The interaction of endorepellin and neurexin triggers neuroepithelial autophagy and maintains neural tube development.

Heparan sulfate proteoglycan 2 (HSPG2) gene encodes the matrix protein Perlecan, and genetic inactivation of this gene creates mice that are embryonic lethal with severe neural tube defects (NTDs). We discovered rare genetic variants of HSPG2 in 10% cases compared to only 4% in controls among a cohort of 369 NTDs. Endorepellin, a peptide cleaved from the domain V of Perlecan, is known to promote angiogenesis and autophagy in endothelial cells. The roles of enderepellin in neurodevelopment remain unclear so far. Our study revealed that endorepellin can migrate to the neuroepithelial cells and then be recognized and bind with the neuroepithelia receptor neurexin in vivo. Through the endocytic pathway, the interaction of endorepellin and neurexin physiologically triggers autophagy and appropriately modulates the differentiation of neural stem cells into neurons as a blocker, which is necessary for normal neural tube closure. We created knock-in (KI) mouse models with human-derived HSPG2 variants, using sperm-like stem cells that had been genetically edited by CRISPR/Cas9. We realized that any HSPG2 variants that affected the function of endorepellin were considered pathogenic causal variants for human NTDs given that the severe NTD phenotypes exhibited by these KI embryos occurred in a significantly higher response frequency compared to wildtype embryos. Our study provides a paradigm for effectively confirming pathogenic mutations in other genetic diseases. Furthermore, we demonstrated that using autophagy inhibitors at a cellular level can repress neuronal differentiation. Therefore, autophagy agonists may prevent NTDs resulting from failed autophagy maintenance and neuronal over-differentiation caused by deleterious endorepellin variants.

Inkjet Printing Photoresist with Ultralow Viscosity on Silicon Wafers for Uniform Coating.

Inkjet printing is introduced into the photoresist coating process for uniform photoresist film formation on silicon wafers with the in-house inkjet experimental prototype. The optimization of a dual negative voltage waveform is proposed to achieve stable droplet jetting for the ultralow viscosity (0.71 mPa·s) photoresist with a 1:10 dilution ratio employed in the semiconductor packaging processes. Moreover, the maximum droplet jetting velocity can reach 9.51 m/s, and the droplet volume is controlled at ∼6.5 pL with excellent droplet concentration. The uniform film of the AZ P4620 photoresist is coated on silicon wafers by quantitatively exploring and optimizing the printhead driving frequency and movement velocity utilizing the droplet deposition model and experimental analysis. Results show that the optimal inkjet parameters with 5 kHz in jetting frequency and 6 mm/s in motion velocity can obtain a film evenness index of 4.81% with the thickness of 0.945 µm, which exhibits a more uniform photoresist film than the spray coating method. The study not only expands the application of the inkjet printing technique but also offers an alternative for photoresist coating in the photolithography process.

Acoustic modulation and non-contact atomization of droplets based on the Fabry-Pérot resonator.

A non-contact ultrasonic atomization based on the Fabry-Pérot resonator is proposed to obtain atomized droplets with a reduced droplet diameter and concentrated droplet distributions. To better understand the mechanism inside the acoustic chamber, the acoustic-fluid interactions are numerically explored inside the Fabry-Pérot resonator to achieve the precise modulation of droplets. The influence of the acoustic chamber's geometry and the ultrasonic properties on the atomized droplet diameter and distributions is investigated, aiming to establish matching relationships between the atomized droplet diameter and the geometry of the acoustic chamber. The dynamic behaviors of droplet breakup are observed with a high-speed camera to reveal the atomization mechanism of liquid droplets in high-intensity acoustic fields. The experiments demonstrate that the proposed non-contact atomization can achieve atomized water droplets with a median diameter of ∼24 µm, providing an alternative to ultrasonic spray.

Dapagliflozin attenuates the vulnerability to atrial fibrillation in rats with lipopolysaccharide-induced myocardial injury.

BACKGROUND: Oxidative stress is an essential component participating in the development and maintenance of atrial fibrillation (AF). Dapagliflozin, a SGLT2 inhibitor, has been shown to exert cardioprotective effects by ameliorating oxidative stress in multiple heart disease models. However, its potential to attenuate lipopolysaccharide (LPS)-induced myocardial injury in rats remains unknown. AIM: This study aims to investigate the role of dapagliflozin in LPS-induced myocardial injury and the potential mechanisms involved. METHODS: Rats were intraperitoneally administered LPS to induce sepsis-like condition. The intervention was conducted with intraperitoneal injection of dapagliflozin or saline 1 h in advance. The effects of dapagliflozin were detected by electrophysiological recordings, western blot, qPCR, ELISA, HE staining, immunohistochemistry and fluorescence. We further validated the mechanism in vitro using HL-1 cells. RESULTS: Dapagliflozin significantly improved LPS-induced myocardial injury, reduced susceptibility to AF, and mitigated atrial tissue inflammatory cell infiltration and atrial myocyte apoptosis. These were correlated with the Nrf2/HO-1 signaling pathway, which subsequently reduced oxidative stress. Subsequently, we used a specific inhibitor of the Nrf2/HO-1 pathway in vitro, reversed the anti-oxidative stress effects of dapagliflozin on HL-1 cells, further confirming the Nrf2/HO-1 pathway's pivotal role in dapagliflozin-mediated cardioprotection. CONCLUSION: Dapagliflozin ameliorated myocardial injury and susceptibility to AF induced by LPS through anti-oxidative stress, which relied on upregulation of the Nrf2/HO-1 pathway.

Polymyxin resistance caused by large-scale genomic inversion due to IS26 intramolecular translocation in Klebsiella pneumoniae.

Polymyxin B and polymyxin E (colistin) are presently considered the last line of defense against human infections caused by multidrug-resistant Gram-negative organisms such as carbapenemase-producer Enterobacterales, Acinetobacter baumannii, and Klebsiella pneumoniae. Yet resistance to this last-line drugs is a major public health threat and is rapidly increasing. Polymyxin S2 (S2) is a polymyxin B analogue previously synthesized in our institute with obviously high antibacterial activity and lower toxicity than polymyxin B and colistin. To predict the possible resistant mechanism of S2 for wide clinical application, we experimentally induced bacterial resistant mutants and studied the preliminary resistance mechanisms. Mut-S, a resistant mutant of K. pneumoniae ATCC BAA-2146 (Kpn2146) induced by S2, was analyzed by whole genome sequencing, transcriptomics, mass spectrometry and complementation experiment. Surprisingly, large-scale genomic inversion (LSGI) of approximately 1.1 Mbp in the chromosome caused by IS26 mediated intramolecular transposition was found in Mut-S, which led to mgrB truncation, lipid A modification and hence S2 resistance. The resistance can be complemented by plasmid carrying intact mgrB. The same mechanism was also found in polymyxin B and colistin induced drug-resistant mutants of Kpn2146 (Mut-B and Mut-E, respectively). This is the first report of polymyxin resistance caused by IS26 intramolecular transposition mediated mgrB truncation in chromosome in K. pneumoniae. The findings broaden our scope of knowledge for polymyxin resistance and enriched our understanding of how bacteria can manage to survive in the presence of antibiotics.

Evolution and development of potent monobactam sulfonate candidate IMBZ18g as a dual inhibitor against MDR Gram-negative bacteria producing ESBLs.

A series of new monobactam sulfonates is continuously synthesized and evaluated for their antimicrobial efficacies against Gram-negative bacteria. Compound 33a (IMBZ18G) is highly effective in vitro and in vivo against clinically intractable multi-drug-resistant (MDR) Gram-negative strains, with a highly druglike nature. The checkerboard assay reveals its significant synergistic effect with ß-lactamase inhibitor avibactam, and the MIC values against MDR enterobacteria were reduced up to 4-512 folds. X-ray co-crystal and chemoproteomic assays indicate that the anti-MDR bacteria effect of 33a results from the dual inhibition of the common PBP3 and some class A and C ß-lactamases. Accordingly, preclinical studies of 33a alone and 33a‒avibactam combination as potential innovative candidates are actively going on, in the treatment of ß-lactamase-producing MDR Gram-negative bacterial infections.

Dapagliflozin ameliorates sepsis-induced heart injury by inhibiting cardiomyocyte apoptosis and electrical remodeling through the PI3K/Akt pathway.

BACKGROUND: Sepsis-induced heart injury is one of the leading causes of circulation disorders worldwide. Dapagliflozin, a sodium-glucose cotransporter 2 inhibitor mainly used for controlling blood glucose, has been shown to exert a protective effect on cardiomyocytes. However, the protective effect of dapagliflozin against sepsis-induced cardiac injury and the underlying mechanism needs to be studied. AIM: This study aims to investigate the effect of dapagliflozin on sepsis-induced cardiomyopathy and the potential mechanisms involved. METHODS: The rat model of sepsis was constructed by intraperitoneal injection of lipopolysaccharide. Echocardiography and electrophysiological studies were performed to detect changes in cardiac function and electrical activity. Cardiac pathological alternation and cardiomyocyte apoptosis were measured by H&E staining, serological analysis, immunohistochemical, immunofluorescence, and TUNEL assays. Western blot and qRT-PCR were performed to elucidate the underlying mechanism of dapagliflozin. Additionally, corresponding experiments in H9c2 cells were performed to further validate the mechanisms in vitro. RESULTS: Dapagliflozin improved cardiac dysfunction and reduced the susceptibility to ventricular arrhythmias in sepsis rats by ameliorating cardiac inflammation, suppressing cardiomyocyte apoptosis, and alleviating ventricular electrical remodeling. The PI3K/Akt signaling pathway inhibitor inhibited the anti-apoptotic effect of dapagliflozin, indicating that the protective effect was related to the activation of the PI3K/Akt pathway. CONCLUSION: Dapagliflozin ameliorated sepsis-induced cardiac injury by suppressing electrical remodeling and cardiomyocyte apoptosis, which could be attributed to the PI3K/Akt pathway.

Protective effect of the novel cyclic peptide ASK0912 on mice with sepsis induced by Acinetobacter baumannii.

BACKGROUND: Sepsis has become a global health concern owing to its increasing incidence and high mortality rate. In the present study, we investigated a novel drug candidate ASK0912 on its protective effects in mice with Acinetobacter baumannii 20-1-induced sepsis, and studied the related mechanisms. MATERIAL AND METHODS: To analyze the protective effect of ASK0912 on septic mice, survival rates, body temperature, organ and blood bacterial loads, white blood cell and platelet counts, organ damage, and cytokine levels were determined. RESULTS: ASK0912 remarkably increased the survival rate of mice with sepsis induced by A. baumannii 20-1 at a low dose of 0.6 mg/kg. Rectal temperature measurements showed that ASK0912 treatment prevented the body temperature decrease of septic mice to some extent. Treatment with ASK0912 can notably reduce the organ and blood bacterial loads and alleviate platelet count reduction due to sepsis. ASK0912 attenuated organ damage, including reduced levels of total bile acids, urea, and creatinine, aggregation of inflammatory cells, and mitigation of structural changes in septic mice, as demonstrated by biochemical analysis and hematoxylin & eosin staining. Additionally, multiplex assay showed that abnormally increased cytokine levels (IL-1ß, IL-3, IL-5, IL-6, IL-10, IL-13, MCP-1, RANTES, KC, MIP-1α, MIP-1ß, and G-CSF) in septic mice decreased after ASK0912 treatment. CONCLUSIONS: ASK0912 can not only improve the survival rate, hypothermia, lower the bacterial loads in the organs and blood, but also alleviate the pathophysiological manifestations such as intravascular coagulation abnormalities, organ damages, and immune system disorder of sepsis mice induced by A. baumannii 20-1.

In vivo pharmacodynamic study of contezolid acefosamil, a prodrug of contezolid for oral and intravenous administration.

OBJECTIVES: Contezolid acefosamil is a novel O-acyl phosphoramidate prodrug of contezolid. In the current study, we aimed to systemically evaluate the efficacy of contezolid acefosamil against infections caused by multiple Gram-positive pathogens, and compare the efficacy of the prodrug by oral and intravenous administrations. METHODS: The in vivo pharmacodynamic efficacy of contezolid acefosamil was evaluated in mouse models of systemic (with five S. aureus, three S. pneumoniae and two S. pyogenes bacterial isolates) and thigh (with two S. aureus isolates) infections using linezolid as the reference agent. RESULTS: In both models, contezolid acefosamil administrated either orally or intravenously, demonstrated high antibacterial efficacy similar to linezolid, and the antibacterial efficacy of oral and intravenous contezolid acefosamil were comparable. CONCLUSIONS: The high aqueous solubility and great efficacy of contezolid acefosamil support its clinical development as an injectable and oral antibiotic suitable for serious Gram-positive infections.

Identification and Quantification of S-Sulfenylation Proteome of Mycobacterium tuberculosis under Oxidative Stress.

The ability to maintain redox homeostasis is critical for Mycobacterium tuberculosis (Mtb) to survive the redox stress of the host. There are many antioxidant systems in Mtb to ensure its normal replication and survival in the host, and cysteine thiols are one of them. S-sulfenylation is one of the reversible modifications of cysteine thiols to resist oxidative stress. In the study, we investigated the total cysteine thiols modification and S-sulfenylation modification of Mtb proteome under the oxidative stress provided by hydrogen peroxide. To determine and quantify the S-sulfenylation modified proteins, high specific IodoTMT6plex reagents and high resolution mass spectrometry were used to label and quantify the peptides and proteins modified. There are significant differences for the total cysteine modification levels of 279 proteins and S-sulfenylation modification levels of 297 proteins under hydrogen peroxide stress. Functional enrichment analysis indicated that these cysteine-modified proteins were involved in the oxidation-reduction process, fatty acid biosynthetic process, stress response, protein repair, cell wall, etc. In conclusion, our study provides a view of cysteine modifications of the Mtb proteome under oxidative stress, revealing a series of proteins that may play a role in maintaining redox homeostasis. IMPORTANCE With the continuous spread of drug-resistant tuberculosis, there is an urgent need for new antituberculosis drugs with new mechanisms. The ability of Mtb to resist oxidative stress is extremely important for maintaining redox homeostasis and survival in the host. The reversible modifications of cysteine residues have a dual role of protection from irreversible damage to protein functions and regulation, which plays an important role in the redox homeostasis system. Thus, to discover cysteine modification changes in the proteome level under oxidative stress is quintessential to elucidate its antioxidant mechanism. Our results provided a list of proteins involved in the antioxidant process that potentially could be considered targets for drug discovery and vaccine development. Furthermore, it is the first study to determine and quantify the S-sulfenylation-modified proteins in Mtb, which provided better insight into the Mtb response to the host oxidative defense and enable a deeper understanding of Mtb survival strategies.

Antibacterial Activity of an FtsZ Inhibitor Celastrol and Its Synergistic Effect with Vancomycin against Enterococci In Vitro and In Vivo.

Enterococci can cause various infectious diseases, including urinary tract infection, wound infection, and life-threatening endocarditis and meningitis. The emergence and transmission of vancomycin-resistant enterococci (VRE) have presented a challenge to clinical treatment. There is an urgent need to develop new strategies to fight against this pathogen. This study investigated the antibacterial and anti-biofilm activity of celastrol (CEL), a natural product originating from Tripterygium wilfordii Hook F, against enterococci, and its adjuvant capacity of restoring the susceptibility of VRE to vancomycin in vitro and in vivo. CEL inhibited all enterococcus strains tested, with MICs ranging from 0.5 to 4 µg/mL. More than 50% of biofilm was eliminated by CEL at 16 µg/mL after 24 h of exposure. The combination of CEL and vancomycin showed a synergistic effect against all 23 strains tested in checkerboard assays. The combination of sub-MIC levels of CEL and vancomycin showed a synergistic effect in a time-kill assay and exhibited significant protective efficacy in Galleria mellonella larval infection model compared with either drug used alone. The underlying mechanisms of CEL were explored by conducting biomolecular binding interactions and an enzyme inhibition assay of CEL on bacterial cell-division protein FtsZ. CEL presented strong binding and suppression ability to FtsZ, with Kd and IC50 values of 2.454 µM and 1.04 ± 0.17 µg/mL, respectively. CEL exhibits a significant antibacterial and synergic activity against VRE in vitro and in vivo and has the potential to be a new antibacterial agent or adjuvant to vancomycin as a therapeutic option in combating VRE. IMPORTANCE The emergence and transmission of VRE pose a significant medical and public health challenge. CEL, well-known for a wide range of biological activities, has not previously been investigated for its synergistic effect with vancomycin against VRE. In the present study, CEL exhibited antibacterial activity against enterococci, including VRE strains, and restored the activity of vancomycin against VRE in vitro and in vivo. Hence, CEL has the potential to be a new antibacterial adjuvant to vancomycin and could provide a promising therapeutic option in combating VRE.

Evaluation of Agar Dilution Method in Susceptibility Testing of Polymyxins for Enterobacteriaceae and Non-Fermentative Rods: Advantages Compared to Broth Microdilution and Broth Macrodilution.

An accurate and reliable susceptibility testing method for polymyxins is urgently needed not only for the clinical laboratory but also for new polymyxin-like lipopeptide development. Reference broth microdilution (rBMD), which was the recommended method by CLSI-EUCAST in clinics, has been proven not to be ideal, while the agar dilution (AD) method that was widely used in new antibiotics discovery has been neglected. In the present study, the AD method was compared with rBMD and broth macrodilution (BMAD) in susceptibility testing of polymyxin B and colistin against >200 Gram-negative isolates. AD showed strong agreement with BMAD for colistin (except for Klebsiella aerogenes and Pseudomonas aeruginosa); however, its performance was poor for polymyxin B or compared to rBMD. MICs of AD method were not affected when different types of Petri dishes were used, while glass-bottom microtiter plates could lower the MIC of polymyxins 2−8 times compared to tissue-culture-treated polystyrene plates when using rBMD, which demonstrated that tissue-culture-treated plates were not suitable. It was then validated with non-tissue-culture-treated plates. The culture volume was another influencing factor of accuracy for rBMD, and 200 µL seemed to be the most suitable volume for MIC detection of polymyxins. Additionally, no lack of growth phenomenon (skipped well) was observed for AD when it frequently occurred for both BMAD and rBMD. As for strains carrying mcr-1 gene, 100% of AD results were in essential agreement (EA) and categorical agreement (CA) with both rBMD and BMAD. Overall, rBMD is convenient and widely accepted for susceptibility testing of polymyxins. Although it may be too early to say that AD is superior compared to rBMD and BMAD, it did show some advantages in repeatability and anti-interference ability.

Efficacy of Human-Recombinant Epidermal Growth Factor Combined with Povidone-Iodine for Pressure Ulcers and Its Influence on Inflammatory Cytokines.

Purpose: To determine the clinical efficacy of recombinant human epidermal growth factor (rh-EGF) combined with povidone-iodine (PVI) on patients with pressure ulcers (PUs). Methods: One hundred and five PU patients treated between January 2018 and January 2021 were enrolled and retrospectively analyzed. Of them, 50 patients who received conventional treatment were assigned to the control group (Con group), while 55 patients treated with rh-EGF combined with PVI were assigned to the observation group (Obs group). The two groups were compared in clinical efficacy, PU alleviation (total area reduction rate, total depth reduction rate, and total volume reduction rate), healing time, pain degree (Visual Analog Scale [VAS] score), inflammatory indexes (interleukin-8 [IL-8], tumor necrosis factor-α [TNF-α], and hypersensitive C reactive protein [hs-CRP]), and hydroxyproline content in the wound. Results: The Obs group yielded a higher total effective rate than the Con group (P < 0.05). The Obs group also experienced statistically shorter healing time and milder pain, with better PU alleviation and lower levels of inflammation indexes compared with the Con group (all P < 0.05). In addition, a higher hydroxyproline content in the wound was found in the Obs group. Conclusions: All in all, rh-EGF combined with PVI has a definite curative effect on patients with PUs. It can promote PU alleviation and hydroxyproline secretion in the wound and inhibit pain and inflammatory reactions, which is worthy of clinical promotion.

Roles of cysteine in the structure and metabolic function of Mycobacterium tuberculosis CYP142A1.

CYP142A1 is a cytochrome P450 (CYP) enzyme expressed in Mycobacterium tuberculosis (Mtb), which supports the growth of Mtb H37Rv relying on cholesterol, in the absence of CYP125A1. Since cysteine residues usually play a fundamental role in maintaining the structure and function of CYP enzymes, in this study, we aimed to determine the potential biochemical functions of six cysteine residues except for the heme-binding cysteine in the amino acid sequence of recombinant Mtb CYP142A1 by replacing each one using site-directed mutagenesis. Recombinant CYP142A1 mutants were heterologously expressed, purified, and analyzed using ESI-MS, far-UV CD spectroscopy, UV-vis spectrophotometric titration, and metabolic function assays. Substitution of the cysteine residues caused various effects on the structure and function of CYP142A1. Separate substitution of the six cysteine residues resulted in numerous changes in the secondary structure, expression level, substrate-binding ability, inhibitor-binding ability, thermal stability and oxidation efficiency of the enzyme. These results contribute to our understanding of the biochemical roles of cysteine residues in the structure and function of Mtb CYP enzymes, especially their effects on the structure and function of CYP142A1.

Effect of Different Tolerable Levels of Constitutive mcr-1 Expression on Escherichia coli.

To study the effect of different tolerable levels of constitutive mcr-1 expression on Escherichia coli, and to provide direct evidence for moderate resistance mediated by mcr-1, construction of E. coli strains carrying mcr-1 on the chromosome with promoters of different strengths was conducted using λ-red recombination. Our results demonstrated that over-high expression of mcr-1 cannot be tolerated, and seven constructs with more than 200-fold mcr-1 transcriptional expression differences were obtained. The colistin MICs of the seven strains increased with the increase of MCR-1 levels, and the highest MIC was 8 µg/mL. Lower expression of mcr-1 didn't demonstrate many effects on bacteria, while higher tolerable expression of mcr-1 tended to show fitness costs in growth rate, competitive ability, and cell structures, but no obvious change of virulence was observed in mice. Bacteria demonstrated colistin MICs of 4-8 µg/mL at mcr-1 expression levels similar to clinical isolates, which were the mcr-1 expression levels with relatively lower fitness costs. IMPORTANCE The effects of relatively lower tolerable levels of mcr-1 were not evaluated thoroughly, and direct evidence for moderate resistance mediated by mcr-1 was lacking. In the present study, we made constructs carrying mcr-1 on the E. coli K12 chromosome under the control of serial constitutive promoters of different strengths and studied the effects of different tolerable levels of mcr-1 expression in vitro and in vivo. The results demonstrated that generally, except QH0007 (the construct with the highest mcr-1 expression that showed some extent of cell death), the fitness costs of tolerable mcr-1 expression on bacteria were not apparent or low. Bacteria demonstrated colistin MICs of 4-8 µg/mL at mcr-1 expression levels similar to clinical isolates, which corresponded to the lower levels of mcr-1 expression that can lead to colistin resistance, indicating the cleverness of bacteria to balance the benefit and cost of MCR-1-mediated colistin resistance.

Activation of the sigma-1 receptor exerts cardioprotection in a rodent model of chronic heart failure by stimulation of angiogenesis.

BACKGROUND: Angiogenesis plays a critical role on post-infarction heart failure (PIHF), the presence of which facilitates additional blood supply to maintain the survival of residual cardiomyocytes. The sigma-1 receptor (S1R) has been substantiated to stimulate angiogenesis, with the effect on a model of PIHF remaining unknown. AIMS: This study aims to investigate the effects of S1R on PIHF and the underlying mechanisms involved. METHODS: Rats were implemented left anterior descending artery ligation followed by rearing for 6 weeks to induce a phenotype of heart failure. Daily intraperitoneal injection of S1R agonist or antagonist for 5 weeks was applied from 2nd week after surgery. The effects exerted by S1R were detected by echocardiography, hemodynamic testing, western blot, Sirius red dyeing, ELISA, immunohistochemistry and fluorescence. We also cultured HUVECs to verify the mechanisms in vitro. RESULTS: Stimulation of S1R significantly ameliorated the cardiac function resulted from PIHF, in addition to the observation of reduced fibrosis in the peri-infarct region and the apoptosis of residual cardiomyocytes, which were associated with augmentation of microvascular density in peri-infarct region through activation of the JAK2/STAT3 pathway. We also indicated that suppression of JAK2/STAT3 pathway by specific inhibitor in vitro reversed the pro-angiogenic effects of S1R on HUVECs, which further confirmed that angiogenesis, responsible for PIHF amelioration, by S1R stimulation was in a JAK2/STAT3 pathway-dependent manner. CONCLUSION: S1R stimulation improved PIHF-induced cardiac dysfunction and ventricular remodeling through promoting angiogenesis by activating the JAK2/STAT3 pathway.

Parallel Reaction Monitoring Mass Spectrometry for Rapid and Accurate Identification of ß-Lactamases Produced by Enterobacteriaceae.

The increasing spread of drug-resistant bacterial strains presents great challenges to clinical antibacterial treatment and public health, particularly with regard to ß-lactamase-producing Enterobacteriaceae. A rapid and accurate detection method that can expedite precise clinical diagnostics and rational administration of antibiotics is urgently needed. Targeted proteomics, a technique involving selected reaction monitoring or multiple reaction monitoring, has been developed for detecting specific peptides. In the present study, a rapid single-colony-processing procedure combined with an improved parallel reaction monitoring (PRM) workflow based on HRAM Orbitrap MS was developed to detect carbapenemases (Klebsiella pneumoniae carbapenemase, KPC; imipenemase, IMP; Verona integron-encoded metallo-ß-lactamase, VIM; New Delhi metallo-ß-lactamase, NDM; and oxacillinase, OXA), extended spectrum ß-lactamases (TEM and CTX-M), and AmpC (CMY-2) produced by Enterobacteriaceae. Specific peptides were selected and validated, and their coefficients of variation and stability were evaluated. In total, 188 Enterobacteriaceae strains were screened using the workflow. Fourteen out of total 19 peptides have 100% specificity; three peptides have specificity >95% and two peptides have specificity ranged from 74∼85%. On the sensitivity, only nine peptides have 95∼100% sensitivity. The other 10 peptides have sensitivity ranged from 27∼94%. Thus, a screening method based on peptide groups was developed for the first time. Taken together, this study described a rapid extraction and detection workflow for widespread ß-lactamases, including KPC, IMP, VIM, NDM, OXA, CMY, CTX-M, and TEM, using single colonies of Enterobacteriaceae strains. PRM-targeted proteomics was proven to be a promising approach for the detection of drug-resistant enzymes.

Bruceine A protects against diabetic kidney disease via inhibiting galectin-1.

Bruceine A is a natural quassinoid compound extracted from the fruit of the Traditional Chinese Medicine Brucea javanica (L.) Merr. that has various types of various biological activities. However, whether the compound has a protective effect on diabetic kidney disease remains unknown. Galectin-1 is actively involved in a variety of chronic inflammation-relevant human diseases including diabetic kidney disease. Here, we identified Bruceine A as a kidney protective molecule against a model of diabetic kidney disease in db/db mice with potent anti-inflammatory activity both in vitro and in vivo. Mechanistically, by selectively binding to the conserved carbohydrate-recognition domain of galectin-1 and disrupting the interaction between galectin-1 and the receptor for activated protein C kinase 1, Bruceine A was found to inhibit galectin-1-mediated inflammatory signal transduction under high glucose stress in rat mesangial HBZY-1 cells. Thus, our findings reveal Bruceine A as an unidentified galectin-1 inhibitor affording significant protection against diabetic kidney disease and may provide novel pharmacological therapeutics for the disease.

Chronic Sigma 1 receptor activation alleviates right ventricular dysfunction secondary to pulmonary arterial hypertension.

Sigma 1 receptor (S1R) has shown a preferable protective effect on left ventricular function, but whether it protects right ventricular (RV) function is still elusive.This study aimed to determine the effects of S1R on RV dysfunction secondary to pulmonary arterial hypertension.Sixty wild-type male Sprague-Dawley rats were randomly divided into the control group, the fluvoxamine group, the pulmonary arterial hypertension group and the pulmonary arterial hypertension combined with fluvoxamine group. Monocrotaline (60 mg/kg) was administered to induce pulmonary arterial hypertension, and fluvoxamine was given for 21 consecutive days to activate S1R after one week of monocrotaline administration. Echocardiographic, serologic, and histologic parameters, qRT-PCR, and western blotting were conducted after 4 weeks of monocrotaline administration.The expression of S1R was decreased in the right ventricle in pulmonary arterial hypertension. TAPSE, and the FAC of the right ventricle were significantly decreased, and RV EDP and the plasma concentration of N-terminal pro-B-type natriuretic peptide was increased in the pulmonary arterial hypertension group, but fluvoxamine partly restored those abnormalities (all P < 0.05). Moreover, pulmonary arteriole remodeling, and fibrosis and hypertrophy in the RV were shown in the pulmonary arterial hypertension group; interestingly, fluvoxamine recovered RV structural remodeling (all P < 0.05) but neither alleviated pulmonary arteriole remodeling nor reduced pulmonary artery pressure. Furthermore, S1R activation protects RV function by upgrading the NRF 2/HO 1-mediated antioxidant stress pathway. In conclusion, chronic S1R activation ameliorates structural remodeling and RV dysfunction secondary to pulmonary arterial hypertension without altering pulmonary artery pressure.

Human embryos in a dish - modeling early embryonic development with pluripotent stem cells.

Stem cell-based embryo models present new opportunities to study early embryonic development. In a recent study, Kagawa et al. identified an approach to create human pluripotent stem cell-based blastoids that resemble the human blastocysts. These blastoids efficiently generated analogs of the EPI, TE, PrE lineages with transcriptomes highly similar to those found in vivo. Furthermore, the formation of these lineages followed the same sequence and pace of blastocyst development, and was also dependent on the same pathways required for lineage specification. Finally, the blastoids were capable of attaching to stimulated endometrial cells to mimic the process of implantation. While more comprehensive analysis is needed to confirm its validity and usefulness, this new blastoid system presents the latest development in the attempt to model early human embryogenesis in vitro.