Estrogen Stimulation of Proinflammatory Cytokine and Matrix Metalloproteinase Gene Expression in Human Corneal Epithelial Cells

Bilateral Aggressive Mooren Ulcer in the Setting of Bilateral Pterygia and Pregnancy: A Unique Case

PURPOSE

To report an unusual case of bilateral aggressive Mooren ulcer that occurred in the setting of bilateral pterygia and showed a relentless course during pregnancy.

METHODS

A 39-year-old woman of Black African ethnicity, 36-week pregnant, presented to the eye casualty with bilateral nasal corneal ulcer and associated melt around preexisting pterygia. A detailed workup including microbial evaluation, culture and sensitivity, polymerase chain reaction for herpes simplex virus, varicella zoster virus, and cytomegalovirus, inflammatory blood profile, autoimmune markers, and human leucocyte antigen (HLA) screening was undertaken. Treatment was initiated in a stepwise approach.

RESULTS

Infections and systemic autoimmune and rheumatologic conditions were ruled out. A diagnosis of bilateral Mooren ulcer was made by exclusion. The peripheral blood was positive for HLA DQ2. As the condition seemed refractory to medical management (topical steroids and intravenous pulse methylprednisolone followed by oral prednisolone and topical cyclosporine), urgent bilateral conjunctival resection with multilayered amniotic membrane transplantation was performed to reduce the inflammatory stimulus and keratolysis. Stabilization of the condition warranted the need for systemic immunosuppressive agents. Using a multidisciplinary approach, in liaison with Obstetricians and Rheumatologists, the patient was planned for an earlier elective Cesarean section and commencement of oral mycophenolate mofetil postpartum, which aided in successful control of the disease.

CONCLUSIONS

Mooren ulcer could follow an aggressive course during pregnancy, especially in the setting of preexisting pterygium. The complex hormonal and immunological changes during pregnancy and the delivery of inflammatory mediators directly onto the cornea by pterygium could contribute to the severity. A well-planned, stepwise, and multidisciplinary management is pivotal for the treatment of this condition.

Sex-Specific Early Retinal Dysfunction in Mutant TDP-43 Transgenic Mice

BACKGROUND

Increasing evidence has highlighted retinal impairments in neurodegenerative diseases. Dominant mutations in TAR DNA-binding protein 43 (TDP-43) cause amyotrophic lateral sclerosis (ALS), and the accumulation of TDP-43 in the cytoplasm is a pathological hallmark of ALS, frontotemporal dementia (FTD), and many other neurodegenerative diseases.

OBJECTIVE

While homozygous transgenic mice expressing the disease-causing human TDP-43 M337V mutant (TDP-43M337V mice) experience premature death, hemizygous TDP-43M337V mice do not suffer sudden death, but they exhibit age-dependent motor-coordinative and cognitive deficits. This study aims to leverage the hemizygous TDP-43M337V mice as a valuable ALS/FTD disease model for the assessment also of retinal changes during the disease progression.

METHODS

We evaluated the retinal function of young TDP-43M337V mice by full field electroretinogram (ERG) recordings.

RESULTS

At 3-4 months of age, well before the onset of brain dysfunction at 8 months, the ERG responses were notably impaired in the retinas of young female TDP-43M337V mice in contrast to their male counterparts and age-matched non-transgenic mice. Mitochondria have been implicated as critical targets of TDP-43. Further investigation revealed that significant changes in the key regulators of mitochondrial dynamics and bioenergetics were only observed in the retinas of young female TDP-43M337V mice, while these alterations were not present in the brains of either gender.

CONCLUSIONS

Together our findings suggest a sex-specific vulnerability within the retina in the early disease stage, and highlight the importance of retinal changes and mitochondrial markers as potential early diagnostic indicators for ALS, FTD, and other TDP-43 related neurodegenerative conditions.

Hyaluronic Acid and Galacto-Xyloglucan Eyedrop Efficacy in Young-Adult Oral Contraceptive Users of Childbearing Age

To assess the efficacy of 0.4% hyaluronic acid and 0.2% galacto-xyloglucan for the subjective symptoms of dry eye disease and tear film invasive and noninvasive signs in 34 young-adult oral contraceptive users of childbearing age, a prospective, longitudinal, single-blind, clinical study was performed in a population of childbearing-age oral-contraceptive consumers. Subjective dry eye disease questionnaires, and invasive and noninvasive tear film assessments were reported before and after six weeks of hyaluronic acid with galacto-xyloglucan (HA-GX) treatment versus hyaluronic acid alone (HA). HA-GX treatment resulted in a greater decrease in the ocular surface disease index (17.01 ± 11.36 score points, p < 0.01) than the HA variation (11.61 ± 11.18 score points, p < 0.01). The standard patient evaluation of eye dryness also decreased more in the HA-GX group (4.06 ± 5.50 score points, p < 0.01) than in the HA alone group (0.70 ± 3.16, p = 0.21). Regarding noninvasive break-up time (NIBUT), the HA-GX group’s first NIBUT achieved an increase of 1.75 ± 1.16 s, p < 0.01, while the HA-alone group increased by only 0.54 ± 1.01 s, p < 0.01. The HA-GX group’s mean NIBUT reported an increase of 3.72 ± 5.69 s, p < 0.01; however, the HA-alone group achieved 2.19 ± 5.26 s, p = 0.05. Hyaluronic acid in combination with galacto-xyloglucan significantly decreased subjective dry eye disease symptoms and increased first and mean NIBUT compared to hyaluronic acid alone. Galacto-xyloglucan added efficacy in young-adult childbearing-age oral contraceptive users.

Sex Hormones and Their Effects on Ocular Disorders and Pathophysiology: Current Aspects and Our Experience

Sex hormones are molecules produced by the gonads and to a small extent by the adrenal gland, which not only determine the primary and secondary sexual characteristics of an individual, differentiating man from woman, but also participate in the functioning of the various systems of the body. The evidence that many eye diseases differ in terms of prevalence between men and women has allowed us, in recent years, to carry out several studies that have investigated the association between sex hormones and the pathophysiology of eye tissues. Specific receptors for sex hormones have been found on the lacrimal and meibomian glands, conjunctiva, cornea, lens, retina, and choroid. This work summarizes the current knowledge on the role that sex hormones play in the pathogenesis of the most common ocular disorders and indicates our clinical experience in these situations. The aim is to stimulate an interdisciplinary approach between endocrinology, neurology, molecular biology, and ophthalmology to improve the management of these diseases and to lay the foundations for new therapeutic strategies.

Associations Between Keratoconus and the Level of Sex Hormones: A Cross-Sectional Study

Purpose

To analyze the level of sex hormone in relation to keratoconus (KC).

Methods

Sixty-two eyes of 62 patients (12 females, 50 males) classified as KC and 120 eyes of 120 patients (21 females, 99 males) with mild to moderate myopia and astigmatism were analyzed. Plasma samples were collected and analyzed using a chemiluminescence immunoassay to determine the concentrations of estriol (E₃), estradiol (E₂), progesterone (P), and testosterone (T). Corneal morphological parameters, such as the central corneal thickness (CCT), thinnest corneal thickness (TCT), and maximum simulated keratometry (K_max), were measured using Pentacam and Sirius.

Results

The mean age was 23.73 ± 5.16 years for patients with KC and 23.68 ± 6.10 years for patients treated with laser vision correction (LVC). Among the patients with KC, 12 were female (19.35%) and 50 were male (80.65%). The majority of patients with KC were between 20 and 30 years old. In female patients, the concentration of T in the KC group was significantly lower than that in the LVC group (0.86 ± 0.33 vs. 1.18 ± 0.58 nmol/L; P = 0.044). There were positive correlations between T, CCT (r = 0.395, P = 0.023) and TCT (r = 0.378, P = 0.030) in female patients. In male patients, E₂ was higher in the KC group than the LVC group (143.75 ± 34.82 vs. 124.80 ± 43.56 pmol/L; P = 0.013), while T was significantly lower (11.59 ± 2.85 vs. 13.58 ± 4.77 nmol/L; P = 0.026). A positive correlation was found between E₂ and K_max (r = 0.222, P = 0.007) in male patients.

Conclusions

Conclusively, our results showed that T level was reduced in both female and male KC plasma, while E₂ was increased in male KC plasma. Different levels of sex hormones are correlated with KC, which, may provide the basis of a new technique for screening and diagnosing KC with or without the assistance of current imaging techniques. Moreover, the correlations between sex hormone alterations and KC provide compelling insight into KC etiopathogenesis.

Sex Hormones, Growth Hormone, and the Cornea

The growth and maintenance of nearly every tissue in the body is influenced by systemic hormones during embryonic development through puberty and into adulthood. Of the ~130 different hormones expressed in the human body, steroid hormones and peptide hormones are highly abundant in circulation and are known to regulate anabolic processes and wound healing in a tissue-dependent manner. Of interest, differential levels of sex hormones have been associated with ocular pathologies, including dry eye disease and keratoconus. In this review, we discuss key studies that have revealed a role for androgens and estrogens in the cornea with focus on ocular surface homeostasis, wound healing, and stromal thickness. We also review studies of human growth hormone and insulin growth factor-1 in influencing ocular growth and epithelial regeneration. While it is unclear if endogenous hormones contribute to differential corneal wound healing in common animal models, the abundance of evidence suggests that systemic hormone levels, as a function of age, should be considered as an experimental variable in studies of corneal health and disease.

Risk factors for corneal epithelial wound healing: Can sex play a role?

PURPOSE

To determine if sex is associated with corneal epithelial wound healing time in patients with persistent corneal epithelial defects (PCEDs).

METHODS

Retrospective case series on patients with PCED from November 2014 to January 2019. Records of 127 patients with diagnosis of PCED were reviewed. Patients with an epithelial defect that lasted more than two weeks in the absence of an active corneal infection were included. Main outcome was corneal epithelial wound healing time.

RESULTS

55 patients (29 males) with a mean age of 65.3 ± 16.5 years were included. No difference was found between female and male patients in terms of risk factors, age, treatment strategies or intervals between visits (median of 15 days in females and 12 days in males; p = 0.24). Median duration of the PCED was 51 days (IQR 32-130), with a median number of 5 clinical visits (IQR 4-8). Female patients had significantly longer healing times (p = 0.004) and a corresponding increase in the number of clinical visits (median of 7 visits vs. 5 clinical visits in males, p = 0.012).

CONCLUSION

Results from this study suggest female patients with PCED might have a longer corneal epithelial wound healing duration and may therefore require earlier intervention.

Correlation of Hair Cortisol and Interleukin 6 with Structural Change in the Active Progression of Keratoconus

PURPOSE

Evaluate interleukin and hair cortisol concentrations (HCC) in progressive keratoconus (KC) and compare them with KC stable eyes and healthy controls. Determine the correlation of these inflammatory mediators and HCC and their relationship with structural damage represented by increased corneal curvature.

SETTING

University of Sao Paulo.

DESIGN

Prospective observational comparative study.

METHODS

The study included 135 eyes of 75 patients.The concentrations of tear cytokines: interleukin (IL) 1B, IL6, IL8, IL10, IL12p70 and tumor necrosis factor α (TNFα) were obtained by capillary flow and measured using flow cytometer.HCC were determined from the most proximal hair segment as an index of cumulative secretion and measured by liquid chromatography mass spectrometry.

RESULTS

Only IL6 was increased in progressive KC tears compared with stable KC (6.59 ± 3.25 pg/ml vs. 4.72 ± 1.91pg/ml; p<0.0001) with a positive correlation between IL6 and maximum keratometry (Kmax) (p<0.0001).Progressive KC exhibited significantly higher HCC than stable KC (0.624 ± 0.160ng/mg vs. 0.368 ± 0.0647ng/mg; p< 0.0001) and healthy controls (0.624 ± 0.160ng/mg vs. 0.351 ± 0.0896ng/mg; p<0.0001).There was a significant correlation between HCC and Kmax (p<0.0001).

CONCLUSIONS

Keratoconus eyes that are progressing have a higher concentration of IL-6 and long-term cortisol than patients with stable forms of KC;Second, there is a significant correlation between this increase in IL6 and cortisol with corneal structural damage.Finally, there is a meaningful relationship between this interleukin and the past few months' cortisol levels.

Dynamics of keratoconus progression after prior successful accelerated cross-linking treatment during and after pregnancy

PURPOSE

To evaluate the effectiveness of previously applied successful accelerated cross-linking (CXL) treatment in keratoconus stabilization during and after pregnancy.

SETTING

Ankara Yildirim Beyazit University, Ataturk Training and Research Hospital, Turkey.

DESIGN

Prospective, clinical study.

METHODS

Patients who became pregnant with stable keratoconus (after having an accelerated CXL procedure) were included. Uncorrected (UDVA) and corrected distance visual acuity (CDVA), manifest astigmatism (MA), keratometry (K)1, K2, K-max, central corneal thickness (CCT), thinnest corneal thickness (TCT), anterior (AE) and posterior elevation (PE) were recorded at baseline (before CXL), before pregnancy (the last visit after CXL), during pregnancy (3rd trimester) and after pregnancy (the last visit after pregnancy).

RESULTS

Study included 24 eyes of 19 patients. The mean time between CXL and conception was 12.4±5.1 months. The mean post-partum follow-up period was 27.6±13.3 months. The mean UDVA, CDVA, MA, and PE values did not show any significant differences during and after pregnancy compared to the post CXL values (p>0.05). The mean K-max flattened significantly after the CXL procedure (p=0.011), however it increased during pregnancy (p=0.037:after CXL-pregnancy) and then decreased back to the pre-pregnancy level after pregnancy (p=0.035:pregnancy-after pregnancy). The mean K1, K2, AE, CCT, and TCT remained stable during pregnancy and significantly decreased after pregnancy (p<0.05).

CONCLUSION

Keratoconus appears to progress during pregnancy in corneas that have previously received successful accelerated CXL treatment. However, this progress is mostly temporary, and generally regression occurs after delivery.

Recent Developments About the Pathogenesis of Dry Eye Disease: Based on Immune Inflammatory Mechanisms

Dry eye disease is a common and frequently occurring ophthalmology with complex and diverse causes, and its incidence is on the upward trend. The pathogenesis of DED is still completely clear. However, the immune response based on inflammation has been recognized as the core basis of this disease. In this review, we will systematically review the previous research on the treatment of DED in immune inflammation, analyze the latest views and research hotspots, and provide reference for the prevention and treatment of DED.

Evaluation of dry eye and Meibomian gland dysfunction in female androgenetic alopecia patients

PURPOSE

To evaluate dry eye tests and Meibomian gland functions in female androgenetic alopecia patients.

MATERIALS AND METHODS

Twenty left eyes of 20 female androgenetic alopecia patients (Group 1) and 20 left eyes of 20 healthy female volunteers (Group 2) were enrolled in the study. The presence of dry eye was evaluated with Schirmer 1 test, invasive tear film break-up time (T-BUT), Oxford scale scoring and Ocular Surface Disease Index (OSDI) score assessments. Evaluation of upper and lower eyelid Meibomian glands was performed using infrared filter of a slit-lamp biomicroscope, and the drop out ratio was scored for each eyelid.

RESULTS

The mean ages of Group 1 and Group 2 were 48.3 ± 6.6 (range, 38-58) and 49.8 ± 5.4 (range, 38-59) years, respectively (P = 0.437). Mean T-BUT was statistically significantly lower in Group 1 (P = 0.013); mean OSDI score was significantly higher in Group 1 (P = 0.049). Mean Schirmer 1 score was lower and mean Oxford score was higher in Group 1, but the differences were not statistically significant (P = 0.291, P = 0.088, respectively). In addition, upper, lower and total meiboscores were significantly higher in Group 1 (P = 0.007, P = 0.003, P = 0.002, respectively).

CONCLUSION

Alterations in sex hormones play a role in the pathogenesis of both female androgenetic alopecia and Meibomian gland dysfunction. Significant differences were detected in the results of dry eye tests and Meibomian gland dropout ratios between subjects with female androgenetic alopecia and healthy control subjects. For this reason, female androgenetic alopecia patients should be examined for dry eye and Meibomian gland dysfunction and should be treated to prevent serious consequences.

Corneal Biomechanical Changes in Third Trimester of Pregnancy

Background and Objectives: There is a clear evidence that pregnancy is associated with high production of sex hormones. During the first, second and third trimester of pregnancy, blood hormones levels increase gradually. Cells with affinity for sex hormones have been identified in different ocular tissues, such as: lid, lacrimal gland, meibomian gland, bulbar and palpebral conjunctivae, cornea, iris, ciliary body, lens, retina (retinal pigment epithelium) and choroid. This is why pregnancy is associated with changes at ocular level, involving anterior and posterior segments. Several clinical trials have been made trying to highlight changes in corneal biomechanics during pregnancy. By conducting this review, we want to evaluate both the changes in parameters that define corneal biomechanics and intraocular pressure values in pregnant. Materials and Methods: Following a systematic search in the literature related mainly to changes in corneal biomechanics during pregnancy, focusing on the paper published in the last decade, we included in a meta-analysis the cumulative results of three prospective comparative studies. Results: Important changes in corneal biomechanics (corneal hysteresis and corneal resistance factor) parameters were observed in women in the third trimester of pregnancy, but these variations were not statistically significant. Also, a decrease in intraocular pressure was mentioned in these women, but only the corneal compensation intraocular pressure showed a decrease with statistical significance. Conclusions: A decrease in corneal compensatory intraocular pressure was observed in pregnant women in the third trimester of pregnancy, but without other statistically significant changes resulting from the analysis of the other three parameters (corneal hysteresis, corneal resistance factor and Goldmann-correlated intraocular pressure).

Deciphering potential pharmacological mechanism of Sha-Shen-Mai-Dong decoction on primary Sjogren's syndrome

Background

Sha-Shen-Mai-Dong decoction (SSMD) is a classical prescription widely used in primary Sjogren’s Syndrome (pSS) therapy. This study aims to explore the potential pharmacological mechanism of SSMD on pSS.

Methods

Active components of SSMD were obtained from Traditional Chinese Medicine Integrative Database and Traditional Chinese Medicine Systems Pharmacology databases and targets of SSMD were predicted by Pharmmapper and STITCH database. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were carried out to explore the function characteristics of SSMD. The expression matrix of microarray of pSS was obtained from Gene Expression Omnibus and we obtained 162 differentially expressed genes (DEGs). Protein-protein interaction (PPI) networks were constructed to identify the hub targets. Principal component analysis (PCA) and molecular docking were conducted to further elucidate the possibility of SSMD for pSS.

Results

SSMD contained a total of 1056 active components, corresponding to 88 targets, among which peripheral myelin protein 2(PMP2), androgen receptor (AR) and glutamic acid decarboxylase 1(GAD1) are associated with multiple active components in SSMD and may be the core targets. Moreover, these targets were closely related to tissue pathological injury in SS, such as lacrimal gland, salivary gland and nervous system injury. GO and KEGG analysis showed that 88 targets enriched in REDOX process, transcriptional regulation and negative regulation of apoptosis process. Besides, SSMD may influence the cell proliferation, gene transcription through regulating Ras and cAMP-related signaling pathways. In addition, SSMD may show effects on immune regulation, such as macrophage differentiation, Toll-like receptor 4 signaling pathway and T-helper 1 in SS. Moreover, PPI network suggested that FN1, MMP-9 may be the hub targets in SSMD. Result of PCA and molecular docking analysis further determined the feasibility of SSMD in treating pSS.

Conclusion

SSMD can regulate multiple biological processes by virtue of its multiple active components, thus showing prominent advantage in the treatment of pSS. The discovery of active ingredients and targets in SSMD provides valuable resources for drug research and development for pSS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-021-03257-7.

Topical Estrogen Therapy for Hyperopia Correction in Vivo

Purpose

In vitro studies found that 17β-estradiol (estrogen) modulates corneal biomechanical properties and reduces tissue stiffness. Therefore we hypothesized that topical estrogen might affect the refractive properties of the cornea, inducing a myopic shift.

Methods

Twelve female New Zealand white rabbits 16 weeks old were used. The rabbits were randomly divided to either the treatment group receiving 1.5% (w/v) estrogen eye drops or a control group receiving vehicle only (n = 6 each group). Both groups were given drops (50 µL) to the right eye every 12 hours for 35 days. Ocular examination, pachymetry, intraocular pressure (IOP), keratometry, and refraction were evaluated at baseline and on a weekly basis.

Results

No significant differences were observed between the two groups at baseline in all outcome measures. Both groups displayed corneal flattening and a hyperopic shift. However, the change rate was slower in the treatment group. Repeated measurements analysis revealed a statistically significant difference in keratometry readings between groups (P = 0.034) with steeper keratometry by up to 0.6 diopters in the treatment group. The difference between the two groups diminished and became statistically insignificant after treatment cessation. No significant changes were observed in IOP and pachymetry throughout the study period. No side effects were observed in either group.

Conclusions

Estrogen eye drops induced a myopic shift in keratometry readings. These results suggest that corneal refractive power might be manipulated pharmacologically. Further studies on the physiology behind this change are warranted to facilitate a pathway for development of novel pharmacologic treatments to correct refractive errors.

The effect of estrogen and progesterone on porcine corneal biomechanical properties

PURPOSE

To determine the effect of the hormones estrogen and progesterone on the biomechanical properties of porcine corneas.

METHODS

Thirty fresh porcine corneas were acquired from an abattoir. The corneas were equally divided into three groups. Groups were incubated for 1 week in Eusol-C solution containing supra-physiologic concentrations of estrogen, progesterone, or control (no added hormone). After incubation, the central corneal thickness (CCT) of each cornea was measured using an electronic caliper, and then the corneas were cut into strips. The strips were then clamped in the pneumatic jaws of a computer-controlled biomaterial tester (Instron 4502, USA) and stretched at a constant rate of 1 mm/min until tissue rupture while constantly recording the stress and strain of the tissue. Stress-strain curves were plotted and Young's modulus was calculated for each corneal strip.

RESULTS

Average corneal thickness was 873.5 ± 143.1 μm for the control group, 928.0 ± 97.7 μm for the estrogen group, and 922.0 ± 116.7 μm for the progesterone group (data presented as mean ± SD). There was no statistically significant difference between the groups regarding the CCT (p = 0.89). The average Young's modulus was 17.00 ± 3.46 MPa for the control group, 16.95 ± 6.83 MPa for the progesterone group, and 12.33 ± 3.24 MPa for the estrogen group. The difference between the control and estrogen groups was statistically significant (p = 0.018) while the difference between the control and progesterone groups was not (p = 0.72).

CONCLUSION

Estrogen has a relaxing effect on the porcine cornea, resulting in reduced stiffness of the tissue. Progesterone has no significant effect on the biomechanical properties of porcine corneas. Estrogen and progesterone do not significantly affect CCT.

Management of meibomian gland dysfunction: a review

Meibomian gland dysfunction is the leading cause of evaporative dry eye disease and is one of the most common conditions encountered by eye care providers. The disorder is characterized by obstruction of the meibomian gland terminal ducts and/or changes in their glandular secretion, resulting in changes in tear film stability, inflammation, and symptoms of irritation. There is no gold standard treatment for meibomian gland dysfunction, but rather a diversity of options. Conservative measures include warm compresses and lid hygiene, but there is growing interest and need for medical treatments and procedures. Potential medical treatments include antibiotics, nonsteroidal and steroidal anti-inflammatory agents, essential fatty acid supplementation, hormone therapy, and control of Demodex infestation. Procedures include intraductal meibomian gland probing, the use of electronic heating devices, intense pulsed light therapy, and intranasal neurostimulation. We provide an update on meibomian gland dysfunction treatments based on recent studies.

Should I Get LASIK If I'm Breastfeeding?

Changes in keratometric values and refraction can occur during pregnancy. For this reason, changing a patient's refractive prescription or undergoing corneal refractive surgery is not recommended during pregnancy. However, the extent to which these corneal changes persist during lactation is not as well reported. Pregnancy and lactation lead to hormonal changes that affect the corneal structure. LASIK, or other types of refractive surgery, is not recommended until all of the following conditions are met: cessation of lactation, the return of regular menses, and a return to pre-pregnancy refraction. Additionally, patients should be cautioned that refractive regression may occur if they become pregnant within 1 year of LASIK. FUNDING: Research to Prevent Blindness, NY, USA.

Sex-related differences in the progressive retinal degeneration of the rd10 mouse

The retinal degeneration 10 (rd10) mouse is a model of autosomal recessive retinitis pigmentosa (RP), a disease that causes blindness through the progressive loss of photoreceptors. This study shows evidence of sex-related differences in RP onset and progression in rd10 retinas. The disease onset was considerably earlier in the female rd10 mice than in the male rd10 mice, as evidenced by a loss of PDE6β proteins and rod-dominated electroretinogram (ERG) responses at an early age. Single photopic flash and flicker ERG responses and immunolabeling of opsin molecules were analyzed in both genders to assess the sex differences in the degeneration of cones in the RP retinas. The averaged amplitudes of cone-mediated ERG responses obtained from the females were significantly smaller than the amplitudes of the responses from the age-matched males in the late stages of the RP, suggesting that cones might degenerate faster in the female retinas as the disease progressed. The rapid degeneration of cones caused a more substantial decrease in the ERG responses derived from the On-pathway than the Off-pathway in the females. In addition, the male rd10 mice had heavier body weights than their female counterparts aged between postnatal (P)18 and P50 days. In summary, female rd10 mice were more susceptible to retinal degeneration, suggesting that the female sex might be a risk factor for RP. The results have important implications for future studies exploring potential sex-related differences in RP development and progression in the clinic.

Keratoconus progression associated with hormone replacement therapy

Purpose

To report a postmenopausal patient with keratoconus who experienced significant progression after using hormone replacement therapy.

Observations

A 51-year-old woman with previously stable keratoconus presented with acute disease progression following hormone replacement therapy in the context of prophylactic hysterectomy and bilateral ovariosalpingectomy. Over a 14-month period after starting hormone therapy, the steepest K increased from 63.7D to 71.5D in the right eye and from 65.8D to 78.1D in the left eye.

Conclusions

Hormone replacement therapy may amplify progression of keratoconus.

Estrogen- and Progesterone-Induced Variation in Corneal Parameters According to Hormonal Status

OBJECTIVES

To determine the effects of estrogen and progesterone on corneal thickness, curvature, and biomechanics in healthy corneas according to hormonal status.

METHODS

The study included four groups of females: group A (menstruating, not pregnant, not lactating, and not menopausal; n=100), group B (pregnant; n=50), group C (lactating; n=50), and group D (menopausal; n=50). Group A was subdivided according to age, as subgroup A15-25 (age 15-25 years) and subgroup A>25 (age >25 years). Blood estradiol and progesterone levels were measured in each participant. All the participants underwent a full ophthalmologic examination, including corneal thickness and corneal topography measurement, and evaluation of corneal biomechanical properties.

RESULTS

The corneal resistance factor and anterior corneal flat keratometry values were significantly higher in group D (P=0.040 and P=0.026, respectively) than in the other three groups. Posterior corneal steep keratometry values were significantly higher in subgroup A>25 during the preovulatory phase than ovulatory and postovulatory phases (P=0.012). In group B, there was a significant negative correlation between gestational week and intraocular pressure (IOP) (r=-0.322, P=0.024). Corneal volume was significantly higher during the early postpartum period than the late postpartum period in group C (P=0.028). Intraocular pressure, Goldman-correlated IOP, and corneal-compensated IOP differed significantly between the groups (P<0.05).

CONCLUSIONS

Blood levels of estrogen and progesterone were associated with variations in IOP, but estrogen and progesterone did not have a consistent effect on topographic parameters or biomechanical properties in healthy corneas.

Effects of glucocorticoid on the eye development in guinea pigs

Glucocorticoid (GC) has been widely used in clinic. However, the effect of GC on normal and myopic development of eyes is still unknown. In this study, 3-week-old guinea pigs were randomly divided into four groups: No-Lens (control), GC+No-Lens, negative lens-induced myopia (LIM), and GC+LIM. To induce myopia, right eyes were covered with a -10 D lens in GC+LIM and LIM groups. GC+No-Lens and GC+LIM groups received intraperitoneal injections of hydrocortisone (10 mg/kg) once daily for 2 weeks, and then received intragastric hydrocortisone (32.5 mg/kg) every other day for the next 4 weeks, while No-Lens (control) and LIM groups were injected intraperitoneally with saline for 2 weeks, and then given saline by intragastric administertion for the next 4 weeks. Several parameters were assessed: ocular axial length and refractive error, sclera thickness, matrix metalloprotein-2 (MMP-2) and tissue inhibitor metalloprotease-2 (TIMP-2) expressions and localization of the posterior sclera, plasma concentrations of free triiodothyronine (FT3), free thyroxine (FT4), testosterone (T), and oestradiol (E2). Results indicated that: (1) in normal eye development, hydrocortisone could inhibit both the axial elongation and the myopic shift; whereas (2) in LIM eye development, hydrocortisone (a) enhanced the axial elongation, myopic shift and sclera thinning; (b) enhanced the MMP-2 expression and decreased TIMP-2 expression, and (c) elevated the plasma concentration of E2 but decreased the levels of FT3, FT4, and T. In conclusion, glucocorticoid may influence both normal and LIM eye development. The balance of the hormones is fundamental for the eye development.

Genetic association of -1562C>T polymorphism in the MMP9 gene with primary glaucoma in a north Indian population

MMP (Matrix metalloproteinase) 9 is reported to affect glaucoma pathogenesis by altering intraocular pressure (IOP) through its role in remodeling the extracellular matrix (ECM) in the trabecular meshwork. A genetic variant at the promoter region in the MMP9 gene (-1562C>T) has a putative role in regulating its transcription rate and hence can affect genetic predisposition to primary glaucoma. The present study examined the association of -1562C>T promoter polymorphism in the MMP9 gene with Primary Open Angle Glaucoma (POAG) and Primary Angle Closure Glaucoma (PACG) in a north Indian population. A total of 729 subjects (POAG = 224, PACG = 138 and 367 controls) were recruited for the study. Genotyping for the promoter sequence variant was done with PCR-RFLP method. Genotypic and allelic frequency distribution of the POAG and PACG data sets were compared to that of controls by chi-square test and genetic association was tested under different genetic models as implemented under PLINK. Statistically significant difference was observed in the genotype frequencies between PACG cases and controls (p = 0.030). However, in the POAG cases, this difference was only borderline (p = 0.052). Genetic model analysis, under the dominant model revealed 1.6 and 1.4 fold increased susceptibility to PACG and POAG (p = 0.012, p = 0.032) respectively. A higher frequency of CT genotype was observed in PACG as well as POAG males as compared to female subjects. According to the dominant model, CT+TT genotype conferred 1.8 fold higher risk of developing PACG among male patients as compared to the control group (p = 0.048, OR = 1.87;1.00–3.50). Current findings suggest significant association of MMP9 -1562C>T polymorphism with primary glaucoma in the targeted north Indian population and warrant further replication of the findings in other populations.

TFOS DEWS II Sex, Gender, and Hormones Report

One of the most compelling features of dry eye disease (DED) is that it occurs more frequently in women than men. In fact, the female sex is a significant risk factor for the development of DED. This sex-related difference in DED prevalence is attributed in large part to the effects of sex steroids (e.g. androgens, estrogens), hypothalamic-pituitary hormones, glucocorticoids, insulin, insulin-like growth factor 1 and thyroid hormones, as well as to the sex chromosome complement, sex-specific autosomal factors and epigenetics (e.g. microRNAs). In addition to sex, gender also appears to be a risk factor for DED. "Gender" and "sex" are words that are often used interchangeably, but they have distinct meanings. "Gender" refers to a person's self-representation as a man or woman, whereas "sex" distinguishes males and females based on their biological characteristics. Both gender and sex affect DED risk, presentation of the disease, immune responses, pain, care-seeking behaviors, service utilization, and myriad other facets of eye health. Overall, sex, gender and hormones play a major role in the regulation of ocular surface and adnexal tissues, and in the difference in DED prevalence between women and men. The purpose of this Subcommittee report is to review and critique the nature of this role, as well as to recommend areas for future research to advance our understanding of the interrelationships between sex, gender, hormones and DED.

Matrix Metalloproteinase 9 Testing in Dry Eye Disease Using a Commercially Available Point-of-Care Immunoassay

PURPOSE

To measure matrix metalloproteinase 9 (MMP-9) in the tear film of patients with dry eye disease (DED) compared with controls and to correlate clinical findings.

DESIGN

In a prospective study, 101 patients and controls underwent MMP-9 testing of the tear film. Thereafter, they were evaluated for symptoms and signs of DED.

PARTICIPANTS

Included patients were those who showed 3 of the following 4 dry eye criteria: ocular surface disease index (OSDI) score of more than 12, tear film break-up time (TBUT) of 10 seconds or less, Schirmer test results without anesthesia of less than 10 mm/5 minutes, and corneal staining results of 1 or more. Fifty-four healthy eyes and 47 eyes fulfilling diagnostic criteria for DED of various levels of severity were included in this study.

METHODS

The tear film was analyzed for MMP-9 by a commercially available test (InflammaDry; Rapid Pathogen Screening, Inc, Sarasota, FL) detecting MMP-9 levels of more than 40 ng/ml. Symptoms and signs of DED were evaluated using the OSDI questionnaire, TBUT, conjunctival and corneal staining, Schirmer test results without anesthesia, and meibomian gland examination. These findings were correlated to results of the MMP-9 test in tears.

MAIN OUTCOME MEASURES

Positive MMP-9 results in tears.

RESULTS

In 19 of 47 patients confirmed with dry eye (40.4%) and in 3 of 54 controls (5.6%), the MMP-9 results were positive. This difference was statistically significant (P < 0.001). Thus, the MMP-9 results indicated a clinically significant inflammation in 40% of dry eye patients. Positive results correlated well with subjective symptoms of DED evaluated by OSDI (P = 0.001), TBUT of less than 5 seconds (P < 0.013), Schirmer test results (P < 0.001), conjunctival staining (P < 0.001), and corneal staining (P = 0.007). Moreover, MMP-9 results correlated with the number of obstructed meibomian ducts (P = 0.005) and a pathologic meibomian gland secretion (P = 0.001). The MMP-9 results were increased significantly in women (P < 0.001) and in patients with autoimmune disease (P = 0.005), especially Sjögren's syndrome (P = 0.001) and thyroid disease (P = 0.012).

CONCLUSIONS

Matrix metalloproteinase 9 testing in DED is a valuable new diagnostic tool. It correlated well with other dry eye tests and identified the presence of ocular surface inflammation in 40% of confirmed dry eye patients. It may be especially helpful to identify patients with ocular surface inflammation and autoimmune disease and may facilitate the decision to institute anti-inflammatory treatment in these patients.

Endocrine and Metabolic Pathways Linked to Keratoconus: Implications for the Role of Hormones in the Stromal Microenvironment

Hormones play a critical role in regulating tissue function by promoting cell survival, proliferation, and differentiation. Our study explores the influence of endocrine function in regulating metabolism and inflammatory pathways in Keratoconus (KC), which is a corneal thinning disease associated with reduced stromal deposition. KC is known to be a multifactorial disease with an elusive pathogenesis. We utilized a cross-sectional study analyzing clinical features and saliva samples from sixty-four KC patients and fourteen healthy controls. In order to determine if endocrine function varied between healthy controls and KC, we measured hormone levels in saliva and found significantly increased dehydroepiandrosterone sulfate (DHEA-S) and reduced estrone levels in KC patients compared to healthy controls. We measured significant variations in metabolites associated with pro-inflammatory processes, including myoinositol and 1-methyl-histidine, by targeted mass spectrometry. We also measured significantly increased IL-16 and stem cell factor in KC saliva samples compared to healthy controls, with higher expression of these pro-inflammatory proteins correlating with increased KC clinical grade, corneal curvature, and stromal thinning. Our results identify a novel mechanism linking KC and pro-inflammatory markers and suggest that altered hormone levels modulate metabolism, cytokine, and growth factor expression leading to increased severity of the KC condition.

High Levels of 17β-Estradiol Are Associated with Increased Matrix Metalloproteinase-2 and Metalloproteinase-9 Activity in Tears of Postmenopausal Women with Dry Eye

Purpose. To determine the serum levels of sex steroids and tear matrix metalloproteinases (MMP) 2 and 9 concentrations in postmenopausal women with dry eye. Methods. Forty-four postmenopausal women with dry eye and 22 asymptomatic controls were enrolled. Blood was drawn and analyzed for serum levels of sex steroids and lipids. Then, the following tests were performed: tear collection, Ocular Surface Disease Index (OSDI) questionnaire, fluorescein tear film break-up time (TBUT), corneal fluorescein staining, Schirmer test, and conjunctival impression cytology. The conjunctival mRNA expression and tear concentrations of MMP-2 and MMP-9 were measured. Results. Serum 17β-estradiol levels were significantly higher in the dry eye subjects than in the controls (P = 0.03), whereas there were no significant differences in levels of testosterone, dehydroepiandrosterone sulfate (DHEA-S), and progesterone. Tear MMP-2 and MMP-9 concentrations (P < 0.001), as well as the MMP-9 mRNA expression in conjunctival samples (P = 0.02), were significantly higher in dry eye subjects than in controls. Serum 17β-estradiol levels were positively correlated with tear MMP-2 and MMP-9 concentrations and negatively correlated with Schirmer test values. Conclusions. High levels of 17β-estradiol are associated with increased matrix metalloproteinase-2 and metalloproteinase-9 activity in tears of postmenopausal women with dry eye.

Sex-steroid imbalance in females and dry eye

Dry eye (DE) is a multifactorial disorder of the ocular surface unit that results in eye discomfort, visual disturbance and ocular surface damage. It is one of the most common complaints in daily ophthalmic practice. The risk of DE increases with age in both sexes, while its incidence is higher among females. In addition, the condition of menopause in aging women may also contribute to DE onset or worsening as a consequence of an overall hormonal imbalance. Sex hormones play a key role in ocular surface physiology and they impact differently on ocular surface tissues. Reduced estrogen levels were historically thought to be responsible in age-related DE onset but more recent investigations have reconsidered the role of androgens that are present and exert a protective function on the ocular surface. Hormone levels themselves, withdrawal changes in hormone levels, and the changes in hormone-receptor responsiveness are all important factors but it remains to be fully elucidated how estrogen or androgen insufficiency act alone or together in a combined imbalance or interplay to raise the risk of disease. The purpose of this review is to briefly outline current scientific evidence on the influence of androgens and estrogens, on the Lachrymal and Meibomian glands and on ocular surface epithelia including conjunctival goblet cells during reproductive and menopausal periods. The role of sex steroids is also discussed in relation to the pathogenesis of different forms of DE and Sjogren's syndrome (SS). The impact of systemic hormone therapy (HT) in DE post-menopausal women still appears as a controversial issue, despite the many clinical studies. Finally, the outcomes of topical applications of steroid-based products are summarized, underlying the need for potential (tear) biomarker(s) in the rationale of DE-targeted therapy.

Pregnancy-induced gingivitis and OMICS in dentistry: in silico modeling and in vivo prospective validation of estradiol-modulated inflammatory biomarkers

Pregnancy-associated gingivitis is a bacterial-induced inflammatory disease with a remarkably high prevalence ranging from 35% to 100% across studies. Yet little is known about the attendant mechanisms or diagnostic biomarkers that can help predict individual susceptibility for rational personalized medicine. We aimed to define inflammatory proteins in saliva, induced or inhibited by estradiol, as early diagnostic biomarkers or target proteins in relation to pregnancy-associated gingivitis. An in silico gene/protein interaction network model was developed by using the STITCH 3.1 with "experiments" and "databases" as input options and a confidence score of 0.700 (high confidence). Salivary estradiol, interleukin (IL)-1β and -8, myeloperoxidase (MPO), matrix metalloproteinase (MMP)-2, -8, and -9, and tissue inhibitor of matrix metalloproteinase (TIMP)-1 levels from 30 women were measured prospectively three times during pregnancy and twice during postpartum. In silico analysis revealed that estradiol interacts with IL-1β and -8 by an activation link when the "actions view" was consulted. In saliva, estradiol concentrations associated positively with TIMP-1 and negatively with MPO and MMP-8 concentrations. When the gingival bleeding on probing percentage (BOP%) was included in the model as an effect modifier, the only association, a negative one, was found between estradiol and MMP-8. Throughout gestation, estradiol modulates the inflammatory response by inhibiting neutrophilic enzymes, such as MMP-8. The interactions between salivary degradative enzymes and proinflammatory cytokines during pregnancy suggest promising ways to identify candidate biomarkers for pregnancy-associated gingivitis, and for personalized medicine in the field of dentistry. Finally, we call for greater investments in, and action for biomarker research in periodontology and dentistry that have surprisingly lagged behind in personalized medicine compared to other fields, such as cancer research.

Serum-induced differentiation of human meibomian gland epithelial cells

PURPOSE

We hypothesize that culturing immortalized human meibomian gland epithelial cells in serum-containing medium will induce their differentiation. The purpose of this investigation was to begin to test our hypothesis, and explore the impact of serum on gene expression and lipid accumulation in human meibomian gland epithelial cells.

METHODS

Immortalized and primary human meibomian gland epithelial cells were cultured in the presence or absence of serum. Cells were evaluated for lysosome and lipid accumulation, polar and neutral lipid profiles, and gene expression.

RESULTS

Our results support our hypothesis that serum stimulates the differentiation of human meibomian gland epithelial cells. This serum-induced effect is associated with a significant increase in the expression of genes linked to cell differentiation, epithelium development, the endoplasmic reticulum, Golgi apparatus, vesicles, and lysosomes, and a significant decrease in gene activity related to the cell cycle, mitochondria, ribosomes, and translation. These cellular responses are accompanied by an accumulation of lipids within lysosomes, as well as alterations in the fatty acid content of polar and nonpolar lipids. Of particular importance, our results show that the molecular and biochemical changes of immortalized human meibomian gland epithelial cells during differentiation are analogous to those of primary cells.

CONCLUSIONS

Overall, our findings indicate that immortalized human meibomian gland epithelial cells may serve as an ideal preclinical model to identify factors that control cellular differentiation in the meibomian gland.

Sex hormones and the dry eye

The greater prevalence of dry eye in women compared to men suggests that sex hormones may have a role in this condition. This review aims to present evidence for how sex hormones may affect the ocular structures involved in the production, regulation and maintenance of the normal tear film. It is hypothesised that hormone changes alter the homeostasis of the ocular surface and contribute to dry eye. Androgens impact on the structure and function of the meibomian and lacrimal glands and therefore androgen deficiency is, at least in part, associated with the aetiology of dry eye. In contrast, reports of the effects of oestrogen and progesterone on these ocular structures and on the conjunctiva are contradictory and the mechanisms of action of these female-specific sex hormones in the eye are not well understood. The uncertainty of the effects of oestrogen and progesterone on dry eye symptoms is reflected in the controversial relationship between hormone replacement therapy and the signs and symptoms of dry eye. Current understanding of sex hormone influences on the immune system suggests that oestrogen may modulate a cascade of inflammatory events, which underlie dry eye.

Corneal biomechanical parameters during pregnancy

PURPOSE

To evaluate the variation in biomechanical properties and central corneal thickness (CCT) for each trimester during pregnancy and to compare the values with those in nonpregnant women.

METHODS

We prospectively studied the eyes of 32 pregnant and 34 age-matched non-pregnant women. The parameters included corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann-correlated intraocular pressure (IOP), and corneal-compensated IOP measured by the Ocular Response Analyzer (ORA). The CCT was also measured with an ultrasonic pachymeter attached to the ORA.

RESULTS

The mean age was 27.0 ± 3.8 years in the study group and 28.0 ± 4.1 years in the control group. The mean CH measurement was 10.6 ± 1.4 mmHg in the study group and 10.1 ± 1.3 mmHg in the control group. The mean CRF value was 9.6 ± 1.7 mmHg in the study group and 10.0 ± 1.4 mmHg in the control group. The mean CCT value was 541.1 ± 22.4 µm in the study group and 536.5 ± 27.1 µm in the control group. No statistically significant differences were found regarding CH, CRF, or CCT values between the 2 groups (independent t test, p = 0.160, p = 0.355, p = 0.450, respectively).

CONCLUSIONS

Hormonal changes during pregnancy may not affect corneal biomechanics. This may be due to the balanced effect of the various hormones on the cornea during pregnancy.

Effects of 17β-estradiol on human corneal wound healing in vitro

PURPOSE

To investigate the effect of 17β-estradiol on corneal wound healing, particularly on epithelial mitosis and migration.

METHODS

Immortalized human corneal epithelial cells (HCECs) were cultured in media with different concentrations of 17β-estradiol (10, 50, 100, and 200 pg/mL), Dulbecco modified Eagle medium: Nutrient Mixture F-12 (negative control), and serum-containing Dulbecco modified Eagle medium: Nutrient Mixture F-12 (positive control). After 6 or 24 hours of hormone treatment, to evaluate the migratory potential of 17β-estradiol, wound healing assays were conducted via the manual scraping of HCECs and western blot analysis of fibronectin and matrix metalloproteinase 9 (MMP9). The proliferative potential of 17β-estradiol was evaluated via a proliferation assay using western blot analysis for proliferating cell nuclear antigen. In addition, epidermal growth factor (EGF) was measured by reverse transcription-polymerase chain reaction, and for the inhibition of epidermal growth factor receptor (EGFR)-mediated signal transduction, a wound healing assay was conducted after HCECs cultured with EGFR small interfering RNA were stimulated with 100 pg/mL 17β-estradiol.

RESULTS

Wound healing assay rates were enhanced as 17β-estradiol increased, with statistically significant changes seen in 50, 100, and 200 pg/mL 17β-estradiol-treated and positive control cells, compared with negative control cells (P < 0.05, in each group). Western blot analysis revealed that the expression of the MMP9 gene was upregulated by 17β-estradiol, and the expression of the fibronectin gene was downregulated by 17β-estradiol. The mitosis assay via western blot analysis showed that the expression cell cycle-associated protein, proliferating cell nuclear antigen, increased gradually as a result of 17β-estradiol treatment. Reverse transcription-polymerase chain reaction showed that EGF was upregulated by 17β-estradiol, and the EGFR small interfering RNA did not totally block the wound healing of the 17β-estradiol-treated cells but statistically significantly reduced the wound healing rate (P = 0.031).

CONCLUSIONS

17β-Estradiol facilitated the maintenance of the beneficial effect on corneal epithelial migration and proliferation, and the promoting effect of 17β-estradiol is partially related to increased EGF in vitro.

Effects of estrogen replacement therapy on apoptosis and vascular endothelial growth factor expression in ocular surface epithelial cells: An experimental study

AIM

To investigate the effects of estrogen replacement therapy (ERT) on apoptosis and vascular endothelial growth factor (VEGF) expression in ocular surface in an experimental rat model.

METHODS

Forty female, Wistar rats were randomized in 4 groups in the study. Subcutaneous ERT (17β-estradiol, 10µg/kg/day) was administered to the first group without ovariectomy and to the second group with ovariectomy for three months. Third group had only ovariectomy and fourth group had sham operation. All rats were sacrificed in estrous cycles determined by vaginal smear test and their right eyes were enucleated at the end of the third month. Enucleated eyes were analyzed by immunohistochemical method for expressions of caspase-3, bcl-2, VEGF and TUNEL assay.

RESULTS

Caspase-3 expression of conjunctival epithelium was significantly higher in group 3 than group 1 (P=0.005), and group 2 (P=0.007). TUNEL score of conjunctival epithelium was significantly higher in group 3 than group1 (P=0.006). TUNEL score of corneal epithelium was significantly higher in group 3 than group 2 (P=0.012), and group 4 (P=0.002). There was no significant difference between groups in that bcl-2 and VEGF expressions.

CONCLUSION

We determined increased apoptosis in ocular surface epithelial cells in ovariectomized rats. ERT and endogen estrogen decreased the apoptosis, and did not result in difference in VEGF expression between the groups. Estrogen may be beneficial for the treatment of apoptosis-mediated ocular surface disorders such as dry eye. Further studies are needed on this subject for a better understanding of the role of estrogen and to provide a new insight for treatment and prevention of apoptosis-mediated ocular surface disorders.

Ocular surface immunity: homeostatic mechanisms and their disruption in dry eye disease

The tear film, lacrimal glands, corneal and conjunctival epithelia and Meibomian glands work together as a lacrimal functional unit (LFU) to preserve the integrity and function of the ocular surface. The integrity of this unit is necessary for the health and normal function of the eye and visual system. Nervous connections and systemic hormones are well known factors that maintain the homeostasis of the ocular surface. They control the response to internal and external stimuli. Our and others' studies show that immunological mechanisms also play a pivotal role in regulating the ocular surface environment. Our studies demonstrate how anti-inflammatory factors such as the expression of vascular endothelial growth factor receptor-3 (VEGFR-3) in corneal cells, immature corneal resident antigen-presenting cells, and regulatory T cells play an active role in protecting the ocular surface. Dry eye disease (DED) affects millions of people worldwide and negatively influences the quality of life for patients. In its most severe forms, DED may lead to blindness. The etiology and pathogenesis of DED remain largely unclear. Nonetheless, in this review we summarize the role of the disruption of afferent and efferent immunoregulatory mechanisms that are responsible for the chronicity of the disease, its symptoms, and its clinical signs. We illustrate current anti-inflammatory treatments for DED and propose that prevention of the disruption of immunoregulatory mechanisms may represent a promising therapeutic strategy towards controlling ocular surface inflammation.

Estrogen negatively regulates epithelial wound healing and protective lipid mediator circuits in the cornea

Estrogen receptors (ERs) are expressed in leukocytes and in every ocular tissue. However, sex-specific differences and the role of estradiol in ocular inflammatory-reparative responses are not well understood. We found that female mice exhibited delayed corneal epithelial wound closure and attenuated polymorphonuclear (PMN) leukocyte responses, a phenotype recapitulated by estradiol treatment both in vivo (topically in male mice) and in vitro (corneal epithelial cell wound healing). The cornea expresses 15-lipoxygenase (15-LOX) and receptors for lipoxin A(4) (LXA(4)), which have been implicated in an intrinsic lipid circuit that regulates corneal inflammation and wound healing. Delayed epithelial wound healing correlated with lower expression of 15-LOX in the regenerated epithelium of female mice. Estradiol in vitro and in vivo down-regulated epithelial 15-LOX expression and LXA(4) formation, while estradiol abrogation of epithelial wound healing was completely reversed by treatment with LXA(4). More important, ERβ and ERα selectively regulated epithelial wound healing, PMN cell recruitment, and activity of the intrinsic 15-LOX/LXA(4) circuit. Our results demonstrate for the first time a sex-specific difference in the corneal reparative response, which is mediated by ERβ and ERα selective regulation of the epithelial and PMN 15-LOX/LXA(4) circuit. These findings may provide novel insights into the etiology of sex-specific ocular inflammatory diseases.

Timing and duration of menopausal hormone treatment may affect cardiovascular outcomes

Largely on the basis of the first publication of findings of net harm with menopausal hormone treatment in the Women's Health Initiative (WHI) hormone trials, current Food and Drug Administration recommendations limit menopausal hormone treatment to the "…shortest duration consistent with treatment goals…," with goals generally taken to mean relief of menopausal symptoms and maximal duration as approximately 5 years. The WHI finding of net harm was due largely to the absence of beneficial effects on coronary heart disease incidence rates. Published analyses of WHI data by age or time since menopause find that excess coronary heart disease risk with menopausal hormone treatment is confined to more remotely menopausal or older women, with younger women showing nonsignificant trends toward benefit (the "timing hypothesis"). Moreover, a recently published reexamination of data from the WHI Estrogen plus Progestin trial suggests that reduced coronary heart disease risk may appear only after 5 to 6 years of treatment. Consistent with this finding, risk ratios for coronary heart disease were calculated as 1.08 (95% confidence interval, 0.86-1.36) in years 1 to 6 and as 0.46 (confidence interval, 0.28-0.78) in years 7 to 8+ in the WHI Estrogen Alone trial. Previous studies also support the beneficial effects of menopausal hormone treatment after prolonged exposure. Thus, current analyses do not support a generalized recommendation for short duration of menopausal hormone treatment. Rather, they suggest that current Food and Drug Administration practice guidelines should be reconsidered to allow individualized care based on risk:benefit considerations. New research is urgently needed evaluating influences of timing, duration, dose, route of administration, and agents on menopausal hormone treatment-related risks and benefits to better understand how to optimize recommendations for individual patients.

Sex-specific lung remodeling and inflammation changes in experimental allergic asthma

There is evidence that sex and sex hormones influence the severity of asthma. Airway and lung parenchyma remodeling and the relationship of ultrastructural changes to airway responsiveness and inflammation in male, female, and oophorectomized mice (OVX) were analyzed in experimental chronic allergic asthma. Seventy-two BALB/c mice were randomly divided into three groups (n=24/each): male, female, and OVX mice, whose ovaries were removed 7 days before the start of sensitization. Each group was further randomized to be sensitized and challenged with ovalbumin (OVA) or saline. Twenty-four hours after the last challenge, collagen fiber content in airways and lung parenchyma, the volume proportion of smooth muscle-specific actin in alveolar ducts and terminal bronchiole, the amount of matrix metalloproteinase (MMP)-2 and MMP-9, and the number of eosinophils and interleukin (IL)-4, IL-5, and transforming growth factor (TGF)-β levels in bronchoalveolar lavage fluid were higher in female than male OVA mice. The response of OVX mice was similar to that of males, except that IL-5 remained higher. Nevertheless, after OVA provocation, airway responsiveness to methacholine was higher in males compared with females and OVX mice. In conclusion, sex influenced the remodeling process, but the mechanisms responsible for airway hyperresponsiveness seemed to differ from those related to remodeling.

Are proteinases the reason for keratoconus?

PURPOSE

Keratoconus is a degenerating disease of the eye that results in an irregularly-shaped cornea. The etiology of the disease is unknown and the prognosis is difficult due to the variability in outcome. Keratoconus has been associated with eye rubbing, atopy, contact lens wear, as well as genetic conditions, such as Down's syndrome, Ehlers-Danlos syndrome, and Marfan's syndrome. Thinning of the cornea in keratoconus has been well studied and is documented to occur as a result of degradation of corneal collagen. The reason for this tissue degradation is unknown but has been hypothesized to be linked with proteases.

METHODS

This study used a literature search to review the role of proteases and inflammatory molecules in the aetiology of keratoconus.

RESULTS

Early studies demonstrated elevated levels of collagenolytic and gelatinolytic activities in laboratory cultures of keratoconic corneas. Matrix metalloproteinases (MMPs) are a family of zinc-dependent proteins that include collagenases and gelatinases. MMPs levels are altered in keratoconus corneas compared to normal corneas and the level of tissue inhibitor of metalloproteinases-1 (TIMP-1) is decreased in keratoconic corneas. Recent studies have demonstrated the involvement of Cathepsin B, G, and K in keratoconus. Although thought to be a non-inflammatory disease, inflammatory molecules, such as interleukins and tumor necrosis factor have been shown to be elevated in keratoconus, and these inflammatory molecules may mediate production and activation of proteases.

CONCLUSIONS

Proteases may be implicated in keratoconus. An in-depth investigation of these proteases may help in better understanding the course of the disease.

Distinct roles for AF-1 and -2 of ER-alpha in regulation of MMP-13 promoter activity

Previous studies have indicated that ER-alpha can influence the activity of the MMP-13 promoter. ER-alpha activity is mediated by two separate transcriptional activation domains (AF-1 and AF-2). The present study focused on analyzing the roles of these domains on the activation of the MMP-13 promoter. Transfection of synoviocytes with an ER-alpha construct lacking the C-terminus AF-2 domain led to significant elevation in MMP-13 promoter activity compared to wild type ER-alpha. Progressive deletions in the N-terminal AF-1 domain led to significant losses in MMP-13 promoter activity. MMP-13 promoter mutagenesis indicated that an AP-1 regulatory site was essential for ER-alpha mutant activity. Thus, both AF-1 and AF-2 domains of ER-alpha are required for regulation of MMP-13 promoter activity. As ER variants and ER related proteins have been implicated in bone and joint disorders, these findings provide understanding of the possible role of ER variants in the development of such conditions.

Spontaneous corneal melting during pregnancy: a case report

INTRODUCTION

Biomechanical changes in the cornea during pregnancy might lead to pathological conditions such as corneal perforation or melting.

CASE PRESENTATION

A 33-year-old Asian female who underwent penetrating keratoplasty in both eyes developed corneal melting in the right eye and marginal keratitis in the left eye in her fifth month of pregnancy. Marginal keratitis in the left eye immediately subsided with topical steroid therapy. However, spontaneous corneal melting progressed in the right eye, despite oral steroid therapy and amniotic membrane transplantation. We performed tectonic penetrating keratoplasty and corneoscleral grafting in the right eye.

CONCLUSION

We advise caution in the ophthalmologic care of pregnant patients who have preexisting corneal thinning disorders or who have undergone multiple corneal surgeries, because physiologic changes during pregnancy might contribute to corneal changes leading to spontaneous melting especially in patients with compromised cornea.

Estradiol increases IL-8 secretion of normal human breast tissue and breast cancer in vivo

IL-8 or CXCL8 has been associated with tumor angiogenesis, metastasis, and poor prognosis in breast cancer. Estrogen is crucial in breast carcinogenesis and tumor progression. Whether sex steroids affect IL-8 secretion of normal breast tissue or breast cancer is not known. Several cell types in a tissue secrete IL-8. Hence, regulatory mechanisms of IL-8 need to be investigated in whole tissue. We used microdialysis to sample IL-8 in normal human breast tissue in situ in pre- and postmenopausal women, preoperatively in breast cancers of women, and in experimental breast cancer in mice. We found a significant positive correlation between IL-8 and estradiol in normal breast tissue and hormone-dependent breast cancer in vivo. Ex vivo, estradiol exposure increased the IL-8 secretion of normal whole breast tissue in culture. In experimental breast cancer, estradiol increased IL-8 whereas the anti-estrogen tamoxifen inhibited the secretion of IL-8 both in vitro and extracellularly in vivo in tumors of nude mice. An anti-IL-8 Ab inhibited endothelial cell proliferation induced by cancer cell produced IL-8 and tumors with low IL-8 levels exhibited decreased angiogenesis. Our results strongly suggest that estradiol has a critical role in the regulation of IL-8 in normal human breast tissue and human breast cancer. IL-8 may present a novel therapeutic target for estrogen driven breast carcinogenesis and tumor progression.

Ocular surface changes over the menstrual cycle in women with and without dry eye

AIM

To analyze whether dry eye symptoms and ocular surface parameters change during different phases of the menstrual cycle.

METHOD

Twenty-nine women of fertile age and with regular, 26-29-day menstrual cycles were included in the study. Fourteen subjects suffered and 15 did not suffer from dry eye symptoms. Symptoms were scored by the validated Ocular Surface Disease Index questionnaire. Tear production was evaluated with the Schirmer I test and the Schirmer II test (Jones test); tear stability with tear breakup time and Ferning test; and degree of dryness by the tear function index and imprint conjunctival cytology. Degree of inflammation was evaluated with conjunctival brush cytology and concentration of exudated serum albumin in tears. Hormonal cytology procedures were applied to exfoliated cells in tears. Patients were analyzed during menstruation, in the follicular phase and the luteal phase over two consecutive cycles, and results were statistically evaluated.

RESULTS

Subjective symptoms, tear production and stability, surface dryness and inflammation were significantly related to hormonal fluctuations in the menstrual cycle. In particular, the impairment of these functions appeared to be related to the estrogen peak occurring during the follicular phase, especially in patients with dry eye.

CONCLUSION

The ocular surface is confirmed to be an estrogen-dependent unit; clinicians should take into account these cyclic variations during examination of subjects affected by symptoms of eye dryness.

Oestrogen-induced changes in biomechanics in the cornea as a possible reason for keratectasia

AIM

The risk of regression after photorefractive keratectomy (PRK) and the tendency to develop keratectasia after laser-assisted in situ keratomileusis (LASIK) procedure is higher in women than men. Currently, interest is focused on the influence of oestrogen on corneal stability after corneal refractive surgery. The aim of this experimental study was to investigate the change in biomechanical properties of the cornea induced by oestrogen.

METHODS

The influence of oestrogen was investigated in 12 fresh porcine corneas incubated in culture medium with 10 micromol/l beta-oestradiol for 7 days. A group of 12 porcine corneas incubated in culture medium without oestradiol for the same time served as a control group. Strips of cornea were cut and the stress-strain was measured in a biomaterial tester. The Young's modulus was calculated.

RESULTS

During incubation the thickness of the cornea changed in the control group by only 6.4% and in the oestradiol group by 12%. However, the difference in the biomechanical stress values at 10% strain was significantly larger. In the control group the stress value was 120.18+/-28.93 kPa and in the oestradiol group 76.87+/-34.63 kPa (p = 0.002), representing a reduction of the corneal stiffness by 36% due to the oestradiol treatment.

CONCLUSION

Oestrogen is a modulating factor of the biomechanical properties of the cornea that is not explainable only by an increased swelling. The significance of the hormone status of patients and its influence on the biomechanical stability of the cornea, a determining factor after refractive surgery, have been underestimated and may contribute to the development of keratectasia.

The effect of 17beta-estradiol on IL-6 secretion and NF-kappaB DNA-binding activity in human retinal pigment epithelial cells

Toll-like receptors (TLRs) and inflammatory cascades participate in the pathology of age-related macular degeneration (AMD). The effect of estrogens on the development of AMD is poorly understood, although many studies indicate that these compounds can modulate inflammatory responses. In this study, we investigated the regulatory role of TLR agonists and 17beta-estradiol (E(2)) on IL-6 expression and NF-kappaB DNA-binding activity in human retinal pigment epithelial cells (ARPE-19). The inflammatory response of ARPE-19 cells to various TLR agonists, e.g. Pam, zymosan, flagellin, SLTA and lipopolysaccharide (LPS) exposures were examined via the secretion of IL-6 cytokine as analyzed by ELISA. In addition, the IL-6 responses to the estrogen-receptor agonist, E(2), and to the estrogen-receptor antagonist ICI 182.780 as well as to the NF-kappaB inhibitor helenalin were compared. The DNA-binding activity of NF-kappaB transcription factor of nuclear cell extracts was analyzed by the gel mobility shift assay (EMSA). TLR4 gene expression was studied by quantitave PCR. The TLR4 agonist, LPS, caused a clear IL-6 response that was attenuated by E(2) in ARPE-19-cells. The anti-inflammatory properties of E(2) were mediated through estrogen receptors and were associated with decreased NF-kappaB DNA-binding activity. The level of TLR4 gene expression was not affected by LPS exposure. Our results indicate that IL-6 expression is regulated through NF-kappaB transcription factor and stereoid-receptor signalling pathways in ARPE-19 cells.