Development and evaluation of RPA-NFO-LFT and RPA-Cas12a-LFT systems for the detection of Candida albicans.

Recently, the growing number of medical interventions has led to the risk of invasive candidiasis. Among them, Candida albicans (C. albicans) infection has the highest incidence, which has led to great demand for developing early diagnosis methods. In this study, two lateral flow device based molecular assay systems, RPA-NFO-LFT and RPA-Cas12a-LFT, were established and optimized to achieve the detection of C. albicans. Firstly, efficient and specific primers for C. albicans detection were designed and screened, and the purification of amplification products was also explored. Then, many important conditions and issues for each system were investigated and discussed to improve the performances of the test strip devices in C. albicans detection. An evaluation study revealed that both systems showed favorable specificity and sensitivity in the detection of C. albicans samples with a lower detection limit of 103 CFU ml-1, while RPA-Cas12a-LFT is more accurate for visual interpretation and more stable toward samples that exhibit serum nucleic acid interference. Finally, the performances of RPA-NFO-LFT and RPA-Cas12a-LFT were compared with that of the conventional qPCR method. This work might provide a reference for the development of molecular assay devices in practical candidiasis diagnosis.

Pseudoginsenoside-F11 Accelerates Microglial Phagocytosis of Myelin Debris and Attenuates Cerebral Ischemic Injury Through Complement Receptor 3.

After ischemic stroke, the degenerated myelin caused by ischemic injury cannot be rapidly cleared away by microglia and interferes with the recovery process. Complement receptor 3 (CR3, CD11b/CD18), belonging to ß2 integrin family primarily expressed in phagocytes, is involved in the microglial phagocytosis of myelin debris. We previously found that pseudoginsenoside-F11 (PF11), an ocotillol-type saponin, exerts neuroprotective effects against ischemic stroke and neuroinflammation. In the present study, we investigated the promotion of PF11 on oxygen-glucose deprivation (OGD)-induced microglial phagocytosis of myelin debris, the neuroprotection of PF11 on permanent middle cerebral artery occlusion (pMCAO)-induced ischemic stroke, and the possible role of CR3. The results indicated that PF11 (50 µM) accelerated the OGD-induced promotion of myelin debris phagocytosis by microglia in the early stage of OGD (2 h, 4 h, 8 h), which was significantly inhibited by anti-CD11b mAb or down-regulated by CD11b-specific siRNA. Meanwhile, PF11 strengthened the OGD-activated RhoA/ROCK signaling associated with the internalization during myelin debris phagocytosis through CR3. Consistently, the anti-CD11b mAb could markedly attenuated the nrueoprotective effects of PF11 (12 mg/kg, i.v.) on infarction and brain edema, neurological functions and loss of neurons of pMCAO rats. These findings suggest that PF11 accelerates the phagocytosis of myelin debris by microglia mainly through CR3, which may likely contribute to its neuroprotection against ischemic stroke.

Role of microglia in ethanol-induced neurodegenerative disease: Pathological and behavioral dysfunction at different developmental stages.

Alcohol abuse can result in significant alterations to the structure of the brain and ultimately to behavioral dysfunctions. Epidemiological studies have shown that alcoholism is closely associated with impaired memory and judgment. However, the degree of deficit (brain injury) depends on factors such as the age of onset, duration of heavy drinking, continuous versus periodic (binge) drinking and the typical amount consumed per session. In recent years, neuroinflammation has been proposed as one of the alcoholism-induced neuropathological mechanisms, since increased levels of microglial markers are observed in the brains of both post-mortem human alcoholics and various alcohol-treated animals, from newborn or adolescent rodents to adult rodents. Many studies have investigated how microglia modulate alcohol-induced behavioral changes such as cognitive deficits, abnormal locomotor activity, motor impairment and mood disturbance. Importantly, we try to characterize and compare the distinct features in different ethanol (EtOH)-induced neurodegenerative disease (NDD) models. Moreover, mounting evidence indicates that in response to certain environmental toxins, microglia can become over-activated under oxidative stress, releasing pro-inflammatory mediators that cause central nervous system (CNS) disease. The molecular mechanisms involve free radical formation and the release of pro-inflammatory cytokines that are detrimental to neighboring neurons and interfere with the molecules regulating cell-cell interactions. The identification and understanding of the cellular and molecular mechanisms of microglial activation are described, as well as multiple downstream targets, in different alcohol-treated animal models. This review might contribute to the development of treatments and/or therapeutic agents that can reduce or eliminate the deleterious effects of alcohol-induced NDD.

Structure-activity relationship study of dibenzocyclooctadiene lignans isolated from Schisandra chinensis on lipopolysaccharide-induced microglia activation.

To explore the relationship of the dibenzocyclooctadiene lignans from Schisandra chinensis to their anti-inflammatory activities, series of dibenzocyclooctadiene lignans were isolated and assessed by testing their inhibitory effects on nitric oxide production in lipopolysaccharide-induced BV2 mouse microglia. It was found, for the first time, that dibenzocyclooctadiene lignans which have S-biphenyl and methylenedioxy groups strongly inhibited LPS-induced microglia activation. The methoxy group on the cyclooctadiene introduced more effectiveness, but the presence of an acetyl group on the cyclooctadiene or hydroxyl group on C-7 decreased the inhibitory activity.

Dibenzocyclooctadiene lignans from Schisandra chinensis and their inhibitory activity on NO production in lipopolysaccharide-activated microglia cells.

Four dibenzocyclooctadiene lignans, schisanchinins A-D, and 10 known compounds were isolated from the EtOAc extract of fruits of Schisandra chinensis (Turcz.) Baill. Structures of compounds 1-4 were elucidated using a combination of spectroscopic techniques, including MS, UV and IR, NMR ((1)H NMR, (13)C NMR, HMQC, HMBC). The stereochemistry of the chiral centers and the biphenyl configuration were determined using NOESY, as well as analysis of CD spectra. In vitro activity assays showed that 11 of the 14 compounds exhibited inhibitory activity on lipopolysaccharide (LPS)-induced NO release in primary murine BV2 microglia cells.

Sildenafil attenuates LPS-induced pro-inflammatory responses through down-regulation of intracellular ROS-related MAPK/NF-κB signaling pathways in N9 microglia.

Excessive activation of microglial cells has been implicated in various neuroinflammation. The present study showed that sildenafil, a PDE5 inhibitor, significantly suppressed NO, interleukin 1ß (IL-1ß) and tumor necrosis factor α (TNF-α) production induced by LPS in microglial cells through decreasing the protein and/or mRNA expressions of inducible NO synthase (iNOS), IL-1ß and TNF-α in a concentration-dependent manner. Sildenafil also blocked IκBα phosphorylation and degradation, inhibited the phosphorylation of mitogen-activated protein kinases (MAPKs), extracellular signal-regulated kinases 1 and 2 (ERK1/2), p38 MAPK, and c-Jun N-terminal kinase (JNK). Moreover, the increase of the expression of gp91phox, a critical and catalytic subunit of NADPH oxidase, and the levels of intracellular reactive oxygen species (iROS) induced by LPS were markedly inhibited by sildenafil. In summary, these data suggest that sildenafil exerts its in vitro anti-inflammatory effect in LPS-activated N9 microglial cells by blocking nuclear factor-κB (NF-κB) and MAPKs activation, which may be partly due to its potent down-regulation of the NADPH-derived iROS production.