Caveolin-1 Is Up-Regulated by GLI1 and Contributes to GLI1-Driven EMT in Hepatocellular Carcinoma

Caveolin-1 (Cav-1) has been recently identified to be over-expressed in hepatocellular carcinoma (HCC) and promote HCC cell motility and invasion ability via inducing epithelial-mesenchymal transition (EMT). However, the mechanism of aberrant overexpression of Cav-1 remains vague. Here, we observed that Cav-1 expression was positively associated with GLI1 expression in HCC tissues. Forced expression of GLI1 up-regulated Cav-1 in Huh7 cells, while knockdown of GLI1 decreased expression of Cav-1 in SNU449 cells. Additionally, silencing Cav-1 abolished GLI1-induced EMT of Huh7 cells. The correlation between GLI1 and Cav-1 was confirmed in tumor specimens from HCC patients and Cav-1 was found to be associated with poor prognosis after hepatic resection. The relationship between protein expression of GLI1 and Cav-1 was also established in HCC xenografts of nude mice. These results suggest that GLI1 may be attributed to Cav-1 up-regulation which plays an important role in GLI1-driven EMT phenotype in HCC.     

Serum Potassium Levels and Its Variability in Incident Peritoneal Dialysis Patients: Associations with Mortality

Background

Abnormal serum potassium is associated with an increased risk of mortality in dialysis patients. However, the impacts of serum potassium levels on short- and long-term mortality and association of potassium variability with death in peritoneal dialysis (PD) patients are uncertain.

Methods

We examined mortality-predictability of serum potassium at baseline and its variability in PD patients treated in our center January 2006 through December 2010 with follow-up through December 2012. The hazard ratios (HRs) were used to assess the relationship between baseline potassium levels and short-term (≤1 year) as well as long-term (>1 year) survival. Variability of serum potassium was defined as the coefficient of variation of serum potassium (CVSP) during the first year of PD.

Results

A total of 886 incident PD patients were enrolled, with 248 patients (27.9%) presented hypokalemia (serum potassium <3.5 mEq/L). During a median follow-up of 31 months (range: 0.5–81.0 months), adjusted all-cause mortality hazard ratio (HR) and 95% confidence interval (CI) for baseline serum potassium of <3.0, 3.0 to <3.5, 3.5 to <4.0, 4.5 to <5.0, and ≥5.0 mEq/L, compared with 4.0 to <4.5 (reference), were 1.79 (1.02–3.14), 1.15 (0.72–1.86), 1.31 (0.82–2.08), 1.33 (0.71–2.48), 1.28 (0.53–3.10), respectively. The increased risk of lower potassium with mortality was evident during the first year of follow-up, but vanished thereafter. Adjusted all-cause mortality HR for CVSP increments of 7.5% to <12.0%; 12.0% to <16.7% and ≥16.7%, compared with <7.5% (reference), were 1.35 (0.67–2.71), 2.00 (1.05–3.83) and 2.18 (1.18–4.05), respectively. Similar association was found between serum potassium levels and its variability and cardiovascular mortality.

Conclusions

A lower serum potassium level was associated with all-cause and cardiovascular mortality during the first year of follow-up in incident PD patients. In addition, higher variability of serum potassium levels conferred an increased risk of death in this population.     

Intraguild predation among the predatory mites Amblyseius eharai,Amblyseius cucumeris and Amblyseius barkeri

Predator species with the same prey interact not only by competition for food and space but also by intraguild predation (IGP). The impact of IGP on introduced phytoseiid mites and native species in the context of biological control is a matter of considerable debate. Amblyseius eharai is the dominant native citrus species in central China, while Amblyseius cucumeris and Amblyseius barkeri are candidates for importation. All three species can feed on the spider mite Panonychus citri, which is the main pest in citrus. This study investigated, in the laboratory, possible IGP among these species in the absence and presence of P. citri, respectively. IGP in different densities of shared prey and intraguild (IG) prey was also studied. All three species consumed heterospecific larvae and eggs but not adults, and the IGP rate of larvae was significantly higher than that of eggs in the absence of shared prey. Additionally, the IGP rate of each group was reduced dramatically in the presence of both shared and IG prey when compared to the absence of shared prey. This occurs most likely because the three species prefer to feed on their natural prey P. citri, rather than on IG prey. Our results showed that A. eharai seems to be a more voracious IG predator than A. cucumeris. A. eharai was much more prone to IGP than A. barkeri.     

ATRA-Induced Cellular Differentiation and CD38 Expression Inhibits Acquisition of BCR-ABL Mutations for CML Acquired Resistance

Acquired resistance through genetic mutations is a major obstacle in targeted cancer therapy, but the underlying mechanisms are poorly understood. Here we studied mechanisms of acquired resistance of chronic myeloid leukemia (CML) to tyrosine kinase inhibitors (TKIs) by examining genome-wide gene expression changes in KCL-22 CML cells versus their resistant KCL-22M cells that acquire T315I BCR-ABL mutation following TKI exposure. Although T315I BCR-ABL is sufficient to confer resistance to TKIs in CML cells, surprisingly we found that multiple drug resistance pathways were activated in KCL-22M cells along with reduced expression of a set of myeloid differentiation genes. Forced myeloid differentiation by all-trans-retinoic acid (ATRA) effectively blocked acquisition of BCR-ABL mutations and resistance to the TKIs imatinib, nilotinib or dasatinib in our previously described in vitro models of acquired TKI resistance. ATRA induced robust expression of CD38, a cell surface marker and cellular NADase. High levels of CD38 reduced intracellular nicotinamide adenine dinucleotide (NAD⁺) levels and blocked acquired resistance by inhibiting the activity of the NAD⁺-dependent SIRT1 deacetylase that we have previously shown to promote resistance in CML cells by facilitating error-prone DNA damage repair. Consequently, ATRA treatment decreased DNA damage repair and suppressed acquisition of BCR-ABL mutations. This study sheds novel insight into mechanisms underlying acquired resistance in CML, and suggests potential benefit of combining ATRA with TKIs in treating CML, particularly in advanced phases.     

High-throughput profiling of point mutations across the HIV-1 genome

Background

The HIV-1 pandemic is not the result of a static pathogen but a large genetically diverse and dynamic viral population. The virus is characterized by a highly mutable genome rendering efforts to design a universal vaccine a significant challenge and drives the emergence of drug resistant variants upon antiviral pressure. Gaining a comprehensive understanding of the mutational tolerance of each HIV-1 genomic position is therefore of critical importance.

Results

Here we combine high-density mutagenesis with the power of next-generation sequencing to gauge the replication capacity and therefore mutational tolerability of single point mutations across the entire HIV-1 genome. We were able to achieve the evaluation of point mutational effects on viral replicative capacity for 5,553 individual HIV-1 nucleotide positions – representing 57% of the viral genome. Replicative capacity was assessed at 3,943 nucleotide positions for a single alternate base change, 1,459 nucleotide positions for two alternate base changes, and 151 nucleotide positions for all three possible alternate base changes. This resulted in the study of how a total of 7,314 individual point mutations impact HIV-1 replication on a single experimental platform. We further utilize the dataset for a focused structural analysis on a capsid inhibitor binding pocket.

Conclusion

The approach presented here can be applied to any pathogen that can be genetically manipulated in a laboratory setting. Furthermore, the methodology can be utilized under externally applied selection conditions, such as drug or immune pressure, to identify genetic elements that contribute to drug or host interactions, and therefore mutational routes of pathogen resistance and escape.

     

Design of novel analogues of short antimicrobial peptide anoplin with improved antimicrobial activity

Currently, novel antibiotics are urgently required to combat the emergence of drug‐resistant bacteria. Antimicrobial peptides with membrane‐lytic mechanism of action have attracted considerable interest. Anoplin, a natural α‐helical amphiphilic antimicrobial peptide, is an ideal research template because of its short sequence. In this study, we designed and synthesized a group of analogues of anoplin. Among these analogues, anoplin‐4 composed of d ‐amino acids displayed the highest antimicrobial activity due to increased charge, hydrophobicity and amphiphilicity. Gratifyingly, anoplin‐4 showed low toxicity to host cells, indicating high bacterial selectivity. Furthermore, the mortality rate of mice infected with Escherichia coli was significantly reduced by anoplin‐4 treatment relative to anoplin. In conclusion, anoplin‐4 is a novel anoplin analogue with high antimicrobial activity and enzymatic stability, which may represent a potent agent for the treatment of infection. Copyright © 2014 European Peptide Society and John Wiley & Sons, Ltd.     

郫县豆瓣发酵过程的微生物多样性及溯源分析

[目的] 解析郫县豆瓣及其酿造半成品-蚕豆醅与辣椒醅微生物多样性和来源,探究郫县豆瓣酿造过程风味化合物特征。[方法] 采用高通量测序法测定蚕豆醅、辣椒醅与混合醅（蚕豆醅-辣椒醅混合物,发酵成熟形成郫县豆瓣）在酿造过程中的微生物群落结构;利用高效气相质谱与高效液相色谱高通量检测蚕豆醅及辣椒醅中基础理化指标及挥发性、非挥发性风味化合物浓度;利用多种生物信息学分析方法对混合醅酿造微生物及风味化合物进行溯源。[结果] 微生物方面：44%–59%的混合醅细菌来源于辣椒醅,5%–22%的混合醅细菌来源于蚕豆醅,其他混合醅细菌来源未知。同时,42%–77%的混合醅真菌来源于辣椒醅,2%–18%的混合醅真菌来源于蚕豆醅,其他混合醅真菌来源未知。另外,16个细菌属由辣椒醅特异性贡献;2个细菌属及2个真菌属由蚕豆醅特异性贡献。化合物方面：1-辛烯-3醇（1-octen-3-ol）、苯乙醛（phenylacetaldehyde）、异丁醛（isobutyraldehyde）、苹果酸（malic acid）与糠醛（furfural）仅由蚕豆醅贡献。辣椒素（capsaicin）、3-甲基-1-丁醇（3-methyl-1-butanol）、已醇（hexanol）与异丁醇（isobutanol）仅由辣椒醅贡献。[结论] 郫县豆瓣发酵中大部分微生物来源于辣椒醅,大部分发酵底物（氨基酸及葡萄糖）来源于蚕豆醅。两种发酵半成品均特异性贡献微生物及风味化合物,形成郫县豆瓣的独特风味密码。     

Clinical features and hematological findings of COVID-19 patients with blood transfusion

This paper aims to illustrate the clinical characteristics, hematological findings, and blood transfusion information of Coronavirus disease 2019 (COVID-19) patients. Twenty-three COVID-19 patients were treated and transfused with blood products in Wuhan First Hospital from February 12 to March 20, 2020. The patients were divided into a survivor group and a non-survivor group, respectively, according to whether the patient had been discharged or died. The results demonstrated at the time of initial blood transfusion, that the non-survivor group possessed a lower platelet (PLT) than that of the survivor group (P<0.001), and PLT were below the normal range in 6 (85.7%) non-survivor group and in 2 (12.5%) survivor group (P<0.01). Over half of these patients had abnormalities in fibrinogen (FIB), activated partial thromboplastin time (APTT), prothrombin time (PT), and international normalized ratio (INR), but no significant difference was found between the non-survivor group and survivor group. The non-survivor group had a dramatically higher D-Dimers and disseminated intravascular coagulation (DIC) scores than those of the survivor group (P<0.01). Six (85.7%) non-survivors but none of the survivors had a DIC score greater than 6 (P<0.001). Fifteen (93.8%) survivors and 2 (28.6%) non-survivors were transfused with RBC (P<0.01). The non-survivors (5/7) possessed a higher proportion for using AP than the survivors (2/16). The study suggests that COVID-19 patients who undergo blood transfusion usually possess coagulation dysfunction, and DIC may be closely related to deteriorating clinical outcomes.