Choroidal vascular changes in silicone oil-filled eyes after vitrectomy for rhegmatogenous retinal detachments.

INTRODUCTION: The tamponade of silicone oil (SO) can affect both the structure and blood flow of the retina. However, there are few studies on the effect of SO tamponade on choroidal blood flow. Our study aimed to compare the effects of SO tamponade on the choroidal vascular index (CVI) and choroidal thickness (CT) in patients with unilateral rhegmatogenous retinal detachment (RRD) with operated eyes and fellow healthy eyes. METHODS: We retrospectively collected demographic and clinical data from 36 patients who underwent 23G pars plana vitrectomy and SO tamponade for unilateral complicated RRD. Enhanced depth imaging-optical coherence tomography (EDI-OCT) scans were performed both within 1 week before SO removal and at the last follow-up visit after SO removal. Using ImageJ software, images were binarized to segment the total choroidal area, luminal area, and stromal area, respectively. The CVI was calculated as CVI=(luminal area)/(total choroidal area), and CT was also evaluated. RESULTS: During SO tamponade, the CVI and luminal area in operated eyes were significantly lower compared to fellow eyes (57.616 ± 0.030 vs. 60.042 ± 0.019, P < 0.0001; 0.909 [0.694; 1.185] vs. 1.091 [0.785; 1.296], P = 0.007). Even after SO removal, the CVI remained lower in operated eyes than in fellow eyes (59.530 ± 0.018 vs. 60.319 ± 0.020, P = 0.031). Both CVI and luminal area were lower in operated eyes before SO removal than after SO removal (57.616 ± 0.030 vs. 59.530 ± 0.018, P = 0.0003; 0.909 [0.694; 1.185] vs. 0.994 [0.712; 1.348], P = 0.028). The duration of SO tamponade was positively correlated with the difference in CVI between fellow eyes and operated eyes during SO tamponade (P = 0.035). Total choroidal area, stromal area, and CT did not differ significantly between fellow eyes and operated eyes or between pre- and post-SO removal. CONCLUSIONS: SO tamponade reduces CVI and decreases choroidal blood circulation in patients with retinal detachments required vitrectomy combined with SO tamponade. The longer the SO tamponade time, the more CVI reduction. In future work, we will aim to reduce these side effects by shortening the duration of silicone oil filling.

Micromechanical Loading Studies in Ex Vivo Cultured Embryonic Rat Bones Enabled by a Newly Developed Portable Loading Device.

Mechanical loading has been described as having the potential to affect bone growth. In order to experimentally study the potential clinical applications of mechanical loading as a novel treatment to locally modulate bone growth, there is a need to develop a portable mechanical loading device enabling studies in small bones. Existing devices are bulky and challenging to transfer within and between laboratories and animal facilities, and they do not offer user-friendly mechanical testing across both ex vivo cultured small bones and in vivo animal models. To address this, we developed a portable loading device comprised of a linear actuator fixed within a stainless-steel frame equipped with suitable structures and interfaces. The actuator, along with the supplied control system, can achieve high-precision force control within the desired force and frequency range, allowing various load application scenarios. To validate the functionality of this new device, proof-of-concept studies were performed in ex vivo cultured rat bones of varying sizes. First, very small fetal metatarsal bones were microdissected and exposed to 0.4 N loading applied at 0.77 Hz for 30 s. When bone lengths were measured after 5 days in culture, loaded bones had grown less than unloaded controls (p < 0.05). Next, fetal rat femur bones were periodically exposed to 0.4 N loading at 0.77 Hz while being cultured ex vivo for 12 days. Interestingly, this loading regimen had the opposite effect on bone growth, i.e., loaded femur bones grew significantly more than unloaded controls (p < 0.001). These findings suggest that complex relationships between longitudinal bone growth and mechanical loading can be determined using this device. We conclude that our new portable mechanical loading device allows experimental studies in small bones of varying sizes, which may facilitate further preclinical studies exploring the potential clinical applications of mechanical loading.

3D Visualization System-Assisted Vitrectomy for Rhegmatogenous Retinal Detachment: Leave Out the Perfluorocarbon Liquid.

INTRODUCTION: Pars plana vitrectomy (PPV) is a primary strategy to restore vision for patients who have rhegmatogenous retinal detachment (RRD). Perfluorocarbon liquid (PFCL) is frequently used during PPV surgery. However, the unintended intraocular retention of PFCL may cause retina toxicity and thus lead to possible postoperative complications. In this paper, the experiences and surgical outcomes of a NGENUITY 3D Visualization System-assisted PPV are shown to evaluate the possibility of excluding the application of PFCL. METHODS: A consecutive series of 60 cases with RRD were presented, all of whom had undergone 23-gauge PPV with the assistance of a three-dimensional (3D) visualization system. Among them, 30 cases used PFCL to assist the drainage of subretinal fluid (SRF), while the other 30 cases did not. Parameters including retinal reattachment rate (RRR), best-corrected visual acuity (BCVA), operation time, and SRF residual were compared between the two groups. RESULTS: Baseline data showed no statistical significance between the two groups. At the last postoperative follow-up, the RRR of all the 60 cases reached 100% and best-corrected visual acuity (BCVA) gained significant improvement. The BCVA (logMAR) increased from 1.293 ± 0.881 to 0.479 ± 0.316 in the PFCL-excluded group, exhibiting better results than the PFCL included group, whose final BCVA was 0.650 ± 0.371. More importantly, excluding PFCL greatly reduced the operation time (decrease of 20%), therefore, avoiding possible complications caused by both the use of PFCL and the operation process. CONCLUSION: With the assistance of the 3D visualization system, it is feasible to treat RRD and perform PPV without using PFCL. The 3D visualization system is highly recommendable, as not only can it achieve the same surgical effect without the assistance of PFCL, but also simplify the operation procedure, shorten the operation time, save costs, and avoid complications related to PFCL.

FOLDABLE CAPSULAR VITREOUS BODY IMPLANTATION FOR COMPLICATED RETINAL DETACHMENT CAUSED BY SEVERE OCULAR TRAUMA.

PURPOSE: To explore the effectiveness, safety and psychological impact of foldable capsular vitreous body (FCVB) implantation for complicated retinal detachment caused by severe ocular trauma. METHODS: This was a prospective, single-arm, surgical interventional case series study. A standard 3-port 23-gauge pars plana vitrectomy was performed, and the FCVB was implanted into the vitreous cavity. Observed indicators, including the best-corrected visual acuity, intraocular pressure (IOP), retinal reattachment, complications, and patient satisfaction, were analyzed to evaluate the study. RESULTS: A total of 28 cases (eyes) were enrolled, with a mean follow-up of 16.93 ± 9.67 months and an average age of 51.11 ± 10.14 years, including 22 men (78.57%). The FCVB was successfully implanted, and the retina was reattached in all cases. The postoperative best-corrected visual acuity improved in 7 cases, and remained unchanged in 21 cases ( P > 0.05). The average IOP was 7.01 ± 2.43 mmHg before surgery and 8.54 ± 2.93 mmHg after surgery ( P < 0.05). Complications such as FCVB displacement, endophthalmitis, secondary glaucoma, silicone oil emulsification, and escape did not occur during the follow-up period. Patients with FCVB implantation are highly satisfied. Most patients feel hope, positive, and optimistic about life. CONCLUSION: Foldable capsular vitreous body implantation for complicated retinal detachment caused by severe ocular trauma is effective and safe, and it allows patients to face life positively and optimistically.

Case Report: Vitreous Amyloidosis Caused by a TTR Lys55Asn Mutation With Intraoperative Suprachoroidal Hemorrhage.

We report a vitreous amyloidosis patient with white vitreous opacities (footplates) adhering to the posterior lens capsule. A positive Congo-red stain and transthyretin (TTR) Lys55Asn mutation confirmed the diagnosis of vitreous amyloidosis. Optical coherence tomography (OCT) revealed fern-like material adhering to the the posterior pole retinal surface in both eyes. Visual acuity significantly improved after the first vitrectomy, but vitreous opacities recurred 4 years later. The patient appeared to have aggravated sensorimotor neuropathy and severe autonomic dysfunction at the same time. He developed intraoperative suprachoroidal hemorrhage during the second vitrectomy.

The Notch Pathway Promotes Osteosarcoma Progression through Activation of Ephrin Reverse Signaling.

Despite significant advancements in the diagnosis and treatment of osteosarcoma, the molecular mechanisms underpinning disease progression remain unclear. This work presents strong clinical and experimental evidence demonstrating that Notch signaling contributes to osteosarcoma progression. First, using a cohort of 12 patients, Notch genes were upregulated in tumors compared with adjacent normal tissue, and high tumor expression of Notch1 intercellular domain (NICD1) and the Notch target gene Hes1 correlated with poor chemotherapy response. Data mining of publicly available datasets confirmed that expression of Notch pathway genes is related to poor prognosis in osteosarcoma. On the basis of in vitro analysis, Notch signaling promoted osteosarcoma proliferation, enhanced chemoresistance, facilitated both migration and invasion, and upregulated stem cell-like characteristics. Xenograft models demonstrated that Notch signaling promotes primary tumor growth and pulmonary metastasis, and Notch inhibition is effective in reducing tumor size and preventing metastasis. Mechanistically, activated Notch signaling induces the expression of ephrinB1 and enhances the tumor-promoting ephrin reverse signaling. Overall, these findings provide functional evidence for Notch pathway genes as candidate biomarkers to predict prognosis in patients with osteosarcoma, and suggest a mechanistic rationale for the use of Notch inhibitors to treat osteosarcoma. IMPLICATIONS: The study provides preclinical evidence for Notch pathway as a molecular marker to predict osteosarcoma prognosis and as a therapeutic target against osteosarcoma. In addition, we identified a novel mechanism that ephrin reverse signaling acts as a key mediator of Notch pathway.

Abnormal Ribosome Biogenesis Partly Induced p53-Dependent Aortic Medial Smooth Muscle Cell Apoptosis and Oxidative Stress.

Ribosome biogenesis is a crucial biological process related to cell proliferation, redox balance, and muscle contractility. Aortic smooth muscle cells (ASMCs) show inhibition of proliferation and apoptosis, along with high levels of oxidative stress in aortic dissection (AD). Theoretically, ribosome biogenesis should be enhanced in the ASMCs at its proliferative state but suppressed during apoptosis and oxidative stress. However, the exact status and role of ribosome biogenesis in AD are unknown. We therefore analyzed the expression levels of BOP1, a component of the PeBoW complex which is crucial to ribosome biogenesis, in AD patients and a murine AD model and its influence on the ASMCs. BOP1 was downregulated in the aortic tissues of AD patients compared to healthy donors. In addition, overexpression of BOP1 in human aortic smooth muscle cells (HASMCs) inhibited apoptosis and accumulation of p53 under hypoxic conditions, while knockdown of BOP1 decreased the protein synthesis rate and motility of HASMCs. The RNA polymerase I inhibitor cx-5461 induced apoptosis, ROS production, and proliferative inhibition in the HASMCs, which was partly attenuated by p53 knockout. Furthermore, cx-5461 aggravated the severity of AD in vivo, but a p53-/- background extended the life-span and lowered AD incidence in the mice. Taken together, decreased ribosome biogenesis in ASMCs resulting in p53-dependent proliferative inhibition, oxidative stress, and apoptosis is one of the underlying mechanisms of AD.

MicroRNA-192-5p suppresses the initiation and progression of osteosarcoma by targeting USP1.

Osteosarcoma is the most frequent primary malignant bone tumor. An increasing body of evidence has suggested that microRNAs (miRNA/miRs) have emerged as critical regulators in the initiation and progression of osteosarcoma. The present study explored the biological function of miR-192-5p and ubiquitin-specific protease 1 (USP1), and investigated whether miR-192-5p could directly interact with USP1 in osteosarcoma. The results revealed that miR-192-5p was significantly downregulated in osteosarcoma tissues and cell lines, while a reverse expression profile of USP1 was observed. Ectopic expression of miR-192-5p restrained cell proliferation, apoptosis, migration and invasion. In addition, it increased the sensitivity of osteosarcoma cells to cisplatin. USP1 was also observed to be a direct target gene of miR-192-5p in osteosarcoma. Overexpression of USP1 promoted cell proliferation, apoptosis, migration and invasion, and decreased cell chemo-sensitivity; however, it could be partially reversed via the overexpression of miR-192-5p in osteosarcoma cell lines. Taken together, the present study demonstrated that miR-192-5p suppressed the initiation and progression of osteosarcoma by targeting USP1. Therefore, miR-192-5p may serve as a valuable biomarker and the miR-192-5p/USP1 axis may function as a novel therapeutic target for osteosarcoma.

Predicting the visual acuity for retinal vein occlusion after ranibizumab therapy with an original ranking for macular microstructure.

The study investigated predictive factors for best-corrected visual acuity (BCVA) after ranibizumab treatment in patients with macular edema (ME) associated with retinal vein occlusion (RVO) with an original ranking for the impairment of macular microstructure. In this retrospective study, 31 eyes of 31 patients with RVO received 3 monthly consecutive ranibizumab injections and another 3 months of follow-up. An original method was applied to rank the impairment of the external limiting membrane (ELM) and the ellipsoid zone (previously called the photoreceptor inner and outer segment junction, IS/OS) integrity on the baseline optical coherence tomography (OCT) images. Univariate and multivariate linear regression analyses were performed to assess the association between the baseline factors and post-treatment BCVA. ELM integrity and baseline BCVA were shown to be independent factors in the prediction of post-treatment BCVA. Comparison of post-treatment BCVA between original ELM ranks after adjusting for the baseline BCVA revealed the ELM integrity beneath the center of the fovea was important to post-treatment BCVA. ELM integrity in particular beneath the center of the fovea and baseline BCVA may be more useful than other factors in the prediction of visual function in patients with ME secondary to RVO after ranibizumab injections.

The synergistic antitumor effect of cinobufagin and cisplatin in human osteosarcoma cell line in vitro and in vivo.

Cisplatin (CDDP) has been shown to be a promising anticancer drug that is effective against many types of cancer, which include osteosarcoma (OS). However, its therapeutic application is restricted by its toxicity in normal tissues and by side effects caused in patients. Reduction of the toxicity of CDDP is necessary to improve cancer treatment. In the present study, we attempted to clarify how cinobufagin, a traditional Chinese medicine, enhances CDDP-induced cytotoxicity in OS cells. OS 143B cells were treated with cinobufagin and CDDP alone or in combination. After low dose combined treatments with cinobufagin and CDDP, the effects of these therapeutics on cell proliferation, apoptosis, cell cycle, migration, invasion, and involvement in Notch pathway, as well as tumor growth and metastatic capability were determined. It was found that the combination of low doses of cinobufagin and CDDP markedly inhibited cell activity, motility, and induced apoptosis and cell cycle arrest in S phase, as well as suppressing tumor growth, metastasis and prolonging longer survival of nude mice in OS xenograft models compared with the actions of either drug alone or vehicle. The results also demonstrated that cinobufagin plus CDDP significantly suppressed the Notch pathway. The anticancer mechanism of these two drugs may involve intervention in the Notch signaling, which may contribute to inhibit tumor growth. All of these results suggest that application of lower concentration cinobufagin plus CDDP could produce a synergistic antitumor effect and this finding warrants further investigation for its potential clinical applications in human OS patients.

Telomerase reverse transcriptase promotes chemoresistance by suppressing cisplatin-dependent apoptosis in osteosarcoma cells.

Cisplatin is one of the most efficacious antimitotic drugs used in the treatment of a range of malignant tumors. However, treatment failures are common due to the development of chemoresistance. In addition to its telomere maintenance function, telomerase plays a pro-survival role, inducing decreased apoptosis and increased resistance against DNA damage. Elucidation of the molecular mechanisms underlying this effect is critical to improve treatment outcomes. Previously, our group showed higher telomerase reverse transcriptase(TERT) expression in cisplatin resistant osteosarcoma cells. In this study, confocal fluorescence microscopy experiments revealed that TERT translocates from the nucleus to mitochondria in cisplatin treated osteosarcoma cells. We observed decreased apoptosis rate and improved mitochondrial function in TERT-overexpressing cells following cisplatin treatment. Based on these results, we further established that TERT inhibits cisplatin-induced apoptosis independently of telomerase reverse transcriptase activity. Moreover, TERT suppressed cisplatin-induced apoptosis and improved mitochondrial function via alleviating intracellular ROS in osteosarcoma cells. Our finding that TERT shuttles from the nucleus to the mitochondrion in response to cisplatin treatment and inhibits cisplatin-induced apoptosis in osteosarcoma cells may be especially important to overcome drug resistance.

Chitosan oligosaccharides protect nucleus pulposus cells from hydrogen peroxide-induced apoptosis in a rat experimental model.

Chitosan has been investigated for its protective effect on nucleus pulposus (NP) cells against intervertebral disc degeneration(IDD), but its high molecular weight prohibits its clinical application. The low molecular derivatives, chitosan oligosaccharides (COS) are easier to absorb; however, the protective effect of COS against IDD remains unclear. In this study, we investigated the effects of COS on NP degeneration. NP cells derived from rats were treated with H2O2 to induce an IDD-like transition. Then, COS was used to pre-treat cells before administering H2O2 and changes occurring in the cells were observed. As shown by the result of a cell counting kit-8(CCK-8) assay, COS protected the viability of the cells. The induced apoptosis rate fell when cells were pre-treated with COS, revealed by annexin-V FITC/PI double staining analysis and Hoechst 33342 staining. COS administration also protected ECM synthesis and prevented its degradation, as shown by western blotting(WB) and polymerase chain reaction(PCR). We analyzed the activity of the PI3K/Akt pathway in H2O2 treated NP cells by WB and the result showed that COS could enhance activity of the pathway. To investigate the relationship between the PI3K/Akt pathway and the protective effects of COS on NP cells, the PI3K/Akt pathway was inhibited by wortmannin, and we subsequently found that this abolished the protective effects. These results support the hypothesis that COS exerts its protective effect on NP cells against H2O2-induced apoptosis via the PI3K/Akt pathway.

Suncon medical adhesive is a suitable alternative to fibrin glue in the 23G minimally invasive vitrectomy.

Fibrin glue is frequently used to close the incision of the sclera and conjunctiva. However, its use is limited due to its blood-borne origins. The study evaluated the suitability of Suncon medical adhesive as a replacement for fibrin glue in 23G minimally invasive vitrectomy as an animal study. One eye of Japanese white rabbits (total, 18 rabbits) received an intravitreal injection of 0.05 ml of Suncon medical adhesive, while the other eye was injected with 0.05 ml of saline and served as the control eye. Slit lamp, indirect ophthalmoscope and electroretinogram (ERG) examinations were carried out before and 28 days after the interventions. At the end of the observation period (28 days), ophthalmectomy was performed for the light microscopy examination. ERG measurements included the b-wave amplitude of rod cell response (Rod-R), maximum mixing response (Max-R) and cone cell response (Cone-R), P2-wave amplitude of oscillatory potentials (Ops) and mean amplitude of 30 Hz scintillation response. The slit lamp examination showed no abnormal inflammatory reactions in the control or treatment eyes. The difference in ERG measurements was not statistically significant between the control or treatment eyes. Furthermore, the cells in each layer of retinas exposed to Suncon medical adhesive or saline were morphologically normal under light microscopy. In conclusion, Suncon medical adhesive injected at doses of 0.05 ml is well-tolerated by the retina. Therefore, the Suncon medical adhesive is a suitable alternative to fibrin glue.

miR-335 negatively regulates osteosarcoma stem cell-like properties by targeting POU5F1.

BACKGROUND: Evidence is accumulating to link cancer stem cells to the pathogenesis and progression of osteosarcoma. The aim of this study is to investigate the role of miR-335 in osteosarcoma stem cells. METHODS: Tumor spheroid culture and flow cytometry were applied to screen out osteosarcoma stem cells. Real-time quantitative PCR was used to detect the expression level of miR-335 in MG63, U2OS and 143B osteosarcoma stem cells. The relationship of miR-335 expression with osteosarcoma stem cells was then analyzed. Transwell assay and transplantation assay were performed to elucidate biological effects of miR-335 on cell invasion and vivo tumor formation. Western Blot and luciferase assays were executed to investigate the regulation of POU5F1 by miR-335. RESULTS: The expression of miR-335 in osteosarcoma stem cells was lower than their differentiated counterparts. Cells expressing miR-335 possessed decreased stem cell-like properties. Gain or loss of function assays were applied to find that miR-335 antagonist promoted stem cell-like properties as well as invasion. Luciferase report and transfection assay showed that POU5F1 was downregulated by miR-335. Pre-miR-335 resulted in tumor enhanced sensitivity to traditional chemotherapy, whereas anti-miR-335 promoted chemoresistance. Finally, the inhibitory effect of miR-335 on in vivo tumor formation showed that combination of pre-miR-335 with cisplatin further reduced the tumor size, and miR-335 brought down the sphere formation capacity induced by cisplatin. CONCLUSIONS: The current study demonstrates that miR-335 negatively regulates osteosarcoma stem cell-like properties by targeting POU5F1, and miR-335 could target CSCs to synergize with traditional chemotherapeutic agents to overcome osteosarcoma.

Cinobufagin induces apoptosis of osteosarcoma cells through inactivation of Notch signaling.

Osteosarcoma (OS) is a major cause of cancer-related mortality in children and young adults worldwide. Due to preexisting or acquired chemoresistance, the current standard neoadjuvant chemotherapy regimens show only moderate activity against OS. In the current study, we explored the potential anti-OS Cinobufagin in vitro and in vivo, and investigated its underlying mechanisms. The antitumor potential of Cinobufagin was assessed using cell viability assays, and cycle and apoptosis were determined. In a cell-based assay, the mRNA and protein expression of Notch-1, Hes-1, Hes-5 and Hey-1 were determined by quantitative polymerase chain reactions and western blotting. The involvement of Notch signaling in Cinobufagin-induced apoptosis was confirmed using gain and loss-of function assays. A xenograft OS model was established and the antitumor effect and biosafety of Cinobufagin were evaluated. Cinobufagin suppressed OS cells growth in a dose- and time-dependent manner, involving both cell cycle arrest at the S phase and programmed cell death. Cinobufagin treatment decreased the expression of Notch-1, and Hes-1, Hes-5 and Hey-1 gene expression in OS cell lines. Furthermore, Notch activation attenuated the Cinobufagin-induced apoptosis, while Notch inhibition enhanced this effect. Using a mouse xenograft model, we found that Cinobufagin inhibited OS cell growth in vivo. The mice showed excellent tolerance to Cinobufagin treatment. Taken together, our data suggested that Cinobufagin inhibited cell survival and induced apoptosis in OS cells both in vitro and in vivo, and these effects were partly mediated through the Notch pathway.

[Endoplasmic reticulum stress participates in the cell apoptosis process in experimental retinal detachment].

OBJECTIVE: To determine whether the endoplasmic reticulum stress participates into the apoptosis process of the retina during experimental retinal detachment-by detecting the level of mRNA and protein of the GADD153, the marker of endoplasmic reticulum stress. METHODS: Completely random design is applied. Experimental retinal detachment was created in the left eyes of 77 wistar rats by injecting hyaluronic acid into the subretinal space. Rats were sacrificed at 1/2 d, 1 d, 2 d, 4 d, 8 d, 16 d and 32 d after creation of retinal detachment. Apoptosis of retinal cells was detected by TdT-mediated fluorescein-16-dUTP nick-end labeling (TUNEL) assay. GADD153 mRNA expression in the retina was determined using semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). The GADD153 protein expression was determined using western blotting. Retinal sections were studied by immunofluorescence labeling and confocal microscopy. The SPSS 10.0 software was applied to analyze data; Kruskal wallis test was applied to analyze the data about the apoptotic rate of retinal cells and the expression of GADD153 mRNA; One-way ANOVA test was applied to analyze the data about expression of GADD153 protein. P < 0.05 represents statistically significant difference. RESULTS: TUNEL positive staining cells were mainly presented in photoreceptor cell layer, peaked at 24 days and markedly decreased at 8 days after retinal detachment. The difference of apoptotic retinal cell rate between groups is significant (chi2 = 22.423, P < 0.05); The expression of retinal GADD153 mRNA was significantly increased at 1/2 d, 1 d, 2 d, 4 d after retinal detachment (chi2 = 27.223, P < 0.05); The expression of retinal GADD153 protein was significantly increased at these days (F = 16.052, P < 0.05). GADD153-positive cells were located in the photoreceptor cell layer. CONCLUSIONS: GADD153, the maker of endoplasmic reticulum stress mediated apoptosis, is activated and over-expressed, associated with the occurrence of apoptosis during retinal detachment. Endoplasmic reticulum stress participates into the apoptosis process during retinal detachment.