Nutrigenetic reprogramming of oxidative stress

Retinal disorders such as retinitis pigmentosa, age-related retinal degeneration, oxygen-induced retinopathy, and ischemia-reperfusion injury cause debilitating and irreversible vision loss. While the exact mechanisms underlying these conditions remain unclear, there has been a growing body of evidence demonstrating the pathological contributions of oxidative stress across different cell types within the eye. Nuclear factor erythroid-2-related factor (Nrf2), a transcriptional activator of antioxidative genes, and its regulator Kelch-like ECH-associated protein 1 (Keap1) have emerged as promising therapeutic targets. The purpose of this review is to understand the protective role of the Nrf2-Keap1 pathway in different retinal tissues and shed light on the complex mechanisms underlying these processes. In the photoreceptors, we highlight that Nrf2 preserves their survival and function by maintaining oxidation homeostasis. In the retinal pigment epithelium, Nrf2 similarly plays a critical role in oxidative stabilization but also maintains mitochondrial motility and autophagy-related lipid metabolic processes. In endothelial cells, Nrf2 seems to promote proper vascularization and revascularization through concurrent activation of antioxidative and angiogenic factors as well as inhibition of inflammatory cytokines. Finally, Nrf2 protects retinal ganglion cells against apoptotic cell death. Importantly, we show that Nrf2-mediated protection of the various retinal tissues corresponds to a preservation of functional vision. Altogether, this review underscores the potential of the Nrf2-Keap1 pathway as a powerful tool against retinal degeneration. Key insights into this elegant oxidative defense mechanism may ultimately pave the path toward a universal therapy for various inherited and environmental retinal disorders

Development of selective blockers for Ca2+-activated Cl- channel using Xenopus laevis oocytes with an improved drug screening strategy

<p>Abstract</p> <p>Background</p> <p>Ca²⁺-activated Cl^-channels (CaCCs) participate in many important physiological processes. However, the lack of effective and selective blockers has hindered the study of these channels, mostly due to the lack of good assay system. Here, we have developed a reliable drug screening method for better blockers of CaCCs, using the endogeneous CaCCs in <it>Xenopus laevis </it>oocytes and two-electrode voltage-clamp (TEVC) technique.</p> <p>Results</p> <p>Oocytes were prepared with a treatment of Ca²⁺ionophore, which was followed by a treatment of thapsigargin which depletes Ca²⁺stores to eliminate any contribution of Ca²⁺release. TEVC was performed with micropipette containing chelerythrine to prevent PKC dependent run-up or run-down. Under these conditions, Ca²⁺-activated Cl^-currents induced by bath application of Ca²⁺to oocytes showed stable peak amplitude when repetitively activated, allowing us to test several concentrations of a test compound from one oocyte. Inhibitory activities of commercially available blockers and synthesized anthranilic acid derivatives were tested using this method. As a result, newly synthesized <it>N</it>-(4-trifluoromethylphenyl)anthranilic acid with trifluoromethyl group (-CF₃) at <it>para </it>position on the benzene ring showed the lowest IC₅₀.</p> <p>Conclusion</p> <p>Our results provide an optimal drug screening strategy suitable for high throughput screening, and propose <it>N</it>-(4-trifluoromethylphenyl)anthranilic acid as an improved CaCC blocker.</p

C-terminally mutated tubby protein accumulates in aggresomes

The tubby protein (Tub), a putative transcription factor, plays important roles in the maintenance and function of neuronal cells. A splicing defect-causing mutation in the 3&apos;-end of the tubby gene, which is predicted to disrupt the carboxy-terminal region of the Tub protein, causes maturity-onset obesity, blindness, and deafness in mice. Although this pathological Tub mutation leads to a loss of function, the precise mechanism has not yet been investigated. Here, we found that the mutant Tub proteins were mostly localized to puncta found in the perinuclear region and that the C-terminus was important for its solubility. Immunocytochemical analysis revealed that puncta of mutant Tub co-localized with the aggresome. Moreover, whereas wild-type Tub was translocated to the nucleus by extracellular signaling, the mutant forms failed to undergo such translocation. Taken together, our results suggest that the malfunctions of the Tub mutant are caused by its misfolding and subsequent localization to aggresomes.ope

Application of CRISPR-Based C-to-G Base editing in rice protoplasts

Recently, new types of base editors, C-to-G base editors (CGBEs), that enable cytosine transversions that are unachievable with cytosine base editors (CBEs) and adenosine base editors (ABEs), have been developed in human cells. However, despite their importance in crop genome editing, the efficacy of CGBEs has not yet been extensively evaluated. In our study, based on the previously reported plant-compatible CBE and human CGBE, we demonstrated that our monocot plant-compatible CGBEs (PcCGBEs) enable cytosine transversions (C-to-G) in rice protoplasts. For all targets tested, PcCGBEs (monocot plant-compatible CGBEs) appeared to have substantial levels of C-to-G editing activity. PcCGBE showed a much higher C-to-G base editing activity and C-to-G specificity among C-to-D conversions than the mini-version of PcCGBE. Our demonstration of PcCGBE could provide a platform for the further development of enhanced CGBEs for reliable application as a new crop breeding technology.This work was supported by the Creative-Pioneering Researchers Program of Seoul National University, National Research Foundation of Korea (NRF) Grant (2019R1F1A1046305), and New Breeding Technologies Development Program (PJ016542) through the Rural Development Administration (RDA), Republic of Korea

Computed tomography–assessed presarcopenia and clinical outcomes after laparoscopic surgery for rectal cancer

Purpose Previous studies have reported that presarcopenia negatively affects rectal cancer treatment. However, most studies have analyzed patients including majority of open surgery, and the association between presarcopenia and clinical outcomes after laparoscopic rectal cancer surgery remains unclear. This study aimed to evaluate the impact of presarcopenia on the clinical and oncological outcomes after laparoscopic rectal cancer surgery. Methods Three hundred and one patients undergoing laparoscopic rectal cancer surgery between December 2009 and May 2016 were enrolled. Body composition was assessed using computed tomography by measuring the muscle and fat areas at the third lumbar (L3) vertebra. The L3 skeletal muscle area was used to calculate the skeletal muscle index and evaluate presarcopenia. Results Presarcopenia was more common in older (≥70 years, P=0.008) or female patients (P=0.045). Patients with presarcopenia had decreased skeletal muscle area (P<0.001), lower hemoglobin level (P=0.034), longer time to first flatus (P<0.001), and more frequent surgical site infection (P=0.001). However, survival rates were not significantly different between those with and without presarcopenia. Conclusion Computed tomography-assessed presarcopenia was associated with delayed functional recovery and increased surgical site infection, although it was not revealed as a prognostic factor for oncological outcomes

Late Simultaneous Presentation of Left Ventricular Pseudoaneurysm and Tricuspid Regurgitation after Blunt Chest Trauma

A 32-yr-old man developed progressive exertional dyspnea 4 yr after blunt chest trauma due to an automobile accident. Two-dimensional echocardiography and computed-tomographic coronary angiography demonstrated a large pseudoaneurysm of the left ventricle and severe tricuspid regurgitation. The patient underwent successful surgical exclusion of the pseudoaneurysm by endoaneurysmal patch closure and repair of the tricuspid valve regurgitation. To the best of our knowledge, this is the first case of these 2 different pathologies presenting late simultaneously after blunt chest trauma and successful surgical repairs in the published literature

Antiviral activity of furanocoumarins isolated from Angelica dahurica against influenza a viruses H1N1 and H9N2

Ethnopharmacological relevance: Angelica dahurica (Hoffm.) Benth. &amp; Hook.f. ex Franch. &amp; Say. (Umbelliferae family) is an herbaceous, perennial plant native to northern and eastern Asia. The root of A. dahurica has traditionally been used under the name &quot;Bai Zhi&quot; as a medicinal plant for colds, dizziness, ulcers, and rheumatism. Moreover, it is also an important ingredient of various prescriptions, such as Gumiganghwal-Tang, for the common cold and influenza. Aim of the study: Even though various biological activities of the root of A. dahurica have been reported along with its chemical components, the detailed mechanism of how it exerts anti-influenza activity at the compound level has not been studied. Therefore, we investigated the anti-influenza properties of furanocoumarins purified by bioactivity-guided isolation. Materials and methods: Bioactivity-guided isolation from a 70% EtOH extract of the root of A. dahurica was performed to produce four active furanocoumarins. The inhibition of cytopathic effects (CPEs) was evaluated to ascertain the antiviral activity of these compounds against influenza A (H1N1 and H9N2) viruses. The most potent compound was subjected to detailed mechanistic studies such as the inhibition of viral protein synthesis, CPE inhibition in different phases of the viral replication cycle, neuraminidase (NA) inhibition, antiapoptotic activity using flow cytometry, and immunofluorescence. Results: The bioactivity-guided isolation produced four active furanocoumarins, isoimperatorin (1), oxypeucedanin (2), oxypeucedanin hydrate (3) and imperatorin (4) from the n-BuOH fraction. Among them, compound 2 (followed by compounds 1, 4 and 3) showed a significant CPE inhibition effect, which was stronger than that of the positive control ribavirin, against both H1N1 and H9N2 with an EC50 (mu M) of 5.98 +/- 0.71 and 4.52 +/- 0.39, respectively. Compound 2 inhibited the synthesis of NA and nucleoprotein (NP) in a dose-dependent manner. In the time course assays, the cytopathic effects of influenza A-infected MDCK cells were reduced by 80-90% when treated with compound 2 for 1 and 2 h after infection and declined drastically 3 h after infection. The level of viral NA and NP production was markedly reduced to less than 20% for both proteins in compound 2 (20 mu M)-treated cells compared to untreated cells at 2 h after infection. In the molecular docking analysis, compound 2 showed a stronger binding affinity for the C-terminus of polymerase acidic protein (PAC; - 36.28 kcal/mol) than the other two polymerase subunits. Compound 2 also exerted an antiapoptotic effect on virus infected cells and significantly inhibited the mRNA expression of caspase-3 and Bax. Conclusion: Our results suggest that compound 2 might exert anti-influenza A activity via the inhibition of the early phase of the viral replication cycle, not direct neutralization of surface proteins, such as hemagglutinin and NA, and abnormal apoptosis induced by virus infection. Taken together, these findings suggest that furanocoumarins predominant in A. dahurica play a pivotal role in its antiviral activity. These findings can also explain the reasons for the ethnopharmacological uses of this plant as an important ingredient in many antiviral prescriptions in traditional Chinese medicine (TCM).N