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Type 2 diabetes (T2D) is the most common endocrine and metabolic disorder, leading to reproductive impairments and infertility in male. Our recent study showed crucial role of adiponectin in the regulation of testicular functions, and the circulating level of adiponectin declines in diabetes. The current study thus aimed to examine the efficacy of adiponectin in improving testicular dysfunction in high-fat diet/streptozotocin-induced T2D mice. T2D was induced in pre-pubertal mice fed with high-fat diet for ∼10 weeks followed by a single dose of streptozotocin. T2D mice showed presence of increased body mass, hyperglycemia, hyperinsulinemia, insulin resistance, increased oxidative stress, and declined serum testosterone compared to vehicle-treated control mice. The spermatogenic, steroidogenic, metabolic, and antioxidative parameters were evaluated in T2D mice treated with adiponectin for both two and four weeks. The exogenous administration of adiponectin to T2D mice showed enhanced serum testosterone and expression of testicular steroidogenic markers proteins, insulin receptor and GLUT8 proteins, increase in intra-testicular concentrations of glucose and lactate and activity of LDH and antioxidant enzymes compared to the levels in untreated T2D mice. This suggests that treatment of adiponectin effectively improves testicular functions by increasing expression of insulin receptor-mediated increased transport of energy substrate (glucose and lactate) and a marked reduction in oxidative stress are the possible mechanism by which adiponectin effectively improves testicular function in T2D mice.

Experimental autoimmune anterior uveitis (EAAU) is a clinically relevant animal model for human idiopathic anterior uveitis (IAU). The role of the immunomodulator transforming growth factor β2 (TGF-β2) in EAAU pathology is unknown. In this study, we investigated the regulatory role of TGF-β2 in EAAU. EAAU was induced in male Lewis rats by footpad injection of melanin-associated antigen (MAA). TGF-β2 was administered intravenously (iv) in MAA-sensitized rats during the induction of EAAU, or after the clinical onset of uveitis. MAA-sensitized rats injected similarly with an equal volume of PBS served as control. Animals were examined daily between days 7 and 30 post-injection for the clinical signs of uveitis using slit lamp biomicroscopy. Animals were sacrificed at various time points and eyes were harvested for histological analysis to assess the course and severity of inflammation. For histopathological analysis, paraffin sections of harvested eyes were stained with hematoxylin and eosin. Popliteal lymph nodes (LNs) were used for CD4+CD25+FoxP3+ T regulatory (Tregs) population analysis and for CD4+ T cell proliferation assay. Administration of recombinant TGF-β2 during the early stages of EAAU prevented the induction of uveitis. Compared to PBS, the presence of TGF-β2 in the cell culture significantly (p

Choroidal neovascularization (CNV) is the hallmark of wet age-related macular degeneration (AMD), a leading cause of irreversible blindness in the modern world. The objective for this study was to investigate the therapeutic potential of known antiangiogenic agents: thalidomide, senicapoc, and sodium butyrate. Dose-dependent effect of the agents on growth of ARPE-19 cells and human umbilical vein endothelial cells (HUVECs) was investigated with cell counting assays. Half-maximal inhibitory concentrations of thalidomide (765 μM and 1520 μM), senicapoc (50 μM and 79 μM), and sodium butyrate (933 μM and 557 μM) were determined for HUVECs and ARPE-19 cells, respectively. Immunofluorescence analysis showed decrease of VEGFA expression in both ARPE-19 cells and HUVECs after treatment only with thalidomide but not with senicapoc or sodium butyrate. Efficacy of the agents was studied in vivo with laser-induced CNV in C57BL/6 mice. Thalidomide (24 μg), senicapoc (4 μg), or sodium butyrate (100 μg) was intravitreally injected the day after CNV induction. Thalidomide, senicapoc, and sodium butyrate inhibited CNV size by 56%, 24%, and 21% respectively on day 7 post-laser. Thalidomide also reduced cobalt chloride induced increase of VEGFA mRNA in ARPE-19 (−33%) and protein in culture medium (−20%). Our results suggest that thalidomide may have more therapeutic potential than senicapoc or sodium butyrate for treatment of CNV or wet AMD.

The mechanisms by which testicular functions decline with aging remain largely speculative. Our recent finding showed the importance of adiponectin in the regulation of testicular functions, whereas its concentration declines during male infertility. Thus, the aim of present study was to explore the potential role of adiponectin during aging. The changes in adiponectin, adiponectin-receptors, and insulin receptor proteins expression in the testis were evaluated and compared with the testicular parameters, mass, and testosterone level in the mice from early post-natal to late senescence period. Further, the current study has examined the effect of exogenous adiponectin treatment on testicular functions in aged mice. The results showed a significant decline in adiponectin/adiponectin-receptors expression simultaneously with a significant decline in testicular mass, insulin receptor expression and testosterone synthesis in the testis of aged mice. Exogenous treatment of adiponectin to aged mice resulted in marked improvements in testicular mass, histological features (cells proliferation), insulin receptor expression, testicular glucose uptake, anti-oxidative enzymes activity and testosterone synthesis as compared with the control. Based on these findings, it may be concluded that a marked decline in adiponectin synthesis and action results in decreased insulin sensitivity (development of insulin resistance) and increased oxidative stress which consequently suppresses testicular functions during aging. This study further showed that treatment with adiponectin ameliorates reduced testicular functions by enhanced expression of insulin receptor in the testis of senescent mice. It is thus hypothesized that systemic adiponectin treatment could be a promising therapeutic strategy for improvement of testosterone production and sperm counts during aging., Mayank Choubey greatly acknowledges financial assistance in the form of a Senior Research Fellowship (SRF) from Indian Council of Medical Research (ICMR File No. RBMH/FW/2018/1), New Delhi, India. This work was also supported by University Grant Commission (UGC), New Delhi and Centre of Advanced Study, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi, India.

Accepted manuscript, Obesity is a major health problem that is linked to decreased sperm count. It is hypothesized that an obesity-associated reduction in adiponectin secretion may be responsible for impairment of spermatogenesis. Therefore, the aim of the study was to evaluate the direct role of adiponectin in spermatogenesis and steroid synthesis in adult mice. This study showed that adiponectin receptors (AdipoR1 and AdipoR2) were localized in Leydig cells and seminiferous tubules in the testis of adult mice. The result of the in vitro study showed the direct action of adiponectin on spermatogenesis by stimulating cell proliferation (PCNA) and survival (Bcl2) and by suppressing cell apoptosis. Treatment of testis with adiponectin also enhanced transport of the energetic substrates glucose and lactate to protect cells from undergoing apoptosis. Adiponectin treatment further showed a significant reduction in oxidative stress and nitric oxide. Our findings suggest that adiponectin effectively facilitates cell survival and proliferation, as well as protects from apoptosis. Thus, adiponectin treatment may be responsible for enhancing sperm counts. Interestingly, this study showed the stimulatory effect of adiponectin in spermatogenesis but showed an inhibitory effect on testosterone and estradiol synthesis in the testes. Based on the present study, it is hypothesized that systemic adiponectin treatment may be a promising therapeutic strategy for the improvement of spermatogenesis and sperm count., University Grants Commission, New-Delhi, India. The authors would like to thank DeAnn Hubberd and Madison Hedrick from the Science Communications Department at the University of Arkansas for Medical Sciences for their work editing this manuscript. This work was also supported by Centre of Advanced Study, Department of Zoology, Banaras Hindu University, Varanasi, India, info:eu-repo/semantics/acceptedVersion

Background To characterize the effect of aspirin (ASA) in mouse models of choroidal neovascularization (CNV) and retinal degeneration. Methods In vivo: Male C57BL/6 mice were given ASA in food or regular rodent diet. CNV was induced by argon laser photocoagulation. Subretinal injections of polyethylene glycol 400 (PEG-400) were administered to induce retinal degeneration. CNV size, laser spot area and mean intensity of VEGF in the laser injured zones were measured. In the PEG injected eyes the thickness of retinal pigment epithelium (RPE) and choroid was measured. In vitro: Human ARPE-19 cells were treated with 0.5 or 2.0 mM/L of ASA for 72 h. ELISA was used to measure the concentration of VEGF and CCL-2 in the supernatants. Additionally, damaged RPE monolayer was treated with ASA (0.5 or 2.0 mM/L) and vehicle separately. Size of damaged area was measured. ELISA was used to measure secretion of VEGF-A and CCL-2 by damaged cells after 24 h. Results No statistically significant effect of ASA on CNV size, laser spot size or VEGF expression was noted in CNV model. In the PEG model, ASA did not have any effect on RPE and choroid thickness; however, a significant increase in RPE atrophy was observed (P = 0.02 + 38%). In addition, ASA had a significant effect on the ability of the RPE cells to regenerate and become confluent after mechanical damage. Conclusions ASA at doses consumed clinically for various medical causes may not worsen CNV in human subjects. However, ASA may increase RPE atrophy when consumed over long periods of time.

Metabolic disorders such as obesity and type 2 diabetes are one of the most familiar risk factors in the present time among every age-group. It is associated with altered levels of adipokines such as adiponectin, chemerin, leptin, resistin, visfatin, and so on. Adiponectin is one of the adipocyte-specific protein with novel applications pertaining to metabolism by promoting insulin sensitivity and regulating glucose and fatty acid catabolism, while chemerin is considered as an inhibitor of insulin signaling and glucose catabolism. Other than these established functions, both the adipokines are intimately involved in coordinating reproductive activities, but they exhibit contrary functions. This review is an amalgamation of recent information related to adiponectin and chemerin in male and female reproduction and further its association with metabolism-related reproductive disorders. The direct effect of adiponectin and chemerin on various reproductive parameters has been investigated, but there was a rampant failure to account for in vivo data which gives a broad outlook on the regulatory mechanism of both adiponectin and chemerin related to male and female reproductive functions. Adiponectin is known to promote gonadal activities, while chemerin exerts antigonadal actions. Recent research suggests that high chemerin/low adiponectin ratio plays a vital role in causing dyslipidemia and metabolic syndrome in patients. The dysregulated ratio of adiponectin to chemerin during various metabolic disorders makes it really worthy in relation to an application for therapeutics. Still, a lot regarding both the adipokines has to be explored and brought forward in order to deal with therapeutics of metabolism-related reproductive disorders.

Polycystic ovary syndrome (PCOS) is a common endocrine and metabolic disorder of reproductive age females, leading to infertility. Despite extensive research, the exact pathophysiology and treatment are lacking. The aim of the current study was to evaluate the direct role of adiponectin either alone or together with luteinizing hormone (LH) on sex hormone synthesis and changes in insulin receptor (IR) in the ovary of dehydroepiandrosterone (DHEA)–treated PCOS-mice. Immunohistochemical study showed decreased expression of adiponectin receptor (AdipoR1) in PCOS-ovary which correlated with increased synthesis of androgen and decreased expression of IR. The treatment with adiponectin with or without LH to PCOS-ovary in vitro caused significant decline in androgen synthesis and increase in IR. This study showed the direct role of adiponectin in ameliorating hyperandrogenism and reducing IR in the ovary of PCOS-mice. Thus adiponectin treatment may be a novel therapeutic strategy for combating PCOS.

The present study examined the efficacy of adiponectin for regulating the reproductive, metabolic and fertility status of mice with polycystic ovary syndrome (PCOS). PCOS was induced in prepubertal (21- to 22-day-old) mice using dehydroepiandrosterone (6 mg 100 g−1 day−1 for 25 days), after which mice were administered either a low or high dose of adiponectin (5 or 15 µg mL−1, s.c., respectively). PCOS mice exhibited typical features, including the presence of numerous cystic follicles, increased circulating androgens, increased body mass, altered steroidogenesis, decreased insulin receptor expression and increased serum triglycerides, serum glucose, Toll-like receptor (TLR)-4 (a marker of inflammation) and vascular endothelial growth factor (VEGF; a marker of angiogenesis). These parameters were significantly correlated with a reduction in adiponectin in PCOS mice compared with vehicle-treated control mice. Exogenous adiponectin treatment of PCOS mice restored body mass and circulating androgen, triglyceride and glucose levels. Adiponectin also restored ovarian expression of steroidogenic markers (LH receptors, steroidogenic acute regulatory protein and 3β-hydroxysteroid dehydrogenase), insulin receptor, TLR-4 and VEGF levels in control mice. Adiponectin restored ovulation in PCOS mice, as indicated by the presence of a corpus luteum and attainment of pregnancy. These findings suggest that adiponectin effectively facilitates fertility in anovulatory PCOS. We hypothesise that systemic adiponectin treatment may be a promising therapeutic strategy for the management of PCOS.

Age-related macular degeneration (AMD) is a leading cause of irreversible blindness. This study was done to characterize dry AMD-like changes in mouse retinal pigment epithelium (RPE) and retina after polyethylene glycol (PEG) treatment. We injected male C57BL/6 mice subretinally with PBS, 0.025, 0.25, 0.5 and 1.0 mg of PEG-400 and the animals were sacrificed on day 5. Eyes were harvested and processed for histological analysis. In all other experiments 0.5 mg PEG was injected and animals were sacrificed on days 1, 3, 5 or 14. Paraffin, 5 μm and plastic, 1 μm and 80 nm sections were used for further analysis. Subretinal injection of 0.5 mg PEG induced a 32% reduction of outer nuclear layer (ONL) thickness, 61% decrease of photoreceptor outer and inner segment length, 49% decrease of nuclear density in the ONL and 31% increase of RPE cell density by day 5 after injection. The maximum level of TUNEL positive nuclei in the ONL (6.8 + 1.99%) was detected at day 5 after PEG injection and co-localized with Casp3act. Histological signs of apoptosis were observed in the ONL by light or electron microscopy. Degeneration of RPE cells was found in PEG injected eyes. Gene expression data identified several genes reported to be involved in human AMD. C3, Cfi, Serping1, Mmp9, Htra1 and Lpl were up-regulated in PEG injected eyes compared to PBS controls. PEG leads to morphological and gene expression changes in RPE and retina consistent with dry AMD. This model will be useful to investigate dry AMD pathogenesis and treatment.

Purpose The purpose of this article is to evaluate the effect of nicotine on anti-vascular endothelial growth factor therapy in the treatment of neovascular age-related macular degeneration. Methods One group of mice received nicotine in drinking water and the other group received water only. Choroidal neovascularization (CNV) was induced with a laser. Nicotinic acetylcholine receptor-α7 (nAChRα7) expression was evaluated by immunohistochemistry. Bevacizumab or adiponectin peptide II (APNpII) was injected intravitreally on Day 7 postlaser, and the effects were evaluated on Days 14 and 21. α-Bungarotoxin was injected intraperitoneally on Days 2 to 5, and its effect was evaluated on Day 14. Results Expression of nAChRα7 was 2 to 7 times higher between Days 3 and 7 postlaser compared with naive mice. In water-fed mice, APNpII, bevacizumab, and α-bungarotoxin significantly reduced CNV size. In nicotine-fed mice, treatment with APNpII or bevacizumab did not significantly reduce CNV size, whereas α-bungarotoxin did have an effect. Comparing water- and nicotine-fed mice, CNV size was 61% to 86% smaller in water-fed mice except for the α-bungarotoxin group, where there was no difference. Platelet-derived growth factor and vascular endothelial growth factor expression was 1.5- to 2.5-fold higher at Day 14 in nicotine-treated mice. Conclusion Nicotine significantly blocks the effect of anti-vascular endothelial growth factor therapy in the treatment of laser-induced neovascular age-related macular degeneration. nAChRα7 is significantly upregulated during the formation of CNV, and treatment with an nAChRα7 antagonist decreases CNV size irrespective of nicotine administration.

This study investigated the role of complement in the protection of retinal ganglion cells (RGCs) in chronic ocular hypertension model of glaucoma. Intraocular pressure (IOP) was elevated in the right eye of Lewis rats by laser photocoagulation (two treatments, 7days apart) of episcleral and limbal veins. Left eye did not receive laser treatment and served as control. Animals were injected with cobra venom factor every fifth day starting day 7 after first laser, to deplete the complement system. Animals were sacrificed at 6-week post-laser. Levels of C3 split products and membrane attack complex (MAC) were elevated in the retina of eyes with increased IOP and complement depletion reduced the loss of Brn3a(+) RGCs accompanied by decreased expression of GFAP and reduced MAC deposition. In complement depleted rats with increased IOP, reduced TUNEL(+) cells in ganglion cell layer, and decreased levels of active caspase-8 and active caspase-9 was observed compared to PBS treated complement sufficient rats with increased IOP. Interestingly, complement depletion also resulted in reduction of calcium influx and levels of BAD in the retinal cells of the eyes with increased IOP. Together, our results provide evidence that complement mediated apoptosis plays a pivotal role in the loss of RGCs in chronic ocular hypertension model of glaucoma.

The present study investigated the interactions among the complement membrane attack complex (MAC), CCL2, and VEGF that occur in vivo during the development of choroidal neovascularization (CNV). We first investigated the sequential expression of MAC, CCL2, and VEGF during laser-induced CNV in C57BL/6 mice. Increased MAC deposition was detected at 1 h, CCL2 increased at 3 h, and VEGF was up-regulated at day 3 post-laser treatment. These results suggested that during laser-induced CNV, MAC, CCL2 and VEGF are formed and/or expressed in the following order: MAC → CCL2 → VEGF. To determine the cross-talk between MAC, CCL2, and VEGF during laser-induced CNV, neutralizing antibodies were injected both systemically and locally to block the bioactivity of each molecule. Blocking MAC formation inhibited CCL2 and VEGF expression and also limited CNV formation, whereas neutralization of CCL2 bioactivity did not affect MAC deposition; however, it reduced VEGF expression and CNV formation. When bioactivity of VEGF was blocked, CNV formation was significantly inhibited, but MAC deposition was not affected. Together, our results demonstrate that MAC is an upstream mediator and effect of MAC on the development of laser-induced CNV can be attributed to its direct effect on VEGF as well as its effect on VEGF that is mediated by CCL2. Understanding the interplay between immune mediators is critical to gain insight into the pathogenesis of CNV.

This study was initiated to explore the effect of recombinant rat Crry linked to the Fc portion of rat IgG2a (Crry-Ig) on the induction of experimental autoimmune anterior uveitis (EAAU) and on established disease. EAAU was induced in Lewis rats by immunization with bovine melanin-associated antigen (MAA). MAA sensitized animals received Crry-Ig, rat IgG2a (isotype control) or PBS separately before the onset of EAAU or after the onset of clinical disease. Administration of Crry-Ig suppressed the induction of EAAU while all animals injected with IgG2a or PBS developed the normal course of EAAU. Treatment with Crry-Ig resulted in the suppression of ocular complement activation as well as the functional activity of complement in the peripheral blood. At the peak of EAAU, levels of IFN-γ, IP-10, ICAM-1 and LECAM-1 were significantly reduced within the eyes of Crry-Ig treated Lewis rats. Importantly, administration of Crry-Ig even after the onset of EAAU resulted in a sharp decline in the disease activity and early resolution of EAAU. Collectively, the evidence presented here demonstrate that inhibition of complement by Crry-Ig results in low levels of inflammatory molecules-C3 activation products, MAC, cytokines, chemokines and adhesion molecules in the eye. Down-regulation of these molecules affects the infiltration and recruitment of inflammatory cells to the eye resulting in the inhibition of EAAU.

Idiopathic anterior uveitis (IAU) is a blinding disease characterized by inflammation of the iris and the ciliary body (CB) of the eye. IAU is treated symptomatically only using non-specific therapies such as steroid and immunosuppressive agents. These treatment modalities do not address the underlying mechanisms and are associated with adverse side effects. Experimental autoimmune anterior uveitis (EAAU) is a clinically relevant animal model of human IAU. In the current study we used EAAU animal model to investigate underlying mechanisms involved in regulation of inflammation in IAU. EAAU was induced in Lewis rats by immunization with melanin associated antigen (MAA). We observed that Th17 cells (IL-17 producing CD4+ cells and CD4+RORγt+ cells) accumulated in rat eyes at the onset and the peak of the disease. During the resolution of EAAU, Th17 cells declined while CD4+CD25+FoxP3+ T regulatory (Tregs) cells accumulated in the eyes. Administration of recombinant TGF-β2 during the early stages of EAAU prevented the induction of uveitis by inhibiting CD4+T proliferation and increasing the number of CD4+CD25+FoxP3+ Tregs. Severity of active (on-going) EAAU was reduced only for the time of active treatment with TGF-β2. Adoptive transfer of CD4+CD25+ T regulatory cells after the onset of EAAU resulted in sharp decline in disease activity and early resolution of EAAU. In conclusion, our results demonstrate that TGF-β2 plays a pivotal role in regulation of intraocular inflammation in EAAU. Collectively, these results raise the possibility that human IAU can be treated perhaps by enhancing the generation of Tregs by TGF-β2. Additionally, Treg cell therapy is potentially a promising strategy in the treatment of established human IAU.

The objective of this study was to inhibit experimental autoimmune anterior uveitis (EAAU) by establishing antigen-specific immune tolerance in animals pre-sensitized with melanin-associated antigen (MAA). Intravenous administration of MAA on days 6, 7, 8 and 9 post-immunization induced tolerance and inhibited EAAU in all Lewis rats. The number of cells (total T cells, CD4(+) T cells and CD8(+) T cells) undergoing apoptosis dramatically increased in the popliteal lymph nodes (LNs) of the tolerized animals compared with non-tolerized animals. In addition, Fas ligand (FasL), TNF receptor 1 (TNFR1) and caspase-8 were upregulated in tolerized rats. Proliferation of total lymphocytes, CD4(+)T cells and CD8(+) T cells (harvested from the popliteal LNs) in response to antigenic stimulation was drastically reduced in the state of tolerance compared with the cells from non-tolerized animals. The level of interferon (IFN)-gamma and IL-2 decreased, whereas TGF-beta2 was elevated in the state of tolerance. Furthermore, the number of CD4(+)CD25(+)FoxP3(+) regulatory T cells (Tregs) increased in the popliteal LNs of tolerized animals compared with non-tolerized animals. In conclusion, our results suggest that deletion of antigen-specific T cells by apoptosis and active suppression mediated by Tregs has an important role in the induction of antigen specific immune tolerance in animals with an established immune response against MAA.

This study was initiated to induce experimental autoimmune anterior uveitis (EAAU) in Lewis rats by melanin-associated antigen (MAA; 22-kDa fragment of type I collagen alpha2 chain) derived from rat iris and ciliary body (CB), to localize MAA within the eye, and to investigate the possible mechanism of MAA generation in vivo. The EAAU model replicates idiopathic human anterior uveitis. Lewis rats sensitized to rat MAA developed anterior uveitis, and EAAU induced by rat MAA can be adoptively transferred to naive syngenic rats by MAA-primed T cells. Animals immunized with rat MAA developed cellular immunity to the antigen. MAA was detected only in the iris and CB of the eye. Iris and CB were the major source of matrix metalloproteinase-1 (MMP-1) in the naive eye, and ocular expression of MMP-1 was up-regulated, whereas expression of tissue inhibitor of metalloproteinase 1 decreased before the onset of EAAU. These results demonstrated that EAAU can be induced by autologous MAA. Uveitogenic antigen is present only in the iris and CB of the eye, and the imbalance between MMP-1 and tissue inhibitor of metalloproteinase 1 may play a role in the generation of MAA in vivo. Collectively, the evidence presented here suggests that MAA is an autoantigen in EAAU. These observations may extend to idiopathic human anterior uveitis and facilitate the development of antigen-specific therapy.

We have investigated the effect of adiponectin (APN) peptide II on new vessel growth in mouse model of choroidal neovascularization (CNV) or wet type age-related macular degeneration (AMD). Mice were injected intraperitoneally with APN peptide II, control peptide, or PBS on day 1–7 or day 5–14. APN, AdipoR1, PCNA, and VEGF localization was investigated using confocal microscopy, immunohistochemistry, and RT-PCR. APN peptide II decreased the relative area of FITC-dextran perfused vessels by 4-fold, PCNA expression by 3-fold, and the number of PCNA stained HUVEC and MAVEC cells by 38 and 46%, respectively. We concluded that APN peptide II inhibits CNV size on days 7 and 14 by inhibiting the proliferation of endothelial cells in vivo and in vitro. APN peptide II may have therapeutic potential to inhibit CNV or wet AMD.

Functionally active complement system and complement regulatory proteins are present in the normal human and rodent eye. Complement activation and its regulation by ocular complement regulatory proteins contribute to the pathology of various ocular diseases including keratitis, uveitis and age-related macular degeneration. Furthermore, a strong relationship between age-related macular degeneration and polymorphism in the genes of certain complement components/complement regulatory proteins is now well established. Recombinant forms of the naturally occurring complement regulatory proteins have been exploited in the animal models for treatment of these ocular diseases. It is hoped that in the future recombinant complement regulatory proteins will be used as novel therapeutic agents in the clinic for the treatment of keratitis, uveitis, and age-related macular degeneration.

Cellular oxidative stress plays an important role in retinal pigment epithelial (RPE) cell death during aging and the development of age-related macular degeneration. Early reports indicate that during phagocytosis of rod outer segments, there is an increase of RPE oxidative stress and an upregulation of PPARγmRNA in these cells. These studies suggest that activation of PPARγmay modulate cellular oxidative stress. This paper presents a brief review of recent studies that investigate RPE oxidative stress under various experimental conditions. This is followed by a detailed review on those reports that examine the protective effect of the natural PPARγligand, 15d-PGJ2, against RPE oxidative stress. This agent can upregulate glutathione and prevent oxidant-induced intracellular reactive oxygen species accumulation, mitochondrial depolarization, and apoptosis. The cytoprotective effect of this agent, however, is not shared by other PPARγagonists. Nonetheless, this property of 15d-PGJ2may be useful in future development of pharmacological tools against retinal diseases caused by oxidative stress.

In the normal eye, the complement system is continuously activated at low levels and both membrane-bound and soluble intraocular complement regulatory proteins tightly regulate this spontaneous complement activation. This allows protection against pathogens without causing any damage to self-tissue and vision loss. The complement system and complement regulatory proteins control the intraocular inflammation in autoimmune uveitis and play an important role in the development of corneal inflammation, age-related macular degeneration and diabetic retinopathy. The evidence derived from both animal models and patient studies support the concept that complement inhibition is a relevant therapeutic target in the treatment of various ocular diseases. Currently, several clinical trials using complement inhibitors are going on. It is possible that, in the near future, complement inhibitors might be used as therapeutic agents in eye clinics.

To characterize the effect of aspirin (ASA) in mouse models of choroidal neovascularization (CNV) and retinal degeneration.In vivo: Male C57BL/6 mice were given ASA in food or regular rodent diet. CNV was induced by argon laser photocoagulation. Subretinal injections of polyethylene glycol 400 (PEG-400) were administered to induce retinal degeneration. CNV size, laser spot area and mean intensity of VEGF in the laser injured zones were measured. In the PEG injected eyes the thickness of retinal pigment epithelium (RPE) and choroid was measured. In vitro: Human ARPE-19 cells were treated with 0.5 or 2.0 mM/L of ASA for 72 h. ELISA was used to measure the concentration of VEGF and CCL-2 in the supernatants. Additionally, damaged RPE monolayer was treated with ASA (0.5 or 2.0 mM/L) and vehicle separately. Size of damaged area was measured. ELISA was used to measure secretion of VEGF-A and CCL-2 by damaged cells after 24 h.No statistically significant effect of ASA on CNV size, laser spot size or VEGF expression was noted in CNV model. In the PEG model, ASA did not have any effect on RPE and choroid thickness; however, a significant increase in RPE atrophy was observed (P = 0.02 + 38%). In addition, ASA had a significant effect on the ability of the RPE cells to regenerate and become confluent after mechanical damage.ASA at doses consumed clinically for various medical causes may not worsen CNV in human subjects. However, ASA may increase RPE atrophy when consumed over long periods of time.

In the mouse, membrane cofactor protein (CD46), a key regulator of the alternative pathway of the complement system, is only expressed in the eye and on the inner acrosomal membrane of spermatozoa. We noted that although Cd46(-/-) mice have normal systemic alternative pathway activating ability, lack of CD46 leads to dysregulated complement activation in the eye, as evidenced by increased deposition of C5b-9 in the retinal pigment epithelium (RPE) and choroid. A knockout of CD46 induced the following cardinal features of human dry age-related macular degeneration (AMD) in 12-month-old male and female mice: accumulation of autofluorescent material in and hypertrophy of the RPE, dense deposits in and thickening of Bruch's membrane, loss of photoreceptors, cells in subretinal space, and a reduction of choroidal vessels. Collectively, our results demonstrate spontaneous age-related degenerative changes in the retina, RPE, and choroid of Cd46(-/-) mice that are consistent with human dry AMD. These findings provide the exciting possibility of using Cd46(-/-) mice as a convenient and reliable animal model for dry AMD. Having such a relatively straight-forward model for dry AMD should provide valuable insights into pathogenesis and a test model system for novel drug targets. More important, tissue-specific expression of CD46 gives the Cd46(-/-) mouse model of dry AMD a unique advantage over other mouse models using knockout strains.

This study was undertaken to explore the role of complement regulatory proteins (CRPs) in experimental autoimmune anterior uveitis (EAAU). We observed that the levels of CRPs, Crry and CD59, in the eyes of Lewis rats increased during EAAU and remained elevated when the disease resolved. The in vivo role of these CRPs in EAAU was explored using neutralizing mAbs, antisense oligodeoxynucleotides (AS-ODNs), and small interfering RNAs against rat Crry and CD59. Suppression of Crry in vivo at days 9, 14, or 19 by neutralizing mAb or AS-ODNs resulted in the early onset of disease, the exacerbation of intraocular inflammation, and delayed resolution. Suppression of CD59 was only effective when the Abs and ODNs were given before the onset of disease. The most profound effect on the disease was observed when a mixture of Crry and CD59 mAbs or AS-ODNs was administered. A similar effect was observed with a combination of Crry and CD59 small interfering RNA. There was no permanent histologic damage to ocular tissue after the inflammation cleared in these animals. Increased complement activation as determined by increased deposition of C3, C3 activation fragments, and membrane attack complex was observed in the eyes of Lewis rats when the function and/or expression of Crry and CD59 was suppressed. Thus, our results suggest that various ocular tissues up-regulate the expression of Crry and CD59 to avoid self-injury during autoimmune uveitis and that these CRPs play an active role in the resolution of EAAU by down-regulating complement activation in vivo.

One of the pathologic complications of exudative (i.e. wet-type) age-related macular degeneration (AMD) is choroidal neovascularization (CNV). The aim of this study was to investigate whether chronic and heavy alcohol consumption influenced the development of CNV in a rat model. The oxidative metabolism of alcohol is minimal or absent in the eye, so that ethanol is metabolized via a nonoxidative pathway to form fatty acid ethyl esters (FAEE). Fatty acid ethyl ester synthase (FAEES) was purified from the choroid of Brown Norway (BN) rats. The purified protein was 60 kDa in size and the antibody raised against this protein showed a single band on western blot. BN rats on a regular diet were fed alcohol for 10 weeks. Control rats were fed water with a regular diet and pair-fed control rats were fed regular diet, water and glucose. We found that FAEES activity was increased 4.0-fold in the choroid of alcohol-treated rats compared with controls. The amount of ethyl esters produced in the choroid of 10 week alcohol-fed rats was 7.4-fold more than rats fed alcohol for 1 week. The increased accumulation of ethyl esters was associated with a 3.0-fold increased expression of cyclin E and cyclin E/CDK2; however, the level of the cyclin kinase inhibitor, p27Kip, did not change. The increased accumulation of ethyl esters was also associated with 3.0-fold decreased expression of APN in the choroid. We also found that the size of CNV increased by 28% in alcohol-fed rats. Thus, our study showed that chronic, heavy alcohol intake was associated with both an increased accumulation of ethyl esters in the choroid and an exacerbation of the CNV induced by laser treatment. These results may provide insight into the link between heavy alcohol consumption and exudative AMD.

Choroidal neovascularization (CNV), or choroidal angiogenesis, is the hallmark of age-related macular degeneration and a leading cause of visual loss after age 55. The pathogenesis of new choroidal vessel formation is poorly understood. Although inflammation has been implicated in the development of CNV, the role of complement in CNV has not been explored experimentally. A reliable way to produce CNV in animals is to rupture Bruch’s membrane with laser photocoagulation. A murine model of laser-induced CNV in C57BL/6 mice revealed the deposition of C3 and membrane attack complex (MAC) in the neovascular complex. CNV was inhibited by complement depletion using cobra venom factor and did not develop in C3−/− mice. Anti-murine C6 Abs in C57BL/6 mice inhibited MAC formation and also resulted in the inhibition of CNV. Vascular endothelial growth factor, TGF-β2, and β-fibroblast growth factor were elevated in C57BL/6 mice after laser-induced CNV; complement depletion resulted in a marked reduction in the level of these angiogenic factors. Thus, activation of complement, specifically the formation of MAC, is essential for the development of laser- induced choroidal angiogenesis in mice. It is possible that a similar mechanism may be involved in the pathophysiology of other angiogenesis essential diseases.

The FAEES/carboxylesterase enzyme nonoxidatively metabolizes alcohol into FAEEs, potentially toxic molecules linked with alcohol-induced end-organ damage. Our laboratory has isolated and characterized a FAEES/carboxylesterase cDNA from human eye and heart (G12). In an effort to further characterize the G12 enzyme, this laboratory has analyzed the FAEES activity, as well as performed mutagenic studies on a proposed active site of G12. We have mutated Ser 204 and His 451 in the G12 enzyme in an attempt to characterize the active site. We found that both mutations cause almost total loss of carboxylesterase enzyme activity with the native enzyme remaining active for carboxylesterase activity (560 nmol/mg protein/h for G12). With oleic acid as a substrate, the FAEES activity was 170 nmol/mg protein/h for G12, 10.8 nmol/mg protein/h for M204, and 8.5 nmol/mg protein/h for M451. When ethanol was used as substrate, the FAEES activity was 240 nmol/mg protein/h for G12, 15.1 nmol/mg protein/h for M204, and 6.2 nmol/mg protein/h for M451. Since both carboxylesterase and FAEES enzyme activities are significantly lowered by mutating Ser 204 and His 451 of the G12 enzyme, this study indicates that these residues may be important for the key enzymatic activities of the enzyme.

Studies performed over the past decade in humans and experimental animals have been a major source of information and improved our understanding of how dysregulation of the complement system contributes to age-related macular degeneration (AMD) pathology. Drusen, the hall-mark of dry-type AMD are reported to be the by-product of complement mediated inflammatory processes. In wet AMD, unregulated complement activation results in increased production of angiogenic growth factors leading to choroidal neovascularization both in humans and in animal models. In this review article we have linked the complement system with modifiable and non-modifiable AMD risk factors as well as with prediction models of AMD. Understanding the association between the complement system, risk factors and prediction models will help improve our understanding of AMD pathology and management of this disease.

Our studies in the cholesterol-fed rabbit model indicate that moderate alcohol consumption reduces the risk of restenosis by preventing low-density lipoprotein (LDL) oxidation. Eighteen hypercholesterolemic rabbits underwent arterial injury by Fogerty balloon endothelial denudation of iliac arteries. Two weeks later, balloon angioplasty of atherogenic or atherosclerotic arterial segments was performed. Nine rabbits (control) received water ad lib, whereas nine rabbits (moderate alcohol treated) received an average of 2.5 ml alcohol per 500 ml water daily, from the day of feeding hypercholesterolemic diet until they were killed, 10 weeks later. There was a 26% increase in lumen size of the moderate alcohol-treated group compared with the control group. The percentage neointima formation (NI) values of the moderate alcohol-treated and control groups were 77 +/- 2.1 and 61 +/- 1.9, respectively (p < 0.001). The lumen/neointima (L/NI) ratio of the moderate alcohol-treated group was 0.71 +/- 0.07 compared with the control group, 0.33 +/- 0.04 (p < 0.001). The number of foam cells in the moderate alcohol-treated group was threefold less than the control group [i.e., 1.4 +/- 0.4 and 3.9 +/- 0.8, respectively (p = 0.005)]. The arterial lesion malondialdehyde (MDA) values of the control and the moderate alcohol-treated groups were 13.6 +/- 2.8 and 4.4 +/- 0.5 (p = 0.004), respectively. By radioimmunoassay, the moderate alcohol-treated group had less macrophage chemotactic protein-1 (MCP-1; 3,277 cpm/microg protein) and platelet-derived growth factor (PDGF; 2,261 cpm/microg protein) compared with the controls (MCP-1, 4,529 cpm/microg protein; PDGF, 3,583 cpm/microg protein). Thus we conclude that low concentrations of alcohol reduce neointimal formation, and the extent of lipid oxidation, the number of foam cells in the neointimal area and may decrease the expression of MCP-1 and PDGF by reducing LDL oxidation in an animal model of postangioplasty restenosis.

The complete gene for human fatty acid ethyl ester Synthase-III(FAEES-III) was isolated from a human genomic lambda phage library forfunctional and structural determination. The gene spans approximately 3.3 kbwhich includes 791 base pairs of the 5′ and 124 base pairs of the 3′flanking regions. The gene is comprised of seven exons and is interrupted bysix introns. Several transcription regulatory sequences were identified inthe promoter region. Primer extension experiments demonstrated the existenceof two possible transcription initiation sites at nucleotide -29 and 32position, 5' to the start of the translation. In addition to a TATA box atposition -29 relative to the transcription initiation site and two SplGGGCGG recognition sequences at nucleotide positions -42 to -37 and -50 to-45, the promoter contains a sequence motif matching the transcriptionactivating factor AP-1. We also found an A + T rich region betweennucleotide -505 and -390 which contained twenty-two AAAAT tandem repeats.The gene for FAEES-III was localized to human chromosome 11 by hybridizingthe genomic fragment Xh01 to Chinese hamster/human somatic cell hybridpanels. These data extend our knowledge of non-oxidative alcohol metabolismand permit linkage analyses between this pathway and alcohol-relatedphenotypes.

Fatty acid ethyl ester synthase metabolizes ethanol non-oxidatively in those extrahepatic organs most commonly damaged by alcohol abuse. This study was designed to purify human myocardial fatty acid ethyl ester synthase (FAEES)/carboxylesterase from human heart. The enzyme was purified to homogeneity after chromatography over DEAE-cellulose, Sephadex G-100 and hydroxylapatite. The homogenous enzyme, 62 kDa, has both synthase and carboxylesterase activities. The N-terminal amino acid sequence of the first 17 residues of the purified enzymes were 88% homologous to that of the carboxylesterase from rat liver and adipose tissue. Antibody was raised against pure synthase/carboxylesterase, cross-reacted with human cytosolic and microsomal fractions. With a constant oleic acid concentration of 0.25 m m , a calculated apparent K m and V max for ethanol were 0.30 m and 3700 nmol/mg protein/h., respectively. With constant ethanol concentrations of 1.2 m , the activity increased with the concentration of oleic acid to 0.17 m m , plateau to 0.25 m m . Because synthase/carboxylesterase esterifies free fatty acids with ethanol to produce its esters with potentially toxic effects, it may now be feasible to establish a link bectween alcohol consumption and end-organ damage.

Age-related macular degeneration (AMD) is a leading cause of central blindness in the elderly population. The wet type of AMD is characterized by extensive growth of new vessels. One of the effective strategies to treat wet AMD is to limit the choroidal neovascularization (CNV). We studied the effects of adiponectin peptide I (APNpI) on new vessel growth in laser-induced rat model of wet AMD and on rat choroidal endothelial cell (CEC) culture. CNV size and vessel density were investigated by microscopy. Immunohistochemical staining (IHC) for von Willebrand Factor (vWF), APN, APN receptors 1 (AdipoR1), 2 (AdipoR2), VEGF, VEGF receptor 2 (VEGF-R2), proliferating cell nuclear antigen (PCNA) was performed in CNV area. The mRNA expression of VEGF and VEGF-R2 in RPE-choroid was investigated by RT-PCR and real-time PCR. APNpI inhibited area of CNV by 4 fold, number of vWF positive vessels by 99% and area of subretinal tissue by 40%. The expression of VEGF and VEGF-R2 at mRNA and protein levels decreased after APNpI treatment in vivo. Proliferative index (PCNA) was 5 folds less in laser spots of APNpI treated rats compared to controls. In conclusion, APNpI inhibited formation of new vessels in rat model of CNV by decreasing VEGF, VEGF-R2 expression and cell proliferation. Thus, APNpI may have potential therapeutic use for AMD treatment since it significantly inhibited CNV.

To investigate the effect of topically applied honey on intact corneas, surgically induced corneal abrasions and endotoxin induced keratitis.The effect of honey on the cornea was investigated by application of honey on intact corneas, wounded corneas and endotoxin-induced keratitis in Lewis rats. The corneas were wounded by creating an epithelial defect using a surgical blade, and the keratitis was induced by topically applying Pseudomonas aeruginosa endotoxin to scarified corneas. After treatment rats were sacrificed and cornea harvested in each case. Corneas were processed for paraffin embedding for histological and immuno-fluorescence staining. Corneas were also harvested and processed for total ribonucleic acid (RNA) isolation for reverse transcriptase-polymerase chain reaction (RT-PCR) analysis for various growth factors and inflammatory chemokines/cytokines). Histological analysis revealed that no inflammation or morphological changes occurred after honey treatment in naive intact corneas. Vascular endothelial growth factor (VEGF) levels were also not altered after honey treatment. Topical application of honey to injured corneas resulted in faster epithelial healing and decreased expression of VEGF, transforming growth factor beta (TGF-β), interferon gamma (IFN-γ), interleukin 12 (IL-12) and tumor necrosis factor alpha (TNF-α) in injured corneas. Our results also established that honey treatment reduced the inflammation in endotoxin-induced keratitis by reducing the levels of angiogenic factors (VEGF and TGF-β), inflammatory cytokines (IL-12) and chemokines (CC chemokine receptor 5(CCR-5)). Short term use of honey on intact corneas can be safe. Honey has anti-angiogenic and anti-inflammatory properties that can be explored in several corneal inflammatory and infectious conditions.

In this study, we describe a new method for inducing choroidal neovascularization (CNV) in C57BL/6 mice, an animal model of wet age-related macular degeneration (AMD). AMD is a disease that causes central blindness in humans. We injected PEG-8 subretinally in different doses (0.125–2 mg) to induce CNV. After PEG-8 injection, we examined CNV at several time points (days 3–42). We also used Western blotting, immunohistochemistry, and ELISA to examine the complement component C3 split products, C9, VEGF, TGF-β2, and basic FGF. As early as day 1 after treatment, we found that a single subretinal injection of 1 mg of PEG-8 increased the C3 split products and the C9, TGF-β2, and basic FGF levels in the retinal pigment epithelium-choroid tissue. By day 3 after PEG-8 injection, the intraocular activation of the complement system caused induction and progression of CNV, including new vessels penetrating the Bruch's membrane. At day 5 after PEG-8 injection, we observed a fully developed CNV and retinal degeneration. Thus, in this study, we present a new, inexpensive, and accelerated mouse model of CNV that may be useful to study AMD.

The objective of the current study was to delineate the pathway of complement activation that is crucial for the induction of experimental autoimmune anterior uveitis (EAAU). We studied the development of EAAU in melanin-associated antigen (MAA)-sensitized Lewis rats treated with antibody against C4 or factor B. Control animals received isotype IgG control. Antibody against C4 had no effect on EAAU, and all of the animals developed EAAU similar to those injected with control IgG. In contrast, EAAU was completely inhibited in all MAA-sensitized Lewis rats injected with factor B antibody. Treatment with anti-factor B antibody resulted in suppression of ocular complement activation. Adoptive transfer of T lymphocytes harvested from draining lymph nodes of donor animals treated with anti-factor B did not transfer EAAU to naïve syngenic rats. Anti-factor B antibody inhibited the ability of MAA-specific CD4(+) T cells to proliferate (in vitro) in response to MAA in a dose-dependent manner. Level of TNF-α and IFN-γ decreased in the presence of anti-factor B. Collectively, our results provide the novel finding that complement activation via the alternative pathway contributes to intraocular inflammation in EAAU, and anti-factor B-mediated inhibition of EAAU is due to diminished antigen-specific CD4(+) T cell responses to MAA. Our findings explain the interactions between the complement system and T cells that are critical for the induction of EAAU and may lead to the development of therapy for idiopathic anterior uveitis based on selective blockade of the alternative pathway.

The objective of this study was to explore the relationship between local (ie, ocular) complement factor H (CFH) and choroidal neovascularization (CNV) associated with wet age-related macular degeneration (AMD), a leading cause of irreversible blindness, in laser-treated C57BL/6 mice. Immunohistochemical and RT-PCR analysis of retinal pigmented epithelium (RPE)-choroid sclera revealed that the expression of CFH was down-regulated on day 1 with a dramatic increase on days 5 and 7 postlaser injury. Flat mount and Western blot analysis further revealed that membrane attack complex (MAC) expression was up-regulated on days 1 and 3 postlaser injury; however, MAC was down-regulated on days 5 and 7 postinjury but was still higher than in non-injured mice. Similar patterns for CFH and MAC were observed for RPE cells when serial paraffin sections of the laser spots were analyzed. Subretinal injection of siRNA directed against CFH resulted in a threefold suppression of CFH in the RPE and choroid without affecting either CFH levels in the liver or the functional activity of the alternative pathway in the peripheral blood. Ocular knock-down of CFH resulted in increased MAC deposition, which leads to the early onset as well as exacerbation of laser-induced CNV. In conclusion, our findings provide evidence that CFH present on RPE and choroid regulates local MAC formation that is critical for the development of laser-induced CNV.

This study was designed to explore the effect of recombinant, membrane-targeted CD59 (rCD59-APT542) on the growth and size of fully developed neovascular complex using the murine model of laser-induced choroidal neovascularization (CNV). CNV was induced by laser photocoagulation in C57BL/6 mice using an argon laser, and the animals received rCD59-APT542 via intravitreal (ivt) route. Western blot analysis, immunohistochemistry, and total complement hemolytic assay demonstrated that exogenously administered rCD59-APT542 was incorporated as well as retained in RPE and choroid and was functionally active in vivo. Single ivt injection during the growth of the CNV (i.e. at day 3 post-laser) resulted in ∼79% inhibition of the further growth of neovascular complex. The size of the CNV complex was significantly (p < 0.05) reduced by the administration of rCD59-APT542 after the CNV complex has fully developed (i.e. at day 7 post-laser). Treatment with rCD59-APT542 blocked the formation of membrane attack complex (MAC), increased apoptosis and decreased cell proliferation in the neovascular complex. On the basis of results presented here we conclude that recombinant membrane targeted CD59 inhibited the growth of the CNV complex and reduced the size of fully developed CNV in the laser-induced mouse model. We propose that a combination of two mechanisms: increased apoptosis and decreased cell proliferation, both resulting from local inhibition of MAC, may be responsible for inhibition of CNV by rCD59-APT542.

The complement system is an important part of innate immune system and plays an important role in the pathology of several diseases. In recent years, the study of the role of the complement system in various ocular diseases has been gaining importance. The complement system protects the eye from various insults but, if left unregulated, then it can cause various ocular diseases. Recombinant complement regulators offer alternative options for designing new therapies for the treatment of ocular diseases.

Fatty acid ethyl ester synthases metabolize ethanol nonoxidatively in those extrahepatic organs most commonly damaged by alcohol abuse. This study was designed to isolate and purify human myocardial synthase-II, one of the enzymes responsible for catalyzing the formation of fatty acid ethyl esters. DEAE-cellulose chromatography of human myocardial cytosol at pH 8.0 separated synthase-I, synthase-II, and synthase-III activities, eluting at conductivities of 5, 7, and 11 mS, respectively. From this elution profile, fatty acid ethyl ester synthase-II accounts for up to 50% of total synthesis in the human heart. This enzyme species was purified over 2200-fold to homogeneity after chromatography over hydroxylapatite, CM-cellulose, and hydroxylapatite. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of this homogeneous species showed a single band at 65 kDa which corresponded to its molecular weight determined by gel filtration. This molecular weight and its lack of glutathione transferase activity indicate that this species is not related to synthase-I and -III. Homogeneous synthase-II has a Vmax for palmitate, stearate, oleate, and linoleate of 70, 80, 140, and 120 nmol/mg/h, respectively. The Km for palmitate, stearate, oleate, and linoleate is 0.19, 0.12, 0.10, and 0.18 mM, respectively. The substrate specificity with respect to alcohol chain length was also investigated in the presence of 0.65 mM [14C]oleic acid. The Vmax for methanol, ethanol, propanol, and butanol was 180, 100, 280, and 410 nmol/mg/h, respectively. The Km for methanol, ethanol, propanol, and butanol was 1.16, 1.04, 0.58, and 0.33 M, respectively. The N-terminal 17-amino acid sequence of human synthase-II does not correspond to any known N-terminal amino acid sequence, indicating that this may be a novel protein. However, it has over 70% homology to a sequence close to the C terminus of rabbit cytochrome P-450IIC1 and over 50% homology to a sequence of human hemopexin starting at residue 16. Synthase-II does not cross-react with human hemopexin antibody and rat cytochrome P-450C antibody. Thus, this study provides evidence that synthase-II is a novel protein, distinct from synthase-I and -III, and it also provides a foundation for subsequent cloning and genetic studies of fatty acid ethyl ester synthase-II in man.

Alcohol metabolism in the human brain has been characterized as essentially nonoxidative in nature, with the esterification of ethanol with fatty acids via fatty acid ethyl ester synthase. This pathway of ethanol metabolism is related to end organ damage in the brain but the neural cell type expressing FAEES has not been identified. In this study human and rodent neuroblastoma and glioma cell lines are assayed for fatty acid ethyl ester synthase activity. Cells with neuronal properties demonstrated higher activity than glioma cell lines. We confirmed the presence of the mRNA for one type of synthase, fatty acid ethyl ester synthase-III in three neuronal cell lines - N1E115 cells, PC12 cells, and SK-N-MC cells. These results support the hypothesis that FAEES activity is expressed chiefly in cells with neuronal properties and suggest that non-oxidative ethanol metabolism is potentially related to the toxic effect of ethanol on the human brain.

Human myocardial fatty acid ethyl ester synthase-III is a newly described acidic glutathione S-transferase that metabolizes both ethanol and carcinogens. Structure-function studies have not been performed relating these two distinct enzymatic activities. Since there are only two histidine residues in fatty acid ethyl ester synthase-III (His 72 and His 163), the role of each was examined by site-specific mutagenesis. Fatty acid ethyl ester synthase-III mutagenized at position 72 to contain either Gln, Pro or Ala had less than 5% of control glutathione S-transferase activity but retained fatty acid ethyl ester synthase activity under standard assay conditions. In contrast, substitution of histidine 163 with proline had no effect on glutathione S-transferase activity, but it slightly increased synthase activity. Thus, this study indicates that histidine plays a differential role in fatty acid ethyl ester synthase III depending on the nucleophilic substrate.

Experimental autoimmune anterior uveitis (EAAU) serves as an animal model for human idiopathic AU, the most common form of intraocular inflammation of significant morbidity whose recurrence can lead to permanent vision loss. This study was undertaken to inhibit EAAU by inducing tolerance to melanin-associated antigen (MAA) and to investigate the underlying mechanisms responsible for tolerance induction. Intravenous administration of MAA both induced tolerance and inhibited EAAU in Lewis rats. Flow cytometric analysis revealed that the proliferation of lymph node cells in response to antigenic stimulation was drastically reduced in the state of tolerance both in vivo and in vitro. Our results from co-culture experiments demonstrated that intravenous administration of MAA led to the generation of T-regulatory cells that suppress T-cell proliferative responses and induce tolerance. Expression levels of both interleukin-10 and transforming growth factor-beta2 were elevated whereas reduced levels of tumor necrosis factor-alpha, interferon-gamma, and interleukin-2 were detected in tolerance-induced animals. Tolerance was reversed by replenishing these animals with recombinant interleukin-2. Tolerance could be adoptively transferred by removing lymph node cells from tolerance-induced donors and giving them to recipient rats. Interestingly, adoptive transfer of tolerance failed when lymph nodes cells were depleted of CD4(+)CD25(+) T cells. In conclusion, T-cell nonresponsiveness because of active suppression mediated by T-regulatory cells facilitates the development of tolerance to MAA in EAAU.

The objective of the present study was to investigate the effect of alcohol and nicotine consumption on the pathogenesis of choroidal neovascularization (CNV) in rats after laser-photocoagulation. Confocal microscopic analysis demonstrated an increase in CNV complex size in rats fed with alcohol (2.3-fold), nicotine (1.9-fold), and the combination of alcohol and nicotine (2.7-fold) compared with the control groups.Immunohistochemical analysis revealed that alcohol and nicotine consumption increased MAC deposition and VEGF expression in laser spots. Expression of CD59 by RT-PCR and Western blot was drastically reduced in the animals that were fed with alcohol, nicotine and alcohol and nicotine compared to those fed with water alone and this was associated with exacerbation of CNV.

Cellular oxidative stress plays an important role in retinal pigment epithelial (RPE) cell death during aging and the development of age-related macular degeneration. Early reports indicate that during phagocytosis of rod outer segments, there is an increase of RPE oxidative stress and an upregulation of PPARγ mRNA in these cells. These studies suggest that activation of PPARγ may modulate cellular oxidative stress. This paper presents a brief review of recent studies that investigate RPE oxidative stress under various experimental conditions. This is followed by a detailed review on those reports that examine the protective effect of the natural PPARγ ligand, 15d-PGJ2, against RPE oxidative stress. This agent can upregulate glutathione and prevent oxidant-induced intracellular reactive oxygen species accumulation, mitochondrial depolarization, and apoptosis. The cytoprotective effect of this agent, however, is not shared by other PPARγ agonists. Nonetheless, this property of 15d-PGJ2 may be useful in future development of pharmacological tools against retinal diseases caused by oxidative stress.

Cellular oxidative stress plays an important role in retinal pigment epithelial (RPE) cell death during aging and the development of age-related macular degeneration. Early reports indicate that during phagocytosis of rod outer segments, there is an increase of RPE oxidative stress and an upregulation of PPARgamma mRNA in these cells. These studies suggest that activation of PPARgamma may modulate cellular oxidative stress. This paper presents a brief review of recent studies that investigate RPE oxidative stress under various experimental conditions. This is followed by a detailed review on those reports that examine the protective effect of the natural PPARgamma ligand, 15d-PGJ(2), against RPE oxidative stress. This agent can upregulate glutathione and prevent oxidant-induced intracellular reactive oxygen species accumulation, mitochondrial depolarization, and apoptosis. The cytoprotective effect of this agent, however, is not shared by other PPARgamma agonists. Nonetheless, this property of 15d-PGJ(2) may be useful in future development of pharmacological tools against retinal diseases caused by oxidative stress.

The complement system is a major component of innate immunity. During an inflammatory reaction, the eye is potentially threatened by homologous complement attack, and unregulated complement activation could lead to tissue damage and vision loss. The complement system is continuously activated at low levels in the normal eye, and intraocular complement-regulatory proteins (CRPs) tightly regulate this spontaneous complement activation so that there is elimination of potential pathogens without the induction of destructive intraocular inflammation. The presence of a complement activation product (iC3b) during the early phase of antigen and antigen-presenting cell contact is essential for the induction of systemic tolerance to antigen injected into the anterior chamber of the eye and the establishment of ocular immune privilege. The complement system and complement-regulatory proteins control intraocular inflammation in autoimmune anterior uveitis and may play an important role in the development of age-related macular degeneration. Thus, in the eye, complement functions as a double-edged sword - on one hand it provides innate immunity against pathogens while simultaneously instructing the adaptive immune response to develop tolerance to such pathogens to avoid inadvertent tissue damage in a critical organ.