HIF-1α-dependent upregulation of angiogenic factors by mechanical stimulation in retinal pigment epithelial cells.

Mechanical stimulation as a mimic of drusen formation in the eye increases the expression of angiogenic factors in retinal pigment epithelial (RPE) cells, but the underlying molecular mechanisms remain unclear. We investigated and characterized the effects of mechanical stimulation on the expression of angiogenic factors in RPE cells both in vitro and in a mouse model. Mechanical stimulation increased the expression of vascular endothelial growth factor (VEGF, encoded by VEGFA) and other angiogenesis-related genes in cultured RPE1 cells. The presence of hypoxia-inducible factor 1α (HIF-1α, encoded by HIF1A) was also increased, and both knockdown of HIF-1α and treatment with the HIF-1α inhibitor CAY10585 attenuated the effect of mechanical stimulation on angiogenesis factor gene expression. Signaling by the tyrosine kinase SRC and p38 mitogen-activated protein kinase was involved in HIF-1α activation and consequent angiogenesis-related gene expression induced by mechanical stimulation. Our results suggest that SRC-p38 and HIF-1α signaling are involved in the upregulation of angiogenic factors in RPE cells by mechanical stimulation. Such in vivo suppression of upregulated expression of angiogenesis-related genes by pharmacological inhibitors of HIF-1α suggests a new potential approach to the treatment of age-related macular degeneration.

SARS-CoV-2 infection status in corneal preservation solution and COVID-19 prevalence after corneal transplantation.

The potential risks associated with organs from COVID-19-infected donors were unclear. To determine the SARS-CoV-2 infection status of corneas transplanted during the COVID-19 pandemic, we performed a polymerase chain reaction (PCR) using the corneal preservation solution that was used for corneal transplantation. We also examined the postoperative health status of the recipients. This study included 144 transplants in 143 eyes. Ninety-nine eyes of imported corneas and 10 of the 14 corneas donated in the prefecture were PCR tested at our hospital, and all were SARS-CoV-2 negative. All corneal transplants were performed after confirming their SARS-CoV-2 negativity by a PCR using a corneal preservation solution at our hospital or a nasopharyngeal swab at a previous facility. Despite postoperative steroid administration, no patient developed COVID-19 infection until discharge. Hence, if the donor's nasopharyngeal swab test is SARS-CoV-2 negative, COVID-19 infection in the recipient due to corneal transplantation may be prevented. Since corneal transplant recipients are susceptible to infection due to prolonged steroid administration and are at high risk for severe diseases if infection occurs, SARS-CoV-2 detection testing using nasopharyngeal swabs in donors should be performed.

Significance of the p38MAPK-CRP2 axis in myofibroblastic phenotypic transition.

We have recently demonstrated that a LIM domain protein, cysteine and glycine-rich protein 2 (CSRP2 [CRP2]), plays a vital role in the functional expression of myofibroblasts and cancer-associated fibroblasts. CRP2 binds directly to myocardin-related transcription factors (MRTF [MRTF-A or MRTF-B]) and serum response factor (SRF) to stabilize the MRTF/SRF/CArG-box complex, leading to the expression of smooth muscle cell (SMC) genes such as α-smooth muscle actin (α-SMA) and collagens. These are the marker genes for myofibroblasts. Here, we show that the adhesion of cultured human skin fibroblasts (HSFs) to collagen reduces the myofibroblastic features. HSF adhesion to collagen suppresses the expression of CRP2 and CSRP2-binding protein (CSRP2BP [CRP2BP]) and reduces the expression of SMC genes. Although CRP2BP is known as an epigenetic factor, we find that CRP2BP also acts as an adaptor protein to enhance the function of CRP2 mentioned above. This CRP2BP function does not depend on its histone acetyltransferase activity. We also addressed the molecular mechanism of the reduced myofibroblastic features of HSFs on collagen. HSF adhesion to collagen inhibits the p38MAPK-mediated pathway, and reducing the p38MAPK activity decreases the expression of CRP2 and SMC genes. Thus, the activation of p38MAPK is critical for the myofibroblastic features. We also show evidence that CRP2 plays a role in the myofibroblastic transition of retinal pigment epithelial cells (RPEs). Like HSFs, such phenotypic modulation of RPEs depends on the p38MAPK pathway.Key words: CRP2, p38MAPK, MRTF, myofibroblasts, retinal pigment epithelial cells.

Simultaneous Vitreoretinal Surgery and Sclerokeratoplasty for Keratoglobus with Intraocular Hemorrhage and Extensive Corneal Rupture.

We reported a case of simultaneous vitrectomy and sclerokeratoplasty (SKP) performed for keratoglobus with extensive corneal rupture and intraocular hemorrhage caused by trauma. A 73-year-old woman was treated for keratoglobus and glaucoma. She was punched in both eyes, her right eye showed corneal rupture and the left eye showed prolapse of the ocular contents due to eyeball rupture. She immediately underwent corneal sutures in the right eye and resection of the prolapsed ocular contents in the left eye at a nearby ophthalmological clinic. Three days after the injury, the patient was referred to our clinic for vision recovery. The best corrected visual acuity of the right eye was measured by counting fingers. Her right eye presented severe corneal edema with a sutured corneal wound in the upper periphery, which was positive in the Seidel test. B-mode ultrasound revealed choroidal detachment and subchoroidal hemorrhage. Fourteen days after injury, simultaneous corneal suture and posterior sclerotomy were performed in the right eye, but corneal fragility and corneal opacity were prominent, and B-mode examination revealed prolonged vitreous hemorrhage and retinal detachment. Twenty-one days after injury, we performed simultaneous SKP and 25-G pars plana vitrectomy (PPV). In this procedure, we initially performed SKP followed by 25-G PPV without a keratoprosthesis or endoscope. The visibility of the fundus through the corneoscleral graft was good during vitrectomy. Three months after surgery, her corrected visual acuity improved to 10/1,000. Although there was mild corneal stromal edema and khodadoust line, there were no obvious fundus complications. Simultaneous SKP and PPV for keratoglobus with extensive corneal rupture and vitreous diseases may be a good option.

Surgical resection of intraorbital metastasis of a gastrointestinal stromal tumor resistant to chemotherapy.

PURPOSE: We present a case of a gastrointestinal stromal tumor (GIST) metastasis of the rectal primary resisting chemotherapy to the right orbit 15 years after excision of the primary lesion. OBSERVATIONS: A 79-year-old man was diagnosed with rectal GIST at the age of 65 years and underwent rectal amputation. He underwent hepatectomy for GIST liver metastases at the age of 69 years and pericardiectomy for GIST pericardial metastases at 72 years of age. At the age of 79 years, positron emission tomography-computed tomography revealed the possibility of liver metastasis and metastasis to the right orbit of 10 mm in size. Magnetic resonance imaging revealed a well-circumscribed mass of 10 mm × 12 mm in the deep medial rectus muscle of the right orbit, which was referred to our department for ophthalmic examination. The latter revealed only mild abduction disorder in the right eye. Although chemotherapy was initiated, the tumor gradually increased, causing exophthalmos in the right eye, visual field impairment due to optic nerve exclusion, and decreased visual acuity. Due to repeated multiple metastases, the patient underwent right orbital exenteration and free flap reconstruction at the age of 83 years for radical cure. Pathological examination revealed c-Kit positive, CD34 positive, S100 protein minority positive, MIB-1 positive rate of 10% or more, and α-SMA negative, and the diagnosis was intraorbital metastasis of GIST. CONCLUSIONS AND IMPORTANCE: Orbital metastases in GISTs are extremely rare, and there is no established standard treatment. Therefore, a comprehensive decision must be made based on the final treatment goal and the patient's background when selecting treatment.

Intravitreal Tissue Plasminogen Activator Injection for Treatment-Resistant Diabetic Macular Edema of the Vitrectomized Eye.

Diabetic macular edema (DME) is the main cause of visual loss in patients with diabetic retinopathy. DME has been treated using intravitreal anti-vascular endothelial growth factor (VEGF) drugs, steroids, laser photocoagulation, vitreoretinal surgery, and their combinations. These modalities are generally effective in preserving vision, but they sometimes produce only limited responses in patients with persistent or refractory DME. The levels of various inflammatory factors, including cytokines, chemokines, and extracellular matrices, as well as VEGF in the vitreous fluid, are increased in patients with DME. Excessive fibrinogen/fibrin levels in the vitreous fluid or fibrin deposition in the retina also contribute to DME pathogenesis. Tissue plasminogen activator (t-PA) promotes the degradation of fibrinogen or fibrin. Intravitreal t-PA injection is a commonly used treatment for subretinal hemorrhage secondary to age-related macular degeneration. Intravitreal t-PA injections have previously been used to restore vision by inducing posterior vitreous detachment in patients with DME. Herein, we describe the visual outcomes of intravitreal t-PA injection in a 78-year-old woman with treatment-resistant DME in her vitrectomized eye after several previous treatments. Before the injection, her best-corrected visual acuity (BCVA) was 0.7 logMAR and central foveal retinal thickness (CRT) was 735 µm. At 1 month after the injection, her BCVA was 0.8 logMAR and CRT was 558 µm, and 3 months later, her BCVA was 0.8 logMAR and CRT was 207 µm. Her BCVA was sustained, and CRT showed gradual improvements. These findings suggested the effectiveness of intravitreal t-PA injections for DME in the vitrectomized eye.