Biosynthesis of Ag2Se nanoparticles as a broad-spectrum antimicrobial agent with excellent biocompatibility

Silver (Ag)-containing nanomaterials have emerged as promising alternatives or adjuvants to antibiotics. Ongoing research is dedicated to enhance their antimicrobial efficacy, stability, biocompatibility, and environmental sustainability. Microorganism-synthesized Ag-containing nanomaterials offer distinct advantages, especially for various surface modification, which potentially fulfill these objectives. In this study, we present the synthesis of silver-selenium (Bio-Ag2Se) nanoparticles using a yeast strain, Rhodotorula mucilaginosa PA-1. These Bio-Ag2Se nanoparticles have small size with a narrow size distribution (12.3 ± 2.9 nm) and long-term stability. They demonstrate a broad antimicrobial spectrum and high antimicrobial efficacy at very low concentrations, effectively targeting microorganisms including Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus, as well as pathogenic fungus Candida albicans. Furthermore, Bio-Ag2Se nanoparticles exhibit excellent efficacy to inhibit and eliminate biofilms formed by notorious pathogen S. aureus. In contrast, Bio-Ag2Se nanoparticles at effective antibacterial concentrations demonstrate favorable biocompatibility and do not show obvious cytotoxic effects on human and plant cells. To elucidate the antibacterial mechanisms of Bio-Ag2Se nanoparticles against S. aureus and E. coli, transcriptomic analysis and phenotypic examination were employed. The results reveal significant and broad up-regulation in carbon metabolism pathways in both S. aureus and E. coli, suggesting it as one of the major antibacterial mechanisms of Bio-Ag2Se. This study presents a green synthesis strategy for Ag-containing nanoparticles with promising applications.

Comparison of the efficacy of Hydroquinone cream versus Hydroquinone cream plus Danggui Shaoyao powder in the treatment of melasma

Introduction

Melasma is an acquired hypermelanosis and occurs in areas exposed to sunlight.

Aim

To investigate the effectiveness of Danggui Shaoyao powder (DSP) as a complementary drug in the treatment of melasma.

Material and methods

A total of 40 melasma patients over the age of 18 who met the inclusion criteria entered the study randomly in two DSP + Hydroquinone (DSP + H) and Hydroquinone (H) groups.

Results

At the beginning of the study, the average MASI score of the two groups of patients had no statistical difference (DSP + H: 15.79 ±1.01 vs. H: 15.37 ±1.17, p = 0.23). But from the eighth week of treatment, the MASI score of the patients decreased significantly and in the DSP + H group it decreased statistically significantly compared to the H group (DSP + H: 5.83 ±0.97 vs. H: 8.29 ±2.23, p < 0.001 for the eighth week and DSP + H: 3.60 ±0.58 vs. H: 5.52 ±1.73, p < 0.001 for the twelfth week of the treatment). It means after 12 weeks of treatment, the average MASI score of patients in the DSP + H group decreased by 77.26 ±2.70%, but in the grroup H, it decreased by 64.31 ±9.68% (p < 0.001). Dynamic PGA showed that excellent treatment occurred in 65% of the + H group H, but only 20% of the H group (p = 0.01).

Conclusions

Oral DSP for 12 weeks along with hydroquinone cream can significantly reduce the MASI score of melasma patients and increase the patients' recovery and satisfaction.

Cost-Effectiveness Analysis of Trastuzumab Deruxtecan Versus Trastuzumab Emtansine for Patients With Human Epidermal Growth Factor Receptor 2 Positive Metastatic Breast Cancer in the United States

OBJECTIVES

To assess the cost-effectiveness of trastuzumab deruxtecan compared with trastuzumab emtansine as second-line therapy for patients with human epidermal growth factor receptor 2 positive metastatic breast cancer from a US healthcare sector perspective.

METHODS

A 3-state partitioned survival model was developed to estimate the cost-effectiveness of trastuzumab deruxtecan compared with trastuzumab emtansine. For both treatments, modeled patients were administered treatment intravenously every 3 weeks indefinitely or until disease progression. Transition parameters were principally derived from the updated DESTINY-Breast03 phase III randomized clinical trial. Costs include drug costs extracted from Centers for Medicare and Medicaid Services average sales price and administrative, adverse event, and third-line therapy costs derived from published literature, measured in 2022 US dollars. Health utilities for health states and disutilities for adverse events were sourced from published literature. Effects were measured in quality-adjusted life years (QALYs). We conducted both probabilistic sensitivity analysis and comprehensive scenario analysis to test model assumptions and robustness, while utilizing a lifetime horizon.

RESULTS

In our base-case analysis, total costs for trastuzumab deruxtecan were $1 266 945, compared with $820 082 for trastuzumab emtansine. Total QALYs for trastuzumab deruxtecan were 5.09, compared with 3.15 for trastuzumab emtansine. The base-case incremental cost-effectiveness ratio was $230 285/QALY. Probabilistic sensitivity analysis indicated that trastuzumab deruxtecan had an 11.1% probability of being cost-effective at a $100 000 per QALY willingness-to-pay threshold.

CONCLUSIONS

Despite the higher efficacy of trastuzumab deruxtecan in patients with human epidermal growth factor receptor 2 positive metastatic breast cancer, our findings raise concern regarding its value at current prices.

Stytontriterpenes A-C, three unusual oleanane-derived triterpenoids from the resin of Styrax tonkinensis as potential immunosuppressive agents in atherosclerosis

Three unusual oleanane-derived triterpenoids, stytontriterpenes A-C (1-3), were isolated from the resin of Styrax tonkinensis together with an oleanane-lactone (stytontriterpene D, 4). Their structures and absolute configurations were characterised using a combination of spectroscopic analysis, electronic circular dichroism, and theoretical calculations. 1 and 2 belong to nor-oleanane with rare spiro D/E rings and 3 contains one infrequent C32 scaffold. 1 considerably suppressed the number of adhered leukemic monocytes (THP-1) to human umbilical vein endothelial cells and attenuated the upregulations of mRNA and protein levels of intracellular adhesion molecule-1 and vascular cell adhesion molecule-1 at 5 μM, suggesting that 1 might be a promising anti-vascular inflammatory chemical for atherosclerosis therapy. Plausible biosynthetic pathways for 1-4 are also proposed.

Gut butyrate-producers confer post-infarction cardiac protection

The gut microbiome and its metabolites are increasingly implicated in several cardiovascular diseases, but their role in human myocardial infarction (MI) injury responses have yet to be established. To address this, we examined stool samples from 77 ST-elevation MI (STEMI) patients using 16 S V3-V4 next-generation sequencing, metagenomics and machine learning. Our analysis identified an enriched population of butyrate-producing bacteria. These findings were then validated using a controlled ischemia/reperfusion model using eight nonhuman primates. To elucidate mechanisms, we inoculated gnotobiotic mice with these bacteria and found that they can produce beta-hydroxybutyrate, supporting cardiac function post-MI. This was further confirmed using HMGCS2-deficient mice which lack endogenous ketogenesis and have poor outcomes after MI. Inoculation increased plasma ketone levels and provided significant improvements in cardiac function post-MI. Together, this demonstrates a previously unknown role of gut butyrate-producers in the post-MI response.

The Role of Large Animal Models in Cardiac Regeneration Research Using Human Pluripotent Stem Cell-Derived Cardiomyocytes

PURPOSE OF REVIEW

Heart failure leads to high mortality. The failing myocardium cannot often be rescued as heart regeneration is mostly compromised by disease progress. Stem cell therapy is a strategy under development to replace the impaired myocardium for recovery after heart injury.

RECENT FINDINGS

Many studies have provided evidence of the beneficial effects of pluripotent stem cell-derived cardiomyocyte (CM) implantation into diseased rodent hearts, but there are still many challenges and limitations to replicating the same effects in large animal models for preclinical validation. In this review, we summarize progress in the use of pluripotent stem cell-derived CMs in large animal models based on three key parameters: species selection, cell source, and delivery. Most importantly, we discuss the current limitations and challenges that need to be solved to advance this technology to the translational stage.

Theoretical study on hydrogen transfer in the dissociation of dimethyl disulfide radical cations

Hydrogen transfer (HT) is of crucial importance in biochemistry and atmospheric chemistry. Here, HT processes involved in the dissociation reaction of dimethyl disulfide radical cations (DMDS˙⁺, CH₃SSCH₃˙⁺) are investigated using quantum chemical calculations. Four HTs from the C to S atom and one HT from the S to S atom are observed and the most probable paths are proposed in the dissociation channel from DMDS˙⁺ to CH_nS⁺ (n = 2-4). The mechanisms of all these five HTs are described as hydrogen atom transfer (HAT) and four of them are accompanied by electron transfer (ET). Considering the catalytic effect of water molecules existing in organisms and the atmosphere, five HT processes in the dissociation of the [DMDS + H₂O]˙⁺ complex are further explored, which show lower free energy barriers. With the participation of water molecules acting as a base, two HTs from the C to the S atom, which have the largest decrease in energy barriers, are characterized as concerted proton-coupled electron transfer (cPCET). These results can be extended to understand the mechanism of the HT process during the dissociation of disulfide and help provide a strategy to design a rare cPCET mechanism for the activation of the C-H bond.

α-Acylation of Alkenes by a Single Photocatalyst

A direct strategy for the difunctionalization of alkenes, with acylation occurring at the more substituted alkene position, would be attractive for complex ketone synthesis. We report herein a reaction driven by a single photocatalyst that enables α-acylation in this way with the introduction of a fluoromethyl, alkyl, sulfonyl or thioether group at the β-position of the alkene with high chemo- and regioselectivity under extremely mild conditions. Crucial to the success of this method are rate differences in the kinetics of radical generation through single-electron transfer (SET) between different radical precursors and the excited photocatalyst (PC*). Thus, the β-position of the alkene is first occupied by the group derived from the radical precursor that can be generated most readily, and α-keto acids could be used as an electrophilic reagent for the α-acylation of alkenes.

Metabolic Changes Associated With Cardiomyocyte Dedifferentiation Enable Adult Mammalian Cardiac Regeneration

BACKGROUND

Cardiac regeneration after injury is limited by the low proliferative capacity of adult mammalian cardiomyocytes (CMs). However, certain animals readily regenerate lost myocardium through a process involving dedifferentiation, which unlocks their proliferative capacities.

METHODS

We bred mice with inducible, CM-specific expression of the Yamanaka factors, enabling adult CM reprogramming and dedifferentiation in vivo.

RESULTS

Two days after induction, adult CMs presented a dedifferentiated phenotype and increased proliferation in vivo. Microarray analysis revealed that upregulation of ketogenesis was central to this process. Adeno-associated virus-driven HMGCS2 overexpression induced ketogenesis in adult CMs and recapitulated CM dedifferentiation and proliferation observed during partial reprogramming. This same phenomenon was found to occur after myocardial infarction, specifically in the border zone tissue, and HMGCS2 knockout mice showed impaired cardiac function and response to injury. Finally, we showed that exogenous HMGCS2 rescues cardiac function after ischemic injury.

CONCLUSIONS

Our data demonstrate the importance of HMGCS2-induced ketogenesis as a means to regulate metabolic response to CM injury, thus allowing cell dedifferentiation and proliferation as a regenerative response.

Porous scaffold for mesenchymal cell encapsulation and exosome-based therapy of ischemic diseases

Ischemic diseases including myocardial infarction (MI) and limb ischemia are some of the greatest causes of morbidity and mortality worldwide. Cell therapy is a potential treatment but is usually limited by poor survival and retention of donor cells injected at the target site. Since much of the therapeutic effects occur via cell-secreted paracrine factors, including extracellular vesicles (EVs), we developed a porous material for cell encapsulation which would improve donor cell retention and survival, while allowing EV secretion. Human donor cardiac mesenchymal cells were used as a model therapeutic cell and the encapsulation system could sustain three-dimensional cell growth and secretion of therapeutic factors. Secretion of EVs and protective growth factors were increased by encapsulation, and secreted EVs had hypoxia-protective, pro-angiogenic activities in in vitro assays. In a mouse model of limb ischemia the implant improved angiogenesis and blood flow, and in an MI model the system preserved ejection fraction %. In both instances, the encapsulation system greatly extended donor cell retention and survival compared to directly injected cells. This system represents a promising therapy for ischemic diseases and could be adapted for treatment of other diseases in the future.

Rates of implantable cardioverter defibrillator implantation and outcomes in octogenarians or older compared to non-octogenarians in a statewide cohort from 2009 to 2018

Background

Octogenarians are underrepresented or excluded in major implantable cardioverter defibrillator (ICD) trials. The deployment of ICDs and their real-world outcomes in octogenarians is unclear.

Purpose

To investigate the prevalence and outcomes of ICD implantation in octogenarian or older vs non-octogenarian.

Methods

We extracted details of all ICD implanted statewide from 2009–2018 including patient's characteristics, in-hospital complications and mortality using the Centre-for-Health-Record-Linkage administrative datasets. Implantation rates were adjusted for the population size by sex, age-groups in decade and calendar-year. Analysis was stratified by age &lt;80 vs ≥80yo.

Results

There were 9304 admissions (12.1% ≥80yo) for de novo ICD implantation (mean±SD implantation: 1163±122 cases per-annum). The mean age for ≥80 vs &lt;80yo groups was 83.5±2.9yo vs 66.2±12.1yo respectively (overall cohort mean age 66.1±13.1yo). Total ICD implantations increased by 8.4±12.4% vs 1.8±8.4% per-annum for ≥80 vs &lt;80yo groups. The mean implantation rates were 52.7±10.8 vs 22.0±2.8 per-100,000-persons in ≥80yo compared to &lt;80yo, respectively, with rates increasing at 7.7±18.3% per-100,000-persons-per-annum in ≥80yo. In contrast, implantation rates declined slightly by 0.2±12.4% per-100,000-persons-per-annum in &lt;80yo groups. There was a non-significant trend towards more in-hospital non-fatal complications in ≥80yo compared to &lt;80yo (10.8% vs 9.0% respectively, p=0.054), with no difference in in-hospital mortality (0.6% vs 0.4% respectively, p=0.32). The 1-year mortality was 10.7% in ≥80yo compared to 4.7% in &lt;80yo (p&lt;0.001), and 2-year mortality was 20.2% vs 8.8% respectively (p&lt;0.001). The 1-yr and 2-yr mortality hazard ratio for ≥80yo was 2.0 (95% confidence interval [CI] 1.6–2.5, p&lt;0.001) and 2.2 (95% CI 1.8–2.5, p&lt;0.001) respectively after adjusting for sex, year of implantation, referral source, indications for ICD, and comorbidities. Overall, the annual rates of total in-hospital non-fatal complications and mortality did not alter significantly during the study period.

Conclusion

Despite limited clinical trials data on efficacy of ICD use in octogenarians or older, implantation rate was more than double that of &lt;80yo age-groups, with the implantation rate observed to be increasing in ≥80yo. There was no significant difference in in-hospital mortality between the two age-groups, however the 1-year and 2-year mortality rates were significantly higher in the ≥80yo.

Funding Acknowledgement

Type of funding sources: None.

The gut microbiota regulates acute foreign body reaction and tissue repair after biomaterial implantation

We hypothesized that the host microbiome may influence foreign body responses following biomaterial implantation. To test this, we implanted a variety of clinically relevant biomaterials into germ-free or antibiotic-treated mice. Surprisingly, these mice displayed less fibrous tissue deposition, reduced host cell recruitment to the implant site, and differential expression of angiogenic and inflammatory markers. These observations were reversed upon fecal microbiome reconstitution, confirming a causal role of the host microbiome. In a clinically relevant disease model, microbiome-depleted mice cleared hyaluronic acid and bone marrow mononuclear cells from ischemic hind limb tissues more slowly, resulting in an improved therapeutic response. Findings were confirmed in pigs which showed reduced fibrotic responses to a variety of implanted materials. Lastly, we profiled changes in the host microbiome following material implantation, implicating several key bacteria phyla.

Lewis Acid-Relayed Singlet Oxygen Reaction with Enamines: Selective Dimerization of Enamines to Pyrrolin-4-ones

Singlet oxygen (¹O₂)-mediated oxidation represents an attractive strategy for incorporation of oxygen atoms from air under mild and environmentally benign conditions. However, the ¹O₂ reaction with enamine suffers from fragmentation, leading to very unsuccessful transformation. Here, Lewis acid is introduced to intercept [2 + 2] or "ene" reaction intermediates of the ¹O₂ reaction and enables oxidative dimerization of enamines to produce pyrrolin-4-ones in good to excellent yields. Mechanistic studies reveal the formation of the imino ketone intermediate from the interaction of ¹O₂ and enamine, which is able to interact with Lewis acid, relaying the ¹O₂ reaction in enamine chemistry. For the first time, selective cross-dimerization of two different enamines is achieved. Due to the advantages of mild conditions, high chemoselectivity, and up to 99% yield, a promising strategy has been developed for synthesizing aza-heterocycles under ambient conditions, which can be further applied for the synthesis of imidazolone, quinoxaline, and highly functionalized imine.

Abstract P3120: Cardio And Neurotoxicity Of Repurposed Anti-COVID-19 Drugs

In December 2019, the novel coronavirus disease 2019 (COVID-19), caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) spread around the globe resulting in ~435 million confirmed cases and ~6 million related deaths as of March 2022, according to the World Health Organization. To combat COVID-19 quickly, there have been many attempts to repurpose current FDA-approved drugs or to revive old drugs with anti-viral properties. However, aside from the biological stress imposed by the virus, many of the current treatment options have been known to cause adverse drug reactions. We established a population-based human induced pluripotent stem cell drug screening platform to assess the toxicity of the first line of anti-COVID-19 drugs and to understand viral infection of cardiomyocytes and neurons. We found that iPSC-derived cardiomyocytes express the ACE2 receptor which correlated with a higher infection of the SARS-CoV-2 virus (r=0.86). However, ACE2 expression was undetectable in neurons which correlated with low infection of neurons. We then assessed the toxicity of anti-COVID-19 drugs and identified two cardiotoxic compounds (remdesivir and arbidol) and 4 neurotoxic compounds (arbidol, remdesivir, hydroxychloroquine, and chloroquine) which were validated by dose-response curves. These data show that this platform can quickly and easily be employed to further our understanding of cell-specific infection and identify drug toxicity of potential treatment options helping clinicians better decide on treatment options.

Cardio- and Neurotoxicity of Selected Anti-COVID-19 Drugs

Since December 2019, the novel coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has infected ~435 million people and caused ~6 million related deaths as of March 2022. To combat COVID-19, there have been many attempts to repurpose FDA-approved drugs or revive old drugs. However, many of the current treatment options have been known to cause adverse drug reactions. We employed a population-based drug screening platform using 13 human leukocyte antigen (HLA) homozygous human induced pluripotent cell (iPSC) lines to assess the cardiotoxicity and neurotoxicity of the first line of anti-COVID-19 drugs. We also infected iPSC-derived cells to understand the viral infection of cardiomyocytes and neurons. We found that iPSC-derived cardiomyocytes express the ACE2 receptor which correlated with a higher infection of the SARS-CoV-2 virus (r = 0.86). However, we were unable to detect ACE2 expression in neurons which correlated with a low infection rate. We then assessed the toxicity of anti-COVID-19 drugs and identified two cardiotoxic compounds (remdesivir and arbidol) and four neurotoxic compounds (arbidol, remdesivir, hydroxychloroquine, and chloroquine). These data show that this platform can quickly and easily be employed to further our understanding of cell-specific infection and identify drug toxicity of potential treatment options helping clinicians better decide on treatment options.

Extensive Variation in Gene Expression is Revealed in 13 Fertility-Related Genes Using RNA-Seq, ISO-Seq, and CAGE-Seq From Brahman Cattle

Fertility is a key driver of economic profitability in cattle production. A number of studies have identified genes associated with fertility using genome wide association studies and differential gene expression analysis; however, the genes themselves are poorly characterized in cattle. Here, we selected 13 genes from the literature which have previously been shown to have strong evidence for an association with fertility in Brahman cattle (Bos taurus indicus) or closely related breeds. We examine the expression variation of the 13 genes that are associated with cattle fertility using RNA-seq, CAGE-seq, and ISO-seq data from 11 different tissue samples from an adult Brahman cow and a Brahman fetus. Tissues examined include blood, liver, lung, kidney, muscle, spleen, ovary, and uterus from the cow and liver and lung from the fetus. The analysis revealed several novel isoforms, including seven from SERPINA7. The use of three expression characterization methodologies (5′ cap selected ISO-seq, CAGE-seq, and RNA-seq) allowed the identification of isoforms that varied in their length of 5′ and 3′ untranslated regions, variation otherwise undetectable (collapsed as degraded RNA) in generic isoform identification pipelines. The combinations of different sequencing technologies allowed us to overcome the limitations of relatively low sequence depth in the ISO-seq data. The lower sequence depth of the ISO-seq data was also reflected in the lack of observed expression of some genes that were observed in the CAGE-seq and RNA-seq data from the same tissue. We identified allele specific expression that was tissue-specific in AR, IGF1, SOX9, STAT3, and TAF9B. Finally, we characterized an exon of TAF9B as partially nested within the neighboring gene phosphoglycerate kinase 1. As this study only examined two animals, even more transcriptional variation may be present in a genetically diverse population. This analysis reveals the large amount of transcriptional variation within mammalian fertility genes and illuminates the fact that the transcriptional landscape cannot be fully characterized using a single technology alone.

[A case of atypical iris corneal endothelial syndrome]

Iridocorneal endothelial syndrome is a rare ophthalmic disease, most of which are unilateral and common in women. The rate of misdiagnosis and missed diagnosis is relatively high due to its various clinical manifestations. In this case, the patient presented uncontrollable high intraocular pressure, corneal edema leading to difficult observation of corneal endothelium morphology, and accompanied by a small amount of iris neovascularization. No clearly diagnosis was made before glaucoma surgery. Further examination was performed after corneal clearance, and the final diagnosis was iris corneal endothelial syndrome (Chandler syndrome).

Direct 1,2-Dicarbonylation of Alkenes towards 1,4-Diketones via Photocatalysis

1,4-Dicarbonyl compounds are intriguing motifs and versatile precursors in numerous pharmaceutical molecules and bioactive natural compounds. Direct incorporation of two carbonyl groups into a double bond at both ends is straightforward, but also challenging. Represented herein is the first example of 1,2-dicarbonylation of alkenes by photocatalysis. Key to success is that N(n-Bu)₄ ⁺ not only associates with the alkyl anion to avoid protonation, but also activates the α-keto acid to undergo electrophilic addition. The α-keto acid is employed both for acyl generation and electrophilic addition. By tuning the reductive and electrophilic ability of the acyl precursor, unsymmetric 1,4-dicarbonylation is achieved for the first time. This metal-free, redox-neutral and regioselective 1,2-dicarbonylation of alkenes is executed by a photocatalyst for versatile substrates under extremely mild conditions and shows great potential in biomolecular and drug molecular derivatization.

Direct C-H Thiolation for Selective Cross-Coupling of Arenes with Thiophenols via Aerobic Visible-Light Catalysis

An aerobic metal-free, visible-light-induced regioselective thiolation of phenols with thiophenols is reported. The cross-coupling protocol exhibits great functional group tolerance and high regioselectivity. Mechanistic studies reveal that the disulfide radical cation plays a crucial role in the visible-light catalysis of aerobic thiolation. Simply controlling the equivalent ratio of substrates enables the selective formation of sulfide or sulfoxide products with high activity in a one-pot reaction.

Modification-bioremediation of copper, lead, and cadmium-contaminated soil by combined ryegrass (Lolium multiflorum Lam.) and Pseudomonas aeruginosa treatment

The principal objective of this study was to investigate the strengthened remediation effect and relevant mechanism of P. aeruginosa on ryegrass (Lolium multiflorum Lam.) for soil contaminated by Cu-Pb-Cd compound heavy metals. The results showed that the complex heavy metals' contamination had remarkable inhibiting effect on the growth of plants (P < 0.01), and the biomass of ryegrass's stem and leaves declined by 28.2%, while that of roots decreased by 34.7% after 45 days. The inoculation of P. aeruginosa promoted the growth of ryegrass in polluted soil, in which the biomass recovered to the same level of that in normal plant; the activity of both catalase and urease in the soil also increased strikingly (by 29.3% and 75.7%, respectively); the ratio of residual heavy metals in the soil decreased, while the acid extractable heavy metals increased notably. Therefore, the absorption and accumulation of ryegrass to the heavy metals in soil were improved to some extent; the bioconcentration factor of Cu, Pb, and Cd in ryegrass increased by 35.9%, 55.6%, and 283.5%, respectively. The exterior microorganism allowed the accumulation of Cu, Pb, and Cd in shoots of ryegrass increasing remarkably, while in roots, only the accumulation of Pb increased by 16.3%, and that of both Cu and Cd decreased. Besides, in the P. aeruginosa-inoculated system, the transfer factor of Cu and Cd in plants increased strikingly, while that of Pb decreased.

Therapeutic potential of ALKB homologs for cardiovascular disease

Cardiovascular diseases (CVDs) are the leading causes of human death. Recently, ALKB homologs, including ALKBH1-8 and FTO, have been found to have a variety of biological functions, such as histone demethylation, RNA demethylation, and DNA demethylation. These functions may regulate the physiological and pathological processes of CVDs, including inflammation, oxidative stress, cell apoptosis, and mitochondrial, endothelial, and fat metabolism dysfunction. In the present review, we summarize the biological functions of ALKB homologs and the relationship between the ALKB homologs and CVDs. Importantly, we discuss the roles of ALKB homologs in the regulation of oxidative stress, inflammation, autophagy, and DNA damage in CVDs, as well as the practical applications of ALKB homologs inhibitors or agonists in treating CVDs. In conclusion, the ALKBH family might be a promising target for CVDs therapy.

Cobaloxime Catalysis for Enamine Phosphorylation with Hydrogen Evolution

Direct phosphorylation of enamine and enamide with hydrogen evolution was realized via cobaloxime catalysis under visible-light irradiation. Control experiments and spectroscopic studies demonstrated a reductive quenching pathway of cobaloxime catalyst to produce phosphinoyl radical, which underwent cross-coupling with various enamines (and enamides) to give diverse β-phosphinoyl products in good to excellent yields. More interestingly, Z/E mixture of acyclic enamines could convert into single Z-products with good reactivity.

Prostaglandin E2 Receptor 2 Modulates Macrophage Activity for Cardiac Repair

Background

Prostaglandin E₂ has long been known to be an immune modulator. It is released after tissue injury and plays a role in modulating macrophage activities, which are essential for tissue regeneration. However, the involvement of prostaglandin E₂ receptor 2 (EP2)–dependent regulation of macrophages in postischemic heart is unclear. This study aims to evaluate the role of EP2 in damaged heart.

Methods and Results

The effect of EP2 in postischemic heart was evaluated using EP2‐deficient transgenic mice. We demonstrated that cardiac function was worse after myocardial injury on loss of EP2. Furthermore, EP2 deficiency also altered proinflammatory response and resulted in a defect in macrophage recruitment to the injured myocardium. Transcriptome analysis revealed that the expression of erythroid differentiation regulator 1 (Erdr1) was significantly induced in EP2‐deficient macrophages. Knocking down Erdr1 expression restored migration ability of EP2‐deficient cells both in vitro and in vivo. By using a genetic fate‐mapping approach, we showed that abolishment of EP2 expression effectively attenuated cell replenishment.

Conclusions

The EP2‐dependent signaling pathway plays a critical role in regulating macrophage recruitment to the injured myocardium, thereby exerting a function in modulating the inflammatory microenvironment for cardiac repair.

Mediation of functional gene and bacterial community profiles in the sediments of eutrophic Chaohu Lake by total nitrogen and season

Microbes in sediments contribute to nutrient release and play an important role in lake eutrophication. However, information about the profiles of functional genes and bacterial communities and the most important environmental factor affecting them in the sediments of eutrophic lake remains unrevealed. In this work, the real-time fluorescent quantitative polymerase chain reaction (qPCR) assay and 16S ribosomal RNA gene next generation sequencing analysis were used to explore the profiles of functional genes and bacterial communities in the sediments of Chaohu Lake. The selected 18 functional genes involved in C, N and P cycles were detected in most of samples. Seasonal variation and sediment variables were found to affect the profiles of functional genes and bacterial communities, and total nitrogen was the dominant environmental factor to drive the formation of bacterial community structure. Proteobacteria and Firmicutes were observed to be the two dominant phyla in the sediments with relative abundance ranging from 10.8% to 36.0% and 7.7%-46.7%, respectively. Three bacterial phyla, i.e., Actinobacteria, Proteobacteria, and Spirochaetes, were found to be significantly positively correlated with the C, N and P-cycle related functional genes. Bacterial community structure was the most important driver to shape the profiles of functional genes. Seasonal variation also influenced the co-occurrence patterns between functional genes and bacterial taxa as revealed by network analysis. The findings from this work facilitate a better understanding about the C, N, and P cycles in the sediments of eutrophic lakes.

Luciferin Regeneration in Firefly Bioluminescence via Proton-Transfer-Facilitated Hydrolysis, Condensation and Chiral Inversion

Firefly bioluminescence is produced via luciferin enzymatic reactions in luciferase. Luciferin has to be unceasingly replenished to maintain bioluminescence. How is the luciferin reproduced after it has been exhausted? In the early 1970s, Okada proposed the hypothesis that the oxyluciferin produced by the previous bioluminescent reaction could be converted into new luciferin for the next bioluminescent reaction. To some extent, this hypothesis was evidenced by several detected intermediates. However, the detailed process and mechanism of luciferin regeneration remained largely unknown. For the first time, we investigated the entire process of luciferin regeneration in firefly bioluminescence by density functional theory calculations. This theoretical study suggests that luciferin regeneration consists of three sequential steps: the oxyluciferin produced from the last bioluminescent reaction generates 2-cyano-6-hydroxybenzothiazole (CHBT) in the luciferin regenerating enzyme (LRE) via a hydrolysis reaction; CHBT combines with L-cysteine in vivo to form L-luciferin via a condensation reaction; and L-luciferin inverts into D-luciferin in luciferase and thioesterase. The presently proposed mechanism not only supports the sporadic evidence from previous experiments but also clearly describes the complete process of luciferin regeneration. This work is of great significance for understanding the long-term flashing of fireflies without an in vitro energy supply.

miR-375 inhibits the proliferation and invasion of glioblastoma by regulating Wnt5a

The aberrant expression of microRNA-375 (miR-375) has been proved to be associated with carcinogenesis. However, the role of miR-375 in glioblastoma (GBM) remains unknown. The aim of this study was to investigate biological functions and its molecular mechanisms of miR-375 in GBM cells. In this study, real-time PCR results showed that the level of miR-375 expression in GBM tissues and GBM cell lines (U87 and U251) was decreased. Using MTT assay, Transwell migration and invasion assay, we demonstrated that miR-375 overexpression significantly suppress cell proliferation, cell migration and cell invasion capacity in U87 and U251 cells. However, downregulation of miR-375 had reverse effects on cell proliferation, migration and invasion. Targeting association analysis, dual luciferase assay, RT-PCR and western blot analysis results confirmed that miR-375 could target the 3'UTR of Wnt5a mRNA and regulated its protein expression. Further studies also find overexpression of Wnt5a could significantly reverse miR-375-mediated proliferation, migration and invasion on U87 and U251 cells. Therefore, we concluded that miR-375 inhibited the proliferation and invasion of GBM by regulating Wnt5a and might be a possible therapeutic agent for GBM.

Palmatine attenuated dextran sulfate sodium (DSS)-induced colitis via promoting mitophagy-mediated NLRP3 inflammasome inactivation

Activation of NLRP3 inflammasomes is crucial in the pathological process of Ulcerative colitis (UC), which could be negatively regulated by PINK1/Parkin-driven mitophagy. Palmatine is a herb derived isoquinoline alkaloid with potent anti-inflammatory and anti-bacteria activities. In present study, we evaluated the effect of palmatine on dextran sulfate sodium (DSS)-induced mice colitis and examined whether its effect is exerted by promoting mitophagy-mediated NLRP3 inflammasome inactivation. The result showed that palmatine (40, 100 mg/kg) significantly prevented bodyweight loss and colonic shortening in DSS mice, and reduced the disease activity index and histopathologic score. The levels of MPO, IL-1β, TNF-α and the number of F4/80+ cells in colon of DSS mice were remarkably decreased by palmatine. Moreover, palmatine suppressed NLRP3 inflammasomes activation, but enhanced the expression of the mitophagy-related proteins involving LC3, PINK1 and Parkin in colonic tissue of DSS mice. These effects was consistent with the in vitro data revealing that palmatine inhibited the activation of NLRP3 inflammasomes, while promoted the expression and mitochondrial recruitment of PINK1 and Parkin in THP-1 cell differentiated macrophages. Furthermore, the effect of palmatine on THP-1 cells was neutralized by a mitophagy inhibitor Cyclosporin A (CsA) and PINK1-siRNA. In parallel, CsA significantly attenuated the therapeutic effect of palmatine in DSS mice, illustrating that the anti-colitis effect of palmatine is closely related to mitophagy. Taken together, the current results demonstrated that palmatine protected mice against DSS-induced colitis by facilitating PINK1/Parkin-driven mitophagy and thus inactivating NLRP3 inflammasomes in macrophage.

Abundance and diversity of iron reducing bacteria communities in the sediments of a heavily polluted freshwater lake

Iron reduction mediated by Fe(III)-reducing bacteria (FeRB) occurs in aqueous environments and plays an essential role in removing contaminates in polluted freshwater lakes. Two model FeRB species, Shewanella and Geobacter, have been intensively studied because of their functions in bioremediation, iron reduction, and bioelectricity production. However, the abundance and community diversity of Shewanella and Geobacter in eutrophic freshwater lakes remain largely unknown. In this work, the distribution, abundance and biodiversity of Shewanella, Geobacter and other FeRB in the sediments of a heavily polluted lake, Chaohu Lake, China, across four successive seasons were investigated. Shewanella, Geobacter, and other FeRB were found to be widely distributed in the sediment of this heavily eutrophic lake. Geobacter was abundant with at least one order of magnitude more than Shewanella in cold seasons. Three Shewanella-related operational taxonomic units were detected and sixty one Geobacter-related operational taxonomic units were grouped into three phylogenetic clades. Thiobacillus, Desulfuromonas and Geobacter were identified as the main members of FeRB in the lake sediments. Interestingly, nutrients like carbon, nitrogen, and phosphorus were found to be the key factors governing the abundance and diversity of FeRB. Total FeRB, as well as Geobacter and Shewanella, were more abundant in the heavily eutrophic zone than those in the lightly eutrophic zone. The abundance and diversity of FeRB in the sediments of freshwater lakes were highly related with the degree of eutrophication, which imply that FeRB might have a great potential in alleviating the eutrophication and contamination in aqueous environments.

[Physiological Responses of Ryegrass in Cadmium-Nonylphenol Co-contaminated Water and the Phytoremediation Effects]

Physiological responses of ryegrass in cadmium-nonylphenol (Cd-NP) co-contaminated water, as well as the phytoremediation effect were studied under laboratory conditions. The experiment revealed that the biomass and chlorophyll content of ryegrass significantly declined at high concentrations of Cd²⁺(10 mg·L^-1), while POD and PPO activities significantly increased. No significant changes to the biomass, chlorophyll content and MDA of ryegrass were observed in the presence of NP. POD activities significantly increased at high concentrations of NP (5 mg·L^-1). The addition of high NP concentrate reduced the inhibition of Cd under co-contaminated stress, the MDA content and PPO activities both reduced. The experiment also revealed that the removal rate of Cd²⁺ by ryegrass reached 55.3% after 12 h. The absorption efficiency was improved by high NP concentration. Absorption efficiency of Cd²⁺ by the subterranean part of the plant significantly increased in presence of NP, and the absorption efficiency increased with the increase of NP concentration. The absorption rate of NP was 44.6% after 24 h at NP concentration of 5 mg·L^-1. The removal rate was slightly influenced at low concentrations of Cd²⁺, but significant inhibition of absorption and degradation was observed at high concentrations of Cd²⁺.

Estimates of abundance and diversity of Shewanella genus in natural and engineered aqueous environments with newly designed primers

Shewanella species have a diverse respiratory ability and wide distribution in environments and play an important role in bioremediation and the biogeochemical cycles of elements. Primers with more accuracy and broader coverage are required with consideration of the increasing number of Shewanella species and evaluation of their roles in various environments. In this work, a new primer set of 640F/815R was developed to quantify the abundance of Shewanella species in natural and engineered environments. In silico tools for primer evaluation, quantitative polymerase chain reaction (qPCR) and clone library results showed that 640F/815R had a higher specificity and coverage than the previous primers in quantitative analysis of Shewanella. Another newly developed primer pair of 211F/815cR was also adopted to analyze the Shewanella diversity and demonstrated to be the best candidate in terms of specificity and coverage. We detected more Shewanella-related species in freshwater environments and found them to be substantially different from those in marine environments. Abundance and diversity of Shewanella species in wastewater treatment plants were largely affected by the process and operating conditions. Overall, this study suggests that investigations of abundance and diversity of Shewanella in various environments are of great importance to evaluate their ecophysiology and potential ecological roles.

Theoretical Development of Near-Infrared Bioluminescent Systems

The luciferin/luciferase system of the firefly has been used in bioluminescent imaging to monitor biological processes. In order to enhance the efficiency and expand the application range, some efforts have been made to tune the light emission, especially the effort to obtain NIR light. However, those case-by-case studies have not together revealed the nature and mechanism of the color tuning. In this paper, we theoretically investigated the fluorescence of all kinds of typical oxyluciferin analogues. The present systematical modifications of both oxyluciferin and luciferase indicate that the essential factor affecting the emission color is the charge distribution (or the electric dipole moment) on the oxyluciferin, which impacts on the charge transfer to form the light emitter and, subsequently, influence the strength and wavelength of the emission light. More negative charge distributed on the "thiazolone moiety" of the oxyluciferin or its analogues leads to a redshift. Based on this conclusion, we theoretically designed optimal pairs of luciferin analogue and luciferase for emitting NIR light, which could inspire new synthetic procedures and practical applications.

Reduction pathway and mechanism of chloronitrobenzenes synergistically catalyzed by bioPd and Shewanella oneidensis MR-1 assisted by calculation

Although microbial synthesized palladium nanoparticles (bioPd) have been demonstrated to exhibit a great activity toward dechlorination of several chlorinated pollutants, there is no systematic investigation into the substituent effect on dechlorination. Chloronitrobenzenes are widely used for manufacturing and known as persistent pollutants with recalcitrance of biodegradation for nitro groups. In this work, bioPd was synthesized by Shewanella oneidensis MR-1. The dechlorination of 2-chloronitrobenzene, 4-chloronitrobenzene and 2,4-dichloronitrobenzene catalyzed by bioPd were investigated. Simultaneous dechlorination and nitro reduction were observed by synergistic catalysis of bioPd and S. oneidensis MR-1. Pd concentration was optimized for the reduction. Producing profiles of intermediates changed with the ratio of Pd to cell, supporting a size- or shape-controlled catalytic activity of bioPd. The removal of chloro atoms at para-position was easier than that at ortho-position in 2,4-DCNB, suggesting a position effect on the reduction, which was further supported by the frontier molecular orbital and frontier electron density of 2,4-DCNB according to density functional theory.

Reprogramming-derived gene cocktail increases cardiomyocyte proliferation for heart regeneration

Although remnant cardiomyocytes (CMs) possess a certain degree of proliferative ability, efficiency is too low for cardiac regeneration after injury. In this study, we identified a distinct stage within the initiation phase of CM reprogramming before the MET process, and microarray analysis revealed the strong up-regulation of several mitosis-related genes at this stage of reprogramming. Several candidate genes were selected and tested for their ability to induce CM proliferation. Delivering a cocktail of three genes, FoxM1, Id1, and Jnk3-shRNA (FIJs), induced CMs to re-enter the cell cycle and complete mitosis and cytokinesis in vitro More importantly, this gene cocktail increased CM proliferation in vivo and significantly improved cardiac function and reduced fibrosis after myocardial infarction. Collectively, our findings present a cocktail FIJs that may be useful in cardiac regeneration and also provide a practical strategy for probing reprogramming assays for regeneration of other tissues.

Multiple variants in 5q31.1 are associated with systemic lupus erythematosus susceptibility and subphenotypes in the Han Chinese population

BACKGROUND

A previous study provided evidence for a genetic association between PPP2CA on 5q31.1 and systemic lupus erythematosus (SLE) across multi-ancestral cohorts, but failed to find significant evidence for an association in the Han Chinese population.

OBJECTIVES

To explore the association between this locus and SLE using data from our previously published genome-wide association study (GWAS).

METHODS

Single-nucleotide polymorphisms (SNPs) rs7726414 and rs244689 (near TCF7 and PPP2CA in 5q31.1) were selected as candidate independent associations from a large-scale study in a Han Chinese population consisting of 1047 cases and 1205 controls. Subsequently, 3509 cases and 8246 controls were genotyped in two further replication studies. We then investigated the SNPs' associations with SLE subphenotypes and gene expression in peripheral blood mononuclear cells.

RESULTS

Highly significant associations with SLE in the Han Chinese population were detected for SNPs rs7726414 and rs244689 by combining the genotype data from our previous GWAS and two independent replication cohorts. Further conditional analyses indicated that these two SNPs contribute to disease susceptibility independently. A significant association with SLE, age at diagnosis < 20 years, was found for rs7726414 (P = 0·001). The expression levels of TCF7 and PPP2CA messenger RNA in patients with SLE were significantly decreased compared with those in healthy controls.

CONCLUSIONS

This study found evidence for multiple associations with SLE in 5q31.1 at genome-wide levels of significance for the first time in a Han Chinese population, in a combined genotype dataset. These findings suggest that variants in the 5q31.1 locus not only provide novel insights into the genetic architecture of SLE, but also contribute to the complex subphenotypes of SLE.

[Effect of Xinfeng Capsule on Pulmonary Function, Thi/Th2 Cells, and Regulatory T Cells of Adjuvant Arthritis Rats]

Objective To observe the effects of Xinfeng Capsule (XFC) at different doses on lung function, Thl/Th2 cells, regulatory T cells (Treg) in adjuvant arthritis (AA) rats. Methods Totally 84 rats were randomly divided into 5 groups, i.e., the normal control group (NC) , the model group (M) , the methotrexate (MTX) group, the Tripterygium Glycosides Table (TGT) group, the low dose XFC (XFC- L) group, the medium dose XFC (XFC-M) group, the high dose XFC (XFC-H) group, 12 in each group. Freund's complete adjuvant (FCA; 0. 1 mL) was intradermally injected to all rats except those in the NC group from right rear paw to induce inflammation. Medication was started from the 19th day after inflam- mation. Normal saline was administered to rats in the NC group and the M group. Rats in the rest groups were correspondingly administered with MTX, TGT, XFC, respectively. Changes of each index were ob- served in all groups. Results (1) Compared with the NC group, rat paw swelling degree (E) , arthritis index (AI) , lung index (LI) , average expiratory flow in 1 second (FEV1/FVC%) , alveolitis integral, TNF- α, Th1/Th2 cells, transforming growth factor-β₁ ( TGF-β₁ ) expression significantly increased in the M group (P <0. 01) ; forced vital capacity (FVC) , peak expiratory flow 25% of vital capacity (FEF25), peak expiratory flow 50% of vital capacity (FEF50), peak expiratory flow 75% of vital capacity (FEF75), the maximum mid-expiratory flow (MMF) , peak expiratory flow (PEF) , CD4 ⁺Treg, CD4⁺CD25 ⁺Treg, IL-10, and Foxp3 expression significantly decreased in the M group (P <0. 01). (2) Compared with the M group, body weight, FVC, FEF25, FEF50, FEF75, MMF, PEF, IL-10, Treg, and Foxp3 expression increased in all treatment groups; E, Al, LI, FEV1/FVC%, TNF-α, Th1/Th2 cells, and TGF-β₁ expression decreased in all treatment groups (P <0. 05, P <0. 01). (3) Compared with the XFC-M group, LI, alveolitis integral, TNF- α, Th1/Th2 cells, and TGF-β1 increased; FVC, FEF25, FEF50, FEF75, IL-10, CD4⁺Treg, CD4⁺CD25⁺ Treg, and Foxp3 decreased in other treatment groups (P <0. 05, P <0. 01). Conclusions AA rats had local swollen paws and decreased lung function. XFC could significantly improve paw swelling and Al of AA rats, and improve lung function. It could reduce inflammatory reaction and immune complexes on tis- sue and organ damage, improve joint and pulmonary symptoms possibly through promoting expressions of IL-10, CD4⁺Treg, CD4⁺CD25⁺Treg, and Foxp3, and inhibiting TNF-α,Th1/Th2 cells, and TGF-β₁ ex- pression.

[Effect of Cadmium on Biodegradation of Nonylphenol by Pseudomonas aeruginosa]

The influence of Cd on the degradation of nonylphenol (NP) by P.aeruginosa SH1 was investigated in this study.The investigation revealed that biomass of the strain was significantly declined with the increase of Cd²⁺ concentration.The biomass was declined by 27.1% in the presence of 10 mg·L^-1Cd²⁺ after 24 h.The addition of Cd²⁺ had a great influence on adsorption of NP by the strain.As for the effect of living stain,adsorption by P.aeruginosa SH1 cells was stimulated at low concentrations of Cd²⁺(0.5 mg·L^-1),while inhibited at higher levels (≥5 mg·L^-1).As for inactivation of microbes,adsorption by cells was stimulated at higher concentrations,but was only slightly influenced at low levels.The results showed that the intracellular enzymes had much greater degradation rate than the living cells.Different concentrations of Cd²⁺ had different effects on bacteria and intracellular enzyme degradation of NP separately.The degradation efficiency when using intracellular enzymes and bacteria was inhibited at higher levels of Cd²⁺ and the intracellular enzyme inhibition was more significant.Degradation by cells was stimulated at low concentrations of Cd²⁺,but no significant impact was found on that by intracellular enzymes.The degradation process of NP by intracellular enzymes of the strain conformed to the first-order kinetic model.The highest reaction rate was achieved when the concentrations of Cd²⁺ was 0.5 mg·L^-1 and the half-life of this substrate was 5.5 h.However,the degradation process of NP by the strain did not conform to the first-order kinetic model.

Mechanisms of pluripotency maintenance in mouse embryonic stem cells

Mouse embryonic stem cells (mESCs), characterized by their pluripotency and capacity for self-renewal, are driven by a complex gene expression program composed of several regulatory mechanisms. These mechanisms collaborate to maintain the delicate balance of pluripotency gene expression and their disruption leads to loss of pluripotency. In this review, we provide an extensive overview of the key pillars of mESC pluripotency by elaborating on the various essential transcription factor networks and signaling pathways that directly or indirectly support this state. Furthermore, we consider the latest developments in the role of epigenetic regulation, such as noncoding RNA signaling or histone modifications.

Redox properties of extracellular polymeric substances (EPS) from electroactive bacteria

Although the capacity for electroactive bacteria to convert environmental metallic minerals and organic pollutants is well known, the role of the redox properties of microbial extracellular polymeric substances (EPS) in this process is poorly understood. In this work, the redox properties of EPS from two widely present electroactive bacterial strains (Shewanella oneidensis and Pseudomonas putida) were explored. Electrochemical analysis demonstrates that the EPS extracted from the two strains exhibited redox properties. Spectroelectrochemical and protein electrophoresis analyses indicate that the extracted EPS from S. oneidensis and P. putida contained heme-binding proteins, which were identified as the possible redox components in the EPS. The results of heme-mediated behavior of EPS may provide an insight into the important roles of EPS in electroactive bacteria to maximize their redox capability for biogeochemical cycling, environmental bioremediation and wastewater treatment.