Ccrk-Mak/Ick signaling is a ciliary transport regulator essential for retinal photoreceptor survival

Chaya T., Maeda Y., Tsutsumi R., et al. Ccrk-Mak/Ick signaling is a ciliary transport regulator essential for retinal photoreceptor survival. Life science alliance 7, (2024); https://doi.org/10.26508/lsa.202402880.Primary cilia are microtubule-based sensory organelles whose dysfunction causes ciliopathies in humans. The formation, function, and maintenance of primary cilia depend crucially on intraflagellar transport (IFT); however, the regulatory mechanisms of IFT at ciliary tips are poorly understood. Here, we identified that the ciliopathy kinase Mak is a ciliary tip-localized IFT regulator that cooperatively acts with the ciliopathy kinase Ick, an IFT regulator. Simultaneous disruption of Mak and Ick resulted in loss of photoreceptor ciliary axonemes and severe retinal degeneration. Gene delivery of Ick and pharmacological inhibition of FGF receptors, Ick negative regulators, ameliorated retinal degeneration in Mak-/- mice. We also identified that Ccrk kinase is an upstream activator of Mak and Ick in retinal photoreceptor cells. Furthermore, the overexpression of Mak, Ick, and Ccrk and pharmacological inhibition of FGF receptors suppressed ciliopathy-related phenotypes caused by cytoplasmic dynein inhibition in cultured cells. Collectively, our results show that the Ccrk-Mak/Ick axis is an IFT regulator essential for retinal photoreceptor maintenance and present activation of Ick as a potential therapeutic approach for retinitis pigmentosa caused by MAK mutations

The Rax homeoprotein in Müller glial cells is required for homeostasis maintenance of the postnatal mouse retina

Müller glial cells, which are the most predominant glial subtype in the retina, play multiple important roles, including the maintenance of structural integrity, homeostasis, and physiological functions of the retina. We have previously found that the Rax homeoprotein is expressed in postnatal and mature Müller glial cells in the mouse retina. However, the function of Rax in postnatal and mature Müller glial cells remains to be elucidated. In the current study, we first investigated Rax function in retinal development using retroviral lineage analysis and found that Rax controls the specification of late-born retinal cell types, including Müller glial cells in the postnatal retina. We next generated Rax tamoxifen–induced conditional KO (Rax iCKO) mice, where Rax can be depleted in mTFP-labeled Müller glial cells upon tamoxifen treatment, by crossing Raxflox/flox mice with Rlbp1-CreERT2 mice, which we have produced. Immunohistochemical analysis showed a characteristic of reactive gliosis and enhanced gliosis of Müller glial cells in Rax iCKO retinas under normal and stress conditions, respectively. We performed RNA-seq analysis on mTFP-positive cells purified from the Rax iCKO retina and found significantly reduced expression of suppressor of cytokine signaling-3 (Socs3). Reporter gene assays showed that Rax directly transactivates the Socs3 promoter. We observed decreased expression of Socs3 in Müller glial cells of Rax iCKO retinas by immunostaining. Taken together, the present results suggest that Rax suppresses inflammation in Müller glial cells by transactivating Socs3. This study sheds light on the transcriptional regulatory mechanisms underlying retinal Müller glial cell homeostasis.Yoshimoto T., Chaya T., Varner L.R., et al. The Rax homeoprotein in Müller glial cells is required for homeostasis maintenance of the postnatal mouse retina. Journal of Biological Chemistry 299, 105461 (2023); https://doi.org/10.1016/j.jbc.2023.105461

The Function of β2-glycoprotein I in Angiogenesis and Its in Vivo Distribution in Tumor Xenografts

Intact β2-glycoprotein I (iβ2GPI) is a glycoprotein that regulates coagulation and fibrinolysis. Nicked β2GPI (nβ2GPI) possesses an angiogenic property at a relatively low concentration, and an antiangiogenic property at a high concentration. Here we investigated the functions of βi 2GPI and nβ2GPI in vascular endothelial growth factor (VEGF)-A-induced endothelial cell proliferation and tube formation. We used noninvasive PET imaging to analyze the in vivo distribution of intravenously injected β2GPI variants in tumor lesions in mice. iβ2GPI was incubated with plasmin to obtain nβ2GPI, and its N-terminal sequence was analyzed. nβ2GPI had at least one other cleavage site upstream of the β2GPIʼs domain V, whereas the former plasmin-cleavage site locates between K317 and T318. Both of intact and nicked β2GPI significantly inhibited the VEGF-A-induced cell proliferation and the tube formation of human umbilical vein endothelial cells (HUVECs). PET imaging visualized considerably distributed intensities of all tested β2GPI variants in tumor lesions of pancreatic tumor cell-xenografts. These results indicate that β2GPI may be physiologically and pathophysiologically important in the regulation of not only coagulation and fibrinolysis, but also angiogenesis

Cerebral air embolism as a complication of peptic ulcer in the gastric tube: case report

<p>Abstract</p> <p>Background</p> <p>The reported incidence of ulcer formation in the gastric tube in esophageal replacement is rare.</p> <p>Case Presentation</p> <p>This is the first report of a case of cerebral air embolism as a result of spontaneous perforation of an ulcer in the constructed gastric tube into the pulmonary vein during post-operative follow-up in a patient with esophageal cancer.</p> <p>Conclusions</p> <p>Cerebral air embolism is a rare complication of penetrating gastric ulcer, but should be considered in patients with a history of esophagectomy with gastric conduit that present with acute neurologic findings.</p

Programmed Chemotherapy for Patients with Metastatic Unresectable Gastric Cancer

BACKGROUND: Recent advances in the treatment of metastatic unresectable gastric cancers (MGC) include the development of new antitumor drugs and new regimens for their use. However, the selection of individually designed regimens by gastric cancer (GC) subtype remains problematic. Here, we investigated the clinical usefulness of programmed chemotherapy. METHODOLOGY/PRINCIPAL FINDINGS: MGC patients were classified into three groups by clinical condition. We implemented a chemotherapy program consisting of S-1 combination regimens. Median survival time (MST) of level 1 patients was 416 days (95% CI: 313-506 days), with an overall response rate of 47%. MSTs of level 2 and 3 patients were 208 (95% CI: 153-287 days) and 95 days (95% CI: 28-136 days), respectively. Grade 3-4 toxicities were neutropenia in 12% and anorexia in 6%. All treatment- related toxicities were resolved, and no treatment-related deaths occurred. CONCLUSIONS/SIGNIFICANCE: This program provided reasonable selection of case-matching regimens and may improve the survival of patients with MGC. Further, it may represent the first clinical tool to provide efficient chemotherapy course selection for MGC. Ongoing analysis of newly developed drugs and regimens will allow the efficacy of this chemotherapy program to be improved

A comprehensive validation of very early rule-out strategies for non-ST-segment elevation myocardial infarction in emergency departments:protocol for a multicentre prospective cohort study

Introduction: Recent advances in troponin sensitivity enabled early and accurate judgement of ruling-out myocardial infarction, especially non-ST elevation myocardial infarction (NSTEMI) in emergency departments (EDs) with development of various prediction-rules and high-sensitive-troponin-based strategies (hs-troponin). Reliance on clinical impression, however, is still common, and it remains unknown which of these strategies is superior. Therefore, our objective in this prospective cohort study is to comprehensively validate the diagnostic accuracy of clinical impression-based strategies, prediction-rules and hs-troponin-based strategies for ruling-out NSTEMIs. Methods and analysis: In total, 1500 consecutive adult patients with symptoms suggestive of acute coronary syndrome will be prospectively recruited from five EDs in two tertiary-level, two secondary-level community hospitals and one university hospital in Japan. The study has begun in July 2018, and recruitment period will be about 1 year. A board-certified emergency physician will complete standardised case report forms, and independently perform a clinical impression-based risk estimation of NSTEMI. Index strategies to be compared will include the clinical impression-based strategy; prediction rules and hs-troponin-based strategies for the following types of troponin (Roche Elecsys hs-troponin T; Abbott ARCHITECT hs-troponin I; Siemens ADVIA Centaur hs-troponin I; Siemens ADVIA Centaur sensitive-troponin I). The reference standard will be the composite of type 1 MI and cardiac death within 30 days after admission to the ED. Outcome measures will be negative predictive value, sensitivity and effectiveness, defined as the proportion of patients categorised as low risk for NSTEMI. We will also evaluate inter-rater reliability of the clinical impression-based risk estimation. Ethics and dissemination: The study is approved by the Ethics Committees of the Kyoto University Graduate School and Faculty of Medicine and of the five hospitals where we will recruit patients. We will disseminate the study results through conference presentations and peer-reviewed journals

Computational study on the roles of amino acid residues in the active site formation mechanism of blue-light photoreceptors

To examine the functional roles of the active site methionine (M-site) and glutamic acid (E-site) residues of blue-light photoreceptors, we performed in silico mutation at the M-site in a systematic manner and focused on the hydrogen bonding between the E-site and the substrate: the cyclobutane–pyrimidine dimer (CPD). Fragment molecular orbital calculations with electron correlations demonstrated that substitution of the M-site methionine with either alanine or glutamine always destabilizes the interaction energy between the E-site and the CPD by more than 12.0 kcal/mol, indicating that the methionine and glutamic acid residues cooperatively facilitate the enzymatic reaction in the active site