Cr(VI) exposure could produce kinds of intermediates and reactive oxygen species, both of which were related to DNA damage. Hyaluronan (HA) has impressive biological functions and was reported to protect corneal epithelial cells against oxidative damage induced by ultraviolet B, benzalkonium chloride, and sodium lauryl sulfate. So the aim of our study was to investigate HA protection on human corneal epithelial (HCE) cells against Cr(VI)-induced toxic effects. The HCE cell lines were exposed to different concentrations of K2Cr2O7(1.875, 3.75, 7.5, 15.0, and 30 μM) or a combination of K2Cr2O7and 0.2% HA and incubated with different times (15 min, 30 min, and 60 min). Our data showed that Cr(VI) exposure could cause decreased cell viability, increased DNA damage, and ROS generation to the HCE cell lines. But incubation of HA increased HCE cell survival rates and decreased DNA damage and ROS generation induced by Cr(VI) in a dose- and time-dependent manner. We report for the first time that HA can protect HCE cells against the toxicity of Cr(VI), indicating that it will be a promising therapeutic agent to corneal injuries caused by Cr(VI).
The clustered regularly interspaced short palindromic repeat (CRISPR)-associated endonuclease Cas13a can specifically bind and cleave RNA. After nucleic acid pre-amplification, bacterial Cas13a has been used to detect genetic mutations. In our study, using a transcription-mediated amplification together with Cas13a, we can isothermally amplify and detect mitochondrial point mutations under non-denaturing conditions from human genomic DNA. Unlike previous reports, we prepared CRISPR DNA with T7 promoter sequences and generated CRISPR RNA via transcription-mediated amplification instead of synthesizing and adding CRISPR RNA in a separate step. As a proof-of-concept, we showed that both m.1494C > T and m.1555A > G mutations were detected within 90 min. In addition, we explored various designs of CRISPR DNA to improve assay specificity, including the location and number of nucleotide mismatches, length of protospacer sequence, and different buffering conditions. We also confirmed the possibility of a “one-step single-tube” reaction for mutation detection. This assay can robustly distinguish circular DNA templates that differ by a single nucleotide. It has the potential to be adapted for automated applications, such as the screening of mitochondrial diseases.
Peripheral arterial disease (PAD) is a common complication associated with diabetes, which can lead to foot ischemia. The condition is often accompanied by infection and necrosis, ultimately leading to diabetic foot ulcers and the risk of amputation. Brown adipose tissue (BAT) and its secreted cytokines play an essential role in the regulation of glucose homeostasis, the modulation of inflammatory responses, and vascular endothelial cell proliferation. The transplantation of BAT into ischemic regions may offer therapeutic benefits in alleviating the symptoms associated with PAD. A diabetic mouse model was established via intraperitoneal administration of streptozocin. Subsequently, a diabetic lower limb ulcer model was constructed by transection of the femoral artery and ligation of the femoral vein. BAT harvested from the subscapular region of the mouse was employed as an adipose graft. The research utilized Laser Doppler monitoring, Western blot analysis, hematoxylin-eosin (HE) staining, immunofluorescence staining, and enzyme-linked immunosorbent assay (ELISA) to evaluate blood flow recovery in ischemic regions, histopathological changes, angiogenesis and tissue remodeling, inflammatory responses, and M1/M2 macrophage polarization. BAT transplantation significantly enhanced blood flow recovery in ischemic regions of diabetic lower limb ulcer mice while concurrently reducing necrotic tissue. Pathological analyses demonstrate that BAT transplantation mitigates ischemic tissue damage, stimulates angiogenesis, and supports tissue remodeling. Furthermore, the Western blotting, immunofluorescence, and ELISA results revealed that BAT transplantation significantly reduces inflammatory levels in ischemic tissues, increases the expression of angiogenic factors, and promotes the polarization of macrophages from the M1 to the M2 phenotype. The research has demonstrated that BAT transplantation can mitigate ischemic injury in diabetic lower limb ulcer mice, attenuate inflammatory responses, and facilitate the restoration of blood flow. These effects may be linked to alterations in macrophage polarization.
20 November 2023 in Frontiers in Cellular and Infection Microbiology
Background: Most of malignant external otitis (MEO) cases reported in the literature are attributed to Pseudomonas aeruginosa. Fungal infections in MEO are also likely but extremely rare. And conventional microbiology tests is difficult to diagnose.Case description: Two patients were diagnosed with Fungal malignant external otitis (FMEO) due to Aspergillus by metagenomic Next-Generation Sequencing (mNGS) and recovered after comprehensive treatment including operation and voriconazole. The antifungal treatment was delayed due to repeated cultures of secretions being negative and pathological examination showed granulation tissue proliferation with extensive neutrophil infiltration.Conclusion: mNGS might be helpful for patients suspected with FMEO, especially when conventional microbiology tests were negative.
29 August 2024 in Advances in Ophthalmology Practice and Research
Retinitis pigmentosa (RP) is a genetically and clinically heterogeneous group of hereditary degenerative disorders affecting approximately one in every 4000 people worldwide. Abnormalities in the retina's photoreceptors can cause night blindness or even complete vision loss. Retinitis Pigmentosa 1 (RP1), also known as the oxygen-regulated protein-1, is a microtubule-associated protein (MAP) that organizes the outer segment of the photoreceptor. Besides, mutations in the RP1 gene are associated with dominant or recessive form of RP. This study aims to identify the potential pathogenic genes in Chinese RP patients and to elucidate the association relationship between the mutant gene and the phenotypes. Multiple ophthalmic examinations, whole-exome sequencing, sanger sequencing, and in silico analysis were performed to evaluate the clinical features and pathogenic genes in a five-generation Chinese family diagnosed with RP. Our findings revealed a novel truncating mutation c.2015_2018del p. (Lys672Argfs∗9) in RP1 that may result in the translation of a protein with deleterious effects on photoreceptors. Therefore, resulting in autosomal dominant retinitis pigmentosa (ADRP). This study broaden the range of genetic mutations associated with RP1 in ADRP and make a valuable contribution to the ongoing endeavors aimed at characterizing the molecular aspects of Chinese ADRP. Future studies would pay more attention in determining the characterization of the mutantations in RP1 gene and the relationship between genotype and phenotype in RP patients.