STING-mediated disruption of calcium homeostasis chronically activates ER stress and primes T cell death

STING gain-of-function mutations cause lung disease and T cell cytopenia through unknown mechanisms. Here, we found that these mutants induce chronic activation of ER stress and unfolded protein response (UPR), leading to T cell death by apoptosis in th

Downregulation of CD4 is required for maintenance of viral infectivity of HIV-1

AbstractDownregulation of virus receptors on the cell surface is considered to be important in preventing superinfection. HIV-1 encodes multiple gene products, Env, Vpu, and Nef, involved in downregulation of CD4, a major HIV-1 receptor. We found that simultaneous mutations in both vpu and nef severely impaired virus replication. We examined the involvement of CD4 downregulation mediated by Vpu and Nef in the modification of virus infectivity. The mutation in vpu increased CD4 incorporation into virions without affecting the Env content in it, inhibiting the attachment step of virions to the CD4-positive cell surface. Although a single mutation in nef suppresses virus infectivity via a CD4-independent mechanism, it could augment CD4 incorporation in virions in combination with a vpu mutation. These results indicated that CD4 downregulation was necessary for maintenance of Env function in the virion

Transition in eye gaze as a predictor of emergence from general anesthesia in children and adults : a prospective observational study

Background: It is useful to monitor eye movements during general anesthesia, but few studies have examined neurological finding of the eyes during emergence from general anesthesia maintained with short-acting opioids and volatile anesthetics. Methods: Thirty children aged 1–6 years and 30 adults aged 20–79 years were enrolled. Patients received general anesthesia maintained with sevoflurane and remifentanil. The timing of three physical-behavioral responses—eye-gaze transition (the cycle from conjugate to disconjugate and back to conjugate), resumption of somatic movement (limbs or body), and resumption of respiration—were recorded until spontaneous awakening. The primary outcome measure was the timing of the physical-behavioral responses. Secondary outcome measures were the incidence of eye-gaze transition, and the bispectral index, concentration of end-tidal sevoflurane, and heart rate at the timing of eye-gaze transition. Results: Eye-gaze transition was evident in 29 children (96.7%; 95% confidence interval, 82.8–99.9). After the end of surgery, eye-gaze transition was observed significantly earlier than resumption of somatic movement or respiration (472 [standard deviation 219] s, 723 [235] s, and 754 [232] s, respectively; p < 0.001). In adults, 3 cases (10%; 95% CI, 0.2–26.5) showed eye-gaze transition during emergence from anesthesia. The incidence of eye-gaze transition was significantly lower in adults than in children (p < 0.001). Conclusion: In children, eye-gaze transition was observed significantly earlier than other physical-behavioral responses during emergence from general anesthesia and seemed to reflect emergence from anesthesia. In contrast, observation of eye gaze was not a useful indicator of emergence from anesthesia in adults

Axial-Vector Duality as a Mirror Symmetry

We study $N=2$ supersymmetric $SU(2)/U(1)$ and $SL(2,R)/U(1)$ gauged Wess-Zumino-Witten models. It is shown that the vector gauged model is transformed to the axial gauged model by a mirror transformation. Therefore the vector gauged model and the axial gauged model are equivalent as $N=(2,2)$ superconformal field theories. In the $SL(2,R)/U(1)$ model, it is known that axial-vector duality relates a background with a singularity to that without a singularity. Implications of the equivalence of these two models to space-time singularities are discussed.Comment: 12 pages, LaTeX, KUNS 129

Enhanced expression of complement C5a receptor mRNA in human diseased kidney assessed by in situ hybridization

Enhanced expression of complement C5a receptor mRNA in human diseased kidney assessed by in situ hybridization.BackgroundAnaphylatoxin C5a mediates inflammatory responses through interaction with a specific C5a receptor (C5aR), the expression of which is thought to be restricted to peripheral blood leukocytes. Although the presence of C5aR on cultured mesangial cells and tubular epithelial cells has recently been documented, the tissue distribution of C5aR in diseased kidney has not yet been determined.MethodsImmunohistochemistry and nonradioactive in situ hybridization for C5aR were performed in 34 tissue samples of kidneys from patients with various renal diseases, including 4 with minimal change nephrotic syndrome (MCNS), 5 with membranous nephropathy (MN), and 25 with mesangial proliferative glomerulonephritis (mesGN; 15 patients with IgA nephropathy, 5 with non-IgA mesGN, and 5 with lupus nephritis). Normal portions of surgically resected kidney served as the control.ResultsIn normal kidneys, C5aR protein was detected in tubular epithelial cells, while C5aR mRNA was detected in a few glomerular cells, tubular epithelial cells, and vascular endothelial and smooth muscle cells. In MCNS, the distribution of C5aR protein and mRNA was similar to that in normal kidneys. In MN and mesGN, C5aR protein and mRNA were detected in mesangial cells, glomerular epithelial and endothelial cells, Bowman's capsule cells, tubular cells, infiltrating cells, and vascular endothelial and smooth muscle cells. The glomerular expression of C5aR mRNA and protein correlated positively with the degree of mesangial hypercellularity and mesangial matrix expansion in mesGN. In the tubulointerstitium, interstitial expression of C5aR mRNA correlated positively with the degree of tubular atrophy and interstitial broadening in mesGN. Furthermore, the interstitial expression of C5aR mRNA correlated positively with the level of serum creatinine.ConclusionsOur results indicate that renal cells produce C5aR and that activation of C5a/C5aR pathway on renal cells may be involved in tissue injury in mesGN

Cytosolic Nuclease TREX1 Regulates Oligosaccharyltransferase Activity Independent of Nuclease Activity to Suppress Immune Activation

SummaryTREX1 is an endoplasmic reticulum (ER)-associated negative regulator of innate immunity. TREX1 mutations are associated with autoimmune and autoinflammatory diseases. Biallelic mutations abrogating DNase activity cause autoimmunity by allowing immunogenic self-DNA to accumulate, but it is unknown how dominant frameshift (fs) mutations that encode DNase-active but mislocalized proteins cause disease. We found that the TREX1 C terminus suppressed immune activation by interacting with the ER oligosaccharyltransferase (OST) complex and stabilizing its catalytic integrity. C-terminal truncation of TREX1 by fs mutations dysregulated the OST complex, leading to free glycan release from dolichol carriers, as well as immune activation and autoantibody production. A connection between OST dysregulation and immune disorders was demonstrated in Trex1−/− mice, TREX1-V235fs patient lymphoblasts, and TREX1-V235fs knock-in mice. Inhibiting OST with aclacinomycin corrects the glycan and immune defects associated with Trex1 deficiency or fs mutation. This function of the TREX1 C terminus suggests a potential therapeutic option for TREX1-fs mutant-associated diseases

Lipocalin function of E.coli zinT (yodA) protein.

重金属やアミトロール(AT)で発現誘導され、大腸菌ストレス応答タンパク質の一種であるzinT (yodA)は、一次構造比較やX線結晶構造解析による三次元立体構造などから、C末端領域に金属結合部位を持つこと、ABC transporter やlipocalinファミリーと一部相同なアミノ酸配列を持つことが明らかとなっているが、zinTの金属以外の低分子結合能については報告がない。そこで本研究では、大腸菌zinTタンパク質の種々の物質との結合能を、野生型zinTおよびN末端22残基欠損体(ΔN22)を用いて検討した。 まず、zinTの分子内TyrまたはTrp蛍光を指標として、種々の物質を添加に伴う蛍光強度の減少を測定した。低分子化合物としては、(1)ATおよびdNTP(2) 脂肪酸および脂質5種、(3) 複素式化合物3種、(4)芳香族化合物3種を検討し、zinTに対しそれぞれ添加し、30℃、10分間保温後、蛍光スペクトルを測定した。その結果、化合物添加によりzinTの最大蛍光強度は濃度依存的に減少し、特にdNTP, Qurcetinおよび8-ANSで顕著に見られた。また、野生型とΔN22において、蛍光減少の濃度依存性に顕著な差異は見られなかった。以上より、zinTは疎水性低分子化合物結合能(lipocalin活性)を有し、N末端領域のlipocalin活性に対する寄与は少ないことが明らかとなった

HER2 G776S mutation promotes oncogenic potential in colorectal cancer cells when accompanied by loss of APC function

Clinical cancer genome sequencing detects oncogenic variants that are potential targets for cancer treatment, but it also detects variants of unknown significance. These variants may interact with each other to influence tumor pathophysiology, however, such interactions have not been fully elucidated. Additionally, the effect of target therapy for those variants also unclarified. In this study, we investigated the biological functions of a HER2 mutation (G776S mutation) of unknown pathological significance, which was detected together with APC mutation by cancer genome sequencing of samples from a colorectal cancer (CRC) patient. Transfection of the HER2 G776S mutation alone slightly increased the kinase activity and phosphorylation of HER2 protein, but did not activate HER2 downstream signaling or alter the cell phenotype. On the other hand, the HER2 G776S mutation was shown to have strong oncogenic potential when loss of APC function was accompanied. We revealed that loss of APC function increased Wnt pathway activity but also increased RAS-GTP, which increased ERK phosphorylation triggered by HER2 G776S transfection. In addition, afatinib, a pan-HER tyrosine kinase inhibitor, suppressed tumor growth in xenografts derived from HER2 G776S-transfected CRC cells. These findings suggest that this HER2 mutation in CRC may be a potential therapeutic target