UVB promotes the initiation of uveitic inflammatory injury in vivo and is attenuated by UV-blocking protection.

PURPOSE: Uveitic inflammatory injury can cause irreversible visual loss; however, no single animal model recapitulates all the characteristics of human uveitis. Ultraviolet radiation (UVR) is one of the risk factors for uveitis, but the role of UVR in the pathogenesis of uveitic injury is unclear. The aim of this study was to elucidate whether UVB promotes the initiation of, and subsequently contributes to, uveitic inflammatory injury. METHODS: Mice were assigned to either a blank control group or one of three UVB treatment groups: no protection, protection with Nelfilcon A contact lens (Food and Drug Administration [FDA] class II, about 46.8% UVB transmittance), or protection with Etafilcon A contact lens (FDA class IV, about 0.55% UVB transmittance). The contact lenses acted as blocking barriers against UVR. After the application of UVR, pathologic injuries were determined with slit-lamp microscopy and histologic examination. RESULTS: Compared with the intact status of the controls, the anterior eyes of the UVB groups showed pathologic alterations in physiologic properties and tissue integrity. UVR promoted anterior uveitic inflammatory injury, with expansion of the hyperemic iris vessels, over-production of aqueous humor protein, disruption of the blood-aqueous barrier, and embedding of infiltrative leukocytes inside the iridocorneal angle. However, blockage of UVR in vivo retarded the progression of uveitic inflammatory injury. The highest level of UV protection in the Etafilcon A group resulted in greater inhibition of uveitic inflammatory injury than that in the Nelfilcon A group. CONCLUSIONS: This study demonstrates that UVB initiated and promoted uveitic inflammatory injury. UV protection is needed for the clinical management of anterior uveitis. The Etafilcon A lenses provide better protection of the anterior segment of the eye against UVB damage compared with the Nelfilcon A lenses.

UV-blocking spectacle lens protects against UV-induced decline of visual performance.

PURPOSE: Excessive exposure to sunlight may be a risk factor for ocular diseases and reduced visual performance. This study was designed to examine the ability of an ultraviolet (UV)-blocking spectacle lens to prevent visual acuity decline and ocular surface disorders in a mouse model of UVB-induced photokeratitis. METHODS: Mice were divided into 4 groups (10 mice per group): (1) a blank control group (no exposure to UV radiation), (2) a UVB/no lens group (mice exposed to UVB rays, but without lens protection), (3) a UVB/UV400 group (mice exposed to UVB rays and protected using the CR-39™ spectacle lens [UV400 coating]), and (4) a UVB/photochromic group (mice exposed to UVB rays and protected using the CR-39™ spectacle lens [photochromic coating]). We investigated UVB-induced changes in visual acuity and in corneal smoothness, opacity, and lissamine green staining. We also evaluated the correlation between visual acuity decline and changes to the corneal surface parameters. Tissue sections were prepared and stained immunohistochemically to evaluate the structural integrity of the cornea and conjunctiva. RESULTS: In blank controls, the cornea remained undamaged, whereas in UVB-exposed mice, the corneal surface was disrupted; this disruption significantly correlated with a concomitant decline in visual acuity. Both the UVB/UV400 and UVB/photochromic groups had sharper visual acuity and a healthier corneal surface than the UVB/no lens group. Eyes in both protected groups also showed better corneal and conjunctival structural integrity than unprotected eyes. Furthermore, there were fewer apoptotic cells and less polymorphonuclear leukocyte infiltration in corneas protected by the spectacle lenses. CONCLUSIONS: The model established herein reliably determines the protective effect of UV-blocking ophthalmic biomaterials, because the in vivo protection against UV-induced ocular damage and visual acuity decline was easily defined.

Assessment of ultraviolet B-blocking effects of weekly disposable contact lenses on corneal surface in a mouse model.

PURPOSE: Weekly disposable soft contact lenses have been widely used recently, but their shield effects against ultraviolet (UV) irradiation remain to be evaluated. This study investigated the bioprotective effects of several weekly soft contact lenses against UVB irradiation on the corneal surface in a mouse model. METHODS: Fifty ICR mice were randomly divided into five groups: (1) blank control, (2) exposed to UVB without contact lens protection, (3) exposed to UVB and protected with Vifilcon A contact lenses, (4) exposed to UVB and protected with Etafilcon A contact lenses, and (5) exposed to UVB and protected with HEMA+MA contact lenses. The exposure to UVB irradiation was performed at 0.72 J/cm²)/day after anesthesia for a 7-day period, followed by cornea surface assessment for smoothness, opacity, and grading of lissamine green staining. Tissue sections were prepared for hematoxylin and eosin staining and immunohistochemical detection by using antibodies against myeloperoxidase, cytokeratin-5, P63, Ki-67, nuclear factor-kappa B (p65), cyclooxygenase-2, Fas L, and Fas. RESULTS: The results showed impaired corneal surface with myeloperoxidase+ polymorphonuclear leukocyte infiltration into the stroma after UVB exposure, in contrast to the intact status of the blank controls. The corneas with Etafilcon A and HEMA+MA contact lenses maintained more cells positive for cytokeratin-5, P63, and Ki-67 compared to those with Vifilcon A or without contact lens protection. Furthermore, less proinflammatory factors, including nuclear factor-kappa (p65), cyclooxygenase-2, Fas L, and Fas, were induced in the corneas protected by Etafilcon A and HEMA+MA. CONCLUSIONS: This study demonstrated various protective effects of weekly disposable contact lenses against UVB irradiation. The mouse model used in the present study may be used extensively for in vivo assessment of UV shield efficacy.

Photoreceptor and vision protective effects of astragaloside IV in mice model with light-evoked retinal damage.

Cone cell-enriched macular degeneration is a major cause of functional vision deterioration. Astragaloside IV (Asg IV), an active triterpenoid saponin component with properties of anti-oxidative and anti-apoptotic damage, which benefit retinal tissue and capillaries. But, the nutraceutical therapeutic effects on functional vision have not been fully evaluated. In this study, mice were administrated to high-intensity light exposure after either receiving a vehicle or Asg IV (0.05, 0.5, and 50 mg/kg, BID). During this time, their spatial-visual performance, visual acuity (VA), and visual contrast sensitivity function (VCSF) were measured using the behavioral optomotor reflex method. Morphological changes in the retina were determined by histological examination. High energy light-evoked visual damage was confirmed by the loss in structural tissue integrity in the retina accompanied by a decline in both VA and VCSF, whereas the retina tissue exhibited loss of cone cell density and severe cone-specific opsin misplacement. In contrast, prophylactic oral Asg IV (0.5, and 50 mg/kg, BID)-treated exerted protective and improvement effects against light-evoked deterioration of functional vision. Asg IV treatment significantly improved the thresholds of VA and VCSF. In particular, Asg IV (50 mg/kg, BID) modulated and increased the survival of the photoreceptors, especially the cone cells, which targeted and enhanced the high spatial frequency-characterized VCSF. In contrast, the cellular protective effect of Asg IV (50 mg/kg, BID) on photoreceptors was significantly reversed by synchronous injection of a glucocorticoid receptor (GR) antagonist (mifepristone). This study demonstrated the major neuroretina-protective effect and functional vision-improving effect of Asg IV in vivo.

The Functional Vision Restorative Effect of Crocin via the BDNF-TrkB Pathway: An In Vivo Study.

Abnormal dislocation of cone opsin protein affects the sensitivity function of photoreceptors and results in depressed central vision. Nutraceutical therapy is needed to restore the residual function of photoreceptors. Crocin is a natural substance for retinal health. However, its effect on the restoration of functional vision and its underlying mechanisms have not been fully studied. This study analyzed the restorative effect of crocin on residual functional vision in vivo in a mouse model. High-energy light-evoked photoreceptor dysfunction was confirmed by M opsin dislocation in the retina accompanied by a loss of functional vision. Crocin treatment significantly increased brain-derived neurotrophic factor (BDNF) protein in retinas, thus contributing to the re-localization of the M opsin protein, restoration of the visual acuity (VA), and high spatial frequency-characterized visual contrast sensitivity function (VCSF). In contrast, such effects were significantly reversed after the washout period. Additionally, the restorative effect of crocin on functional vision and M opsin re-localization can be reversed and blocked by synchronous injection of a tropomyosin receptor kinase B (TrkB) receptor antagonist (ANA-12). This study demonstrated the major functional vision-rescuing or restoring effect of crocin in vivo by modulating M opsin location plasticity and increasing the capacity of the residual photoreceptor function through the BDNF-TrkB receptor pathway.

Protective Effect of a Water-Soluble Carotenoid-Rich Extract of Cordyceps militaris against Light-Evoked Functional Vision Deterioration in Mice.

Light-evoked retinal photodamage is considered an important factor contributing to functional vision deterioration and can even lead to light maculopathy or dry age-related macular degeneration. Loss of visual acuity (VA) and visual contrast sensitivity function (VCSF) are the major symptoms of retinal degenerative diseases. Cordyceps militaris is a carotenoid-rich Chinese medicinal fungus with antioxidant, anti-inflammatory, and immunomodulatory functions. C. militaris extract is a natural substance, and its bioactive constituents have been shown to confer health benefits, but their application in retinal tissue and functional vision protection in vivo remain incompletely understood. In the present study, we evaluated the influence of water-soluble, carotenoid-rich C. militaris extracts on the visual performance of light-damaged mouse retinas in vivo, using adult female CD-1® (ICR) albino mice. We showed that oral administration of this C. militaris extract (10 mg/kg, twice daily) protected the neural retina tissue against light-evoked photoreceptor cell death, reduced Müller cell hypertrophic gliosis, and elevated GSH levels and promoted the recovery of VA- and VCSF-thresholds, especially for high spatial frequency-characterized vision. These results suggest that, probably because of its water-soluble carotenoids, C. militaris extract has the potential to prevent or treat light-induced visual dysfunction.

Dietary zerumbone prevents against ultraviolet B-induced cataractogenesis in the mouse.

PURPOSE: To investigate the preventive effect of dietary zerumbone against UVB-induced cataractogenesis. METHODS: A total of 50 six-week-old female ICR mice were split into five groups (each contained 10 mice) and exposed to UVB (0.72 J/cm(2)/daily) at noon for 7 days, except for the blank control group. The mice with UVB exposure were fed with zerumbone as a dietary supplement at 0, 1, 10, and 100 mg/kg of bodyweight, respectively, starting from one day before UVB exposure. On day 7, at 4 h after UVB exposure, all mice were subjected to cataract examination and lens opacity scoring, in correlation with levels of MDA (malondialdehyde), GSH (glutathione), GR (GSH reductase), GPx (glutathione peroxidase), and SOD (superoxide dismutase) in the lens. RESULTS: Dietary zerumbone at 100 mg/kg after UVB exposure was effective in decreasing lens opacity scores (p<0.001) and to reduce MDA (p<0.001), while GSH and GR levels were significantly increased (both p<0.001) in the lens. SOD was also increased with dietary zerumbone at 100 mg/kg (p=0.115), whereas GPx (p=0.171) levels were lower as compared with those without zerumbone after UVB exposure. CONCLUSIONS: These results suggest that zerumbone may protect against UVB-induced cataractogensis through reducing lipid peroxides and enhancing the endogenous antioxidant GSH level and GR activity.

Dietary zerumbone prevents mouse cornea from UVB-induced photokeratitis through inhibition of NF-κB, iNOS, and TNF-α expression and reduction of MDA accumulation.

PURPOSE: Ultraviolet B (UVB) irradiation activates nuclear factor-kappa B (NF-κB) and inducible nitric oxide synthase (iNOS) in the cornea, resulting in inflammatory responses and malondialdehyde (MDA) accumulation. This study aims to determine the effect of zerumbone, a potent NF-κB inhibitor and inflammation modulators, on UVB-induced corneal damages in a mouse model. METHODS: Fifty female imprinting control region (ICR) mice were randomly divided into five groups. The mice were anaesthetized with their ocular surfaces exposed to UVB light (0.72J/cm(2)/daily), followed by daily dietary zerumbone supplements at 0, 1, 10, and 100 mg/kg of bodyweight. Mice without zerumbone supplements were used as treatment controls and mice without UVB irradiation as blank controls. Corneal surface damages were graded according to smoothness, opacity, and the extent of lissamine green staining. Histopathological changes were also examined, along with the expression of NF-κB, iNOS, and tumor necrosis factor-α (TNF-α). MDA accumulation and the levels of two antioxidant enzymes, glutathione (GSH) and GSH reductase (GR) were also examined. RESULTS: UVB irradiation caused significant damages to cornea, including sustained inflammation, apparent corneal ulcer, and severe epithelial exfoliation, leading to thinning of corneal epithelial layer, and infiltration of polymorphonuclear leukocytes. NF-κB expression was highly activated with nuclear translocation. The expression of iNOS and TNF-α were increased. MDA accumulation was also increased in both the corneal epithelial layer and the stroma. With dietary zerumbone, corneal damages were ameliorated in a dose-dependent manner. NF-κB activation and its nuclear translocation were blocked with decreased expression of iNOS and TNF-α. Infiltration of polymorphonuclear leukocytes was also blocked by dietary zerumbone. Besides, MDA accumulation was reduced with concomitant increase of GSH and GR levels. CONCLUSIONS: Dietary zerumbone prevents UVB-induced corneal damages by inhibition of NF-κB, iNOS, and TNF-α, with concomitant reduction of MDA accumulation and increase of GSH and GR levels in the mouse model. Results of this study suggest that dietary zerumbone may be used as a prophylactic agent against UVB-induced photokeratitis.

Intravitreal homocysteine-thiolactone injection leads to the degeneration of multiple retinal cells, including photoreceptors.

PURPOSE: Hyperhomocysteinemia is known to cause degeneration of retinal ganglion cells, but its influence on photoreceptors remains largely unknown. In particular, the role of homocysteine-thiolactone (Hcy-T)--the physiologic metabolite of homocysteine that has been proven to be more cytotoxic than homocysteine itself--as a factor that causes retinopathy, has not been defined. This study aimed to investigate the toxic effects of excessive Hcy-T in a mouse model. METHODS: A total of 60 six-week-old female ICR mice were used in this study. The mice were divided into 3 experimental groups and 2 control groups. The mice in the experimental groups were subjected to intravitreal injections of Hcy-T to reach final estimated intravitreal concentrations at 5, 25, and 200 µM, respectively. Mice without injection (blank) and with 0.9 NaCl injections (sham injection) were used as controls. The mice with 200 µM Hcy-T were sacrificed at days 7, 15, 45, and 90 after injection and the mice with 5 or 25 µM Hcy-T were sacrificed at day 90, with the controls sacrificed at day 15 or 90 for comparison. Semi-quantitative dot-blot analysis was performed for confirmation of retinal homocysteinylation. The mouse retinas were evaluated microscopically, with the thickness of total and specific retinal layers determined. Immunohistochemical analysis was performed and the labeled cells were quantified to determine the effects of excessive Hcy-T on specific retinal cells. RESULTS: Dose-dependent retinal homocysteinylation after Hcy-T injection was confirmed. The homocysteinylation was localized in the outer and inner segments of photoreceptors and the ganglion cell layer (GCL). Retinal cell degenerations were found in the GCL, inner nuclear layer, and outer nuclear layer at day 90 after 200 µM Hcy-T injection. Significant thickness reduction was found in the total retina, outer nuclear layer, and the outer and inner segment layers. A trend of thickness reduction was also found in the GCL and inner nuclear layer, although this was not statistically significant. The rhodopsin⁺ photoreceptors and the calbindin⁺ horizontal cells were significantly reduced at day 15, and were nearly ablated at day 90 after 200 µM Hcy-T injection (p<0.001 for both day 15 and day 90), which was not seen in the sham injection controls. The Chx-10⁺ or the Islet-1⁺ bipolar cells and the Pax-6⁺ amacrine cells were severely misarranged at day 90, but no significant reduction was found for both cell types. The GFAP⁺ Müller cells were activated at day 15, but were not significantly increased at day 90 after the injection. CONCLUSIONS: Excessive retinal homocysteinylation by Hcy-T, a condition of hyperhomocysteinemia, could lead to degeneration of photoreceptors, which might lead to retinopathies associated with severe hyperhomocysteinemia or diabetes mellitus.

Hedgehog overexpression leads to the formation of prostate cancer stem cells with metastatic property irrespective of androgen receptor expression in the mouse model.

BACKGROUND: Hedgehog signalling has been implicated in prostate tumorigenesis in human subjects and mouse models, but its effects on transforming normal basal/stem cells toward malignant cancer stem cells remain poorly understood. METHODS: We produced pCX-shh-IG mice that overexpress Hedgehog protein persistently in adult prostates, allowing for elucidation of the mechanism during prostate cancer initiation and progression. Various markers were used to characterize and confirm the transformation of normal prostate basal/stem cells into malignant cancer stem cells under the influence of Hedgehog overexpression. RESULTS: The pCX-shh-IG mice developed prostatic intraepithelial neoplasia (PIN) that led to invasive and metastatic prostate cancers within 90 days. The prostate cancer was initiated through activation of P63+ basal/stem cells along with simultaneous activation of Hedgehog signalling members, suggesting that P63+/Patch1+ and P63+/Smo+ cells may serve as cancer-initiating cells and progress into malignant prostate cancer stem cells (PCSCs). In the hyperplastic lesions and tumors, the progeny of PCSCs differentiated into cells of basal-intermediate and intermediate-luminal characteristics, whereas rare ChgA+ neuroendocrine differentiation was seen. Furthermore, in the metastatic loci within lymph nodes, kidneys, and lungs, the P63+ PCSCs formed prostate-like glandular structures, characteristic of the primitive structures during early prostate development. Besides, androgen receptor (AR) expression was detected heterogeneously during tumor progression. The existence of P63+/AR-, CK14+/AR- and CD44+/AR- progeny indicates direct procurement of AR- malignant cancer trait. CONCLUSIONS: These data support a cancer stem cell scenario in which Hedgehog signalling plays important roles in transforming normal prostate basal/stem cells into PCSCs and in the progression of PCSCs into metastatic tumor cells.

The Functional Vision Protection Effect of Danshensu via Dopamine D1 Receptors: In Vivo Study.

Danshensu, a traditional herb-based active component (Salvia miltiorrhiza Bunge), has garnered attention, due to its safety, nutritional value, and antioxidant effects, along with cardiovascular-protective and neuroprotective abilities; however, its effect on the retinal tissues and functional vision has not been fully studied. The objective of this study was to analyze the protective effect of danshensu on retinal tissues and functional vision in vivo in a mouse model of light-induced retinal degeneration. High energy light-evoked visual damage was confirmed by the loss in structural tissue integrity in the retina accompanied by a decline in visual acuity and visual contrast sensitivity function (VCSF), whereas the retina tissue exhibited severe Müller cell gliosis. Although danshensu treatment did not particularly reduce light-evoked damage to the photoreceptors, it significantly prevented Müller cell gliosis. Danshensu exerted protective effects against light-evoked deterioration on low spatial frequency-based VCSF as determined by the behavioral optomotor reflex method. Additionally, the protective effect of danshensu on VCSF can be reversed and blocked by the injection of a dopamine D1 receptor antagonist (SCH 23390). This study demonstrated that the major functional vision promotional effect of danshensu in vivo was through the dopamine D1 receptors enhancement pathway, rather than the structural protection of the retinas.

Congenital eye malformations associated with extensive periocular neural crest apoptosis after influenza B virus infection during early embryogenesis.

PURPOSE: Congenital eye malformations are a leading cause of blindness in children. Influenza virus infections prevail worldwide and have been implicated in congenital defects. Infections acquired during gestation may disrupt eye morphogenesis. We investigated the effects of influenza B virus infection on eye malformations during early embryogenesis. METHODS: Chick embryos were exposed to influenza B virus at Hamburger-Hamilton stage 9. Maternal infection was conducted by exposing pregnant ICR mice to influenza B virus at the embryonic gestation stage E 5.0. After infection, virus RNA distribution was detected by in situ hybridization at various developmental stages. The distribution of periocular neural crest cells and the extent of apoptosis were examined by immunohistochemical staining, in correlation with eye malformations. RESULTS: Microphthalmos and anophthalmos, together with neural tube defects, were found in the chick and mouse embryos following the infections. The viral RNA was detected in the head neuroepithelium, optic vesicle, periocular mesenchyme, and the forming ventricles of the developing brain. Immunohistochemical staining revealed aberrant neural crest distribution and extensive apoptosis in the head surface ectoderm, periocular mesenchyme, and optic vesicle in the chick embryos. Furthermore, transplacental infection was confirmed by the presence of viral RNA in the mouse fetuses, with eye and neural tube defects similar to those found in the chick embryos after experimental infections. CONCLUSIONS: Influenza B virus may act as a teratogen to cause aberrant periocular neural crest cell contribution to eye development and extensive apoptosis, resulting in congenital eye malformations.

Sonic hedgehog promotes porcine oocyte maturation and early embryo development.

In the present study, we investigated the effects of the Sonic hedgehog (Shh) protein on porcine oocyte maturation and early embryo development. Immunohistochemistry showed activation of Shh signalling in cumulus-oocyte complexes (COCs), as reflected by Patched (Ptc), Smoothened (Smo) and Gli1 expression in oocytes, cumulus cells and granulosa cells, particularly those of small follicles (<2 mm in diameter). Western blot analysis showed Smo expression in COCs and in denuded oocytes derived from small and medium (3-7 mm)-sized follicles. Small follicles contained the highest concentration of Shh in follicular fluid compared with medium-sized and large (>7 mm in diameter) follicles. Supplementation with Shh (0.5 or 1 microg mL(-1)) enhanced oocyte maturation compared with the control group (92.4% and 90.4% v. 81.9%, respectively; P < 0.05). This effect was reversed by the simultaneous addition of cyclopamine (1-2 microm), an Shh inhibitor. Similar to intact COCs, denuded COCs showed enhanced maturation following Shh supplementation. Furthermore, cyclin B1 content, extracellular signal-regulated kinase 1/2 phosphorylation, intracellular calcium release, blastocyst rate and total cell numbers were greater (P < 0.05) in oocytes matured in the presence of 0.5 and 1 microg mL(-1) Shh compared with control oocytes. The findings of the present study provide the first evidence that the Shh signalling pathway is active, or at least partially activated, in the porcine ovary and is likely to promote oocyte cytoplasmic and nuclear maturation, as well as subsequent in vitro development, although the underlying mechanisms remain to be elucidated.

Advances in exosomes technology.

Exosomes, also called extracellular vesicles (EVs), are membranous structures measuring between 40 and 100 nm. Exosomes, secreted by various cells of the human body into body fluids, contain protein, mRNA, miRNA, and signaling molecules. Physiologically, exosomes assist in the intercellular transport of protein and RNA. Immunologically, exosomes exhibit antigen-presenting capability. In recent studies, exosomes were found to be associated with the pathophysiology of cardiovascular, renal, neurological, and ocular diseases. In addition, exosomes may play a major role in cancer metastasis. Due to the extremely small size and scarcity of exosomes in living samples, many early studies utilized sucrose density gradient ultracentrifugation for exosome collection. However, sucrose density gradient ultracentrifugation is rather time consuming and requires large biological sample quantities. Newer exosome studies combined immunoaffinity and microfluidic system approaches for more efficient exosome collection. Our review summarizes existing methods for EV isolation and notes their advantages and disadvantages. These promising approaches are all characterized by isolation efficiency, and savings in cost, labor, and time. Optimization of current methods is a necessary step toward clinically-relevant diagnostic product production, but the fact that EVs are already widely used in disease diagnosis and treatment encourages continued efforts.

Danshensu Decreases UVB-Induced Corneal Inflammation in an Experimental Mouse Model via Oral Administration.

BACKGROUND: Danshensu is a bioactive constituent of Salvia miltiorrhiza, a plant commonly used in traditional Chinese medicine. In this study, we investigated the pharmacological efficacy of sodium danshensu, or named salvianic acid A sodium (SAS) on ultraviolet B (UVB)-mediated corneal inflammatory injury in mice. METHODS: Albino mice were divided into one blank control group, and three UVB radiation groups, i.e. SAS-untreated group, and prophylactic treatment groups with SAS at 1 and 10 mg/kg via oral administration. The structure integrity and inflammatory changes of cornea were assessed by surface evaluation of smoothness, topographic distortion, opacity, lissamine green staining, and histologic tissue staining. The inflammatory cytokines was measured by bead-based ELISA assays. RESULTS: Prophylactic treatment of SAS significantly inhibited pathologic changes, improved tissue structural integrity, and reduced inflammatory injury in the cornea after UVB exposure. Dosing with SAS treatment attenuated the incidence rate of leukocyte influx by inhibit increase of interleukin (IL)-1ß, IL-6, monocyte chemoattractant protein-1, and tumor necrosis factor-α. Treatment with 10 mg/kg SAS was more effective in preventing the onset of corneal damage than that with 1 mg/kg SAS. CONCLUSIONS: These results indicate that SAS exhibit the pharmacological efficacy on corneal protection through its inhibition of UVB induced photodamage and subsequently inflammatory injury in vivo.

Male germ line stem cells: from cell biology to cell therapy.

Research using stem cells has several applications in basic biology and clinical medicine. Recent advances in the establishment of male germ line stem cells provided researchers with the ability to identify, isolate, maintain, expand and differentiate the spermatogonia, the primitive male germ cells, as cell lines under in vitro conditions. The ability to culture and manipulate stem cell lines from male germ cells has gradually facilitated research into spermatogenesis and male infertility, to an extent beyond that facilitated by the use of somatic stem cells. After the introduction of exogenous genes, the spermatogonial cells can be transplanted into the seminiferous tubules of recipients, where the transplanted cells can contribute to the offspring. The present review concentrates on the origin, life cycle and establishment of stem cell lines from male germ cells, as well as the current status of transplantation techniques and the application of spermatogonial stem cell lines.

Dietary α-lipoic acid prevents UVB-induced corneal and conjunctival degeneration through multiple effects.

PURPOSE: This study investigated the effects of dietary α-lipoic acid (α-LA) against ultraviolet B (UVB)-induced corneal and conjunctival degeneration in a mouse model. METHODS: Female CBA mice were randomly divided into five study groups, including blank control, UVB without α-LA, and UVB with dietary α-LA at 1, 10, and 100 mg/kg body weight. Following UVB exposure, corneal surfaces were assessed along with immunohistochemistry for nuclear factor-κB (NF-κB), cyclooxygenase-2 (COX-2), malondialdehyde (MDA) accumulation, and P63⁺ basal cell distribution. Matrix metalloproteinase (MMP)-2 and MMP-9 activities were determined by gelatin zymography. ELISA assay was performed to confirm the findings of immunohistochemistry for NF-κB, COX-2, and MDA, along with the levels of TNF-α and IL-6. Tear production and goblet cell density were determined after tear strip assay and periodic acid Schiff staining, respectively. RESULTS: The results showed that UVB irradiation caused corneal surface damage, polymorphonuclear leukocyte infiltration, and loss of P63⁺ basal cells. Dietary α-LA ameliorated the UVB-induced corneal damage while simultaneously reducing MDA accumulation and maintaining P63⁺ basal cell survival. NF-κB-p65, COX-2, TNF-α, IL-6, and MMP-9 activity were all reduced by dietary α-LA. In addition, α-LA helped to reverse aqueous tear reduction, conjunctival squamous epithelium metaplasia, and goblet cell loss after UVB exposure. CONCLUSIONS: Dietary α-LA can prevent UVB-induced corneal damage and can be used as a prophylactic agent prior to excessive UVB exposure.

Characterising visual deficits in children of an urban elementary school in Taiwan.

PURPOSE: The aim was to screen children from Grades 1 to 6 in an urban elementary school in Central Taiwan for visual deficits and associated parameters and, as an extension, to examine the acceptance of cycloplegic therapy as well as the lag in optimal vision correction. METHODS: Of 900 students in one school, 731 participated in the study, with parental consent. Data from 694 students, who had also completed a vision correction history were analysed. In addition to body height and weight, the screening included vision, non-cycloplegic autorefraction and distance retinoscopy, axial length and functional testing. RESULTS: There was a decrease in students with vision of 1.0 or better from 55.8 per cent in Grade 1 to 20.0 per cent in Grade 6. The decreases between Grades 2 and 3 and Grades 5 and 6 were significant. These trends were in general agreement with those based on refractive error and axial length. The students had abnormal functional findings including: stereoscopic vision, 9.2 per cent; cover tests, 14.1 per cent; pupillary responses, 13.8 per cent; and less commonly in extraocular muscular functions (3.0 per cent) and colour vision (5.2 per cent). A full 40 per cent of students received cycloplegic therapy with 25 per cent dropping out for various reasons. These cases were generally associated with lower vision and higher myopia. A lag between subnormal vision and optical correction was also observed with 55.1 per cent apparently not optimally corrected. Other parameters, including body height, weight and body mass index were not correlated with vision or refractive error. CONCLUSIONS: Age-dependent increase in the prevalence of myopia appears to continue despite the common practice of topical cycloplegic therapy in Taiwan. Timely correction of the refractive error is also lacking. While maintaining a visual acuity of 1.0 or better for all students at all times is not possible, this lag might be shortened by more frequent screening and/or direct provision of optical aids.

Hedgehog is involved in prostate basal cell hyperplasia formation and its progressing towards tumorigenesis.

The role of Hedgehog signaling in human basal cell hyperplasia formation and its progressing towards tumorigenesis was investigated. Hedgehog signaling members including PTCH1, GLI1, GLI2, and GLI3 were found co-localized with p63 expression in most hyperplastic basal cells, but rarely in normal basal cells, suggesting Hedgehog involvement in basal cell hyperplasia formation. Both CK-14 and CK-8 markers were found co-localized in the majority of hyperplastic basal cells, but relatively few in the normal basal cells, indicating a Hedgehog-promoted transitory differentiation. Furthermore, CK-14 and PTCH1 were found co-localized with CD44 in the hyerplastic basal cells, in a way similar to the CD44 co-localization with PTCH1 and GLI1 in the cancer cells. Together, the present study indicated Hedgehog involvement in forming basal cell hyperplasia and its progressing towards cancer, presumably by transforming the normal basal stem cells into the cancer stem cells where persistent Hedgehog activation might be mandatory for tumorigenesis.

A mouse prostate cancer model induced by Hedgehog overexpression.

Hedgehog is a regulatory protein during embryonic development and its abnormal activation in adult tissues has been implicated in tumorigenesis within sites where epithelial-mesenchymal interactions take place. In the prostate, Hedgehog signaling activation was observed during advanced cancer progression and metastasis, but whether Hedgehog overexpression can initiate prostate tumorigenesis remains unknown. We introduced a Hedgehog-expressing vector by intra-prostate injection and electroporation to address the effects of Hedgehog overexpression. The manipulation caused lesions with characteristic prostatic intraepithelial neoplasia or even prostatic cancer (CaP) phenotypes within 30 days, with Hedgehog overexpression demonstrated by immunohistochemistry and Western blot detections. The tumorigenic phenotypes were confirmed by discontinuity of basal cell marker p63, mix-up of CK-8/CK-18 positive epithelial cells in the stoma as well as absence of alpha-SMA positive fibro-muscular sheath. Comparable Hedgehog overexpression was found in human CaP specimen. Thus, Hedgehog overexpression induced prostate tumorigenesis starting from the normal status. Furthermore, a mouse prostate cancer model induced by Hedgehog overexpression was established and may be used for testing novel therapeutical approaches targeting at Hedgehog signaling pathway.