Identification of Key lncRNAs in Gout Under Copper Death and Iron Death Mechanisms: A Study Based on ceRNA Network Analysis and Random Forest Algorithm

This study focused on identifying potential key lncRNAs associated with gout under the mechanisms of copper death and iron death through ceRNA network analysis and Random Forest (RF) algorithm, which aimed to provide new insights into the molecular mechanisms of gout, and potential molecular targets for future therapeutic strategies of gout. Initially, we conducted an in-depth bioinformatics analysis of gout microarray chips to screen the key cuproptosis-related genes (CRGs) and key ferroptosis-related genes (FRGs). Using these data, we constructed a key ceRNA network for gout. Finally, key lncRNAs associated with gout were identified through the RF algorithm combined with ROC curves, and validated using the Comparative Toxicogenomics Database (CTD). We successfully identified NLRP3, LIPT1, and DBT as key CRGs associated with gout, and G6PD, PRKAA1, LIG3, PHF21A, KLF2, PGRMC1, JUN, PANX2, and AR as key FRGs associated with gout. The key ceRNA network identified four downregulated key lncRNAs (SEPSECS-AS1, LINC01054, REV3L-IT1, and ZNF883) along with three downregulated mRNAs (DBT, AR, and PRKAA1) based on the ceRNA theory. According to CTD validation inference scores and biological functions of target mRNAs, we identified a potential gout-associated lncRNA ZNF883/hsa-miR-539-5p/PRKAA1 regulatory axis. This study identified the key lncRNA ZNF883 in the context of copper death and iron death mechanisms related to gout for the first time through the application of ceRNA network analysis and the RF algorithm, thereby filling a research gap in this field and providing new insights into the molecular mechanisms of gout. We further found that lncRNA ZNF883 might function in gout patients by regulating PRKAA1, the mechanism of which was potentially related to uric acid reabsorption in the proximal renal tubules and inflammation regulation. The proposed lncRNA ZNF883/hsa-miR-539-5p/PRKAA1 regulatory axis might represent a potential RNA regulatory pathway for controlling the progression of gout disease. This discovery offered new molecular targets for the treatment of gout, and had significant implications for future therapeutic strategies in managing the gout.

[Arterial spin labeling in assessment of interstitial fibrosis in renal allografts]

Objective: To explore the feasibility and application value of arterial spin labeling (ASL) in evaluating the degree of renal fibrosis after kidney transplantation. Methods: This is a cross-sectional study. Renal transplant recipients who received treatment at the First Affiliated Hospital of Soochow University from December 2021 to December 2022 were enrolled. All participants underwent ASL scan, and the values of renal cortical renal blood flow (RBF) were measured through post-processing software. The participants were divided into different groups according to the Banff interstitial fibrosis score (ci score) of the transplanted kidneys, and then relevant indicators were compared. One-way analysis of variance was conducted to compare the differences in renal cortical RBF among the groups. Spearman correlation analysis was employed to investigate the association between renal cortical RBF and ci score of the transplanted kidney. Receiver operating characteristic curve was used to analyze the diagnostic effectiveness of renal cortical RBF and laboratory indicators for distinguishing varying degrees of fibrosis in transplanted kidneys. The Delong test was utilized to compare the area under the curve (AUC). Results: A total of 60 patients (42 males and 18 females) were included in the study, with a mean age of (44.6±10.8) years. All patients were divided into 4 groups: ci0 group (ci score=0, 11 cases), ci1 group (ci score=1, 21 cases), ci2 group (ci score=2, 20 cases), and ci3 group (ci score=3, 8 cases). With an increase in the degree of fibrosis in the transplanted kidney, there was a corresponding decrease in the renal cortical RBF value. The differences in renal cortical RBF values among the 4 groups were statistically significant[ci0 group: (214.9±28.5) ml·(100 g)-1·min-1; ci1 group: (181.7±29.3) ml·(100 g)-1·min-1; ci2 group: (158.8±39.2) ml·(100 g)-1·min-1; ci3 group: (123.1±27.2) ml·(100 g)-1·min-1; F=14.02, P<0.001]. The renal cortical RBF was moderately negatively correlated with the ci score (r=-0.644, P<0.001). The AUC for discriminating between ci0 and ci1-3 of renal cortical RBF and 24-hour urine protein was 0.881 (95%CI: 0.772-0.950) and 0.680 (95%CI: 0.547-0.795), respectively. The AUC for renal cortical RBF was significantly higher than that for 24-hour urine protein (P=0.047). The renal cortical RBF can distinguish between ci0-1 and ci2-3, as well as ci0-2 and ci3, with the corresponding AUC value of 0.796 (95%CI: 0.673-0.889) and 0.900 (95%CI: 0.795-0.963), respectively. Conclusion: ASL can quantitatively assess renal blood perfusion in transplanted kidneys and demonstrates high operational efficacy in distinguishing varying degrees of fibrosis in the transplanted kidneys.

Establishment of a rabbit model of extrascleral extension of ocular melanoma

PURPOSE

To establish an animal model of extrascleral extension of choroidal melanoma.

METHODS

Pigmented choroidal tumors were established in nine New Zealand albino rabbit eyes using B16F10 melanoma cell line. The sclerotomy site was not closed in the subgroup of six rabbits where extrascleral extension was desired. For the control group, the sclerotomy site was sutured with 8-0 nylon. Animals were treated with daily injections of cyclosporine and followed by serial fundus examinations, color Doppler imaging, and fundus photography. All tumor-bearing eyes were enucleated at the end of the follow-up period and examined for extrascleral extension.

RESULTS

Extrascleral extension of choroidal melanoma occurred in all six animals with open sclerotomy sites. No extrascleral extension was observed in the control group. Color Doppler imaging identified extrascleral extension which was confirmed on gross histology.

CONCLUSIONS

Our animal model of extrascleral extension of choroidal melanoma requires minimal surgery to establish, and is reproducible and easy to follow with standard diagnostic equipment.

Digital angiography of experimental choroidal melanomas using benzoporphyrin derivative

PURPOSE

To examine benzoporphyrin derivative angiography as a modality for studying photosensitizer biodistribution in experimental choroidal melanomas.

METHODS

A liposomal preparation of benzoporphyrin derivative was used in this study. Digital benzoporphyrin derivative angiograms were performed in 10 rabbits (six for experimental choroidal melanomas, two for normal choroids, and two for irides) using a Topcon ImageNet H1024 digital imaging system, a Kodak Megaplus video camera, and a Topcon TRC-50-VT fundus camera. Only one eye from each rabbit was used. Filters specifically designed for benzoporphyrin derivative (peak absorption at 580 nm and peak emission at 695 nm) were used. Benzoporphyrin derivative (1 mg/kg) was injected into an ear vein while images of tumor, normal choroid, or iris were being obtained. Follow-up images were obtained during the first 3 hours and at 24 hours after injection. Fluorescence microscopy was performed in all 10 rabbits using 1 mg/kg of benzoporphyrin derivative. Tumor-bearing eyes were enucleated at the same time points that angiograms were performed, and the two sets of results were compared for maximum dye accumulation.

RESULTS

Digital angiography demonstrated that maximal benzoporphyrin derivative fluorescence occurred in tumors 15 to 45 minutes after injection. Fluorescence photometry corroborated these results.

CONCLUSION

Photosensitizer angiography is a valid modality for determining the optimum treatment time for photodynamic therapy.

Photodynamic therapy of pigmented choroidal melanomas of greater than 3-mm thickness

PURPOSE

The purpose of the study is to determine the effect of photodynamic therapy in the destruction of experimental pigmented choroidal melanomas > or = 3 mm in thickness using a liposomal preparation of benzoporphyrin derivative, verteporfin.

METHODS

Pigmented choroidal tumors were established in 32 New Zealand albino rabbit eyes. Animals were treated with daily injections of cyclosporine, and tumor growth was followed by serial fundus examinations and ultrasonography. When a tumor exceeded 3 mm in thickness (tumor height ranged from 3.1-4.6 mm), the authors administered benzoporphyrin derivative intravenously (1 mg/kg) and irradiated the tumor at 692-nm through an argon-pumped dye laser at different total light doses ranging from 60 to 120 J/cm2. Control animals were treated with light or benzoporphyrin derivative only. Each animal then was followed-up for 4 to 6 weeks by fundus photography, fluorescein angiography, and ultrasonography.

RESULTS

All animals treated with benzoporphyrin derivative and light at fluences of > or = 80 J/cm2 showed complete tumor arrest. In contrast, both control groups showed continuous tumor growth in all animals with tumors filling most of the vitreous cavity by 3 weeks. Histologic examination results of tumors treated with dye plus light immediately after treatment showed prominent vascular closure. No vascular changes were noted in the control eye treated with light or dye alone. Examination results of the eyes that showed tumor regression after a 4-week follow-up period showed tumor necrosis and extensive infiltration of mononuclear cells and pigment-laden macrophages at the tumor site.

CONCLUSIONS

These data suggest that photodynamic therapy may have a role in the management of pigmented choroidal melanomas.

Photodynamic therapy of pigmented choroidal melanomas using a liposomal preparation of benzoporphyrin derivative

OBJECTIVE

To evaluate the effectiveness of photodynamic therapy of pigmented choroidal melanoma using a liposomal preparation of benzoporphyrin derivative monoacid (BPD), verteporfin.

DESIGN

Pigmented choroidal melanomas were established in 25 New Zealand albino rabbit eyes. The animals were treated with daily injections of cyclosporine, and tumor growth was monitored with funduscopic examination and ultrasonography. Fifteen minutes after intravenous injection of BPD (2 mg/kg), the tumors were irradiated at 692 nm through an argon-pumped dye laser with the delivered fluence ranging between 40 and 150 J/cm2. Control animals were treated with light only, photosensitizer only, or observation only. Tumor growth was monitored by indirect ophthalmoscopy, fundus photography, fluorescein angiography, and ultrasonography. Histologic examination was performed.

RESULTS

Eighteen tumor-bearing rabbits were treated with light and BPD; 16 were followed up for 1 month, and two were killed immediately for histologic examination. Tumors regressed in all eyes treated with 60 J/cm2 or more. With fluence of 40 J/cm2, tumor regrowth was observed in one animal within 10 days of treatment. In the three control groups, all animals showed continuous tumor growth. Histologic examination of the eyes treated with photosensitizer and light immediately after treatment showed prominent vascular occlusion throughout the full thickness of the tumor. One month after treatment, tumor necrosis and infiltration of mononuclear cells and pigment-laden macrophages were the predominant findings.

CONCLUSIONS

Photodynamic therapy with BPD may have a role in the treatment of pigmented choroidal melanomas.

Photoimmunotherapy of human uveal melanoma cells

To examine whether tumor-reactive monoclonal antibodies can be used to enhance photodestruction of human uveal melanoma cells, we conjugated photosensitizer chlorin e6 monoethylenediamine monoamide (CMA) with a melanoma-reactive monoclonal antibody IG12 and evaluated the effectiveness of this immunoconjugate (IC) in the destruction of OCM431 human uveal melanoma cells in vitro. RPMI1846 melanoma cells do not react with IC and were used as non-target cells. For control, target and non-target cells were treated with IC or light alone. The effects of IC and free CMA in the destruction of melanoma cells were compared. Cell survival was assessed by a colorimetric assay using tetrazolium salt MTT. Target (OCM431) cells preincubated with IC and irradiated with 5-40 J cm-2 showed light dose-dependent decrease in cell survival. At 40 J cm-2, OCM431 cells preincubated with IC showed only 6 +/- 1.4% viability. Under same treatment, non-target (RPMI1846) cells showed much less phototoxicity; cell survival was 54 +/- 2.1%. Treatment with free CMA and light at 40 J cm-2 showed similar phototoxicity to both target and non-target cells, with cell survival being 24.3 +/- 3.5% and 23.7 +/- 1.5%, respectively. These results show that our IC is effective in causing photodestruction of human uveal melanoma cells in vitro. The phototoxicity is selective and more potent than free CMA.

Photodynamic therapy of pigmented choroidal melanomas

PURPOSE

To evaluate the effectiveness of photodynamic therapy with chloroaluminum sulfonated phthalocyanine in the treatment of pigmented choroidal melanomas in a rabbit model.

METHODS

Pigment containing B16F10 murine melanoma cells were implanted transclerally into the subchoroidal space of 28 immunosuppressed New Zealand albino rabbits. The animals were treated with daily injections of cyclosporine and were followed up until tumors at least 2 mm in height were detected by ultrasonography. Twenty-four hours after the intravenous injection of chloroaluminum sulfonated phthalocyanine (CASPc, 5 mg/kg), tumors were irradiated at 675 nm through an argon-pumped dye laser at estimated total light doses of 25 to 70 J/cm2. Control animals were treated with light only or photosensitizer only. The animals were followed up for 4 1/2 to 8 weeks with regular fundus examinations.

RESULTS

Twenty tumor-bearing rabbits were treated with light and dye. The tumor regressed in 12 animals. Five of these animals were followed up for at least 4 1/2 weeks and the other seven for 8 weeks after treatment. At light doses under 40 J/cm2, tumor regrowth was observed in five animals within 10 days of treatment. In all control groups, the tumor-bearing eyes were filled with tumor cells by the third week after implantation. Histologic examination of tumors treated with photosensitizer and light revealed prominent vascular damage early after treatment that resulted in vascular occlusion. Tumor necrosis was evident within 24 hours of treatment.

CONCLUSIONS

Results suggest that photodynamic therapy may have a role in the treatment of pigmented choroidal melanomas.

Establishment of pigmented choroidal melanomas in a rabbit model

PURPOSE

To establish an animal model of pigmented choroidal melanoma.

METHODS

Four melanoma cell lines originally isolated from melanotic tumors (B16F10, RPMI 1846, OCM 1, and IIB) were used to establish choroidal melanomas in 105 rabbits; 88 animals were immunosuppressed with cyclosporine. Tumor cells were implanted transclerally and examined with indirect ophthalmoscopy, ultrasound, and photography.

RESULTS

Characteristic growth patterns were noted for each cell line. Animal cell lines typically produced choroidal tumors 3 to 4 mm in height within 2 weeks; human cell lines took an additional 7 to 10 days to achieve tumors of similar height. Tumors of heaviest pigmentation were generated consistently with the B16F10 cells, and with the other three cell lines only mild pigmentation was observed. Tumor shape varied depending on the source of implantation: diffuse, flat tumors were observed when cell suspensions were implanted, and nodular tumors were obtained with tumor fragments. Histopathologically, lesions were highly cellular, with rich vascularity and large numbers of mitotic figures.

CONCLUSION

As the majority of human uveal melanomas are pigmented, the added feature of pigmentation associated with this model makes it more suitable for evaluating the role of newly developed phototherapies in the management of uveal melanoma.