Kidney fibrosis is generally confirmed to have a significant role in chronic kidney disease, resulting in end-stage kidney failure. Epithelial–mesenchymal transition (EMT) is an important molecular mechanism contributing to fibrosis. Tubular epithelial cells (TEC), the major component of kidney parenchyma, are vulnerable to different types of injuries and are a significant source of myofibroblast by EMT. Furthermore, TRPC6 knockout plays an anti-fibrotic role in ameliorating kidney damage. However, the relationship between TRPC6 and EMT is unknown. In this study, TRPC6^−/−and wild-type (WT) mice were subjected to a unilateral ureteric obstruction (UUO) operation. Primary TEC were treated with TGF-β1. Western blot and immunofluorescence data showed that fibrotic injuries alleviated with the inhibition of EMT in TRPC6^−/−mice compared to WT mice. The activation of AKT-mTOR and ERK1/2 pathways was down-regulated in the TRPC6^−/−mice, while the loss of Na⁺/K⁺-ATPase and APQ1 was partially recovered. We conclude that TRPC6 knockout may ameliorate kidney fibrosis by inhibition of EMT through down-regulating the AKT-mTOR and ERK1/2 pathways. This could contribute to the development of effective therapeutic strategies on chronic kidney diseases.

Polypoidal choroidal vasculopathy (PCV) is the predominant subtype of exudative age-related macular degeneration in Asians. Although photodynamic therapy (PDT) is widely used for PCV treatment, its long-term beneficial effects are unsatisfactory. Accumulating clinical investigations suggest that combined therapy with anti-vascular endothelial growth factor (anti-VEGF) and PDT is superior to PDT monotherapy. However, the optimal time of anti-VEGF before or after PDT remains controversial, hence it needs to further explore the mechanism underlying combined therapy. PDT causes selective damage to endothelial cells, which determines its angio-occlusive efficiency, yet the impact of anti-VEGF on PDT-induced endothelial injury is unclear. Here, we found that pre-compared to post-treatment with anti-VEGF ranibizumab (rani) significantly aggravates PDT injury in the rhesus macaque choroid-retinal endothelial (RF/6A) cell line. PDT activates apoptosis, necroptosis and NLRP3 inflammasome in RF/6A cells. Pre-treatment with rani promotes PDT-caused apoptosis via triggering caspase 8-mediated extrinsic apoptosis, and caspase 8 might also play a pivotal role in the rani’s function of suppressing PDT-induced necroptosis and NLRP3 inflammasome activation. Our results implicate that pre-treatment with rani may enhance the angio-occlusive efficiency of PDT and alleviate endothelial inflammatory response, which gives it a great advantage over post-treatment.

Purpose: Retinitis pigmentosa (RP) is a heterogeneous group of inherited disorders characterized by photoreceptor degeneration. The rhodopsin gene (RHO) is the most frequent cause of autosomal dominant RP (ADRP), yet it remains unclear how RHO mutations cause heterogeneous phenotypes. Energy failure is a main cause of the secondary cone death during RP progression; however, its role in primary rod death induced by ADRP RHO mutants is unknown. Methods: Three RHO missense mutations were chosen from different clinical classes. Wild-type (WT) RHO and its mutants, P23H (class B1), R135L (class A), and G188R (class B2), were overexpressed in 661w cells, a mouse photoreceptor cell line, and their effects on oxidative phosphorylation (OXPHOS) and aerobic glycolysis were compared separately. Results: Here, we report that energy failure is an early event in the cell death caused by overexpression of WT RHO and its mutants. RHO overexpression leads to OXPHOS deficiency, which might be a result of mitochondrial loss. Nonetheless, only in WT RHO and P23H groups, energy stress triggers AMP-activated protein kinase activation and metabolic reprogramming to increase glycolysis. Metabolic reprogramming impairment in R135L and G188R groups might be the reason why energy failure and cell injury are much more severe in those groups. Conclusions: Our results imply that overexpression of RHO missense mutants have distinct impacts on the two energy metabolic pathways, which might be related to their heterogeneous phenotypes.

Focal choroidal excavation (FCE) is a common concurrent disease with central serous chorioretinopathy (CSC) and choroidal neovascularization (CNV). Photodynamic therapy (PDT) was able to cease the course of CSC with efficacy and safety. To retrospectively observed and followed up a special course in eyes with CSC and concurrent FCE treated by a half-dose of PDT. In this case report analysis, two eyes with CSC and concurrent FCE treated with half-dose PDT, were followed up with monthly retinal fundus examinations. Best corrected visual acuity (BCVA) and ophthalmic fundus examination were examined, including fundus photos, optical coherence tomography (OCT) and angiography. In Case 1, a 46-year-old female has been diagnosed as CSC and concurrent FCE. The baseline BCVA was 10/20. After a half-dose of PDT, complete resolution of SRF was achieved at one-month with stable BCVA. At 3 months, the patient complained of obvious metamorphosis. Multimodal images confirmed the existence of CNV, derived from the FCE, inside the zone of PDT irradiation. The development of CNV stopped promptly 1 month post the injection of ranibizumab. In Case 2, a 39 year-old male was diagnosed as bilateral CSC. The BCVA was 8/20 (od), and 16/20 (os). The multimodal images showed classic CSC manifestation in left eye, but atypical manifestation in right eye with subtle SRF and FCE. Post half-dose treatment, the SRF in left eye completely resolved at three-months, and the BCVA improved to 24/20. However, a lesion of CNV grew in the FCE after 1 month in right eye, with decreased BCVA, 4/20. One month post-injection of ranibizumab, obvious regression was witnessed, with improved BCVA, 6/20. The CNV proceeded to be a scar 2 months after injection. The BCVA maintained at 8/20. In this study, type II CNV was induced in two cases of CSC concurrent with FCE in 3 months post half-dose PDT. The CNV grew right from the FCE, inside the zone of PDT irradiation.