Helicobacter pylori infection is a major etiological factor in gastric diseases. However, clinical antibiotic therapy for H. pylori is limited by continuously decreased therapeutic efficacy and side effects to symbiotic bacteria. Herein, we develop an in vivo activatable pH-responsive graphitic nanozyme, PtCo@Graphene (PtCo@G), for selective treatment of H. pylori. Such nanozymes can resist gastric acid corrosion, exhibit oxidase-like activity to stably generate reactive oxygen species only in acidic gastric milieu and demonstrate superior selective bactericidal property. C18-PEGn-Benzeneboronic acid molecules are modified on PtCo@G, improving its targeting capability. Under acidic gastric pH, graphitic nanozymes show notable bactericidal activity toward H. pylori, while no bacterial killing is observed under intestinal conditions. In mouse model, high antibacterial capability toward H. pylori and negligible side effects toward normal tissues and symbiotic bacteria are achieved. Graphitic nanozyme displays the desired enzyme-like activities at corresponding physiological sites and may address critical issues in clinical treatment of H. pylori infections.
BackgroundGlaucoma is a major blinding disease characterized by progressive loss of retinal ganglion cells (RGCs) and axons. Optineurin is one of the candidate genes identified so far. A mutation of Glu50 to Lys (E50K) has been reported to be associated with a more progressive and severe disease. Optineurin, known to interact with Rab8, myosin VI and transferrin receptor (TfR), was speculated to have a role in protein trafficking. Here we determined whether, and how optineurin overexpression and E50K mutation affect the internalization of transferrin (Tf), widely used as a marker for receptor-mediated endocytosis.Methodology/Principal FindingsHuman retinal pigment epithelial (RPE) and rat RGC5 cells transfected to overexpress wild type optineurin were incubated with Texas Red-Tf to evaluate Tf uptake. Granular structures or dots referred to as foci formed in perinuclear regions after transfection. An impairment of the Tf uptake was in addition observed in transfected cells. Compared to overexpression of the wild type, E50K mutation yielded an increased foci formation and a more pronounced defect in Tf uptake. Co-transfection with TfR, but not Rab8 or myosin VI, construct rescued the optineurin inhibitory effect, suggesting that TfR was the factor involved in the trafficking phenotype. Forced expression of both wild type and E50K optineurin rendered TfR to colocalize with the foci. Surface biotinylation experiments showed that the surface level of TfR was also reduced, leading presumably to an impeded Tf uptake. A non-consequential Leu157 to Ala (L157A) mutation that displayed much reduced foci formation and TfR binding had normal TfR distribution, normal surface TfR level and normal Tf internalization.Conclusions/SignificanceThe present study demonstrates that overexpression of wild type optineurin results in impairment of the Tf uptake in RPE and RGC5 cells. The phenotype is related to the optineurin interaction with TfR. Our results further indicate that E50K induces more dramatic effects than the wild type optineurin, and is thus a gain-of-function mutation. The defective protein trafficking may be one of the underlying bases why glaucoma pathology develops in patients with E50K mutation.
Optineurin is a gene linked to amyotrophic lateral sclerosis, Paget disease of bone, and glaucoma, a major blinding disease. Mutations such as E50K were identified in glaucoma patients. We investigated herein the involvement of ubiquitin-proteasome pathway (UPP) and autophagy, two major routes for protein clearance, in processing of optineurin in a retinal ganglion cell model line RGC5 and neuronal PC12 cells. It was found that the endogenous optineurin level in neuronal cells was increased by treatment of proteasomal inhibitor but not by autophagic and lysosomal inhibitors. Multiple bands immunoreactive to anti-ubiquitin were seen in the optineurin pulldown, indicating that optineurin was ubiquitinated. In cells overexpressing wild type and E50K optineurin, the level of the proteasome regulatory 5 subunit (PSMB5, indicative of proteasome activity) was reduced, whereas that for autophagy marker microtubule-associated protein 1 light chain 3 was enhanced compared with controls. Autophagosome formation was detected by electron microscopy. The foci formed after optineurin transfection were increased upon treatment of an autophagic inhibitor but were decreased by treatment of an inducer, rapamycin. Moreover, the level of optineurin-triggered apoptosis was reduced by rapamycin. This study thus provides compelling evidence that in a normal homeostatic situation, the turnover of endogenous optineurin involves mainly UPP. When optineurin is up-regulated or mutated, the UPP function is compromised, and autophagy comes into play. A decreased PSMB5 level and an induced autophagy were also demonstrated in vivo in retinal ganglion cells of E50K transgenic mice, validating and making relevant the in vitro findings.
BackgroundThe incidence of Penicillium marneffei infection has recently increased. This fungus can cause fatal systemic mycosis in both immunocompetent and immunocompromised patients without HIV infection.MethodsWe retrospectively analysed Penicilliosis patients between January 1, 2003 and August 1, 2014 at the First Affiliated Hospital of Guangxi Medical University. HIV-negative patients with Penicilliosis were divided into two groups: patients with underlying disease (Group D) and patients without underlying disease (Group ND). HIV-positive patients were excluded. The relationships between overall survival and the study variables were assessed using univariate and multivariate analyses.ResultsDuring 11 years, Penicillium marneffei infection was diagnosed in 109 patients. Sixty-six (60.55 %) patients were HIV-positive and excluded from these cases. Forty-three patients were HIV-negative were enrolled. Among these patients, 18 (41.86 %) patients were in Group D, and 25 (58.14 %) were in Group ND. The most common underlying disease was diabetes. There were no statistically significant differences between the two groups in clinical characteristics, except for immune state and prognosis. Group ND had higher lymphocyte cell counts, CD4 cell counts, and CD4 T-cell percentages than Group D (P < 0.05). Patients in Group D had higher recurrence and mortality rates than Group ND (P < 0.05). In the univariate analysis, only underlying disease, CD4 cell percentage, and T lymphocyte cell percentage were significantly associated with overall survival.ConclusionsPenicillium marneffei can infect HIV-negative patients and can cause fatal systemic mycosis. There were no clear differences in clinical manifestations among HIV-negative patients with and without underlying disease. However, Penicillium marneffei in HIV-negative patients in with underlying diseases may cause immune function decline and a deficiency in T-cell-mediated immunity. Underlying disease, CD4 cell percentage, and T lymphocyte cell percentage may be potential risk factors affecting prognosis. Timely, effective, and longer courses of antifungal treatments are important in improving prognoses.
Myocilin and optineurin are two genes linked to glaucoma , a major blinding disease characterized by progressive loss of retinal ganglion cells (RGCs) and their axons. To investigate the effects of force-expressed wild-type and mutant myocilin and optineurin on neurite outgrowth in neuronal cells , we transiently transfected cells with pEGFP-N1 (mock control) as well as myocilin and optineurin plasmids including pMYOC WT -EGFP, pMYOC P370L -EGFP, pMYOC 1-367 -EGFP, pOPTN WT -EGFP , and pOPTN E50K -EGFP. PC12 cells transfected with pEGFP-N1 produced , as anticipated, long and extensive neuritis on nerve growth factor induction. The neurite length in those cells transfected with myocilin constructs was shortened and the number of neurites was also reduced. A similar inhibitory effect on neurite outgrowth was also elicited by myocilin transfection in RGC5 cells. In contrast , neither transfection of the optineurin constructs pOPTN WT -EGFP and pOPTN E50K -EGFP nor the myocilin and optineurin small-interfering RNA treatments induced significant alterations in neurite outgrowth. Transfection with the wild-type optineurin construct , but not with that of the wild-type myocilin, increased the apoptotic activity in cells. These results demonstrated that the two glaucoma genes , myocilin and optineurin, exhibited differential effects on neurite outgrowth. They may contribute to the development of neurodegenerative glaucoma via distinct mechanisms.
Background Few reports of Talaromyces marneffei (TM) or cryptococcosis infections among HIV-negative patients with high-titeranti–IFN-γautoantibodies (nAIGAs) have been published. We investigated the clinical manifestations of patients with nAIGAs and TM infections. Methods HIV-negative adults (≥18 years) were enrolled if they haddisseminated TM infection (group 1; further divided into nAIGAs positive [group 1P] and negative [group 1N]); cryptococcosis(pulmonary cryptococcosis and/or cryptococcosis of the brain)(group 2); pulmonary tuberculosis (group 3); and healthy controls (group 4) with nAIGAs detected. Complete histories, physical examinations, and routine clinical laboratory tests were obtained at baseline. Results Overall, 88 participants were in the four groups (20,13,23, and 32 in groups 1 to 4, respectively). Significant differences occurred between groups with higher nAIGAs titers (P < 0.001), and higher total white-cell and absolute neutrophil counts (P < 0.001) in group1. Lungs (90.0%), lymph nodes (60.0%), skin (55.0%), and bones (50.0%) were most common sites of involvement. Significant differences in total white-cell and absolute neutrophil counts occurred between groups IP and 1N.Patients with recurrent TM infections, particularly group 1P, had higher initial nAIGA titer. Conclusions Patients with persistent infection who died tended to have positive initial nAIGA titer. It suggests that nAIGAs may play a critical role in the pathogenesis of TM infections, and may be associated with more severe, refractory infection.
BackgroundPenicillium marneffei disseminates hematogenously and can infect most organs, though infection leading to osteolysis is extremely rare. We describe the clinical and laboratory features, management, and outcomes of patients with penicilliosis marneffei (PSM) with osteolytic lesions.MethodsThis retrospective study was conducted between January 1, 2003 and May 1, 2014 at the First Affiliated Hospital of Guangxi Medical University. Patients who presented with culture and/or histopathologic proof of disseminated PSM within osteolytic lesions were included.ResultsP. marneffei infection was diagnosed in 100 patients (65 HIV-infected and 35 HIV-negative). Fourteen patients, all HIV-negative, (14/35, 40%) had osteolytic lesions. The most common comorbidity was diabetes mellitus, though previous glucocorticoid therapy, β-thalassemia, breast cancer, and Langerhans cell histiocytosis also occurred. Five patients had no comorbidity. Fever, malaise, ostealgia, weight loss, and anemia were the most common symptoms, followed by cutaneous lesions, lymphadenopathy, hepatosplenomegaly, cough, sputum, and stethalgia. Ostealgia, joint pain, and joint disorders were also recorded. White blood cell and neutrophil counts were increased (mean 22.3 ± 7.4 × 109 cells/L; mean 18.84 ± 4.5 × 109 cells/L, respectively). The most common sites were the vertebrae, skull and femur, ribs and ilium, though the clavicle, scapula, humerus, and tibia were also involved. Radiography and computed tomography (CT) showed multiple radiolucencies with moth-eaten bone destruction, periosteal proliferation, bone fracture, and surrounding soft-tissue swelling. Emission CT showed significantly increased uptake in many skeletal regions. Positron emission tomography/CT showed generalized lymphadenopathy, bone metabolic activity, and bone destruction. The 18 F-FDG standard uptake value was increased in the entire skeleton (mean 6.16). Twelve patients received antifungal therapy, four of whom died during treatment, and eight recovered, though four of these eight relapsed within 3–24 months. Two patients discontinued treatment because of severe multiple organ failure and died.ConclusionsOsteolysis is often overlooked in HIV-negative individuals with disseminated P. marneffei infection. However, P. marneffei involving the bone and leading to osteolysis may indicate severe systemic disturbance, and is characterized by a poor prognosis, high recurrence rate, and the need for prolonged antifungal treatment.
Antibiotic resistance is becoming significantly prominent and urgent in clinical practice with the increasing and wide application of antibacterial drugs. However, developing and synthesizing new antimicrobial drugs is costly and time-consuming. Recently, researchers shifted their sights to traditional Chinese medicine (TCM). Here, we summarized the inhibitory mechanism of TCM herbs and their active ingredients on bacteria, discussed the regulatory mechanism of TCM on antibiotic-resistant bacteria, and revealed preclinical results of TCM herbs and their active components against antibiotic-resistant bacteria in mouse models. Those data suggest that TCM herbs and their effective constituents exhibit potential blockage ability on antibiotic-resistant bacteria, providing novel therapeutic ideas for reversing antibiotic resistance.
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