Anterior Lens Epithelium Research Articles

Towards the Identification and Characterization of Putative Adult Human Lens Epithelial Stem Cells.

The anterior lens epithelium has the ability to differentiate into lens fibres throughout its life. The present study aims to identify and functionally characterize the adult stem cells in the human lens epithelium. Whole mounts of lens epithelium from donor eyes (normal/cataract) were immunostained for SOX2, gap junction protein alpha 1 (GJA1), PAX6, α, β and γ-crystallins, followed by a confocal analysis. The functional property of adult stem cells was analysed by their sphere forming ability using cultured lens epithelial cells from different zones. Based on marker expression, the lens epithelium was divided into four zones: the central zone, characterized by a small population of PAX6+, GJA1-, β-crystallin- and γ-crystallin- cells; the germinative zone, characterized by PAX6+, GJA1+, β-crystallin- and γ-crystallin-; the transitional zone, characterized by PAX6+, GJA1+, β-crystallin+ and γ-crystallin-; and the equatorial zone, characterized by PAX6+/-, GJA1+, β-crystallin+, and γ-crystallin+ cells. The putative lens epithelial stem cells identified as SOX2+ and GJA1 membrane expression negative cells were located only in the central zone (1.89 ± 0.84%). Compared to the other zones, a significant percentage of spheres were identified in the central zone (1.68 ± 1.04%), consistent with the location of the putative adult lens epithelial stem cells. In the cataractous lens, an absence of SOX2 expression and a significant reduction in sphere forming ability (0.33 ± 0.11%) were observed in the central zone. The above findings confirmed the presence of putative stem cells in the central zone of the adult human lens epithelium and indicated their probable association with cataract development.

Structural Characteristics of the Lens in Presenile Cataract.

The purpose of this work is to examine the structure of the anterior lens epithelial cells (aLECs) of presenile idiopathic cortical cataract to investigate the possible structural reasons for its development. The anterior lens capsules (aLCs: basement membrane and associated lens epithelial cells) were obtained from routine uneventful cataract surgery of 5 presenile cataract patients (16 and 41 years old women and 29, 39, and 45 years old men). None of the patients had family history of cataract, medication, or trauma and they were otherwise healthy. In addition, the patients did not have any other abnormal features in the ocular status except cataract. The aLCs were prepared for scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The most prominent abnormal features observed by SEM for all 5 studied presenile cataract patients were the changes of the aLECs structure with the dents, the selective concavity of some LECs, at their apical side centrally toward the nucleus. In addition, TEM showed the thinning of the lens epithelium with the segmentally concave cells and the compressed and elongated nuclei. Abnormal and distinguishable structural features were observed in the anterior lens epithelium aLECs in all 5 patients with presenile cataract. Disturbed structure of aLECs, regularly present in presenile cataract type is shown that might be associated with water accumulation in the presenile idiopathic cortical cataract lens.

Changes in the Anterior Lens Epithelium and Basement Membrane in Pseudoexfoliation Syndrome undergoing Surgery for Senile Cataracts: A Transmission Electron Microscopic Study.

To compare the electron microscopic lens findings with and without pseudoexfoliation syndrome (XFS), in patients undergoing surgery for senile cataract. A descriptive study. Place and Duration of the Study: Ophthalmology Department, Hacettepe University Hospital between December 2019 and March 2020. Anterior lens capsules (basement membrane and lens epithelial cells) taken from 20 eyes of 20 patients with senile cataract were examined. XFS was detected by slit-lamp examination in 10 of 20 patients. Remaining 10 were included in the control group. All patients and controls were of similar age and had no systemic disease. The anterior lens capsules were obtained from cataract surgery and prepared for observation under a transmission electron microscope. The mean age of individuals in the XFS and control groups was 69.4 ± 6.9 (56-82) years and 65.2 ± 6.9 (54-73) years, respectively. The best-corrected visual acuity in the XFS and control groups was 0.7 ± 0.4 (0.3-1.3) logMAR and 0.9 ± 0.4 (0.4-1.3) logMAR, respectively. Marked ultrastructural changes were observed in the anterior lens capsules of all eyes with pseudoexfoliation. Degenerative changes and thinning in lens epithelial cells were observed in all samples. The lens epithelial cells were loosely attached to the basement membrane in places. Numerous apoptotic cells with pyknotic nuclei were observed in lens epithelial cells, and many vacuoles within the cytoplasm in different areas were detected. Transmission electron microscopic examination revealed ultrastructural abnormalities in the XFS epithelium of all patients in the XFS group. Many aspects of the pathogenetic process of XFS remain uncertain, hence requiring further exploration. Key Words: Capsule, Electron microscopy, Epithelium, Pseudoexfoliation syndrome.

Scanning and transmission electron microscopy study of anterior lens epithelium in presenile cataract.

To study the structure of lens epithelial cells (LECs) in the anterior lens epithelium of presenile cataract and to further explore the possible reasons for presenile cataract development. The anterior lens capsules (aLCs) of patients with presenile cataracts and patients with ordinary age-related cataracts were obtained from routine cataract surgery, and the 5-5.5mm circles of the central aLC were cut in half and prepared for transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The most obvious structural changes in the LECs observed in both cataract groups by TEM were uneven thickness of the anterior lens epithelium, vacuolated cytoplasm and elongated nuclei. SEM showed abnormal structural changes in the LECs, with swollen cells and spheres on the anterior lens epithelium observed in both groups and holes formed by the LECs stretching observed only in the presenile cataract patients. The degeneration of the anterior lens epithelium and the structural changes in the LECs were observed more prominently in presenile cataract patients. Abnormal and prominently affected structural features of LECs were observed in the presenile compared to age-related cataract patients by TEM and SEM. We suppose that ultrastructural pathological changes in the anterior lens epithelial cells are one of the important reasons for the development of presenile and age-related cataract.

Ultrastructural Analysis of the Anterior Lens Epithelium in Cataracts Associated with Uveitis

Purpose: To investigate the transmission electron microscopic findings of lens epithelial cells (LECs) in patients with different subtypes of uveitis and to compare the findings with those in age-matched controls. Methods: In this prospective case-control study, the anterior lens capsules were taken from 47 eyes of 47 patients with uveitis of different subtypes (17 with Fuchs uveitis syndrome [FUS], 13 with ­Behçet’s uveitis, 10 with idiopathic uveitis, and 7 with herpetic keratouveitis) and from 15 eyes of 15 control patients. Results: In the FUS group, the LECs had homogeneous thickening and irregularity, with some small vacuoles and widespread, oval-shaped pigment clusters in some areas. In the Behçet uveitis group, there was evident thinning in the lens epithelium. The subepithelial tissue under the epithelium was thickened, and edematous areas were detected. In the idiopathic uveitis group, the LECs were thinner with small vacuoles, and the cubic structure of the LECs was transformed into a squamous one. Moreover, the LECs included some small vacuoles, similar to those in the FUS group. In the herpetic keratouveitis group, two prominent cell types were observed: (1) completely normal LECs and (2) degenerated-type LECs with pyknotic nuclei, condensation of chromatin, swelling in the cytoplasm, membrane ruptures, and intra­cytoplasmic inclusion bodies. In the control group, the LECs and all of their elements occurred in normal ultrastructural patterns, with the exception of a few small intraepithelial vacuoles, which were fewer in number and smaller than those in the FUS and idiopathic uveitis groups. Conclusion: The electron microscopic analysis of LECs of patients with different subtypes of uveitis revealed significant ultrastructural alterations, which may be related to the summation of oxidative stress and intraocular inflammation.

A comprehensive spatial-temporal transcriptomic analysis of differentiating nascent mouse lens epithelial and fiber cells

Elucidation of both the molecular composition and organization of the ocular lens is a prerequisite to understand its development, function, pathology, regenerative capacity, as well as to model lens development and disease using in vitro differentiation of pluripotent stem cells. Lens is comprised of the anterior lens epithelium and posterior lens fibers, which form the bulk of the lens. Lens fibers differentiate from lens epithelial cells through cell cycle exit-coupled differentiation that includes cellular elongation, accumulation of crystallins, cytoskeleton and membrane remodeling, and degradation of organelles within the central region of the lens. Here, we profiled spatiotemporal expression dynamics of both mRNAs and non-coding RNAs from microdissected mouse nascent lens epithelium and lens fibers at four developmental time points (embryonic [E] day 14.5, E16.5, E18.5, and P0.5) by RNA-seq. During this critical time window, multiple complex biosynthetic and catabolic processes generate the molecular and structural foundation for lens transparency. Throughout this developmental window, 3544 and 3518 genes show consistently and significantly greater expression in the nascent lens epithelium and fibers, respectively. Comprehensive data analysis confirmed major roles of FGF-MAPK, Wnt/β-catenin, PI3K/AKT, TGF-β, and BMP signaling pathways and revealed significant novel contributions of mTOR, EIF2, EIF4, and p70S6K signaling in lens formation. Unbiased motif analysis within promoter regions of these genes with consistent expression changes between epithelium and fiber cells revealed an enrichment for both established (e.g. E2Fs, Etv5, Hsf4, c-Maf, MafG, MafK, N-Myc, and Pax6) transcription factors and a number of novel regulators of lens formation, such as Arntl2, Dmrta2, Stat5a, Stat5b, and Tulp3. In conclusion, the present RNA-seq data serves as a comprehensive reference resource for deciphering molecular principles of normal mammalian lens differentiation, mapping a full spectrum of signaling pathways and DNA-binding transcription factors operating in both lens compartments, and predicting novel pathways required to establish lens transparency.

Electron Microscopic Investigation of Anterior Lens Capsule and Epithelium in Patients with Diabetes Mellitus

Purpose: To evaluate the histopathologic alterations of organelles in the epithelium of the anterior lens capsule. Methods: The interventional study included 26 eyes; of which 11 had non-proliferative diabetic retinopathy (diabetic group) and cataract, and 15 had age-related cataract (control group). We investigated the anterior lens capsule in patients with diabetes mellitus by using electron microscopy and to compare it between diabetic eyes and healthy eyes. Anterior capsule samples were obtained by circular continuous capsulorhexis during phacoemulsification procedures. All the samples were fixed and conventionally processed for electron microscopy analysis. Results: Demographic characteristics of the diabetic group and the control group were similar (p > 0.05). In the diabetic group, electron dense cells with an apoptotic appearance were seen and these cells had an apoptotic nucleus and prominent mitochondrial crystalysis. In addition, there was dilatation of the endoplasmic reticulum cistern. In the control group, lens epithelial cells and all their elements had a normal pattern. Neither cells with an apoptotic appearance nor mitochondrial crystalysis was seen, but there was dilatation of the endoplasmic reticulum cistern. Conclusions: Diabetes mellitus can engender structural abnormalities of organelles in the epithelium of the anterior lens capsule including mitochondrial crystalysis, dilatation of the endoplasmic reticulum cistern and apoptotic dense nucleus. It can be suggested that diabetes mellitus affects organelles of anterior lens epithelium in eyes with cataracts, while it causes non-proliferative changes in the retina.

Anterior lens capsule and epithelium thickness measurements using spectral-domain optical coherence tomography

BackgroundTo investigate the anterior lens capsule and epithelium thickness (defined as anterior lens capsular complex: ALCC) in normal Chinese subjects using spectral-domian optical coherence tomography (SD-OCT) and examine the factors that may influence the ALCC, such as age, gender, pupil diameter (PD) and signal strength index (SSI).MethodsA prospective observational case series. One-hundred-thirty-four normal subjects (134 eyes) were included. The ALCCs were determined manually via SD-OCT. Using the pupil center as a reference position, the central ALCC (CALCC), nasal 1-mm ALCC (NALCC), temporal 1-mm ALCC (TALCC) and PD were measured manually.ResultsThe mean CALCC, NALCC and TALCC were 33 ± 6 μm, 36 ± 7 μm and 34 ± 6 μm, respectively. The NALCC was significantly thicker than the CALCC (P < .001) and TALCC (P < .001). Moreover, CALCC was significantly thinner than TALCC (P = 0.013). Age was positively correlated with the CALCC (r = 0.292, P < .001), NALCC (r = 0.400, P < .001) and TALCC (r = 0.521, P < .001). PD, gender and SSI were not significantly correlated with the three ALCC parameters.ConclusionsThe SD-OCT can be used to demonstrate the ALCC thickness, and age is positively correlated with the ALCC in the central, nasal and temporal sides.

This issue of ACTA

This issue of ACTA

Anterior lens epithelium in cataract patients with retinitis pigmentosa - scanning and transmission electron microscopy study.

In retinitis pigmentosa (RP) patients, relatively minor lens opacity in central part of posterior pole of the lens may cause disproportionate functional symptoms requiring cataract operation. To investigate the possible structural reasons for this opacity development, we studied the structure of the lens epithelium of patients with RP. The anterior lens capsule (aLC: basement membrane and associated lens epithelial cells, LECs) was obtained from cataract surgery and prepared for scanning and transmission electron microscopy (SEM and TEM). Both SEM and TEM show a number of abnormal features in the anterior lens epithelium of cataract patients with RP. The abnormalities appear mainly as holes, thinning and degradation of the epithelium, with the dimensions from <1μm to more than 50μm. Other types of holes in size up to 20μm were seen that may be formed by gradual stretching of the lens epithelium. Another type of abnormalities was cracks that were seen between adjacent LECs, with dimensions 0.1-2μm×up to 10μm. Abnormal structural features were observed in the anterior lens epithelium that may cause water influx into the lens. This may lead to clouding along the water clefts leading towards the posterior pole in the RP cataractous lens. We suggest that the lens epithelium has a role in the development of the cataract in patients with RP.

Human anterior lens epithelium in presenile cataract‐ scanning and transmission electron microscopy study

PurposePresenile cataracts, including juvenile and congenital cataract, are rare. As a presenile cataract is considered a subcapsular senile cataract in a person under 45 years of age. Clinical examination before the cataract surgery showed the subcapsular changes in the opacity on the anterior lens. The purpose was to study the structure of the lens epithelial cells (LECs) of presenile cataract in order to investigate possible structural reasons for its development.MethodsThe anterior lens capsule (aLC: basement membrane and associated lens epithelial cells) were obtained from cataract surgery and prepared for scanning electron microscopy (SEM) and transmission electron microscopy (TEM).ResultsWe present the results of the SEM and TEM study of the anterior lens epithelium. The most prominent abnormal features observed by SEM for all studied presenile cataract patients were the changes of the LECs structure with the dents on the apical side centrally toward the nucleus. The individual LECs or smaller regions of lens epithelium are damaged with the several lesions of this type that are present diffusely. TEM also showed the thinning of the lens epithelium with the segmentally concave cells and the compressed and elongated nucleuses.ConclusionsAbnormal, distinguishable structural features were observed in the anterior lens epithelium LECs in presenile cataract patients. Disturbed structure of LECs may play a role in water accumulation in the presenile cataract lens. We suggest that the presence of LECs with damaged nucleuses may be associated with the genetic/congenital origin of the presenile cataracts.

Anterior lens epithelium in intumescent white cataracts - scanning and transmission electron microscopy study.

Our purpose was to study the structure of the lens epithelial cells (LECs) of intumescent white cataracts (IC) in comparison with nuclear cataracts (NC) in order to investigate possible structural reasons for development of IC. The anterior lens capsule (aLC: basement membrane and associated LECs) were obtained from cataract surgery and prepared for scanning electron microscopy (SEM) and transmission electron microscopy (TEM). We observed by SEM that in IC, LEC swelling was pronounced with the clefts surrounding the groups of LECs. Another structural feature was spherical formations, that were observed on the apical side of LEC's, towards the fibre cell layer, both by SEM and TEM. Development of these structures, bulging out from the apical cell membrane of the LEC's and disrupting it, could be followed in steps towards the sphere formation. The degeneration of the lens epithelium and the structures of the aLC in IC similar to Morgagnian globules were also observed. None of these structural changes were observed in NC. We show by SEM and TEM that, in IC, LECs have pronounced structural features not observed in NC. This supports the hypothesis that the disturbed structure of LECs plays a role in water accumulation in the IC lens. We also suggest that, in IC, LECs produce bulging spheres that represent unique structures of degenerated material, extruded from the LEC.

Anterior lens epithelium in cataract patients with retinitis pigmentosa ‐ scanning and transmission electron microscopy study

PurposeIn retinitis pigmentosa (RP) patients, relatively minor lens opacity posteriorly centrally may cause disproportionate functional symptoms requiring cataract operation. To investigate possible structural reasons for this opacity development, we studied the structure of the lens epithelium of RP patients.MethodsThe anterior lens capsule (aLC: basement membrane and associated LECs) were obtained from cataract surgery and prepared for scanning and transmission electron microscopy (SEM and TEM).ResultsBoth SEM and TEM show the holes in the anterior lens epithelium of cataract patients with RP. Mainly, the holes appear as thinning and degradation of the epithelium, with the dimensions from less than 1 μm to more than 10 ηm and covering the region of several aLECs. A step towards the formation of denuded regions with the dimensions even bigger than 50 ηm may be the detachment of the lens epithelium. Other type of holes in size up to 20 ηm, may be formed by gradual stretching of the lens epithelium. Another type of holes is formed between adjacent LECs where lateral connections are absent, with dimensions 0.1‐2 ηm × up to 10 ηm.ConclusionsShowing of holes in the anterior lens epithelium supports the hypothesis that disturbed structure of the lens epithelium plays a role in water accumulation in the RP cataractous lens. We suggest that the lens epithelium has a role in the development of the cataract in RP patients.

Anterior lens epithelium in cataract patients with retinitis pigmentosa – scanning and transmission electron microscopy study

PurposeIn retinitis pigmentosa (RP) patients, relatively minor lens opacity posteriorly centrally may cause disproportionate functional symptoms requiring cataract operation. To investigate possible structural reasons for this opacity development, we studied the structure of the lens epithelium of RP patients.MethodsThe anterior lens capsule (aLC: basement membrane and associated LECs) were obtained from cataract surgery and prepared for scanning and transmission electron microscopy (SEM and TEM).ResultsBoth SEM and TEM show the holes in the anterior lens epithelium of cataract patients with RP. Mainly, the holes appear as thinning and degradation of the epithelium, with the dimensions from &lt;1 μm to more than 10 ηm and covering the region of several aLECs. A step towards the formation of denuded regions with the dimensions even bigger than 50 ηm may be the detachment of the lens epithelium. Other type of holes in size up to 20 ηm, may be formed by gradual stretching of the lens epithelium. Another type of holes is formed between adjacent LECs where lateral connections are absent, with dimensions 0.1‐2 ηm × up to 10 ηm.ConclusionsShowing of holes in the anterior lens epithelium supports the hypothesis that disturbed structure of the lens epithelium plays a role in water accumulation in the RP cataractous lens. We suggest that the lens epithelium has a role in the development of the cataract in RP patients.

Aquaporins 6-12 in the human eye

Aquaporins (AQPs) are widely expressed and have diverse distribution patterns in the eye. AQPs 0-5 have been localized at the cellular level in human eyes. We investigated the presence of the more recently discovered AQPs 6-12 in the human eye. RT-PCR was performed on fresh tissue from two human eyes divided into the cornea, corneal limbus, ciliary body and iris, lens, choroid, optic nerve, retina and sclera. Each structure was examined to detect the mRNA of AQPs 6-12. Twenty-one human eyes were examined using immunohistochemical and immunofluorescence techniques to determine the topographical localization of AQPs 6-12. mRNA transcripts of AQP7, AQP9 and AQP11 were found in the ciliary body, corneo-limbal tissue, optic nerve, retina and sclera. AQP9 and AQP11 mRNA was also detected in the choroid. No mRNA of AQP6, AQP8, AQP10 or AQP12 was detected. Anti-AQP7 immunolabelling was detected in the corneal epithelium, corneal endothelium, trabecular meshwork endothelium, ciliary epithelia, lens epithelium, the inner and outer limiting membrane of the retina, the retinal pigment epithelium and the capillary endothelium of all parts of the eye. AQP9 immunolabelling was detected in the nonpigmented ciliary epithelium and retinal ganglion cells. AQP11 immunolabelling was detected in the corneo-limbal epithelium, nonpigmented ciliary epithelium and inner limiting membrane of the retina. Selective expression of AQP7, AQP9 and AQP11 was found within various structures of the human eye. The detection of these aquaporins in the eye implies a role that may be related not only to water transport but also to the transport of glycerol, lactate and ammonia, with importance for metabolism, especially in the retina.

Expression patterns of ADAMs in the developing chicken lens

In the present study the expression patterns of ADAM (a disintegrin and metalloprotease) genes in the chicken developing lens were analyzed. Using in situ hybridization, we found that seven members of the ADAM family including ADAM9, ADAM10, ADAM12, ADAM13, ADAM17, ADAM22, and ADAM23 are expressed in the developing embryonic lens. From embryonic incubation day (E) 2 to E3, most of the ADAMs investigated here are expressed in the lens placode and lens vesicle. From E5 to E7, all seven ADAMs, but predominantly ADAM9 and ADAM10, are throughly expressed in the central epithelium, as well as in the proliferating lens epithelium and the equatorial lens epithelium. From E9 to E14, expression of ADAM9, ADAM10, and ADAM17 decreases moderately in these regions. ADAM12 and ADAM13 are weakly expressed in the central epithelium and the lens epithelium, and are not detectable from E14 onward. ADAM22 and ADAM23 are expressed in the central epithelium, the lens epithelium and the equatorial lens epithelium at E5 and decrease gradually afterwards in the same regions. At E16, only weak ADAM9, ADAM10 and ADAM17 signals are found in the anterior lens epithelium. The changing spatiotemporal expression of the seven ADAMs suggests a regulatory role for these molecules during chicken lens development.

Ultrastructure of the Anterior Lens Capsule and Epithelium in Cataracts Associated with Uveitis

Aims: To study the ultrastructure of the anterior lens capsule and epithelium, and capsular thickness in uveitic cataracts. Methods: Capsulorhexis samples from 20 uveitic cataracts were compared to 20 nuclear cataracts using the semi- and ultra-thin techniques. Results: Extensive epithelial and capsular-epithelial border changes and epithelial-mesenchymal transition in some fibrotic capsules were found only in the uveitic group. All these changes were observed predominately in white uveitic cataracts. Mild and moderate ultrastructural changes were seen in both groups. Surface deposition of amorphous material was also found only in uveitic cataracts. Capsular thickness was not different between the two groups. Conclusions: Uveitic capsules showed more extensive and different ultrastructural changes that probably occurred because of inflammation in the eye and epithelial-mesenchymal transition. These changes might be an additional reason for altered behavior of the lens capsule at capsulorhexis.

Aldo-Keto Reductases in the Eye

Aldose reductase (AKR1B1) is an NADPH-dependent aldo-keto reductase best known as the rate-limiting enzyme of the polyol pathway. Accelerated glucose metabolism through this pathway has been implicated in diabetic cataract and retinopathy. Some human tissues contain AKR1B1 as well as AKR1B10, a closely related member of the aldo-keto reductase gene superfamily. This opens the possibility that AKR1B10 may also contribute to diabetic complications. The goal of the current study was to characterize the expression profiles of AKR1B1 and AKR1B10 in the human eye. Using quantitative reverse transcriptase-PCR and immunohistochemical staining, we observed expression of both AKR genes in cornea, iris, ciliary body, lens, and retina. Expression of AKR1B1 was the highest in lens and retina, whereas AKR1B10 was the highest in cornea. Lenses from transgenic mice designed for overexpression of AKR1B10 were not significantly different from nontransgenic controls, although a significant number developed a focal defect in the anterior lens epithelium following 6 months of experimentally induced diabetes. However, lenses from AKR1B10 mice remained largely transparent following longterm diabetes. These results indicate that AKR1B1 and AKR1B10 may have different functional properties in the lens and suggest that AKR1B10 does not contribute to the pathogenesis of diabetic cataract in humans.

Electric currents and lens regeneration in the rat

We studied the process of lens regeneration in the rat following an extracapsular lens extraction preserving the anterior lens capsule and anterior lens epithelium. We assessed clinically the clarity of the newly regenerated lens, evaluated changes in the lens electrical currents following surgery and during the regeneration process and correlated these changes with findings on light microscopy. Protein analysis of the regenerated lens was also undertaken. Experiments were performed in 41 Sprague–Dawley rats, sacrificed at 0, 2, 4 and 8 weeks postoperatively. Our results showed that complete lens regeneration occurred 8 weeks postoperatively only if the anterior epithelium was preserved and the lens capsule was closed surgically. Lens electrical currents, altered following surgery, recovered in parallel with the process of regeneration of the lens. The newly regenerated lens was optically clear and biochemical analysis revealed a pattern of protein expression resembling that observed during lens development. In conclusion, complete lens regeneration occurs in the rat and it is possible that lens electrical signals, together with other cues, may play an important role in this process.

Expression of PTPIP51 during mouse eye development

The expression pattern of the novel tyrosine phosphatase interacting protein 51 (PTPIP51) was studied during the organogenesis of mouse eye on a transcriptional (RT-PCR and in situ hybridization) and translational level (immunohistochemistry and immunoblotting). Timed developmental stages from day E12 to day E18 were analyzed regarding the distribution of PTPIP51 and compared to the expression patterns observed during postnatal developmental stages and adult eye. PTPIP51 was found to be expressed in all investigated developmental stages in derivatives of mesoderm and ectoderm, such as developing cornea, lens, neuroretina and extraocular muscles. Conjuctiva and corneal epithelia were PTPIP51 reactive during all investigated developmental stages including the mature eye. Embryonic differentiation led to reactive keratocytes of the corneal stroma and remained so in post partal stages, as well as in the adult eye. On day E12, all cells comprising the developing lens body showed PTPIP51 expression. Further development unto the adult eye resulted in a restriction of PTPIP51 expression to the anterior lens epithelium and finally to the equatorial region of the lens epithelium. The developing neuroretina showed a strong PTPIP51 expression in the inner neuroblastic layer and the future receptor cell layer. In the adult eye, the retinal ganglion cells and the inner nuclear layer remained PTPIP51 reactive. The data presented here suggests PTPIP51 to be integrated in signaling cascades regulating differentiation and apoptosis during eye development.