Identification of a small molecule that facilitates the differentiation of human iPSCs/ESCs and mouse embryonic pancreatic explants into pancreatic endocrine cells.

AIMS/HYPOTHESIS: Pancreatic beta-like cells generated from human induced pluripotent stem cells (hiPSCs) or human embryonic stem cells (hESCs) offer an appealing donor tissue source. However, differentiation protocols that mainly use growth factors are costly. Therefore, in this study, we aimed to establish efficient differentiation protocols to change hiPSCs/hESCs to insulin (INS)+ cells using novel small-molecule inducers. METHODS: We screened small molecules that increased the induction rate of INS+ cells from hESC-derived pancreatic and duodenal homeobox 1 (PDX1)+ pancreatic progenitor cells. The differentiation protocol to generate INS+ cells from hiPSCs/hESCs was optimised using hit compounds, and INS+ cells induced with the compounds were characterised for their in vitro and in vivo functions. The inducing activity of the hit compounds was also examined using mouse embryonic pancreatic tissues in an explant culture system. Finally, RNA sequencing analyses were performed on the INS+ cells to elucidate the mechanisms of action by which the hit compounds induced pancreatic endocrine differentiation. RESULTS: One hit compound, sodium cromoglicate (SCG), was identified out of approximately 1250 small molecules screened. When SCG was combined with a previously described protocol, the induction rate of INS+ cells increased from a mean ± SD of 5.9 ± 1.5% (n = 3) to 16.5 ± 2.1% (n = 3). SCG induced neurogenin 3-positive cells at a mean ± SD of 32.6 ± 4.6% (n = 3) compared with 14.2 ± 3.6% (n = 3) for control treatment without SCG, resulting in an increased generation of endocrine cells including insulin-producing cells. Similar induction by SCG was confirmed using mouse embryonic pancreatic explants. We also confirmed that the mechanisms of action by which SCG induced pancreatic endocrine differentiation included the inhibition of bone morphogenetic protein 4 signalling. CONCLUSIONS/INTERPRETATION: SCG improves the generation of pancreatic endocrine cells from multiple hiPSC/hESC lines and mouse embryonic pancreatic explants by facilitating the differentiation of endocrine precursors. This discovery will contribute to elucidating the mechanisms of pancreatic endocrine development and facilitate cost-effective generation of INS+ cells from hiPSCs/hESCs. DATA AVAILABILITY: The RNA sequencing data generated during the current study are available in the Gene Expression Omnibus ( www.ncbi.nlm.nih.gov/geo ) with series accession number GSE89973.

Three-year epidemiological analysis of penetrating ocular traumatic endophthalmitis.

The characteristics of patients with endophthalmitis due to penetrating ocular trauma are still limited. The aim of the study was to fill these gaps among Chinese population. This retrospective study included patients diagnosed as penetrating ocular traumatic endophthalmitis between January 2016 to December 2018. During the past 3-year period, a total of 201 patients with antecedent penetrating eye injuries were evaluated. Of which, 42 (20.9%) patients presented a clinical course compatible with acute infectious endophthalmitis. 39 (92.86%) patients were males, and 15 (35.71%) patients had mechanical injuries from intraocular foreign body (IOFB), the rate of endophthalmitis due to IOFB was 13.43%, higher to the rate among patients without IOFB (7.46%). The duration between injury occurrence and endophthalmitis onset was 1 day in 10 (23,80%) patients; 2 to 7 days in 31 (73.80%) patients, and 7 to 14 days in 1 (2.38%) patient. After 1 year follow-up, best corrected visual acuity (BCVA) better than 20/400 was observed in 15 (35.71%) patients, counting fingers and hand move in 17 (40.48%) patients, light perception in 5 (11.9%) patients and no light perception in 5 (11.9%) patients, respectively. Patients with promising outcomes had better initial BCVA at baseline (P < .001). Endophthalmitis is a severe ocular infectious condition that may lead to irreversible vision loss. A greater attention must be paid to penetrating eye injuries within males, who had poor BCVA at baseline, particularly with obvious IOFB.

Clinical efficacy of conbercept injection on neovascular age-related macular degeneration under different levels of inflammation.

BACKGROUND: Age-related macular degeneration (AMD) is considered one of the most common causes of irreversible blindness among elderly patients. Neovascular AMD, which accounts for 10% of all AMD cases, can cause devastating vision loss due to choroidal neovascularization (CNV). The clinical effects and safety of intravitreal injection of conbercept in patients suffering from neovascular AMD have not been fully evaluated. OBJECTIVES: The aim of the study was to evaluate the efficacy and safety of intravitreal injection of conbercept in patients with neovascular AMD with different levels of inflammation. MATERIAL AND METHODS: A total of 120 consecutive patients with neovascular AMD who underwent intravitreal injection of conbercept (3 injections per month + pro re nata (3 + PRN)) were included and stratified based on the intraocular level of high-sensitivity C-reactive protein (hs-CRP). The level of inflammation was defined as low, medium or high, based on the concentration of hs-CRP prior to injection. Before and after conbercept injections, best-corrected visual acuity (BCVA) and central retinal thickness (CRT) were compared, respectively. Moreover, cytokine markers as well as the frequency of injections and adverse events (AEs) were measured. RESULTS: There were significant differences in BCVA and CRT between low, medium and high tertiles. Compared to the baseline, improved BCVA was observed, and CRT declined significantly after operation. Adverse events were most observed in high tertiles. A significant decrease in vascular endothelial growth factor (VEGF), interleukin (IL)-6 and IL-8 was observed after 1 year. CONCLUSIONS: The effectiveness of conbercept on neovascular AMD varies depending on the level of inflammation, which could be achieved by administering different injection frequencies at different levels of inflammation. Furthermore, conbercept is associated with the reduction of inflammatory factor (IL-6 and IL-8) levels after intravitreal injection, which suggests that suppressing inflammatory response might contribute to the clinical efficacy of anti-VEGF treatment. Our results provide a novel mechanism for conbercept in patients with neovascular AMD.

Factors for recurrence in acute central serous chorioretinopathy patients underwent one-third dose verteporfin photodynamic therapy.

PURPOSE: To investigate the factors for recurrence in acute central serous chorioretinopathy (aCSC) for patients who underwent one-third dose verteporfin photodynamic therapy (PDT). MATERIALS AND METHODS: A retrospective study was performed in aCSC patients treated with one-third dose PDT and followed up for 36 months. Demographic information and clinical features were compared. A logistic regression model was used to evaluate the associated factor of aCSC recurrence. RESULTS: There were 162 patients with aCSC included in current study. 36-month after one-third dose PDT, good recovery was identified in 131 patients (80.86%), whereas 31 cases (19.14%) developed recurrence. Significant between-group differences were observed in baseline age, the right, left and both eyes, best-corrected visual acuity (BCVA), presenting with pigment epithelium detachment (PED), retinal pigment epithelium (RPE) damage and subfoveal choroidal thickness (SCT) level (P = 0.005, P < 0.001, P < 0.001, P < 0.001, P = 0.006, and P < 0.001, respectively). The recurrence of aCSC was associated with presenting with PED (odds ratio = 1.78; 95% CI, 1.45-1.98; P < 0.001), RPE damage (OR = 1.13; 95%CI: 1.08-1.23; P < 0.001), baseline BCVA (OR = 0.96; 95%CI: 0.95 - 0.99; P = 0.001), and SCT level (OR = 1.18; 95%CI: 1.02-1.20; P < 0.001). CONCLUSION: In acute CSC after treatment of one-third dose PDT, recurrence is associated with RPE damage, baseline BCVA and SCT level. Our findings will assist clinicians to evaluate aCSC in clinical practice and provide insights into the prevention of recurrence.

Vitrectomy using 0.025% povidone-iodine irrigation for treating post-traumatic endophthalmitis due to intraocular foreign bodies: Two case reports.

Traumatic eye injury-related endophthalmitis is a serious traumatic complication that threatens the vision of many patients worldwide. Herein, we present two cases of traumatic endophthalmitis that underwent 0.025% povidone-iodine treatment and hoped to introduce the bactericidal effect of 0.025% povidone-iodine in balanced salt solution PLUS (0.025% PI-BSS PLUS) and its use in vitrectomy for traumatic endophthalmitis. The 0.025% PI-BSS PLUS solution is bactericidal and nontoxic when used as an irrigation solution in pars plana vitrectomy. The two cases of traumatic endophthalmitis were resolved by pars plana vitrectomy using 0.025% PI-BSS PLUS.

Three-dimensional ex vivo imaging and analysis of intraportal islet transplants.

In clinical islet transplantation, because the long-term insulin-independence rate is still poor, a method for detailed analysis of the transplanted islets in the liver after transplantation is required. We have established a novel imaging technique suitable for analysis of transplanted islets in liver using an optical projection tomography (OPT) method. A three-dimensional tomographic image of the transplanted islets in liver was reconstructed. The number of islets transplanted and the number of transplanted islets observed using OPT showed good correlation. The OPT method was used to compare the numbers of transplanted islets in mouse syngeneic and allogeneic transplantation models. Blood glucose concentrations of streptozotocin (STZ)-induced diabetic mice transplanted with syngeneic islets remained normoglycemic and the number of transplanted islets was largely preserved 11 days after transplantation. In mice transplanted with allogeneic islets, hyperglycemia recurred from 7 days after transplantation and the number and the volume of transplanted islets was significantly reduced 11 days after transplantation. These results indicate that OPT imaging and analysis may be a useful tool to quantitatively and sterically evaluation of transplanted islets in liver at the cellular level.

Overexpression of SIRT5 confirms its involvement in deacetylation and activation of carbamoyl phosphate synthetase 1.

SIR2 protein, an NAD-dependent deacetylase, is localized to nucleus and is involved in life span extension by calorie restriction in yeast. In mammals, among the seven SIR2 homologues (SIRT1-7), SIRT3, 4, and 5 are localized to mitochondria. As SIRT5 mRNA levels in liver are increased by fasting, the physiological role of SIRT5 was investigated in liver of SIRT5-overexpressing transgenic (SIRT5 Tg) mice. We identified carbamoyl phosphate synthetase 1 (CPS1), a key enzyme of the urea cycle that catalyzes condensation of ammonia with bicarbonate to form carbamoyl phosphate, as a target of SIRT5 by two-dimensional electrophoresis comparing mitochondrial proteins in livers of SIRT5 Tg and wild-type mice. CPS1 protein was more deacetylated and activated in liver of SIRT5 Tg mice than in wild-type. In addition, urea production was upregulated in hepatocytes of SIRT5 Tg mice. These results agree with those of a previous study using SIRT5 knockout (KO) mice. Because ammonia generated during fasting is toxic, SIRT5 protein might play a protective role by converting ammonia to non-toxic urea through deacetylation and activation of CPS1.

Eugenol Attenuates Cerebral Ischemia-Reperfusion Injury by Enhancing Autophagy via AMPK-mTOR-P70S6K Pathway.

Eugenol, as an active compound isolated from Acorus gramineus, has been shown to protect against cerebral ischemia-reperfusion (I/R) injury. Nonetheless, the detailed neuroprotective mechanisms of eugenol in cerebral I/R injury have not been elaborated. In the present study, cerebral I/R injury model was established by middle cerebral artery occlusion (MCAO) in rats. HT22 cells were subjected to oxygen-glucose deprivation/reperfusion (OGD/R) to mimic cerebral I/R injury in vitro. The results showed that eugenol pre-treatment relieved cerebral I/R injury as evidenced by improving neurological deficits and reducing infarct volume. Autophagy was induced by MCAO, which was further promoted by eugenol administration. Moreover, rapamycin, an activator of autophagy, promoted eugenol-induced decreases in neurological score, infarct volume, brain water content, and apoptosis. However, pretreatment with 3-MA, an inhibitor of autophagy, led to the opposite results. Similarly, eugenol pretreatment increased the viability and restrained apoptosis of OGD/R-challenged HT22 cells. OGD/R-induced autophagy was strengthened by eugenol. Mechanically, eugenol promoted autophagy through regulating AMPK/mTOR/P70S6K signaling pathway in vivo and in vitro. In conclusion, pretreatment with eugenol attenuated cerebral I/R injury by inducing autophagy via AMPK/mTOR/P70S6K signaling pathway.

A Novel Insertion Variant of CRYGD Is Associated with Congenital Nuclear Cataract in a Chinese Family.

OBJECTIVE: To investigate a novel insertion variant of CRYGD identified in a Chinese family with nuclear congenital cataract. METHODS: A Chinese family with congenital nuclear cataract was recruited for the mutational screening of candidate genes by direct sequencing. Recombinant N-terminal Myc tagged wildtype or mutant CRYGD was expressed in HEK293T cells. The expression pattern, protein solubility and subcellular distribution were analyzed by western blotting and immunofluorescence. PRINCIPAL FINDINGS: A novel insertion variant, c.451_452insGACT, in CRYGD was identified in the patients. It causes a frameshift and a premature termination of the polypeptide to become Y151*. A significantly reduced solubility was observed for this mutant. Unlike wildtype CRYGD, which existed mainly in the cytoplasm, Y151* was mis-located in the nucleus. CONCLUSIONS: We have identified a novel mutation, c.451_452insGACT, in CRYGD, which is associated with nuclear cataract. This is the first insertion mutation of CRYGD found to cause autosomal dominant congenital cataract. The mutant protein, with loss of solubility and localization to the nucleus, is hypothesized to be the major cause of cataract in these patients.

FGF-21 enhances islet engraftment in mouse syngeneic islet transplantation model.

To clarify the effect of fibroblast growth factor-21 (FGF-21) on islet transplantation, a suboptimal number of islets were transplanted into streptozotocin (STZ)-induced diabetic mice with or without FGF-21 treatment. Three-day treatment with FGF-21 contributed to restoration of normoglycemia by suppressing islet graft loss. The FGF-21-treated mice showed lower glycemic levels despite similar insulin content in the graft than that in untreated mice on day 3, indicating that FGF-21 not only has a cytoprotective effect but also decreases ß-cell load by increasing insulin sensitivity. These results suggest that FGF-21 may be useful as a treatment to improve islet engraftment rates in clinical islet transplantation.

Neuroprotective effect of recombinant human erythropoietin on optic nerve injury in rats.

BACKGROUND: Optic nerve injury, caused by retinal and optic nerve diseases, can eventually result in vision loss. To date, few effective treatments have been discovered to restore visual function. Previous studies showed that recombinant human erythropoietin (rhEPO) has a neuroprotective effect on the central nervous system, particularly in nerve injury. In this study, we investigated the effects of rhEPO on axonal regeneration and functional restoration following optic nerve injury. This was done by measuring the expression of growth associated protein 43 (GAP-43), a marker for neuronal regeneration, on the retina and flash-visual evoked potential (F-VEP). METHODS: Adult Wistar rats were randomly assigned to rhEPO and control (saline) groups. Optic nerve crush injury models were established and rhEPO or saline were immediately injected into the vitreous cavity. The expression of GAP-43 was detected by immunohistochemistry and the F-VEP was measured pre-injury, immediately after injury, 1 week and 2 weeks post-injury. RESULTS: No detectable staining for GAP-43 was observed in normal retina. In the control group, the level of GAP-43 expression was higher at 1 week post-injury, but decreased at 2 weeks. In the rhEPO group, the level of GAP-43 expression was notably higher at both 1 week and 2 weeks. At each time point post-injury, the expression of GAP-43 in rhEPO group was significantly higher than the control group (P < 0.05). Obvious changes in F-VEP examination were detected immediately after optic nerve injury, including significantly prolonged latency and decreased amplitude of the P1 wave. In the control group, the changes were still obvious at 1 week. The latency was decreased and the amplitude had slightly recovered to 28.23% of the normal value at 2 weeks. In rhEPO group, there was significantly more recovery than the control group at 1 week and 2 weeks post-injury (P < 0.05). The latency most close to the normal level and the amplitude had recovered to 65.51% of the normal value at 2 weeks. CONCLUSIONS: rhEPO can prolong the expression of GAP-43 and increase its intensity after optic nerve injury, thereby promoting neural repair and axonal regeneration. Under the protection of rhEPO, the conduction velocity of the optic nerve recovered significantly. Therefore, rhEPO has neuroprotective effects on the optic nerve and promotes functional restoration of the optic nerve.