Circumlimbal suture and laser burns: Comparison between two different chronic glaucoma models. / çŽ¯è§’è†œç¼˜ç¼åˆä¸Žæ¿€å ‰å ‰å‡æ¨¡åž‹ï¼šä¸¤ç§æ ¢æ€§é«˜çœ¼åŽ‹æ¨¡åž‹çš„æ¯”è¾ƒï¼ˆè‹±æ–‡ï¼‰.

OBJECTIVES: Glaucoma is a multifactorial optic neuropathy with a high rate of irreversible visual loss, and its pathogenesis is complex and still unclear. Elevated intraocular pressure (IOP) is well recognized as the sole modifiable risk factor for the development of glaucoma in the majority of cases. This study aims to compare 2 different methods of inducing chronic ocular hypertension by circumlimbal suture or by laser burns in degree and lasting time of the IOP, different status of the retina and retinal ganglion cells (RGCs), and changes of the microstructure of neurons. METHODS: The chronic ocular hypertension models were induced by 2 different ways. One kind of the models was built by unilateral circumlimbal suture (10/0) implantation (suture group), another kind of model was built by laser burns at trabecular meshwork and episcleral veins (laser group). The untreated contralateral eye served as the control group. Changes in IOP were observed and regularly monitored in the 2 groups of rats. HE staining was applied to observe the retinal and optic nerve pathology. Transmission electron microscope (TEM) was used to observe the mitochondrial morphology. RGCs were specifically labeled with Brn3b antibody and counted. The expression of caspase-3 was detected by Western blotting to clarify the apoptosis of RGCs. RESULTS: Compared with the control group, IOP were significantly increased in the suture group and the laser group (both P<0.05). The suture group induced a 1.5-fold elevation of IOP, and sustained for 8 weeks. The laser group induced a 2-fold elevation of IOP for 12 weeks. Both methods could cause RGCs loss (both P<0.05), which were verified by pathology and immune staining of Brn3b. The expressions of caspase-3 were also increased (both P<0.05). The mitochondrial morphology became more fragment, which changed from long shape to round and small one under TEM in 2 models. For comparison, the pathology changes of retinal structure in suture group were not obviously than those in the laser group. CONCLUSIONS: Circumlimbal suture can build an effective model of chronic elevated IOP and induce glaucomatous pathologic changes similar to those in the laser photocoagulation, but the pathologic changes are milder than those in laser photocoagulation. Compare with translimbal laser photocoagulation, equipment and skill demand for circumlimbal suture is less.

Single-cell RNA sequencing reveals roles of unique retinal microglia types in early diabetic retinopathy.

BACKGROUND: The pathophysiological mechanisms of diabetic retinopathy (DR), a blinding disease, are intricate. DR was thought to be a microvascular disease previously. However, growing studies have indicated that the retinal microglia-induced inflammation precedes microangiopathy. The binary concept of microglial M1/M2 polarization paradigms during inflammatory activation has been debated. In this study, we confirmed microglia had the most significant changes in early DR using single-cell RNA sequencing. METHODS: A total of five retinal specimens were collected from donor SD rats. Changes in various cells of the retina at the early stage of DR were analyzed using single-cell sequencing technology. RESULTS: We defined three new microglial subtypes at cellular level, including two M1 types (Egr2+ M1 and Egr2- M1) and one M2 type. We also revealed the anatomical location between these subtypes, the dynamic changes of polarization phenotypes, and the possible activation sequence and mutual activation regulatory mechanism of different cells. Furthermore, we constructed an inflammatory network involving microglia, blood-derived macrophages and other retinal nonneuronal cells. The targeted study of new disease-specific microglial subtypes can shorten the time for drug screening and clinical application, which provided insight for the early control and reversal of DR. CONCLUSIONS: We found that microglia show the most obvious differential expression changes in early DR and reveal the changes in microglia in a high-glucose microenvironment at the single-cell level. Our comprehensive analysis will help achieve early reversal and control the occurrence and progression of DR.

Near-Infrared BODIPY Photosensitizer for Modulating Mitochondrial Fusion Proteins and Inhibiting Choroidal Neovascularization.

Photosensitizers have emerged as cytotoxic reactive oxygen species (ROS) activators in photodynamic therapy (PDT), which induced cell apoptosis. As the major contributors to ROS and oxidative stress, mitochondria play an important role in cell apoptosis. Although there are many reports about near-infrared 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) as photosensitizers (PSs) for PDT, this kind of PS has rarely been used for treating mitochondrial function and choroidal neovascularization application at the same time. Herein, a novel near-infrared PS (BDP2) characterized by good water solubility, long wavelength excitation, and high ROS quantum yield has been made. Under near-infrared light irradiation, BDP2 would generate ROS with high yield, induce a mitochondrial morphology change, and trigger cell apoptosis by changing the fusion protein level. Deep investigation revealed that BDP2 can cause oxidative stress, break the balance between fusion and fission of mitochondrial dynamics protein through decreasing fusion protein MFN2 and OPA1 expression, and finally cause cell apoptosis. Due to these characteristics, the BDP2 PS was used to treat choroidal neovascularization in animal models and can inhibit neovascularization.

Determination of intermolecular and intramolecular isotopic compositions of low-abundance gaseous hydrocarbons using an online hydrocarbon gas concentration method.

The stable isotopic composition of natural gas can be used to identify its origin and source. However, low concentrations of gaseous hydrocarbons in high-mature natural and shale gases hinder accurate determination of their compound- and position-specific isotopic compositions. In this study, an online C2+ hydrocarbon gas concentration system combined with gas chromatography-isotope ratio mass spectrometry (GC-IRMS) or gas chromatography-pyrolysis-gas chromatography-isotope ratio mass spectrometry (GC-Py-GC-IRMS) was developed to determine compound- and position-specific isotopic compositions of low-abundance gaseous hydrocarbons. The lower limit of the gas concentration required for isotope ratio determination using the online concentration system is 0.001% (0.003%) for compound-specific carbon (hydrogen) isotopes and 0.005% for position-specific carbon isotopes and is thus applicable to most natural gas samples. The online concentration technique does not cause significant isotopic fractionation effects, and the combination with GC-IRMS and GC-Py-GC-IRMS can accurately and precisely determine the compound-specific δ13C and δD values of low-content C2+ gaseous hydrocarbons and the position-specific δ13C values (δ13Ca, δ13Cb, and SP values) of propane in low-content propane samples, respectively. The application of our method to two natural gas samples from the Ordos and Sichuan basins further confirms that the online concentration method allows simple and rapid determination of the compound- and position-specific isotopic compositions of low-abundance gaseous hydrocarbons.

Analysis of the epidemiological burden of age-related macular degeneration in China based on the data of global burden of disease. / 基于GBDæ•°æ®åº“ä¸­å›½å¹´é¾„ç›¸å ³æ€§é»„æ–‘å˜æ€§æµè¡Œç— å­¦è´Ÿæ‹ åˆ†æž.

OBJECTIVES: Age-related macular degeneration (AMD) is one of the 3 major eye diseases recognized by WHO to prevent blindness, and which is the main cause of irreversible visual impairment in the elderly. This study aims to analyze the disease epidemiological burden, and provide a theoretical foundation for the prevention and control of AMD in China based on the data in global burden of disease (GBD) 2019. METHODS: The prevalent cases/prevalence, disability-adjusted life year (DALYs)/DALY rate of AMD and socio-demographic index (SDI) for global and China were searched from the GBD 2019 database to analyze the epidemiological trend, age-period-gender trend of AMD in China from 1990 to 2019, and to evaluate the relations between the prevalence and SDI. RESULTS: In 2019, the prevalence of AMD in China was at a high level in the world, and the number of prevalent cases were 1.93 times of that in 1990. The prevalence and DALY rates continued to rise. The age trend of AMD in China was high at the middle of the age stages and low at the two ends, and which was higher in the female than in the male. With the increase of SDI, the prevalence of AMD was increased linearly. CONCLUSIONS: The disease burden of AMD in China is increased significantly and is positively correlated with the social development from 1990 to 2019. It is of great significance to study the relationship between epidemilolgical data of AMD and social development level for diagnosis treatment and policy of AMD.

Determination of carbon isotopic composition of crocetane in sediments by heart-cutting two-dimensional gas chromatography-isotope ratio mass spectrometry.

Compound-specific isotope analysis of crocetane in sediments can be used to determine its origin. However, the co-elution of crocetane with phytane and complex substrates hinders the accurate determination of its isotopic composition. A heart-cutting two-dimensional gas chromatography-isotope ratio mass spectrometry (2D-GC-IRMS) method was developed to determine δ13C values of crocetane. Full chromatographic separation of crocetane was achieved with a 30 m CycloSil-B chiral capillary first column and a 60 m Chiraldex B-pH capillary second column (two series-connected 30 m Chiraldex B-pH capillary columns). Analyses of standard mixtures confirmed that the new method has satisfactory accuracy (deviations from the authentic values <0.5‰) and precision (RSDs <5%) for carbon isotope analyses of crocetane and phytane. The application of the method to two sediment samples indicates that baseline resolution is achieved (R >1.5) for crocetane and phytane, with 13C-depleted crocetane (δ13C values of -119.5‰ and -111.5‰ in the two natural samples, respectively) being an indicator of anaerobic oxidation of methane in cold seep areas. The new 2D-GC-IRMS method allows simple and efficient determination of the compound-specific carbon isotopic compositions of crocetane.

Altered oxylipin levels in human vitreous indicate imbalance in pro-/anti-inflammatory homeostasis in proliferative diabetic retinopathy.

Proliferative diabetic retinopathy (PDR) is an advanced stage of diabetic retinopathy (DR), characterized by retinal neovascularization. It is a progressive fundus disease and a severe complication of diabetes that causes vision impairment. Hyperglycemia-induced persistent low-grade inflammation is a crucial factor underlying the pathogenesis of DR-associated damage and contributing to the progression of PDR. Highly enriched polyunsaturated fatty acids (PUFAs) in the retina are precursors to oxidized metabolites, namely, oxylipins, which exert pro-inflammatory or anti-inflammatory (resolving) effects under different pathological conditions and have been implicated in diabetes. To evaluate differences in oxylipin levels in the vitreous obtained from PDR and non-diabetic subjects, we performed a targeted assessment of oxylipins. A total of 41 patients with PDR and 22 non-diabetic control subjects were enrolled in this study. Vitreous humor obtained during routinely scheduled vitrectomy underwent a targeted but unbiased screening for oxylipins using mass spectrometry-based lipidomics. We found 21 oxylipins showing statistically significant differences in their levels between PDR and non-diabetic subjects (p < 0.05). Lipoxygenase (LOX)- and cytochrome P450 (CYP)- derived oxylipins were the most affected, while cyclooxygenase (COX) oxylipins were affected to a lesser extent. When categorized by their precursor PUFAs, ±19,20-EpDPE, a CYP product of docosahexaenoic acid (DHA) and 12S-HETE, a LOX product of arachidonic acid (ARA), were increased by the largest magnitude. Moreover, of these 21 oxylipins, 7 were considered as potential biomarkers for discriminating PDR patients from the non-diabetic controls. Our results indicate that altered oxylipin levels in the vitreous implicate an underlying imbalanced inflammation-resolution homeostasis in PDR.

Receptor-selective interleukin-4 mutein attenuates laser-induced choroidal neovascularization through the regulation of macrophage polarization in mice.

Macrophage polarization has been recognized as an important inflammatory regulator in choroidal neovascularization (CNV). However, the mechanisms regulating macrophage activation and polarization, as well as their effects on angiogenesis and CNV, have not yet been elucidated. IL-4 is implicated in macrophage activation and exerts different functions in various diseases through several receptors. In the current study, the effect of IL-4 muteins on CNV was investigated in vivo. CNV was induced by laser coagulation in wild type mice. IL-4 muteins were recombined into adenoviruses and injected into mice via the tail vein. To evaluate CNV, fluorescein fundus angiography and optical coherence tomography were performed on day 7 after coagulation. Quantitative PCR, western blotting and immunofluorescence staining were used to assess the levels of inflammatory markers. AdIL-4/Q116E, an adenovirus-expressed recombinant IL-4 mutein, selectively activated macrophages, alleviated laser-induced CNV in mice with reduced expression of M2 macrophages and increased the expression of M1 macrophages. Furthermore, the expression of monocyte to macrophage differentiation-associated and delta-like 4 (Dll4) in CNV lesions was upregulated. Employing AdIL-4/Q116E, a IL-4RI-selective mutein, may serve as a new strategy for CNV therapy. Moreover, the results indicated that Dll4 signaling served an important role in the regulation of macrophage polarization.

Case report: an unusual unilateral pterygium - a secondary pterygium caused by parasitosis in the scleral fistula.

BACKGROUND: Ocular parasitosis can cause eye damage, which contribute to eye symptoms such as burning, itching and even blindness. It is uncommon to see the parasitosis lying in the sclera layer, neither it causing pterygium. Here, we present an unusual case of a secondary pterygium caused by intrascleral worm. CASE PRESENTATION: A 52-year-old women complained about discomfort in right eye for 6 years. Slit-lamp examination indicated a thickened triangular layers of conjunctiva extending from the nasal edge to the cornea. The diagnosis was pterygium in the right eye. To our surprise, after scleral of nasal side exposed, we could see a tiny fistula right in the sclera which lied right under the pterygium, with an alive and motile worm inside. An intrascleral fistula was noted. Then the worm was removed by forceps from the fistula, which was creamy white, thread-like and 1 cm long. DISCUSSION AND CONCLUSIONS: As far as we known, it is the first case of an intrascleral worm hidden beneath the conjunctiva which caused the secondary pterygium. It is hard to know the etiology of the secondary pterygium which caused by parasitosis in the scleral fistula untill excision surgery. It is hard to imagine the worm was living in the sclera of the patient for a long-time.

Role of sodium nitroprusside in regulating retinal ganglion cell damage through mitochondrial transcription factor A.

Accumulating evidence has reported that nitric oxide (NO) can be cytotoxic and induce apoptosis. NO can also be genotoxic and cause DNA damage and mutations. It has been shown that NO damages mitochondrial DNA (mtDNA) to a greater extent than nuclear DNA. Sodium Nitroprusside (SNP), a NO donor, could efficiently promote NO formation. The viability of retinal ganglion cells (RGC) and the mtDNA copy numbers could also be altered by SNP conduction. Mitochondrial transcription factor A (TFAM), an mtDNA transcription factor, plays an essential role in the maintenance of mtDNA and mitochondrial homeostasis. The expression of TFAM was up-regulated by low dose SNP while down-regulated by high dose SNP. TFAM overexpression attenuated the regulatory effect of SNP on RGC viability and mtDNA numbers, while TFAM inhibition even amplified the regulatory effect of SNP. Moreover, the expression of apoptosis-related proteins in the mitochondria, Bcl-2 and Bax, were both altered by SNP treatment. These results suggested that TFAM impacted in SNP regulation of RGC viability and mtDNA numbers through the mitochondria-dependent pathway mediated by Bcl-2 and Bax subfamily.

Adeno-associated virus mediated SOD gene therapy protects the retinal ganglion cells from chronic intraocular pressure elevation induced injury via attenuating oxidative stress and improving mitochondrial dysfunction in a rat model.

PURPOSE: This study aimed to determine whether chronic intraocular pressure (IOP) elevation induces retinal oxidative stress and alters mitochondrial morphology and function of retinal ganglion cells (RGC) and to explore the effects of AAV-SOD2 gene therapy on the RGC survival and mitochondrial dysfunction. METHODS: Chronic experimental glaucoma was induced unilaterally in adult male Sprague-Dawley rats by laser burns at trabecular meshwork and episcleral veins 2 times with an interval of one week. One eye of each rat was intravitreally pretreated with recombinant adeno-associated virus expressing SOD2 (AAV-SOD2) or recombinant AAV expressing GFP (AAV-GFP) 21 days before glaucoma induction. RGCs counting, morphometric analysis of retina and optic nerve, and detection of activities of retinal SOD2 and catalase, MDA, mitochondrial morphology, mitochondrial dynamin protein OPA1 and DRP-1 expressions were conducted at 4, 8, 12 and 24 weeks. RESULTS: Severe RGC loss, degeneration of optic nerve, reduced thickness of RGC layer and nerve fiber layer, significant decrease in total SOD and catalase activities, mitochondrial dysfunction and increased MDA were observed at 4, 8, 12 and 24 weeks after glaucoma. Pretreatment with AAV-SOD2 significantly reduced MDA and attenuated the damage to RGCs through a mitochondria-related pathway. CONCLUSION: AAV mediated pre-treatment with SOD2 is able to attenuate oxidative stress and improve mitochondrial dysfunction of RGC and optic nerve secondary to glaucoma. Thus, SOD2 may be used to prevent the retinal RGCs from glaucoma, which provides a promising strategy for glaucoma therapy.

The mitochondrial Ca2+ uniporter: regulation by auxiliary subunits and signal transduction pathways.

Mitochondrial Ca(2+) homeostasis, the Ca(2+) influx-efflux balance, is responsible for the control of numerous cellular functions, including energy metabolism, generation of reactive oxygen species, spatiotemporal dynamics of Ca(2+) signaling, and cell growth and death. Recent discovery of the molecular identity of the mitochondrial Ca(2+) uniporter (MCU) provides new possibilities for application of genetic approaches to study the mitochondrial Ca(2+) influx mechanism in various cell types and tissues. In addition, the subsequent discovery of various auxiliary subunits associated with MCU suggests that mitochondrial Ca(2+) uptake is not solely regulated by a single protein (MCU), but likely by a macromolecular protein complex, referred to as the MCU-protein complex (mtCUC). Moreover, recent reports have shown the potential role of MCU posttranslational modifications in the regulation of mitochondrial Ca(2+) uptake through mtCUC. These observations indicate that mtCUCs form a local signaling complex at the inner mitochondrial membrane that could significantly regulate mitochondrial Ca(2+) handling, as well as numerous mitochondrial and cellular functions. In this review we discuss the current literature on mitochondrial Ca(2+) uptake mechanisms, with a particular focus on the structure and function of mtCUC, as well as its regulation by signal transduction pathways, highlighting current controversies and discrepancies.

A case of uveitis in adult-onset Still's disease with ophthalmologic symptoms.

Adult-onset Still's disease (AOSD) is a rare and systemic inflammatory disorder of unknown etiology and pathogenesis. AOSD is characterized by high fever accompanied by a range of systemic symptoms. However, there are rare cases of AOSD with ophthalmologic symptoms as well as with an obvious causation of corticosteroid withdrawal. In this case, a 43-year-old male patient diagnosed with AOSD showed ocular inflammation after withdrawing from corticosteroid treatment. This patient was treated with prednisolone for AOSD and discharged after achieving complete remission of breathlessness, backache, thoracalgia, joint pain, and spiking fever. The patient unauthorizedly stopped taking prednisolone after he was discharged from the hospital and returned to the Department of Ophthalmology with the complaint of decreased visual acuity in both eyes for half a month and sudden vision loss in the left eye for 3 days. After regular ophthalmologic examinations and fluorescence angiography examination, he was diagnosed with acute panuveitis as the manifestation of AOSD. Uveitis was effectively treated with corticosteroid drugs. This case reported a rare manifestation of AOSD in an ophthalmological system that was associated with the withdrawal of corticosteroid treatment. This report highlighted the therapeutic effect of local and systemic corticosteroid use for AOSD manifested with uveitis. This case is interesting for both rheumatologists and ophthalmologists.