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Rod/cone-driven signals mediate ipRGC contribution to corneal development in normal visual environment. (A) Flow diagram of experimental procedure and data collection. (B) Schematic illustration of ipRGC ablation in Opn4 Cre/Cre mice by intravitreal administration of AAV-CAG-DIO-DTA (DTA virus). Fellow eyes were injected with AAV-CAG-DIO-GFP (control virus) for comparison. (C) Representative confocal images of whole-mount Opn4 Cre/Cre : Ai14 retinas captured at D21 after DTA virus and control virus injection. Scale bar, 100 m. (D) Grouped data show that tdTomato-labeled ipRGCs in DTA virus-injected Opn4 Cre/Cre : Ai14 retinas were significantly fewer as compared to those in control virus-injected ones. (E) Change in refractive error as a function of postinjection time of Opn4 Cre/Cre mice housed in normal visual conditions. Note that DTA virus-injected eyes were significantly more myopic than control virus-injected fellow eyes at all sampling time points over a 42-day period. (F and G) Ocular dimension measurements conducted at D42 revealed that the CRC was significantly reduced in DTA virus-injected eyes as compared to that in control virus-injected eyes (F), whereas the AL was similar between two eyes (G). Error bars represent SEM. ***P < 0.001.
Source publication
The increasing global prevalence of myopia calls for elaboration of the pathogenesis of this disease. Here, we show that selective ablation and activation of intrinsically photosensitive retinal ganglion cells (ipRGCs) in developing mice induced myopic and hyperopic refractive shifts by modulating the corneal radius of curvature (CRC) and axial len...
Contexts in source publication
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... t test, P > 0.05; Fig. 3E). However, axial growth in Opn4 Cre/Cre mice was much slower than that in WTs (2.696 ± 0.008 mm versus 2.725 ± 0.009 mm; unpaired t test, P < 0.05; Fig. 3F). Highly comparable results were obtained in Opn4 −/− mice, in which tau-lacZ was targeted into the melanopsin gene locus, thus abolishing melanopsin expression ( fig. S4) ...
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... understand the contribution of rod/cone-driven signals of ipRGCs in ocular refractive development, the melanopsin-deficient mouse (Opn4 Cre/Cre ) was used again (Fig. 4, A and B). Since there were only rod/cone-driven signals, ipRGC ablation by intravitreal injection of AAV-CAG-DIO-DTA was equivalent to the abolishment of rod/cone-driven signals of these cells. Because ipRGCs in Opn4 Cre/Cre mice could not be immunolabeled by melanopsin antibodies, the ipRGC ablation efficiency of this approach was ...
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... in Opn4 Cre/Cre mice could not be immunolabeled by melanopsin antibodies, the ipRGC ablation efficiency of this approach was instead evaluated in Opn4 Cre/Cre : Ai14 mice in which ipRGCs also lacked melanopsin but could be visualized by tdTomato fluorescence. Under our conditions, the ablation efficiency of AAV-CAG-DIO-DTA was around 70% at D21 (Fig. 4, C and D), quite comparable to that achieved by 400 ng of MEL-SAP in C57BL/6 mice (78%; Fig. 1, E and ...
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... weekly before (D0) and after injection (D7 to D42). Just as seen in MEL-SAP-injected eyes, a myopic shift was detected in DTA virus-injected eyes versus control virus-injected fellow eyes across time (two-way repeated-measures ANOVA, F 1,40 = 238.5, P < 0.001; Sidak multiple comparisons test, P < 0.001 at all postinjection sampling time points; Fig. 4E). However, ocular biometry performed at D42 (data are summarized in table S3) showed that, as compared to control fellow eyes, the CRC in DTA virus-injected Cre/Cre mice housed in normal visual conditions. Note that DTA virus-injected eyes were significantly more myopic than control virus-injected fellow eyes at all sampling time ...
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... dimension measurements conducted at D42 revealed that the CRC was significantly reduced in DTA virus-injected eyes as compared to that in control virus-injected eyes (F), whereas the AL was similar between two eyes (G). Error bars represent SEM. ***P < 0.001. eyes was smaller (1.543 ± 0.004 mm versus 1.586 ± 0.006 mm; paired t test, P < 0.001; Fig. 4F), but the AL was quite comparable (2.702 ± 0.013 mm versus 2.694 ± 0.016 mm; paired t test, P > 0.05; Fig. 4G and table S3). These results strongly suggest that rod/cone-driven signals of ipRGCs are specifically responsible for controlling CRC ...
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... the cornea (52, 53). However, our results found it unlikely that corneal melanopsin directly modulates developmental changes of the corneal curvature, in that melanopsin knockout only induced AL shortening, but did not cause appreciable changes in the CRC (Fig. 3, E and F). Instead, the CRC seems to be modulated by the rod/cone inputs to ipRGCs (Fig. 4). Thus, melanopsin expressed in the cornea is likely to exert functions other than shaping its ...
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... t test, P > 0.05; Fig. 3E). However, axial growth in Opn4 Cre/Cre mice was much slower than that in WTs (2.696 ± 0.008 mm versus 2.725 ± 0.009 mm; unpaired t test, P < 0.05; Fig. 3F). Highly comparable results were obtained in Opn4 −/− mice, in which tau-lacZ was targeted into the melanopsin gene locus, thus abolishing melanopsin expression ( fig. S4) ...
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... understand the contribution of rod/cone-driven signals of ipRGCs in ocular refractive development, the melanopsin-deficient mouse (Opn4 Cre/Cre ) was used again (Fig. 4, A and B). Since there were only rod/cone-driven signals, ipRGC ablation by intravitreal injection of AAV-CAG-DIO-DTA was equivalent to the abolishment of rod/cone-driven signals of these cells. Because ipRGCs in Opn4 Cre/Cre mice could not be immunolabeled by melanopsin antibodies, the ipRGC ablation efficiency of this approach was ...
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... in Opn4 Cre/Cre mice could not be immunolabeled by melanopsin antibodies, the ipRGC ablation efficiency of this approach was instead evaluated in Opn4 Cre/Cre : Ai14 mice in which ipRGCs also lacked melanopsin but could be visualized by tdTomato fluorescence. Under our conditions, the ablation efficiency of AAV-CAG-DIO-DTA was around 70% at D21 (Fig. 4, C and D), quite comparable to that achieved by 400 ng of MEL-SAP in C57BL/6 mice (78%; Fig. 1, E and ...
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... weekly before (D0) and after injection (D7 to D42). Just as seen in MEL-SAP-injected eyes, a myopic shift was detected in DTA virus-injected eyes versus control virus-injected fellow eyes across time (two-way repeated-measures ANOVA, F 1,40 = 238.5, P < 0.001; Sidak multiple comparisons test, P < 0.001 at all postinjection sampling time points; Fig. 4E). However, ocular biometry performed at D42 (data are summarized in table S3) showed that, as compared to control fellow eyes, the CRC in DTA virus-injected Cre/Cre mice housed in normal visual conditions. Note that DTA virus-injected eyes were significantly more myopic than control virus-injected fellow eyes at all sampling time ...
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... dimension measurements conducted at D42 revealed that the CRC was significantly reduced in DTA virus-injected eyes as compared to that in control virus-injected eyes (F), whereas the AL was similar between two eyes (G). Error bars represent SEM. ***P < 0.001. eyes was smaller (1.543 ± 0.004 mm versus 1.586 ± 0.006 mm; paired t test, P < 0.001; Fig. 4F), but the AL was quite comparable (2.702 ± 0.013 mm versus 2.694 ± 0.016 mm; paired t test, P > 0.05; Fig. 4G and table S3). These results strongly suggest that rod/cone-driven signals of ipRGCs are specifically responsible for controlling CRC ...
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... the cornea (52, 53). However, our results found it unlikely that corneal melanopsin directly modulates developmental changes of the corneal curvature, in that melanopsin knockout only induced AL shortening, but did not cause appreciable changes in the CRC (Fig. 3, E and F). Instead, the CRC seems to be modulated by the rod/cone inputs to ipRGCs (Fig. 4). Thus, melanopsin expressed in the cornea is likely to exert functions other than shaping its ...
Citations
... RGCs may code differently in the myopic retina (Miura et al., 2009). Recent research has also reported the involvement of certain types of RGCs, such as ON-delayed RGCs (Mani and Schwartz, 2017) and ipRGCs (Liu et al., 2022), in myopia development. αRGCs were chosen as a representative for several reasons. ...
... Specific visual alterations that experimentally induce refractive errors in chick each alter the diurnal expression of clock and circadian rhythm genes 24 . In mice, retinal-specific knockout of the clock gene Bmal1 induces myopia 32 , knockout of the melanopsin gene in retina alters normal eye development and augments experimental myopia 33 , and ablating intrinsically photosensitive retinal ganglion cells (ipRGCs) suppresses myopia 34 . ...
The prevalence of myopia (nearsightedness) is increasing to alarming levels, but its etiology remains poorly understood. Because both laboratory and clinical findings suggest an etiologic role for circadian rhythms in myopia development, we assayed gene expression by RNA-Seq in retina and choroid at the onset of unilateral experimental myopia in chick, isolating tissues every 4 h during a single 24-h period from myopic and contralateral control eyes. Occluded versus open eye gene expression differences varied considerably over the 24-h sampling period, with some occurring at multiple times of day but with others showing differences at only a single investigated timepoint. Some of the genes identified in retina or choroid of chick myopia were previously identified as candidate genes for common human myopia. Like differentially expressed genes, pathways identified by Gene Set Enrichment Analysis also varied dramatically by sampling time. Considered with other laboratory data, human genetic and epidemiology data, these findings further implicate circadian events in myopia pathogenesis. The present results emphasize a need to include time of day in mechanistic studies of myopia and to assess circadian biology directly in trying to understand better the origin of myopia and to develop more effective therapies.
... Although some improvements in ΔT sol and T lum has been achieved by elements (including Mg [26], Zn [27], F [28], W [29], Zr [30] and Ti [31] et al.) doping, multi-layered [32], and nanoporous structural design [33,34]. It is still challenging for VO 2 based smart windows to have a ΔT sol above 25 % whilst maintaining a T lum at 50 % [35]; and (3) the VO 2 films almost filtered the blue light with wavelength smaller than 500 nm, both in cold and hot state, which means it would have a poor color rendering performance [36] in blue light, and improper photo-biological effects [37]. In a healthy lighting environment, enough exposure to blue light around 480 nm (which is also called the melanopic light) in the early parts of the day is desired, which is closely associated with the suppression of melatonin secretion [38,39]. ...
A R T I C L E I N F O Keywords: Thermal-responsive smart window Ammonia pressure powered Broadband solar spectrum management Building energy saving A B S T R A C T Thermal responsive windows are highly promising for the next-generation architecture for their self-powered solar transmittance. However, existing thermochromic techniques, include VO 2-and hydrogel-based systems, have not been used for large-scale in window applications, because of the technical obstacles such as low luminous transmittance (T lum), poor solar modulation ability (ΔT sol), high transition temperature (T c) and high haze rate. To tackle those issues, a new thermal-responsive design, i.e., the Ammonia Pressure Powered smart (APPs) window, was proposed, with Cu 2+ and sodium copper chlorophyllin (SCC) providing solar spectrum management. In comparisons to traditional thermochromic windows, the new concept of APPs window shows significant energy-related advances. Particularly, a feasible T c (24-36 • C), outstanding ΔT sol (67 %), and high T lum in both cold (84 %) and hot (47.4 %) states are reported in this study. In addition, outdoor experimental test of the APPs window demonstrated that it could produce a rational daylight level of both photopic effects and melanopic effects, whilst reduce the room temperature by about 4 • C on hot sunny day. Furthermore, energy simulations conducted for the APPs window in three different cities (Singapore, Hong Kong and Harbin) indicate its superior performance, compared to the double-layered low-e glazing windows, across various climatic conditions. With cost-effective materials and excellent performance, the authors believe that this new APPs window represents a smart and sustainable solution for the development of next-generation green buildings.
... It has been found that lncRNA Gm35369 might be related to myopia, and this lncRNA is mainly located in ganglion cells and horizontal cells [14]. Studies have reported that RGC alterations are associated with the occurrence and development of myopia, including changes in the number of RGCs, abnormal axonal projections and changes in protein expression in RGCs [19][20][21][22]38]. However, whether lncRNAs in RGCs are involved in the pathogenesis of myopia and the role of lncRNAs as ceRNAs in myopia are still largely unknown. ...
Background
Long noncoding RNAs (lncRNAs) play a key role in the occurrence and progression of myopia. However, the function of lncRNAs in retinal ganglion cells (RGCs) in the pathogenesis of myopia is still unknown. The aim of our study was to explore the lncRNA-mediated competing endogenous RNA (ceRNA) network in RGCs during the development of myopia.
Methods
RNA sequencing was performed to analyze lncRNA and mRNA expression profiles in RGCs between guinea pigs with form-deprived myopia (FDM) and normal control guinea pigs, and related ceRNA networks were constructed. Then, potentially important genes in ceRNA networks were verified by qRT‒PCR, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed to explore biological functions in the RGCs of FDM guinea pigs. The important genes and related signaling pathways were further verified by qRT‒PCR, immunohistochemistry, immunofluorescence and Western blot in myopia in FDM guinea pigs, FDM mice, and highly myopic adults.
Results
The distribution of RGCs was uneven, the number of RGCs was decreased, and RGC apoptosis was increased in FDM guinea pigs. In total, 873 lncRNAs and 2480 mRNAs were determined to be differentially expressed genes in RGCs from normal control and FDM guinea pigs. Via lncRNA-mediated ceRNA network construction and PCR verification, we found that lncRNA-XR_002792574.1 may be involved in the development of myopia through the miR-760-3p/Adcy1 pathway in RGCs. Further verification in FDM guinea pigs, FDM mice, and highly myopic adults demonstrated that the lncRNA-XR_002792574.1/miR-760-3p/Adcy1 axis in RGCs might be related to cGMP/PKG, the apelin signaling pathway and scleral remodeling.
Conclusion
We demonstrated that the lncRNA-XR_002792574.1/miR-760-3p/Adcy1 axis in RGCs might be related to myopia. On the one hand, the lncRNA-XR_002792574.1/miR-760-3p/Adcy1 axis might inhibit the cGMP/PKG and apelin signaling pathways in RGCs, thereby causing RGC damage in myopia. On the other hand, the lncRNA-XR_002792574.1/miR-760-3p/Adcy1 axis may cause myopic scleral remodeling through the ERK-MMP-2 pathway. These findings may reveal novel potential targets in myopia and provide reference value for exploration and development of gene editing therapeutics for hereditary myopia.
... Axial length and other features of the eye were reported to be subject to rhythmic oscillations [13]. Light, intrinsically photosensitive retinal ganglion cells (ipRGCs), and dopamine (DA) have been reported to be involved in circadian rhythm and myopia [16][17][18][19][20][21]. Although the role of retinal signal together with circadian rhythm in the regulation of myopia has been proposed [13], the specific ocular and ocular brain mechanisms of postnatal eye growth and refraction remain unelucidated. ...
... Reportedly, ipRGCs not only participate in non-imaging visual processes, such as circadian rhythm regulation and pupillary light reflex, but also impact imaging visual processes [53,54]. Notably, ipRGCs were shown to play an important role in ocular development and myopia formation [17,55]. After selective destruction of ipRGCs via intravitreal injection of ipRGC-targeting immunotoxin (MEL-SAP), C57BL/6 mice raised in a normal visual environment were reported to shift towards myopia, with steeper corneas and shortened axial lengths [17]. ...
... Notably, ipRGCs were shown to play an important role in ocular development and myopia formation [17,55]. After selective destruction of ipRGCs via intravitreal injection of ipRGC-targeting immunotoxin (MEL-SAP), C57BL/6 mice raised in a normal visual environment were reported to shift towards myopia, with steeper corneas and shortened axial lengths [17]. Moreover, ipRGCs were specifically activated via injecting AAV-DIO-hM3D(Gq)-GFP into the vitreous cavity of the Opn4 cre mice, and their dioptric state shifted to hyperopia, with flatter corneas and elongated axial lengths [17]. ...
Myopia, a common ophthalmic disorder, places a high economic burden on individuals and society. Genetic and environmental factors influence myopia progression; however, the underlying mechanisms remain unelucidated. This paper reviews recent advances in circadian rhythm, intrinsically photosensitive retinal ganglion cells (ipRGCs), and dopamine (DA) signalling in myopia and proposes the hypothesis of a circadian rhythm brain retinal circuit in myopia progression. The search of relevant English articles was conducted in the PubMed databases until June 2023. Based on the search, emerging evidence indicated that circadian rhythm was associated with myopia, including circadian genes Bmal1, Cycle, and Per. In both humans and animals, the ocular morphology and physiology show rhythmic oscillations. Theoretically, such ocular rhythms are regulated locally and indirectly via the suprachiasmatic nucleus, which receives signal from the ipRGCs. Compared with the conventional retinal ganglion cells, ipRGCs can sense the presence of light because of specific expression of melanopsin. Light, together with ipRGCs and DA signalling, plays a crucial role in both circadian rhythm and myopia. In summary, regarding myopia progression, a circadian rhythm brain retinal circuit involving ipRGCs and DA signalling has not been well established. However, based on the relationship between circadian rhythm, ipRGCs, and DA signalling in myopia, we hypothesised a circadian rhythm brain retinal circuit.
... 16 However, due to the difficulty of conducting lens induction on mice, 16 more studies chose FDM model rather than LIM model. 9,17 Whereas previous studies have used commendable methods to construct an LIM model, such as gluing, 18 stitching, 19 and head-mounted spectacle frames, [20][21][22] there are still some limitations to be acknowledged. Therefore, the development of a refined LIM model holds promising potential for significant benefits. ...
Purpose
The purpose of this study was to investigate the underlying molecular mechanism of lens-induced myopia (LIM) through transcriptome and proteome analyses with a modified mouse myopia model.
Methods
Four-week-old C57BL/6J mice were treated with a homemade newly designed –25 diopter (D) lens mounting by a 3D printing pen before right eyes for 4 weeks. Refraction (RE) and axial dimensions were measured every 2 weeks. Retinas were analyzed by RNA-sequencing and data-independent acquisition liquid chromatography tandem mass spectrometry. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) annotation, and STRING databases were used to identify significantly affected pathways in transcriptomic and proteomic data sets. Western blot was used to detect the expression of specific proteins.
Results
The modified model was accessible and efficient. Mice displayed a significant myopic shift (approximately 8 D) following 4 weeks’ of lens treatment. Through transcriptomics and proteomics analysis, we elucidated 175 differently expressed genes (DEGs) and 646 differentially expressed proteins (DEPs) between binoculus. The transcriptomic and proteomic data showed a low correlation. Going over the mRNA protein matches, insulin like growth factor 2 mRNA binding protein 1 (Igf2bp1) was found to be a convincing biomarker of LIM, which was confirmed by Western blot. RNA-seq and proteome profiling confirmed that these two “omics” data sets complemented one another in KEGG pathways annovation. Among these, metabolic and human diseases pathways were considered to be correlated with the LIM forming process.
Conclusions
The newly constructed LIM model provides a useful tool for future myopia research. Combining transcriptomic and proteomic analysis may potentially brighten the prospects of novel therapeutic targets for patients with myopia.
... More recently, studies have shown that light can also regulate nociception [25,26]. And finally, the light environment may exert an important role during development, including neonatal aversive behaviours [27,28], retinal vasculature development [29], ocular growth associated with myopia [30,31] and synapse formation in the brain [32]. Together, these data illustrate the wide-ranging influence of light on mammalian physiology and behaviour (Figure 1). ...
... Indeed, it is now apparent that, in mice, spectral signals originating from cones influence neural activity within the master circadian clock (the suprachiasmatic nucleus) and can modulate the timing and robustness of behavioural and physiological rhythms [6,89]. Finally, there are emerging data of a protective role of 'violet' (360-13 400nm) light against the development of myopia in mice and other species via as yet incompletely resolved mechanisms [30,31,[90][91][92][93][94]. ...
Light enables vision and exerts widespread effects on physiology and behaviour, including regulating circadian rhythms, sleep, hormone synthesis, affective state, and cognitive processes. Appropriate lighting in animal facilities may support welfare and ensure that animals enter experiments in a controlled physiological and behavioural state. Proper consideration of light during experimentation - both when it is explicitly employed as an independent variable and as a general feature of the environment - has the potential to provide more informative experimental designs and more reliable outcomes, contributing to Reduction and Refinement, helping to ensure more ethical animal use, and improving data quality. As such, it is unfortunate that ambient light for animals is typically quantified in units (lux) designed for human observers. We report the consensus views of an expert working group, with expertise spanning mammalian photobiology, neurobiology and animal husbandry and welfare, convened in February 2023 to agree upon metrics for light appropriate for non-human mammals and their application to improve animal welfare and the quality of animal research. We conclude that species-specific versions of the recently standardised a-opic metrology represent the best available approach to quantifying light. We provide methods for measuring these quantities; practical guidance for their implementation in husbandry and experimentation; and quantitative guidance on appropriate light exposure for laboratory mammals.
... The control eye received an equal volume of AAV2/2-EF1α-fDIO-eGFP (BrainVTA). In both groups, a mixture (the total volume = 0.7 μL) containing an equal volume of AAV2/retro-EF1α-DIO-eYFP-eYFP (BrainVTA) and AAV2/retro-EF1α-DIO-Flp (BrainVTA) were delivered to the SC [17,18]. For selective chemogenetic inhibition of PV + RGCs projecting to the SC, 2 μL of AAV2/2-EF1α-fDIO-hM4D(Gi)-eGFP (hM4Di) (BrainVTA) was intravitreally injected. ...
... To manipulate the PV + RGC−PV + SC visual pathway, we created a dual-injection strategy to specifically ablate PV + RGCs projecting to the SC (Fig. 4A). We implemented an AAV vector carrying a gene encoding diphtheria toxin A (DTA) by Cre-and Flp-mediated recombination [17]. First, we injected the Cre-dependent AAV (AAV-EF1α-DIO-Flp and AAV-EF1α-DIO-eYFP-eYFP) into the bilateral SC (Fig. S3A). ...
Parvalbumin-positive retinal ganglion cells (PV+ RGCs) are an essential subset of RGCs found in various species. However, their role in transmitting visual information remains unclear. Here, we characterized PV+ RGCs in the retina and explored the functions of the PV+ RGC-mediated visual pathway. By applying multiple viral tracing strategies, we investigated the downstream of PV+ RGCs across the whole brain. Interestingly, we found that the PV+ RGCs provided direct monosynaptic input to PV+ excitatory neurons in the superficial layers of the superior colliculus (SC). Ablation or suppression of SC-projecting PV+ RGCs abolished or severely impaired the flight response to looming visual stimuli in mice without affecting visual acuity. Furthermore, using transcriptome expression profiling of individual cells and immunofluorescence colocalization for RGCs, we found that PV+ RGCs are predominant glutamatergic neurons. Thus, our findings indicate the critical role of PV+ RGCs in an innate defensive response and suggest a non-canonical subcortical visual pathway from excitatory PV+ RGCs to PV+ SC neurons that regulates looming visual stimuli. These results provide a potential target for intervening and treating diseases related to this circuit, such as schizophrenia and autism.
... It was found that the ablation of intrinsically photosensitive RGCs in the mouse retina induced myopia, indicating that RGCs are crucial to the development of myopia. 25 Therefore, it is speculated that the Piezo1 channel mediates the production of ROS induced by retinal stretch during the development of myopia. However, whether Piezo1 senses myopia-induced retinal stretching stimuli and how it is involved in myopia remains unclear. ...
... 27,37 Given that RGC can influence refractive development, this could be the reason why GsMTx4 delays the development of myopia. 25 The ROS system coexists with antioxidant systems in the human body to maintain the balance of redox reactions. Owing to the downregulation of antioxidants, oxidative stress caused by the inability of the body to eliminate excess ROS is an important factor in the pathogenesis of many ocular diseases, including myopia. ...
Purpose:
To identify the expression of the mechanosensitive ion channel Piezo1 in the retina of guinea pigs with form deprivation myopia (FDM) and to investigate mechanisms by which Piezo1 channels might regulate myopia.
Method:
Sixty 3-week-old guinea pigs were divided into four groups randomly: normal control, FDM, FDM + vehicle control (DMSO), and FDM + Piezo1 inhibitor (GsMTx4). Measurements of spherical equivalent (SE) and axial length (AL) of the guinea pig were taken using retinoscopy and A-scan ultrasound examination, respectively. Location of Piezo1 protein was determined using immunohistochemistry. The histological structure and thickness changes of the guinea pig retina were observed by hematoxylin and eosin. Expression of Piezo1 in the retina was detected using quantitative RT-PCR and Western blot. Reactive oxygen species (ROS) levels in the retina were measured using flow cytometry.
Result:
After 4 weeks of form deprivation, the FDM group exhibited a significantly increased myopic degree and axial length compared with the normal control group (all P < 0.001), and had higher expression levels of Piezo1 and ROS than the normal control group (P < 0.001 and P = 0.002, respectively). Piezo1 protein expression was down-regulated in guinea pigs given GsMTx4 compared with the DMSO group (P = 0.037). Additionally, the GsMTx4 group showed lower myopic degree (P < 0.001) and lower ROS levels (P = 0.019) compared with the DMSO group.
Conclusions:
The Piezo1 channel may be activated in the retinas of FDM guinea pigs and be involved in the development of myopia by regulating intraocular ROS levels.
... Mouse myopia has been shown to mirror that of other myopia models, including primates, while providing access to the unique genetic tools of the mouse model [21,22]. Through genetic manipulation made possible by the mouse model, all opsins investigated have been proven to play a role in refractive development, including the expected roles of both rod [23,24] and cone opsins [25,26], and recently, the noncanonical opsins OPN4 [27,28] and OPN5 [29] as well. Only OPN3, a blue-light-sensing noncanonical opsin, remains to be investigated. ...
... However, there is substantial overlap of Opn3 expression with the M2 and the M4 subtypes of OPN4 RGCs ( Figure 1I). The population of OPN4 RGCs, and the M2 subtype specifically (as well as M1 and M3 populations where Opn3 is not expressed), have been implicated in refractive development and induced myopia responses [27,28]. Outside of the RGCs, Opn3-eGFP also showed that Opn3 is expressed in a distinct layer of cells just outside the retinal pigmented epithelium (RPE, Figure 1A,B,J). ...
... It is therefore unsurprising that refractive phenotypes have been documented in every opsin signaling pathway studied [23][24][25], including the non-canonical opsins. Loss of melanopsin/Opn4 function or of the ipRGCs that express Opn4 can result in early myopia and late hyperopia [27] or persistent hyperopia [28]. Neuropsin/Opn5-dependent violet light stimulation is protective against induced myopia [55] and can explain why sunlight is protective against myopia [74]. ...
Purpose:
Myopia, or nearsightedness, is the most common form of refractive error and is increasing in prevalence. While significant efforts have been made to identify genetic variants that predispose individuals to myopia, these variants are believed to account for only a small portion of the myopia prevalence, leading to a feedback theory of emmetropization, which depends on the active perception of environmental visual cues. Consequently, there has been renewed interest in studying myopia in the context of light perception, beginning with the opsin family of G-protein coupled receptors (GPCRs). Refractive phenotypes have been characterized in every opsin signaling pathway studied, leaving only Opsin 3 (OPN3), the most widely expressed and blue-light sensing noncanonical opsin, to be investigated for function in the eye and refraction.
Methods:
Opn3 expression was assessed in various ocular tissues using an Opn3eGFP reporter. Weekly refractive development in Opn3 retinal and germline mutants from 3 to 9 weeks of age was measured using an infrared photorefractor and spectral domain optical coherence tomography (SD-OCT). Susceptibility to lens-induced myopia was then assessed using skull-mounted goggles with a -30 diopter experimental and a 0 diopter control lens. Mouse eye biometry was similarly tracked from 3 to 6 weeks. A myopia gene expression signature was assessed 24 h after lens induction for germline mutants to further assess myopia-induced changes.
Results:
Opn3 was found to be expressed in a subset of retinal ganglion cells and a limited number of choroidal cells. Based on an assessment of Opn3 mutants, the OPN3 germline, but not retina conditional Opn3 knockout, exhibits a refractive myopia phenotype, which manifests in decreased lens thickness, shallower aqueous compartment depth, and shorter axial length, atypical of traditional axial myopias. Despite the short axial length, Opn3 null eyes demonstrate normal axial elongation in response to myopia induction and mild changes in choroidal thinning and myopic shift, suggesting that susceptibility to lens-induced myopia is largely unchanged. Additionally, the Opn3 null retinal gene expression signature in response to induced myopia after 24 h is distinct, with opposing Ctgf, Cx43, and Egr1 polarity compared to controls.
Conclusions:
The data suggest that an OPN3 expression domain outside the retina can control lens shape and thus the refractive performance of the eye. Prior to this study, the role of Opn3 in the eye had not been investigated. This work adds OPN3 to the list of opsin family GPCRs that are implicated in emmetropization and myopia. Further, the work to exclude retinal OPN3 as the contributing domain in this refractive phenotype is unique and suggests a distinct mechanism when compared to other opsins.
