. CONCLUSIONS: Our research offers new insight into the PTG of SCI patients and their spouses at the individual and dyadic levels. Resilience partially mediates the relationship between DC and PTG in couples coping with SCI. Specifically, DC between SCI patient-spouse dyads can not only directly influence the level of PTG but also impact PTG through resilience. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

The impact of high-altitude migration on cardiac structure and function: a 1-year prospective study.

Introduction: The trend of human migration to terrestrial high altitudes (HA) has been increasing over the years. However, no published prospective studies exist with follow-up periods exceeding 1 month to investigate the cardiac change. This prospective study aimed to investigate the changes in cardiac structure and function in healthy young male lowlanders following long-term migration to HA. Methods: A total of 122 Chinese healthy young males were divided into 2 groups: those migrating to altitudes between 3600 m and 4000 m (low HA group, n = 65) and those migrating to altitudes between 4000 m and 4700 m (high HA group, n = 57). Traditional echocardiographic parameters were measured at sea level, 1 month and 1 year after migration to HA. Results: All 4 cardiac chamber dimensions, areas, and volumes decreased after both 1 month and 1 year of HA exposure. This reduction was more pronounced in the high HA group than in the low HA group. Bi-ventricular diastolic function decreased after 1 month of HA exposure, while systolic function decreased after 1 year. Notably, these functional changes were not significantly influenced by altitude differences. Dilation of the pulmonary artery and a progressive increase in pulmonary artery systolic pressure were observed with both increasing exposure time and altitude. Additionally, a decreased diameter of the inferior vena cava and reduced bicuspid and tricuspid blood flow velocity indicated reduced blood flow following migration to the HA. Discussion: 1 year of migration to HA is associated with decreased blood volume and enhanced hypoxic pulmonary vasoconstriction. These factors contribute to reduced cardiac chamber size and slight declines in bi-ventricular function.

[ABCC8, KCNJ11 and GLUD1 gene mutation analysis in congenital hyperinsulinism pedigree].

OBJECTIVE: To explore the ABCC8, KCNJ11, and GLUD1 gene mutations of the 11 patients diagnosed as congenital hyperinsulinism (CHI). METHODS: A total of 11 CHI children hospitalized in Beijing Children's Hospital from November 2008 to February 2012 and their parents were chosen as the study subjects. Direct sequencing of PCR-DNA was used to analyze the 39 exons of ABCC8 gene, non-translational region and exon of KCNJ11 gene and 6, 7, 10, 11 and 12 exons of GLUD1 gene. RESULTS: An P629PfsX17 heterozygous mutation of ABCC8 gene was detected in case 1 and his father, an W288X heterozygous mutation of ABCC8 gene was detected in case 4 and his father, A640V and Q1196X mutations in ABCC8 gene in case 5 whose father only carried the Q1196X mutation. In case 6 and his father, an R269H mutation was found in GLUD1 gene. The genotype of 4 children's mothers was normal. No mutations were found in other 7 patients and their parents. CONCLUSIONS: The ABCC8 gene mutations are the main pathogenic mechanisms of Chinese children with CHI. In Chinese, P629PfsX17, W288X, A640V and Q1196X heterozygous mutation of ABCC8 gene and R269H heterozygous mutation of GLUD1 gene may lead to CHI. The inheritance mode of the mutations may be paternally or de novo.

Changes of Melanopsin Expression in the Retina of Guinea Pig during Experimental Myopia and Recovery Period.

PURPOSE: To explore whether melanopsin is associated with the development of myopia. METHODS: Seventy-two guinea pigs (3 weeks older) were randomly assigned to 6 groups: the form-deprivation myopia (FDM) group (monocularly covering the right eye for 14 days, n = 15), the FDM recovery group (removing the eye mask for 3 days, n = 13), the lens-induced myopia (LIM) group (monocularly wearing a -4D lens for 3 days, n = 15), the LIM recovery group (removing the lens for 2 days, n = 13), and another 2 age-matched normal groups (n = 8 each). The diopter, the vitreous chamber depth (VCD), and the axial length (AXL) were measured to confirm the effect of the treatments. Immunofluorescence and western blotting methods were used to examine the expression of melanopsin in the retina. RESULTS: Immunofluorescent results showed that in the FDM group, the melanopsin intensity in the retina of experimental eyes significantly decreased compared to those of contralateral eyes, but no significant difference was observed during their recovery periods. Western blotting showed that the expression of melanopsin in the experimental eyes of the FDM group was lower than that of the contralateral eyes (fold: 1.00 versus 1.36). The expression of melanopsin in the experimental eyes increased 3 days after removing form deprivation, although a slight reduction in melanopsin expression compared to that of the contralateral eyes (fold: 1.41 versus 1.58). For the LIM group, immunofluorescent showed an obvious decreased intensity of melanopsin-labeled cells in the experimental eyes compared to the contralateral eyes. Western blotting showed that although melanopsin expression in the experimental eyes decreased compared to that of the contralateral eyes (fold: 1.00 versus 1.96), no differences were found between two eyes 2 days after lens removal (fold: 1.99 versus 2.00). CONCLUSION: The decreased expression of melanopsin in the retina may potentially participate in the development of FDM and LIM.

Clinical application of an expanded reverse-island flap with two dorsal metacarpal arteries and dorsal metacarpal nerves in index- and middle-finger-degloving injury repair and amputation reconstruction.

The dorsal metacarpal artery flap (DMAF) is irrefutable as an effective way of repairing long finger defects, and hand surgeons might consider using it for long finger reconstruction or degloved injury repair. Unfortunately, the DMAF containing a single dorsal metacarpal artery (DMA) hinders the treatment effect. The sensory restoration of long fingers and the reconstruction of phalangeal joints and tendon grafts are unsolved challenges as well. We reported our experience in reconstructing the index and middle finger by a reverse-island flap with two DMAs and dorsal metacarpal nerves (DMNs) with blood supply. We reviewed ten patients with finger-crush injuries affecting eight index fingers and two middle fingers. Degloving injuries occurred in two patients, and finger amputations occurred in eight others. Two patients received simple flap reconstruction, and eight received finger reconstruction, including seven from abandoned phalangeal joints and tendon grafts of the severed finger and one from the iliac crest bone graft. All patients underwent finger reconstruction by an expanded reverse-island flap consisting of two DMAs and DMNs up to a maximal size of 9 × 8 cm2. Postoperative follow-up evaluation showed a satisfactory appearance and functional recovery of the reconstructed fingers. We posit that the expanded reverse-island flap involving two DMAs and DMNs constitutes a feasible and safe option for restoring a severely damaged index or middle finger, particularly for patients who are unwilling to undergo toe-to-finger transplantation to reconstruct the injured long fingers.

Purification, characterization and antitumor activities of a new protein from Syngnathus acus, an officinal marine fish.

Discovery and development of new antitumor agents from abundant marine fish are attracting an increasing interest. In the present study, we extracted and purified a novel antitumor protein Syngnathusin from the whole body of Syngnathus acus L., a precious marine fish traditionally used for tumors. Syngnathusin was comprised of 16 kinds of amino acids, mainly acidic amino acids. Its molecular weight was 67.3 kDa and its isoelectric point was 4.57. The N-terminal amino acid sequence of Syngnathusin was determined to be Lys-Arg-Asp-Leu-Gly-Phe-Val-Asp-Glu-Ile-Ser-Ala-His-Tyr and showed no significant homology with the known proteins. Syngnathusin could significantly inhibit the growth of A549 and CCRF-CEM cells. However, the obvious proliferation inhibition against human non-tumor cell lines was not observed. Flow cytometry, morphologic assessment and comet assay revealed that Syngnathusin could induce apoptosis in A549 and CCRF-CEM cells and strongly cooperated with MTX. Syngnathusin could inhibit the growth of S180 tumor transplanted in mice. Syngnathusin may be developed as a novel, selective and effective antineoplastic agent.

RNA-seq analysis reveals differentially expressed inflammatory chemokines in a rat retinal degeneration model induced by sodium iodate.

OBJECTIVE: Retinal degeneration (RD) is a group of serious blinding eye diseases characterized by photoreceptor cell apoptosis and progressive degeneration of retinal neurons. However, the underlying mechanism of its pathogenesis remains unclear. METHODS: In this study, retinal tissues from sodium iodate (NaIO3)-induced RD and control rats were collected for transcriptome analysis using RNA-sequencing (RNA-seq). Analysis of white blood cell-related parameters was conducted in patients with retinitis pigmentosa (RP) and age-related cataract (ARC) patients. RESULTS: In total, 334 mRNAs, 77 long non-coding RNAs (lncRNAs), and 20 other RNA types were identified as differentially expressed in the retinas of NaIO3-induced RD rats. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses showed that differentially expressed mRNAs were mainly enriched in signaling pathways related to immune inflammation. Moreover, we found that the neutrophil-to-lymphocyte ratio was significantly higher in RP patients than in ARC patients. CONCLUSION: Overall, this study suggests that multiple chemokines participating in systemic inflammation may contribute to RD pathogenesis.

Polymorphism rs11200638 enhanced HtrA1 responsiveness and expression are associated with age-related macular degeneration.

OBJECTIVES: To investigate the role of polymorphism rs11200638 of high-temperature requirement factor A-1 (HtrA1) gene in the pathogenesis of age-related macular degeneration (AMD). METHODS: Cultured adult retinal pigment epithelial cells (ARPE-19) expressing HtrA1 gene were treated with H2O2 or lipopolysaccharides (LPS) and analysed using western blot and quantitative polymerase chain reaction to illustrate the effects of oxidative and inflammatory stress on HtrA1 gene expression. Luciferase reporter plasmid driven by HtrA1 promoter with either normal allele G or risk allele A at SNP rs11200638 was transfected to ARPE-19 cells to investigate the effect of the G/A variation on HtrA1 promoter activity. The effects of HtrA1 overexpression on ARPE-19 cells were analysed with respect to percentage of cell proliferation inhibition and cell apoptosis. RESULTS: HtrA1 expression was significantly increased with LPS or H2O2 stimulations (p < 0.05). In ARPE-19 cells, HtrA1 promoters (-1 to -2175 bp from translation starting point) with risk allele A or normal G at rs11200638 did not show statistically significant differences in their luciferase reporter expression (p = 0.054425173), however, both promoters showed a persistent trend of higher luciferase expressions after 100 ng/ml LPS treatment. The luciferase expression level was significantly greater in the promoter with risk A when compared to that with normal G. Overexpression of HtrA1 resulted in apoptosis of ARPE-19 cells with 53.8 ± 1.6% of proliferation inhibition (p < 0.01). CONCLUSIONS: Risk haplotype A at rs11200638 significantly increased the responsiveness of HtrA1 promoter to inflammation and subsequently enhanced HtrA1 expression. HtrA1 overexpression induced ARPE-19 apoptosis and growth inhibition, relevant to pathogenesis of AMD.