Emotional intelligence and self-esteem among Saudi Arabian and Indian nursing students: findings from two countries.

INTRODUCTION: Understanding the emotional intelligence (EI) and self-esteem of Indian and Saudi nursing students is important because their future nurse-patient relationships may be influenced by factors related to their unique cultural contexts. Hence, this study sought to investigate the EI and self-esteem of nursing students in Saudi Arabia and India. METHODS: A descriptive-comparative research design was used to compare 660 nursing students from Saudi Arabia and India who were enrolled in the study from September 2022 to January 2023. Nursing students were recruited from University A in Riyadh and University B in Abha, Saudi Arabia, and from University C in India. RESULTS: The study found significant differences in EI scores based on year of study (p < .011), age (p < .024), residence (p < .005), and academic performance (p < .008). Students in later years, over 20 years old, from urban areas, and with good grades, had higher EI scores. Conversely, only age showed a significant difference in the self-esteem scores (p < .002). The year of study (p > .670), residence (p > .430), and academic performance (p > .526) did not significantly affect self-esteem. Finally, urban residence and good academic performance were significant predictors of EI (p < .005), while none of the demographics predicted self-esteem (p > .005). CONCLUSION: Higher emotional intelligence among nursing students can be associated with several variables, such as being in the higher years of study, older age, residing in an urban area, and good academic performance, whereas self-esteem appears to be hardly affected by these indicators but probably influenced by other aspects that were not measured. This implies that educators in relation to self-esteem should know the relationship between emotional intelligence and nursing practice besides healthcare establishments; they need to enhance their teaching methods so that learners can have more resilient attitudes towards work, provide quality patient care, and promote a better learning environment for nurses who will become stronger professionally in the future.

Impact of Sleep and Psychological Well-Being on the Academic and Clinical Performance of Nursing Students in Saudi Arabia.

Introduction: Nursing students frequently encounter the challenge of balancing their studies with the demanding requirements of hands-on practice and this can greatly affect their mental wellbeing. This study aimed to investigate the impact of sleep and psychological well-being on the academic and clinical performance of nursing students in Saudi Arabia. Methods: This study used a cross-sectional approach with 218 student nurses selected through convenience sampling from King Khalid University, Abha, Saudi Arabia. The sleep quality, psychological wellbeing, academic performance and clinical performance questionnaires were adopted to measure the variables. The Google Forms survey was used to gather the data, which were collected in August through October 2023. t-test and chi-square were used to analyze the data. Results: The sleep quality was higher with good/very good performers (p < 0.001). There was a significant difference with academic performance on positive relations (p < 0.007) and purpose in life (p < 0.004). Additionally, there was a significant difference in autonomy (p < 0.01), environmental mastery (p < 0.026), positive relations (p < 0.001), and purpose in life (p < 0.001) with clinical performance. Among students with good academic performance, those who were older than 25 years of age (p < 0.043) and level 3 students (p < 0.001) were found to have a significant correlation. Furthermore, those who were 25 years of age (p < 0.012) and level 3 students (p < 0.001) were also found to have a significant correlation with clinical performance. Conclusion: The sleep quality, positive relations, purpose in life, autonomy, and environmental mastery are all important factors for academic and clinical success. Moreover, older students and level 3 students may be more likely to have the skills and knowledge necessary to succeed in these areas. Further research exploring factors influencing academic and clinical success must be conducted.

The mouse retinal pigment epithelium mounts an innate immune defense response following retinal detachment.

The retinal pigment epithelium (RPE) maintains photoreceptor viability and function, completes the visual cycle, and forms the outer blood-retinal barrier (oBRB). Loss of RPE function gives rise to several monogenic retinal dystrophies and contributes to age-related macular degeneration. Retinal detachment (RD) causes separation of the neurosensory retina from the underlying RPE, disrupting the functional and metabolic relationships between these layers. Although the retinal response to RD is highly studied, little is known about how the RPE responds to loss of this interaction. RNA sequencing (RNA-Seq) was used to compare normal and detached RPE in the C57BL6/J mouse. The naïve mouse RPE transcriptome was compared to previously published RPE signature gene lists and from the union of these 14 genes (Bmp4, Crim1, Degs1, Gja1, Itgav, Mfap3l, Pdpn, Ptgds, Rbp1, Rnf13, Rpe65, Slc4a2, Sulf1 and Ttr) representing a core signature gene set applicable across rodent and human RPE was derived. Gene ontology enrichment analysis (GOEA) of the mouse RPE transcriptome identified expected RPE features and functions, such as pigmentation, phagocytosis, lysosomal and proteasomal degradation of proteins, and barrier function. Differentially expressed genes (DEG) at 1 and 7 days post retinal detachment (dprd) were defined as mRNA with a significant (padj≤0.05) fold change (FC) of 0.67 ≥ FC ≥ 1.5 in detached versus naïve RPE. The RPE transcriptome exhibited dramatic changes at 1 dprd, with 2297 DEG identified. The KEGG pathways and biological process GO groups related to innate immune responses were significantly enriched. Lipocalin 2 (Lcn2) and several chemokines were upregulated, while numerous genes related to RPE functions, such as pigment synthesis, visual cycle, phagocytosis, and tight junctions were downregulated at 1 dprd. The response was largely transient, with only 18 significant DEG identified at 7 dprd, including upregulation of complement gene C4b. Validation studies confirmed RNA-Seq results. Thus, the RPE quickly downregulates cell-specific functions and mounts an innate immune defense response following RD. Our data demonstrate that the RPE contributes to the inflammatory response to RD and may play a role in attraction of immune cells to the subretinal space.

Delineating effects of angiopoietin-2 inhibition on vascular permeability and inflammation in models of retinal neovascularization and ischemia/reperfusion.

Introduction: Clinical trials demonstrated that co-targeting angiopoietin-2 (Ang-2) and vascular endothelial growth factor (VEGF-A) with faricimab controls anatomic outcomes and maintains vision improvements, with strong durability, through 2 years in patients with neovascular age-related macular degeneration and diabetic macular edema. The mechanism(s) underlying these findings is incompletely understood and the specific role that Ang-2 inhibition plays requires further investigation. Methods: We examined the effects of single and dual Ang-2/VEGF-A inhibition in diseased vasculatures of JR5558 mice with spontaneous choroidal neovascularization (CNV) and in mice with retinal ischemia/reperfusion (I/R) injuries. Results: In JR5558 mice, Ang-2, VEGF-A, and dual Ang-2/VEGF-A inhibition reduced CNV area after 1 week; only dual Ang-2/VEGF-A inhibition decreased neovascular leakage. Only Ang-2 and dual Ang-2/VEGF-A inhibition maintained reductions after 5 weeks. Dual Ang-2/VEGF-A inhibition reduced macrophage/microglia accumulation around lesions after 1 week. Both Ang-2 and dual Ang-2/VEGF-A inhibition reduced macrophage/microglia accumulation around lesions after 5 weeks. In the retinal I/R injury model, dual Ang-2/VEGF-A inhibition was statistically significantly more effective than Ang-2 or VEGF-A inhibition alone in preventing retinal vascular leakage and neurodegeneration. Discussion: These data highlight the role of Ang-2 in dual Ang-2/VEGF-A inhibition and indicate that dual inhibition has complementary anti-inflammatory and neuroprotective effects, suggesting a mechanism for the durability and efficacy of faricimab in clinical trials.

Psychological effects of COVID- 19 lockdown among Aseer residents, Saudi Arabia.

Objectives: To analyse the impact on mental health of the lockdown forced by the coronavirus disease-2019 pandemic. METHODS: This descriptive, cross-sectional study was conducted in Aseer, Saudi Arabia, in May and June 2020, and comprised adult natives of either gender ho could read and write Arabic. Data was collected using a self-developed questionnaire which was distributed online via Google Forms. Data was analysed using SPSS 22. RESULTS: Of the 306 respondents, 238(77.8%) were females, 163(53.3%) were age 18-30 years 121(39.5%) were students, 166(54.2%) lived in a joint family, 257(84%) had undergone university education, 157(51.3%) were single, and 247(80.7%) resided in urban areas. During the lockdowns, 195(60%) participants felt moderate distress symptoms. Emotional distress and gender were significantly interlinked (p<0.01). CONCLUSIONS: The lockdowns forced by the coronavirus disease-2019 pandemic had a moderate impact on the mental health of the participants, especially on females.

Tricuspid Valve Dysplasia at Fetal Autopsy.

Introduction: Tricuspid valve abnormalities detected in fetal life include Ebstein anomaly and tricuspid valve dysplasia. The differentiation between these 2 entities can sometimes be challenging in the 2nd trimester fetus. We report a case of tricuspid valve dysplasia diagnosed on fetal autopsy. Case Report: A primigravida was diagnosed at 22 weeks' gestation to have Ebstein anomaly with severe tricuspid regurgitation. There was intra-uterine fetal demise. On fetal autopsy, the tricuspid valve leaflets were not apically displaced and the leaflets were nodular with rolled up edges. This supported a diagnosis of tricuspid valve dysplasia. Conclusion: The difficulties in differentiating Ebstein anomaly from tricuspid valve dysplasia due to inherent limitations in fetal imaging can be resolved by fetal autopsy. Valvular dysplasia will not have apical displacement of the valve leaflets.

Inflammatory resolution and vascular barrier restoration after retinal ischemia reperfusion injury.

BACKGROUND: Several retinal pathologies exhibit both inflammation and breakdown of the inner blood-retinal barrier (iBRB) resulting in vascular permeability, suggesting that treatments that trigger resolution of inflammation may also promote iBRB restoration. METHODS: Using the mouse retinal ischemia-reperfusion (IR) injury model, we followed the time course of neurodegeneration, inflammation, and iBRB disruption and repair to examine the relationship between resolution of inflammation and iBRB restoration and to determine if minocycline, a tetracycline derivative shown to reverse microglial activation, can hasten these processes. RESULTS: A 90-min ischemic insult followed by reperfusion in the retina induced cell apoptosis and inner retina thinning that progressed for approximately 2 weeks. IR increased vascular permeability within hours, which resolved between 3 and 4 weeks after injury. Increased vascular permeability coincided with alteration and loss of endothelial cell tight junction (TJ) protein content and disorganization of TJ protein complexes. Shunting of blood flow away from leaky vessels and dropout of leaky capillaries were eliminated as possible mechanisms for restoring the iBRB. Repletion of TJ protein contents occurred within 2 days after injury, long before restoration of the iBRB. In contrast, the eventual re-organization of TJ complexes at the cell border coincided with restoration of the barrier. A robust inflammatory response was evident a 1 day after IR and progressed to resolution over the 4-week time course. The inflammatory response included a rapid and transient infiltration of granulocytes and Ly6C+ classical inflammatory monocytes, a slow accumulation of Ly6Cneg monocyte/macrophages, and activation, proliferation, and mobilization of resident microglia. Extravasation of the majority of CD45+ leukocytes occurred from the superficial plexus. The presence of monocyte/macrophages and increased numbers of microglia were sustained until the iBRB was eventually restored. Intervention with minocycline to reverse microglial activation at 1 week after injury promoted early restoration of the iBRB coinciding with decreased expression of mRNAs for the microglial M1 markers TNF-α, IL-1ß, and Ptgs2 (Cox-2) and increased expression of secreted serine protease inhibitor Serpina3n mRNA. CONCLUSIONS: These results suggest that iBRB restoration occurs as TJ complexes are reorganized and that resolution of inflammation and restoration of the iBRB following retinal IR injury are functionally linked.

Green synthesis of lignin nanorods/g-C3N4 nanocomposite materials for efficient photocatalytic degradation of triclosan in environmental water.

Triclosan (TCS) is a common anti-microbial ingredient in pharmaceutical and personal care products. The usage of TCS was banned by the United States Food and Drug Administration (in 2016) due to its potential health risks. However, TCS has been frequently detected in the aquatic environment. Therefore, it is vital to design low-cost and highly efficient photocatalysts to enhance TCS's photocatalytic degradation in wastewater treatment to eliminate its toxicity to environmental health. In this study, we developed a highly efficient catalyst by incorporating lignin nanorods (LNRs) into graphitic carbon nitride (GCN) nanomaterials as green LNRs/GCN-based nanocomposite photocatalysts for the effective degradation of TCS in waters. LNRs/GCN nanosheets (NSs) and LNRs/GCN-NRs based nanocomposite materials were prepared using a simple wet-impregnation method. The surface morphology and optical properties of as-synthesized materials were well-characterized using FE-SEM, XRD, XPS, and UV-DRS. The photocatalyst (LNRs/GCN-NRs) material showed maximum TCS degradation efficiency of 99.9% and a high rate constant of 0.0661 min-1 under pH-10 with crucial reactive spices (OH and O2-), and excellent cycling performance (over five cycles) within 90 min of UV-light illumination. LNRs/GCN-NRs nanocomposite indicated enhanced photocatalytic performances for TCS degradation due to its strong synergistic effect between LNRs and GCN-NRs as bifunctional catalyst substrate morphology with efficient bandgap energy and accessible active sites compared to LNRs/GCN-NSs. Therefore, LNRs/GCN-NRs nanocomposite was observed to be a highly-active, low-cost, stable, eco-friendly, and efficient photocatalyst for complete degradation of TCS under UV-light irradiation.

All-trans-Retinaldehyde Contributes to Retinal Vascular Permeability in Ischemia Reperfusion.

Purpose: Extracellular accumulation of all-trans-retinaldehyde (atRAL), a highly reactive visual cycle intermediate, is toxic to cells of the outer retina and contributes to retinal and macular degenerations. However, the contribution of atRAL to retinal capillary function has not been studied. We hypothesized that atRAL released from the outer retina can contribute to retinal vascular permeability. We, therefore, tested the contribution of atRAL to retinal ischemia-reperfusion (IR)-induced vascular permeability. Methods: IR was induced in mice by transient increase in intraocular pressure followed by natural reperfusion. The visual cycle was ablated in the Lrat-/- mice, reduced by dark adaptation or the use of the RPE65 inhibitor and atRAL scavenger emixustat. Accumulation of FITC-BSA was used to assess vascular permeability and DNA fragmentation quantified cell death after IR. Primary bovine retinal endothelial cell (BREC) culture was used to measure the direct effects of atRAL on endothelial permeability and cell death. Results: Inhibition of the visual cycle by Lrat-/-, dark adaptation, or with emixustat, all reduced approximately half of IR induced vascular permeability at 48 hours. An increase in BREC permeability with atRAL coincided with lactate dehydrogenase (LDH) release, a measure of cell death. Both permeability and toxicity were blocked by emixustat. Conclusions: Outer retinal pathology may contribute to vascular permeability by release of atRAL, which can act directly on vascular endothelial cells to alter barrier properties and induce cell death. These studies may have implications for a variety of blinding eye diseases that include outer retinal damage and retinal vascular permeability.

Mitochondrial uncoupling has no effect on microvascular complications in type 2 diabetes.

Diabetic peripheral neuropathy (DPN), diabetic kidney disease (DKD), and diabetic retinopathy (DR) contribute to significant morbidity and mortality in diabetes patients. The incidence of these complications is increasing with the diabetes epidemic, and current therapies minimally impact their pathogenesis in type 2 diabetes (T2D). Improved mechanistic understanding of each of the diabetic complications is needed in order to develop disease-modifying treatments for patients. We recently identified fundamental differences in mitochondrial responses of peripheral nerve, kidney, and retinal tissues to T2D in BKS-db/db mice. However, whether these mitochondrial adaptations are the cause or consequence of tissue dysfunction remains unclear. In the current study BKS-db/db mice were treated with the mitochondrial uncoupler, niclosamide ethanolamine (NEN), to determine the effects of mitochondrial uncoupling therapy on T2D, and the pathogenesis of DPN, DKD and DR. Here we report that NEN treatment from 6-24 wk of age had little effect on the development of T2D and diabetic complications. Our data suggest that globally targeting mitochondria with an uncoupling agent is unlikely to provide therapeutic benefit for DPN, DKD, or DR in T2D. These data also highlight the need for further insights into the role of tissue-specific metabolic reprogramming in the pathogenesis of diabetic complications.

Vitreous Cytokine Expression and a Murine Model Suggest a Key Role of Microglia in the Inflammatory Response to Retinal Detachment.

Purpose: Retinal detachment (RD) separates the retina from the underlying retinal pigment epithelium, resulting in a gradual degeneration of photoreceptor (PR) cells. It is known that RD also results in an inflammatory response, but its contribution to PR degeneration is unknown. In this study we examine the inflammatory responses to RD in patient vitreous and validate a mouse experimental RD as a model of this phenomenon. Methods: Multiplex bead arrays were used to examine cytokine levels in vitreous samples from 24 patients with macula-off rhegmatogenous retinal detachment (RRD) undergoing reattachment surgery and from 10 control patients undergoing vitrectomy for vitreous opacities or epiretinal membrane. Activation of the innate immune response was then examined in a mouse model of RD. Results: Twenty-eight factors were significantly increased in vitreous from RD patients versus controls. Notable were the cytokines MCP-1 (CCL2), IP-10 (CXCL10), fractalkine (CX3CL1), GRO (CXCL1), MDC (CCL22), IL-6, and IL-8, which all exhibited relatively high concentrations and several-fold increases in the vitreous of RD patients. Concentrations of various analytes correlated with a range of clinical variables such as duration of detachment and visual acuity. Retinal detachment in the mouse resulted in cytokine mRNA expression changes consistent with human RD vitreous results, as well as microglial proliferation and migration toward the outer retina. Conclusions: The findings suggest that an inflammatory response involving microglia is a component of the reaction to retinal detachment that may impact visual acuity after surgical repair and that mouse experimental RD can serve as a model to study this effect.

Gross morphological study of the renal pelvicalyceal patterns in human cadaveric kidneys.

INTRODUCTION: The knowledge of detailed calyceal anatomy is essential for performing urologic procedures such as percutaneous nephrolithotomy, percutaneous nephrostomy, flexible ureterorenoscopy, endopyelotomy, and retrograde renal surgery. This study was performed to analyze the various patterns of pelvicalyceal system in the South Indian population, and compare these with previously published studies in different populations. METHODS: The study was conducted in 100 kidney specimens. Morphologically undamaged kidneys belonging to both sexes were removed en bloc from cadavers and autopsy cases of the Departments of Anatomy and Forensic Medicine, respectively. The specimens were carefully dissected, and the percentage of various patterns was compared with previous studies. RESULTS: The renal pelvis was found to be intrarenal in 79% of the specimens. The most common type of anatomy was a bicalyceal system with two major calyces, one each from the upper and lower poles, with the middle zone drainage dependent on any one or both of them. An interesting and rare variation of extrarenal calyces with the absence of renal pelvis was observed in 1% of the specimens. In addition, the presence of minor calyces opening directly into the renal pelvis was seen in 8% of the specimens. CONCLUSION: A biclayceal system of drainage with intrarenal pelvis is the most common calyceal pattern in the kidneys. The patterns must be borne in mind while examining a radiological report involving the kidneys.

Insulin-like growth factor 1 rescues R28 retinal neurons from apoptotic death through ERK-mediated BimEL phosphorylation independent of Akt.

Insulin-like growth factor 1 (IGF-1) can provide long-term neurotrophic support by activation of Akt, inhibition of FoxO nuclear localization and suppression of Bim gene transcription in multiple neuronal systems. However, MEK/ERK activation can also promote neuron survival through phosphorylation of BimEL. We explored the contribution of the PI3K/Akt/FoxO and MEK/ERK/BimEL pathways in IGF-1 stimulated survival after serum deprivation (SD) of R28 cells differentiated to model retinal neurons. IGF-1 caused rapid activation of Akt leading to FoxO1/3-T32/T24 phosphorylation, and prevented FoxO1/3 nuclear translocation and Bim mRNA upregulation in response to SD. IGF-1 also caused MAPK/MEK pathway activation as indicated by ERK1/2-T202/Y204 and Bim-S65 phosphorylation. Overexpression of FoxO1 increased Bim mRNA expression and amplified the apoptotic response to SD without shifting the serum response curve. Inhibition of Akt activation with LY294002 or by Rictor knockdown did not block the protective effect of IGF-1, while inhibition of MEK activity with PD98059 prevented Bim phosphorylation and blocked IGF-1 protection. In addition, knockdown of Bim expression was protective during SD, while co-silencing of FoxO1 and Fox03 expression had little effect. Thus, the PI3K/Akt/FoxO pathway was not essential for protection from SD-induced apoptosis by IGF-1 in R28 cells. Instead, IGF-1 protection was dependent on activation of the MEK/ERK pathway leading to BimEL phosphorylation, which is known to prevent Bax/Bak oligomerization and activation of the intrinsic mitochondrial apoptosis pathway. These studies demonstrate the requirement of the MEK/ERK pathway in a model of retinal neuron cell survival and highlight the cell specificity for IGF-1 signaling in this response.

CX3CR1 deficiency accelerates the development of retinopathy in a rodent model of type 1 diabetes.

In this study, the role of CX3CR1 in the progression of diabetic retinopathy (DR) was investigated. The retinas of wild-type (WT), CX3CR1 null (CX3CR1gfp/gfp, KO), and heterozygous (CX3CR1+/gfp, Het) mice were compared in the presence and absence of streptozotocin (STZ)-induced diabetes. CX3CR1 deficiency in STZ-KO increased vascular pathology at 4 months of diabetes, as a significant increase in acellular capillaries was observed only in the STZ-KO group. CX3CR1 deficiency and diabetes had similar effects on retinal neurodegeneration measured by an increase in DNA fragmentation. Retinal vascular pathology in STZ-KO mice was associated with increased numbers of monocyte-derived macrophages in the retina. Furthermore, compared to STZ-WT, STZ-KO mice exhibited increased numbers of inflammatory monocytes in the bone marrow and impaired homing of monocytes to the spleen. The induction of retinal IL-10 expression by diabetes was significantly less in KO mice, and when bone marrow-derived macrophages from KO mice were maintained in high glucose, they expressed significantly less IL-10 and more TNF-α in response to LPS stimulation. These findings support that CX3CR1 deficiency accelerates the development of vascular pathology in DR through increased recruitment of proinflammatory myeloid cells that demonstrate reduced expression of anti-inflammatory IL-10. KEY MESSAGES: • CX3CR1 deletion in STZ-diabetic mice accelerated the onset of diabetic retinopathy (DR). • The early onset of DR was associated with increased retinal cell apoptosis. • The early onset of DR was associated with increased recruitment of bone marrow-derived macrophages to the retina. • Bone marrow-derived macrophages from CX3CR1 KO diabetic mice expressed more TNF-α and less IL-10. • The role of IL-10 in protection from progression of DR is highlighted.

Ischemia-reperfusion injury induces occludin phosphorylation/ubiquitination and retinal vascular permeability in a VEGFR-2-dependent manner.

Retinal ischemia-reperfusion (IR) induces neurodegenaration as well as blood-retinal barrier (BRB) breakdown causing vascular permeability. Whereas the neuronal death has been extensively studied, the molecular mechanisms related to BRB breakdown in IR injury remain poorly understood. In this study, we investigated the early changes in tight junctional (TJ) proteins in response to IR injury. Ischemia-reperfusion injury was induced in male rat retinas by increasing the intraocular pressure for 45 minutes followed by natural reperfusion. The results demonstrate that IR injury induced occludin Ser490 phosphorylation and ubiquitination within 15 minutes of reperfusion with subsequent vascular permeability. Immunohistochemical analysis revealed a rapid increase in occludin Ser490 phosphorylation and loss of Zonula occludens-1 (ZO-1) protein, particularly in arterioles. Ischemia-reperfusion injury also rapidly induced the activation and phosphorylation of vascular endothelial growth factor receptor-2 (VEGFR-2) at tyrosine 1175. Blocking vascular endothelial growth factor (VEGF) function by intravitreal injection of bevacizumab prevented VEGFR-2 activation, occludin phosphorylation, and vascular permeability. These studies suggest a novel mechanism of occludin Ser490 phosphorylation and ubiquitination downstream of VEGFR2 activation associated with early IR-induced vascular permeability.

Minocycline prevents retinal inflammation and vascular permeability following ischemia-reperfusion injury.

BACKGROUND: Many retinal diseases are associated with vascular dysfunction accompanied by neuroinflammation. We examined the ability of minocycline (Mino), a tetracycline derivative with anti-inflammatory and neuroprotective properties, to prevent vascular permeability and inflammation following retinal ischemia-reperfusion (IR) injury, a model of retinal neurodegeneration with breakdown of the blood-retinal barrier (BRB). METHODS: Male Sprague-Dawley rats were subjected to 45 min of pressure-induced retinal ischemia, with the contralateral eye serving as control. Rats were treated with Mino prior to and following IR. At 48 h after reperfusion, retinal gene expression, cellular inflammation, Evan's blue dye leakage, tight junction protein organization, caspase-3 activation, and DNA fragmentation were measured. Cellular inflammation was quantified by flow-cytometric evaluation of retinal tissue using the myeloid marker CD11b and leukocyte common antigen CD45 to differentiate and quantify CD11b+/CD45low microglia, CD11b+/CD45hi myeloid leukocytes and CD11bneg/CD45hi lymphocytes. Major histocompatibility complex class II (MHCII) immunoreactivity was used to determine the inflammatory state of these cells. RESULTS: Mino treatment significantly inhibited IR-induced retinal vascular permeability and disruption of tight junction organization. Retinal IR injury significantly altered mRNA expression for 21 of 25 inflammation- and gliosis-related genes examined. Of these, Mino treatment effectively attenuated IR-induced expression of lipocalin 2 (LCN2), serpin peptidase inhibitor clade A member 3 N (SERPINA3N), TNF receptor superfamily member 12A (TNFRSF12A), monocyte chemoattractant-1 (MCP-1, CCL2) and intercellular adhesion molecule-1 (ICAM-1). A marked increase in leukostasis of both myeloid leukocytes and lymphocytes was observed following IR. Mino treatment significantly reduced retinal leukocyte numbers following IR and was particularly effective in decreasing the appearance of MHCII+ inflammatory leukocytes. Surprisingly, Mino did not significantly inhibit retinal cell death in this model. CONCLUSIONS: IR induces a retinal neuroinflammation within hours of reperfusion characterized by inflammatory gene expression, leukocyte adhesion and invasion, and vascular permeability. Despite Mino significantly inhibiting these responses, it failed to block neurodegeneration.

Effects of ischemic preconditioning and bevacizumab on apoptosis and vascular permeability following retinal ischemia-reperfusion injury.

PURPOSE: Using transient ischemia followed by reperfusion (IR) to model ischemic retinal disease, this study compares the effects of ischemic preconditioning (IPC) and therapies targeting vascular endothelial growth factor (VEGF) and tumor necrosis factor (TNF)-α on retinal apoptosis, vascular permeability, and mRNA expression. METHODS: Rats were subjected to 30 or 45 minutes of retinal ischemia followed by reperfusion for up to 48 hours. Neurodegeneration was quantified by caspase-3 (DEVDase) activity and by measuring nucleosomal DNA content (cell death ELISA). Vascular leakage was quantified by the Evans Blue dye method. A set of IR-responsive mRNAs was identified by whole-genome microarray and confirmed by RT-PCR analyses. VEGF protein was measured by Western blot analysis. IPC was accomplished with 10 minutes of ischemia 24 hours before IR. VEGF and TNFα signaling was inhibited by intravitreal injection of bevacizumab or etanercept, respectively. RESULTS: IR caused significant retinal cell apoptosis and vascular permeability after 4 and 48 hours. Whereas IR decreased VegfA mRNA, VEGF protein was significantly increased. IPC effectively inhibited neurodegeneration, bevacizumab effectively inhibited vascular permeability, and etanercept failed to affect either outcome. IPC significantly altered the IR responses of 15 of 33 IR-responsive mRNAs, whereas bevacizumab had no significant effect on these mRNAs. CONCLUSIONS: IR provides an acute model of ischemic retinopathy that includes neurodegeneration and VEGF-dependent vascular permeability and is amenable to rapid drug therapy testing. The distinct effects of IPC and bevacizumab demonstrate that the apoptotic and vascular responses to IR may be separated and that therapeutics targeting each pathologic endpoint may be warranted in treating ischemic retinal diseases.

Effect of IL-1beta on survival and energy metabolism of R28 and RGC-5 retinal neurons.

PURPOSE: Interleukin-(IL)1beta expression is increased in the retina during a variety of diseases involving the death of retinal neurons and contributes to neurodegenerative processes through an unknown mechanism. This study was conducted to examine the effects of IL-1beta on the metabolism and viability of RGC-5 and R28 retinal neuronal cells. METHODS: Cellular reductive capacity was evaluated using WST-1 tetrazolium salt. Mitochondrial transmembrane potential was determined by JC-1 fluorescence. Cellular ATP levels were measured with a luciferase assay. Caspase-3/7 activation was detected with a DEVDase activity assay. Cell death and lysis was evaluated by measuring release of lactate dehydrogenase (LDH). Glycolysis was assessed by measuring glucose disappearance and lactate appearance in cell culture medium. Cellular respiration was followed polarographically. RESULTS: IL-1beta treatment caused a pronounced decrease in cellular reductive potential. IL-1beta caused depletion of intracellular ATP, loss of mitochondrial transmembrane potential, caspase-3/7 activation, and LDH release. IL-1beta treatment increased rates of glucose utilization and lactate production. The cells were partially protected from IL-1beta toxicity by ample ambient glucose. However, glucose did not block the ability of IL-1beta to cause a decline in mitochondrial transmembrane potential or ATP depletion. IL-1beta decreased oxygen consumption of the R28 cells by nearly half, but did not lower cytochrome c oxidase activity. CONCLUSIONS: The present results suggest that IL-1beta inhibits mitochondrial energy metabolism of these retinal neuronlike cells.

Loss of PTEN promotes tumor development in malignant melanoma.

Loss of tumor suppressor genes on chromosome 10 plays an important role in the development of 30-60% of melanomas; however, the identity of these genes and the mechanisms by which loss of these genes leads to tumor formation remain uncertain. The phosphatase and tensin homologue deleted from chromosome 10 (PTEN) is one of the genes on chromosome 10 whose of which the loss or inactivation may play an important role in melanoma tumorigenesis, but functional studies directly demonstrating PTEN involvement in melanomas are necessary to confirm this role. To determine the biological importance of PTEN loss in melanomas, we established a novel model in which an intact chromosome 10 was transferred into melanoma cells lacking PTEN protein to express the protein at normal physiological levels and to measure the consequent effects on melanoma tumorigenesis. PTEN expression in these cells retarded tumor development in mice unless, by analogy with loss of heterozygosity, the PTEN gene was deleted or inactivated during tumor formation. Mechanistically, PTEN loss led to the activation of Akt, which consequently down-regulated the apoptotic pathway of melanoma cells. In contrast, expression of PTEN attenuated Akt activation, thereby increasing sensitivity to apoptotic stimuli in cell culture and in vivo in animal models. This model demonstrated that PTEN loss is critical for melanoma tumorigenesis and allowed a dissection of the underlying mechanism by which PTEN loss facilitated melanoma tumor development. In summary, loss of PTEN reduces apoptosis and promotes cell survival, thereby favoring melanoma tumor formation. Thus, these observations provide an etiological basis for PTEN loss during the genesis of sporadic melanomas.