Inhibition of viral suppressor of RNAi proteins by designer peptides protects from enteroviral infection in vivo.

RNA interference (RNAi) is the major antiviral mechanism in plants and invertebrates, but the absence of detectable viral (v)siRNAs in mammalian cells upon viral infection has questioned the functional relevance of this pathway in mammalian immunity. We designed a series of peptides specifically targeting enterovirus A71 (EV-A71)-encoded protein 3A, a viral suppressor of RNAi (VSR). These peptides abrogated the VSR function of EV-A71 in infected cells and resulted in the accumulation of vsiRNAs and reduced viral replication. These vsiRNAs were functional, as evidenced by RISC-loading and silencing of target RNAs. The effects of VSR-targeting peptides (VTPs) on infection with EV-A71 as well as another enterovirus, Coxsackievirus-A16, were ablated upon deletion of Dicer1 or AGO2, core components of the RNAi pathway. In vivo, VTP treatment protected mice against lethal EV-A71 challenge, with detectable vsiRNAs. Our findings provide evidence for the functional relevance of RNAi in mammalian immunity and present a therapeutic strategy for infectious disease.

Association between serum uric acid and deep venous thrombosis in European populations: A two-sample Mendelian randomization study.

BACKGROUND AND AIM: Previous experimental and observational studies showed that serum uric acid (SUA) was associated with deep venous thrombosis (DVT), but the causal relationship is unclear. This study aimed to explore the potential causal association between SUA and DVT. METHODS AND RESULTS: We designed a two-sample Mendelian randomization (MR) analysis by using summary-level data from large genome-wide association studies performed in European individuals. A total of 14 SUA-related single-nucleotide polymorphisms (SNPs) (P value < 5 × 10-8) were identified as instrumental variables. The inverse variance weighted method was used as the primary method to compute the odds ratios (ORs) and 95 % confidence intervals (95 % CIs) for per standard deviation increase in SUA. MR Egger, weighted median, weighted mode, and simple mode were also applied to test the robustness of the results. We found no significant causal effects of serum uric acid on deep venous thrombosis (odds ratio [OR]: 1.000, 95 % confidence interval [CI]: 0.998-1.002, p = 0.78) by using inverse variance weighted. MR analyses based on other methods showed similar results. CONCLUSIONS: There was no potential causal associations between higher genetically predicted SUA levels and increased risk of deep venous thrombosis. Further, MR studies with more valid SNPs and more DVT cases are needed. Validation of the findings is also recommended.

Systematic review and meta-analysis of the efficacy of olprinone and MEFV gene in treating heart failure.

Cardiovascular failure is the main cause of death in industrialized societies. The results of recent studies have shown that some mutations in the MEFV gene are common in heart failure patients. For this reason, the study of mutations and genetic factors has been of great help in the treatment of this disease, but despite this, due to the heterogeneity of clinical symptoms, multiple pathophysiological processes, and environmental genetic factors, the complete understanding of the genetic causes of this disease is very complicated. As the new generation of phosphodiesterase (PDE) III inhibitor, olprinone, the inhibition of human heart PDE III by olprinone is highly selective. It is suitable for the treatment of acute heart failure (HF) and acute cardiac insufficiency after cardiac surgery. In this study Olprinone, milrinone, PDE inhibitors, cardiac failure, and HF were selected as the search terms to retrieve articles published between January 1999 and March 2022. RevMan5.3 and Stata were employed to analyze and evaluate the risk bias of the included articles. Besides, the Q test and heterogeneity were utilized to evaluate the heterogeneity between articles. The results of this research showed No heterogeneity was found between each research group. The sensitivity (Sen) and specificity (Spe) of the two methods were compared. Olprinone showed more significant therapeutic effects than other PDE inhibitors. Besides, the therapeutic effect on the patients with HF in the two groups was obvious. The incidence of postoperative adverse reactions among the patients without relieving HF was low. The influences on urine flow of the two group's demonstrated heterogeneity, and its effect revealed no statistical meaning. The meta-analysis confirmed that the Spe and Sen of olprinone treatment were higher than those of other PDE inhibitors. In terms of hemodynamics, there was little difference between various treatment methods.

Adaptive structural changes in the motor cortex and white matter in Parkinson's disease.

Parkinson's disease (PD) is a movement disorder characterized by the early loss of nigrostriatal dopaminergic pathways producing significant network changes impacting motor coordination. Recently three motor stages of PD have been proposed (a silent period when nigrostriatal loss begins, a prodromal motor period with subtle focal manifestations, and clinical PD) with evidence that motor cortex abnormalities occur to produce clinical PD[8]. We directly assess structural changes in the primary motor cortex and corticospinal tract using parallel analyses of longitudinal clinical and cross-sectional pathological cohorts thought to represent different stages of PD. 18F-FP-CIT positron emission tomography and subtle motor features identified patients with idiopathic rapid-eye-movement sleep behaviour disorder (n = 8) that developed prodromal motor signs of PD. Longitudinal diffusion tensor imaging before and after the development of prodromal motor PD showed higher fractional anisotropy in motor cortex and corticospinal tract compared to controls, indicating adaptive structural changes in motor networks in concert with nigrostriatal dopamine loss. Histological analyses of the white matter underlying the motor cortex showed progressive disorientation of axons with segmental replacement of neurofilaments with α-synuclein, enlargement of myelinating oligodendrocytes and increased density of their precursors. There was no loss of neurons in the motor cortex in early or late pathologically confirmed motor PD compared to controls, although there were early cortical increases in neuronal neurofilament light chain and myelin proteins in association with α-synuclein accumulation. Our results collectively provide evidence of a direct impact of PD on primary motor cortex and its output pathways that begins in the prodromal motor stage of PD with structural changes confirmed in early PD. These adaptive structural changes become considerable as the disease advances potentially contributing to motor PD.

Selective isolation of hyaluronan by solid phase adsorption to silica.

A solid phase adsorption method for selective isolation of hyaluronan (HA) from biological samples is presented. Following enzymatic degradation of protein, HA can be separated from sulfated glycosaminoglycans, other unsulfated glycosaminoglycans, nucleic acids, and proteolytic fragments by adsorption to amorphous silica at specific salt concentrations. The adsorbed HA can be released from silica using neutral and basic aqueous solutions. HA ranging in size from ∼9 kDa to MDa polymers has been purified by this method from human serum and conditioned medium of cultured cells.

Comparison of Locus Coeruleus Pathology with Nigral and Forebrain Pathology in Parkinson's Disease.

BACKGROUND: Pathology in the noradrenergic A6 locus coeruleus has not been compared with more rostral dopaminergic A9 substantia nigra and A10 ventral tegmental area, and cholinergic Ch4 basal nucleus and Ch1/2 septal regions in the same cases of Parkinson's disease (PD). OBJECTIVE: To determine whether there is a gradient of caudal to rostral cell loss in PD. METHODS: Postmortem brains were collected from longitudinally followed donors with PD (n = 14) and aged-matched healthy donors (n = 13), six with restricted brainstem Lewy pathology (RLP), fixed in formalin and serial tissue slabs processed for cell and pathological quantitation. Noradrenergic A6 neurons were assessed and compared with previously published midbrain and basal forebrain data. From these data, regression estimates of pathological onset and progression were determined. RESULTS: Restricted Lewy pathology (RLP) cases had high pathological variability but no significant reduction in neurons. Pathology containing A6 neuron loss started at PD diagnosis and progressed faster (2.4% p.a) than the loss of dopaminergic A9 neurons (2% loss p.a.). Cases with dementia had significantly more pathology in noradrenergic and cholinergic neurons, had greater noradrenergic A6 neuron loss (29% more, progressing at 3.2% p.a.), and a selective loss of lateral A10 nonmelanized dopamine-producing neurons (starting a decade following diagnosis). CONCLUSIONS: These findings show that in the same Parkinson's disease cases cell loss in these neurotransmitter systems does not follow a strict caudal to rostral trajectory and suggests symptom onset may relate to substantial pathology in the noradrenergic A6 locus coeruleus neurons in people with reduced dopamine-producing A9 substantia nigra neurons. © 2021 International Parkinson and Movement Disorder Society.

MicroRNAs: Potential Targets in Diabetic Retinopathy.

Diabetic retinopathy (DR), a serious microvascular complication of diabetes, is a leading cause of blindness in adults. The pathogenesis of DR involves a variety of tissues and complex mechanisms, such as inflammation, oxidative stress, optic neurodegeneration, and autophagy. Nowadays, microRNAs (miRNAs), a novel group of non-coding small RNAs, have been extensively studied and recognized to play a key role in the pathogenesis of DR through aforementioned pathways. Furthermore, some miRNAs have been proposed as biomarkers that may be utilized to screen for DR. Also, miRNAs are a new therapy for DR. In this review, we summarize several miRNAs and, their roles in the pathogenesis of DR. miRNAs, as potential pharmacological targets for the diabetic retinopathy, may provide new insights for the treatment of DR.

Hypoxia-inducible factor-1α: A promising therapeutic target for vasculopathy in diabetic retinopathy.

Diabetic retinopathy (DR) is a serious condition that can cause blindness in diabetic patients. It is a neurovascular disease, but the pathogenesis leading to the onset of this disease is still not completely understood. However, hypoxia with subsequent neovascularization is a characteristic phenomenon observed with DR. Cellular response to hypoxia is mediated by the transcriptional regulator hypoxia-inducible factor (HIF). Long-term research has shown that one isotype of HIF, HIF-1α, may play a pivotal role under hypoxic conditions, and an increasing number of studies have shown that HIF-1α and its target genes contribute to retinal neovascularization. Therefore, targeting HIF-1α may lead to more effective DR treatments. This review describes the possible mechanisms of HIF-1α in neovascularization of DR. Furthermore, various inhibitors of HIF-1α that may have viable potential in the treatment of DR are also discussed.

Alpha-synuclein aggregates activate calcium pump SERCA leading to calcium dysregulation.

Aggregation of α-synuclein is a hallmark of Parkinson's disease and dementia with Lewy bodies. We here investigate the relationship between cytosolic Ca2+ and α-synuclein aggregation. Analyses of cell lines and primary culture models of α-synuclein cytopathology reveal an early phase with reduced cytosolic Ca2+ levels followed by a later Ca2+ increase. Aggregated but not monomeric α-synuclein binds to and activates SERCA in vitro, and proximity ligation assays confirm this interaction in cells. The SERCA inhibitor cyclopiazonic acid (CPA) normalises both the initial reduction and the later increase in cytosolic Ca2+ CPA protects the cells against α-synuclein-aggregate stress and improves viability in cell models and in Caenorhabditis elegans in vivo Proximity ligation assays also reveal an increased interaction between α-synuclein aggregates and SERCA in human brains affected by dementia with Lewy bodies. We conclude that α-synuclein aggregates bind SERCA and stimulate its activity. Reducing SERCA activity is neuroprotective, indicating that SERCA and down-stream processes may be therapeutic targets for treating α-synucleinopathies.

Optimization of globomycin analogs as novel gram-negative antibiotics.

Discovery of novel classes of Gram-negative antibiotics with activity against multi-drug resistant infections is a critical unmet need. As an essential member of the lipoprotein biosynthetic pathway, lipoprotein signal peptidase II (LspA) is an attractive target for antibacterial drug discovery, with the natural product inhibitor globomycin offering a modestly-active starting point. Informed by structure-based design, the globomycin depsipeptide was optimized to improve activity against E. coli. Backbone modifications, together with adjustment of physicochemical properties, afforded potent compounds with good in vivo pharmacokinetic profiles. Optimized compounds such as 51 (E. coli MIC 3.1 µM) and 61 (E. coli MIC 0.78 µM) demonstrate broad spectrum activity against gram-negative pathogens and may provide opportunities for future antibiotic discovery.

Arylsulfatase A, a genetic modifier of Parkinson's disease, is an α-synuclein chaperone.

Mutations in lysosomal genes increase the risk of neurodegenerative diseases, as is the case for Parkinson's disease. Here, we found that pathogenic and protective mutations in arylsulfatase A (ARSA), a gene responsible for metachromatic leukodystrophy, a lysosomal storage disorder, are linked to Parkinson's disease. Plasma ARSA protein levels were changed in Parkinson's disease patients. ARSA deficiency caused increases in α-synuclein aggregation and secretion, and increases in α-synuclein propagation in cells and nematodes. Despite being a lysosomal protein, ARSA directly interacts with α-synuclein in the cytosol. The interaction was more extensive with protective ARSA variant and less with pathogenic ARSA variant than wild-type. ARSA inhibited the in vitro fibrillation of α-synuclein in a dose-dependent manner. Ectopic expression of ARSA reversed the α-synuclein phenotypes in both cell and fly models of synucleinopathy, the effects correlating with the extent of the physical interaction between these molecules. Collectively, these results suggest that ARSA is a genetic modifier of Parkinson's disease pathogenesis, acting as a molecular chaperone for α-synuclein.

Synthesis of high-performance hierarchically porous carbons from rice husk for sorption of phenol in the gas phase.

Phenol as a semi-volatile organic compound (SVOC) extensively presents in industrial wastewater. Moreover, it is a main compound of tar existing in the vapor phase from biomass pyrolysis or gasification. So far, most of works on the phenol adsorption by activated carbons have been conducted in the liquid phase. However, the adsorption of phenol in the gas phase has not been reported. This work aims to synthesize the hierarchically porous carbons from the unaltered and pelletized rice husk (RH) via a facile pyrolysis followed by the ball-milling-assisted KOH activation. Herein, the silica nanoparticles in RH acted as a self-template to remarkably increase specific surface areas and pores, thereby giving rise to the formation of hierarchically porous carbons, which showed a relatively high adsorption capacity (maximum value: 1919 mg/g) of phenol in the vapor phase. Generally, the process of phenol adsorption onto porous carbons in the gas phase followed with various interactions, including pore filling, electrostatic interaction, hydrophobic effect, and functional groups effect (e.g., π-π interaction). And the pseudo-second-order model could well describe the adsorption kinetic. It is noted that the pelletized RH was more favorable to develop the porous carbons with the hierarchically meso-microporous structures that could enhance the transfer of the phenol molecules via the outer layer and subsequent uptake by the adsorption sites on the inner layer. Further, the SVOC phenol was hard to volatilize under ambient conditions due to its relatively higher boiling point (181.7 °C), so the thermal desorption was a potential way to regenerate the spent activated biochars.

Nigrostriatal pathology with reduced astrocytes in LRRK2 S910/S935 phosphorylation deficient knockin mice.

Leucine-rich repeat kinase 2 (LRRK2) is genetically implicated in both familial and sporadic Parkinson's disease (PD). Moreover, LRRK2 has emerged as a compelling therapeutic target for the treatment of PD. Consequently, there is much interest in understanding LRRK2 and its role in PD pathogenesis. LRRK2 is constitutively phosphorylated on two serines, S910 and S935, that are required for interaction of LRRK2 with members of the 14-3-3 family of scaffolding proteins. Pathogenic LRRK2 missense mutations impair the phosphorylation of LRRK2 at these sites, but whether this contributes to PD pathology is unclear. To better understand how loss of LRRK2 phosphorylation relates to PD pathology, we have studied double knockin mice in which Lrrk2's serine 910 and 935 have both been mutated to alanine and can therefore no longer be phosphorylated. Nigrostriatal PD pathology was assessed in adult mice, aged mice, and mice inoculated with α-synuclein fibrils. Under all paradigms there was evidence of early PD pathology in the striatum of the knockin mice, namely alterations in dopamine regulating proteins and accumulation of α-synuclein. Striatal pathology was accompanied by a significant decrease in the number of astrocytes in the knockin mice. Despite striatal pathology, there was no degeneration of dopamine neurons in the substantia nigra and no evidence of a PD motor phenotype in the knockin mice. Our results suggest that modulation of LRRK2 serine 910 and 935 phosphorylation sites may have implications for dopamine turnover and astrocyte function, but loss of phosphorylation at these residues is not sufficient to induce PD neurodegeneration.

In Vitro Activity of Clofazimine against Nontuberculous Mycobacteria Isolated in Beijing, China.

Due to the natural resistance of nontuberculous mycobacteria (NTM) to many antibiotics, the treatment of diseases caused by NTM is often long-term but unsuccessful. The main goal of this study was to evaluate the in vitro susceptibilities to clofazimine of 209 isolates consisting of different NTM species isolated in Beijing, China. Furthermore, 47 reference strains were also tested, including 30 rapidly growing mycobacterium (RGM) species and 17 slowly growing mycobacterium (SGM) species. The potential molecular mechanism contributing to clofazimine resistance of NTM was investigated as well. Clofazimine exhibited excellent activity against both reference strains and clinical isolates of different SGM species, and most of the strains had MICs far below 1 µg/ml. Although the majority of the clinical isolates of Mycobacterium abscessus and Mycobacterium fortuitum had MICs higher than 2 µg/ml, 17 out of the 30 reference strains of different RGM species had MICs below 1 µg/ml in vitro According to the MIC distributions, the tentative epidemiological cutoff (ECOFF) values for Mycobacterium kansasii, Mycobacterium avium, and Mycobacterium intracellulare were defined at 0.5 µg/ml, 1 µg/ml, and 2 µg/ml, respectively. Intriguingly, single-direction cross-resistance between bedaquiline- and clofazimine (Cfz)-resistant isolates was observed among the tested NTM species. This study demonstrates that clofazimine had strong activity against most SGM species in vitro, as well as some RGM species. The data provide important insights into the possible clinical application of Cfz to treat NTM infections.

In Vitro Drug Susceptibility of Bedaquiline, Delamanid, Linezolid, Clofazimine, Moxifloxacin, and Gatifloxacin against Extensively Drug-Resistant Tuberculosis in Beijing, China.

Extensively drug-resistant tuberculosis (XDR-TB) is a deadly form of TB that can be incurable due to its extreme drug resistance. In this study, we aimed to explore the in vitro susceptibility to bedaquiline (BDQ), delamanid (DMD), linezolid (LZD), clofazimine (CLO), moxifloxacin (MFX), and gatifloxacin (GAT) of 90 XDR-TB strains isolated from patients in China. We also describe the genetic characteristics of XDR-TB isolates with acquired drug resistance. Resistance to MFX, GAT, LZD, CLO, DMD, and BDQ was found in 82 (91.1%), 76 (84.4%), 5 (5.6%), 5 (5.6%), 4 (4.4%), and 3 (3.3%) isolates among the XDR-TB strains, respectively. The most frequent mutations conferring fluoroquinolone resistance occurred in codon 94 of the gyrA gene (57.8%), and the strains with these mutations (69.2%) were associated with high-level MFX resistance compared to strains with mutations in codon 90 (25.0%) (P < 0.01). All 5 CLO-resistant isolates exhibited ≥4-fold upward shifts in the BDQ MIC, which were attributed to mutations of codons 53 (60.0%) and 157 (20.0%) in the Rv0678 gene. Additionally, mutation in codon 318 of the fbiC gene was identified as the sole mutation related to DMD resistance. In conclusion, our data demonstrate that the XDR-TB strains exhibit a strikingly high proportion of resistance to the current anti-TB drugs, whereas BDQ, DMD, LZD, and CLO exhibit excellent in vitro activity against XDR-TB in the National Clinical Center on TB of China. The extensive cross-resistance between OFX and later-generation fluoroquinolones indicates that MFX and GAT may have difficulty in producing the desired effect for XDR-TB patients.

Toll-like receptor 2 is increased in neurons in Parkinson's disease brain and may contribute to alpha-synuclein pathology.

Inflammation is likely a key contributor to the pathogenesis of Parkinson's disease (PD), a progressively debilitating neurodegenerative disease that is accompanied by a pathological accumulation of the α-synuclein protein in a staged manner through the brain. What leads to the accumulation of α-synuclein in PD and how this relates to inflammatory pathways, however, is not entirely clear. Toll-like receptor (TLR) signaling is a major pathway mediating inflammation and, in particular, TLR2 is increasingly being implicated in PD. We have, therefore, examined the expression of TLR2 in postmortem brain tissue from PD patients and matched controls. We confirm that TLR2 is increased in PD brain, and find that levels of TLR2 correlate with the accumulation of pathological α-synuclein. TLR2 was expressed on neurons as well as microglia; however, the neuronal rather than glial expression of TLR2 was significantly increased in PD brain in accordance with disease staging, and TLR2 was strongly localized to α-synuclein positive Lewy bodies. In cell culture, activation of neuronal TLR2 induced an inflammatory response, including the secretion of inflammatory cytokines and microglial-activating chemokines, as well as the production of reactive oxygen species. Moreover, activation of neuronal TLR2 increased levels of endogenous α-synuclein protein, which was in turn associated with increased levels of the autophagy/lysosomal pathway marker p62. Finally, promoting autophagy with rapamycin or pharmacological inhibition of the TLR2 signaling pathway prevented the TLR2-mediated increase in α-synuclein in neuronal cell cultures. These results implicate neuronal TLR2 expression in human PD pathogenesis. In particular, the increased expression of TLR2 on neurons may provide new insight into disease pathogenesis and/or options for therapeutic intervention.

Unraveling the Mystery of Stöber Silica's Microporosity.

Puzzling aspects of the microporous structure of Stöber silica, including inconsistencies in the BET specific surface area and the long measurement time required for N2 adsorption, hinder further research on and potential applications of this material. In this work, Stöber silica samples prepared using systematic and detailed post-treatment methods were characterized by N2 adsorption, scanning electron microscopy, transmission electron microscopy, inductively coupled plasma optical emission spectrometry, elemental analysis, and Fourier transform infrared spectroscopy. We have found that the often overlooked sample preparation conditions may be the main causes that perplex the gas adsorption characterization results of Stöber silica samples. The pore-blocking processes associated with a variety of sample treatment methods are discussed in detail. Strong evidence for the particle growth model and pore-blocking mechanism involving ethoxyl groups, Si species, and condensation of silanols is provided. A remarkable result is that the measurement time is shortened from 1 month in our previous work to 2-3 days for samples with large specific surface areas. A suitable post-treatment condition is recommended to obtain microporous Stöber silica with a short measurement time, including water washing, low temperature drying without a vacuum, and a short storage time.

Understanding Stöber silica's pore characteristics measured by gas adsorption.

Controversial reports regarding Stöber silica's microporosity and specific surface area remain in the literature despite decades of widespread applications. In this work, Stöber silica samples prepared under controlled reaction time and postsynthesis washing/drying conditions were characterized by nitrogen adsorption at 77 K, transmission electron microscopy, elemental analysis, Fourier transform infrared spectroscopy, thermal analysis, and evolved gas analysis. Our experimental results demonstrated the important but often overlooked effects of reaction time and postsynthesis treatments on Stöber silica's pore characteristics, as evidenced by the strikingly large range of BET specific surface area (11.3-309.7 m(2)/g). A simple micropore filling and blocking mechanism compatible with an existing Stöber silica growth model incorporating both aggregation and monomer addition steps was proposed to explain all our experimental findings. The carbon and nitrogen contents appear to serve well as the indicative link between our experimental variables and the resulting pore blocking by TEOS and its derivatives. A suitable combination of experimental conditions is recommended in order to make microporous Stöber silica samples with large specific surface area, including a short reaction time, water washing, and drying at moderate temperature preferably under vacuum.

[Detection of mutations in the gyrA and gyrB genes associated with fluoroquinolone-resistance among clinical isolates of Mycobacterium abscessus in China].

OBJECTIVE: To determine molecular mutations in gyrA and gyrB genes and their association with fluoroquinone-resistance among Mycobacterium abscessus isolates from China. METHODS: Antimicrobial susceptibility profile of Mycobacterium abscessus isolates was evaluated for resistance to levofloxacin (LFX) and moxifloxacin (MFX). The quinolone resistant determing regions (QRDR) of gyrA and gyrB genes of all the isolates was sequenced and analyzed. RESULTS: A total 70 Mycobacterium abscessus isolates were analyzed, including 45 (64%) M. abscessus subsp. abscessus and 25 (36%) M. abscessus subsp. massiliense. Analysis of antimicrobial susceptibility profile showed 97% (n=68) of isolates were resistance to LFX and 14.3% (n=10) of isolates were resistance to MFX. All the MFX-resistant strains were resistant to LFX. Cross-resistance to LFX and MFX was noted in 14.3% (n=10) of isolates. Sequencing analysis revealed that the Ser83Ala substitution in the gyrA gene and Lys447Arg and Ser464Asn substitutions in the gyrB gene were found in all the isolates from both M. abscessus subsp. abscessus and M. abscessus subsp. massiliense. No mutation was found to be associated with cross-resistance of M. abscessus to LFX and MFX in the entire gyrA and gyrB gene. CONCLUSIONS: Our data suggest that there is no clear correlation between the type of mutation in the gene gyrA and gyrB, and the MIC levels of LFX and MFX for resistant M. abscessus strains.