Bacterial pathogens like Mycobacterium tuberculosis (Mtb) encounter acidic microenvironments in the host and must maintain their acid-base homeostasis to survive. A genetic screen identified two Mtb strains that cannot control intrabacterial pH (pHIB) in an acidic environment; infection with either strain led to severe attenuation in mice. To search for additional proteins that Mtb requires to survive at low pH, we introduced a whole-cell screen for compounds that disrupt pHIB, along with counter-screens that identify ionophores and membrane perturbors. Application of these methods to a natural product library identified four compounds of interest, one of which may inhibit novel pathway(s). This approach yields compounds that may lead to the identification of pathways that allow Mtb to survive in acidic environments, a setting in which Mtb is resistant to most of the drugs currently used to treat tuberculosis.

Mycobacterium tuberculosis (Mtb) maintains its intrabacterial pH (pHIB) near neutrality in the acidic environment of phagosomes within activated macrophages. A previously reported genetic screen revealed that Mtb loses this ability when the mycobacterial acid resistance protease (marP) gene is disrupted. In the present study, a high throughput screen (HTS) of compounds against the protease domain of MarP identified benzoxazinones as inhibitors of MarP. A potent benzoxazinone, BO43 (6-chloro-2-(2′-methylphenyl)-4H-1,3-benzoxazin-4-one), acylated MarP and lowered Mtb’s pHIB and survival during incubation at pH 4.5. BO43 had similar effects on MarP-deficient Mtb, suggesting the existence of additional target(s). Reaction of an alkynyl-benzoxazinone, BO43T, with Mycobacterium bovis variant bacille Calmette-Guérin (BCG) followed by click chemistry with azido-biotin identified both the MarP homologue and the high temperature requirement A1 (HtrA1) homologue, an essential protein. Thus, the chemical probe identified through a target-based screen not only reacted with its intended target in the intact cells but also implicated an additional enzyme that had eluded a genetic screen biased against essential genes.

Gelsemium elegans Benth. (G. elegans), which is a famous Chinese folk medicine, has been commonly used to treat certain types of skin ulcers and alleviate inflammation, headaches, and cancer pain. However, the extensive clinical use of G. elegans has been greatly hampered by its toxicity. As one of the most widely used herbal medicines, Glycyrrhiza uralensis Fisch, has a unique effect on detoxification of G. elegans. In the present study, a rapid and sensitive method using ultra-liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was established and validated for determination of koumine, the most abundant molecule among the alkaloids of G. elegans, in rat plasma, tissue, and liver microsome. The developed method was successfully applied to the pharmacokinetics, tissue distribution, and in vitro metabolism study in rat with or without pre-treated Glycyrrhiza uralensis Fisch extract. Meanwhile, the expression level of CYP3A1 mRNA was analyzed to explain the detoxification mechanism of Glycyrrhiza uralensis Fisch on G. elegans. As a result, our work demonstrated that Glycyrrhiza uralensis Fisch could significantly affect the pharmacokinetics and tissue distribution of koumine in rats. The detoxification mechanism of Glycyrrhiza uralensis Fisch on G. elegans may be its cytochrome enzyme up-regulation effect.

BackgroundThe objective of this study was to evaluate the safety of total thyroidectomy for thyroid disorders and summarise the treatment experience in a less-developed region.MethodsThis was a retrospective observational cohort study using the computerised database of the First Affiliated Hospital of Harbin Medical University. All consecutive thyroidectomy patients from 2003 to 2014 were included in this study. Demographics, surgical procedure, diagnoses, morbidity and mortality were retrospectively reviewed.ResultsThere were a total of 714 men and 4845 women in this study, with a mean age of 55 (range 9–87) years. A total of 4632 patients underwent total thyroidectomy for primary surgical treatment, and 189 patients previously underwent partial thyroidectomy. A total of 56.2 % of the patients had multinodular goitre, including 12.23 % who were thyrotoxic. Graves’ disease and Hashimoto’s disease were diagnosed in 2.82 and 7.23 % of the patients, respectively. Papillary thyroid cancer was identified in 1336 patients, 44.99 % of whom had papillary microcarcinoma. The total prevalence of permanent complications of first-time and secondary surgeries was 0.35 and 7.41 %, respectively. During thyroid surgery, 945 patients underwent parathyroid autotransplantation.ConclusionsInitial total thyroidectomy can be safely performed for both benign and malignant thyroid diseases in a less-developed region. The morbidity of a secondary surgical procedure after subtotal thyroidectomy is significantly high compared to first-time surgery.

Mycobacterial tuberculosis (Mtb) is able to preserve its intrabacterial pH (pHIB) near neutrality in the acidic phagosomes of immunologically activated macrophages and to cause lethal pathology in immunocompetent mice. In contrast, when its ability to maintain pHIB homeostasis is genetically compromised, Mtb dies in acidic phagosomes and is attenuated in the mouse. Compounds that phenocopy the genetic disruption of Mtb’s pHIB homeostasis could serve as starting points for drug development in their own right or through identification of their targets. A previously reported screen of a natural product library identified a phloroglucinol, agrimophol, that lowered Mtb’s pHIB and killed Mtb at an acidic extrabacterial pH. Inability to identify agrimophol-resistant mutants of Mtb suggested that the compound may have more than one target. Given that polyphenolic compounds may undergo covalent reactions, we attempted an affinity-based method for target identification. The structure-activity relationship of synthetically tractable polyhydroxy diphenylmethane analogs with equivalent bioactivity informed the design of a bioactive agrimophol alkyne. After click-chemistry reaction with azido-biotin and capture on streptavidin, the biotinylated agrimophol analog pulled down the Mtb protein Rv3852, a predicted membrane protein that binds DNA in vitro. A ligand-protein interaction between agrimophol and recombinant Rv3852 was confirmed by isothermal calorimetry (ITC) and led to disruption of Rv3852’s DNA binding function. However, genetic deletion of rv3852 in Mtb did not phenocopy the effect of agrimophol on Mtb, perhaps because of redundancy of its function.

Schistosomiasis is a devastating parasitic disease caused by tremotodes of the genus Schistosoma. Eggs produced by sexually mature schistosomes are the causative agents of for pathogenesis and transmission. Elucidating the molecular mechanism of schistosome development and sexual maturation would facilitate the prevention and control of schistosomiasis. Acetylation of lysine is a dynamic and reversible post-translational modification playing keys role in many biological processes including development in both eukaryotes and prokaryotes. To investigate the impacts of lysine acetylation on Schistosoma japonicum (S. japonicum) development and sexual maturation, we used immunoaffinity-based acetyllysine peptide enrichment combined with mass spectrometry (MS), to perform the first comparative analysis of proteome-wide lysine acetylation in both female and male, juvenile (18 days post infection, 18 dpi) and adult (28 dpi) schistosome samples. In total, we identified 874 unique acetylated sites in 494 acetylated proteins. The four samples shared 47 acetylated sites and 46 proteins. More acetylated sites and proteins shared by both females and males were identified in 28 dpi adults (189 and 143, respectively) than in 18 dpi schistosomula (76 and 59, respectively). More stage-unique acetylated sites and proteins were also identified in 28 dpi adults (494 and 210, respectively) than in 18 dpi schistosomula (73 and 44, respectively). Functional annotation showed that in different developmental stages and genders, a number of proteins involving in muscle movement, glycometabolism, lipid metabolism, energy metabolism, environmental stress resistance, antioxidation, etc., displayed distinct acetylation profiles, which was in accordance with the changes of their biological functions during schistosome development, suggesting that lysine acetylation modification exerted important regulatory roles in schistosome development. Taken together, our data provided the first comparative global survey of lysine acetylation in juvenile and adult S. japonicum, which would deepen our understanding of the molecular mechanism of schistosome development and sexual maturation, and provide clues for the development of new anti-schistosome strategies.

This article reports the rational medicinal chemistry of a natural product, agrimophol (1), as a new disruptor of intrabacterial pH (pH IB ) homeostasis in Mycobacterium tuberculosis (Mtb). Through the systematic investigation of the structure−activity relationship of 1, scaffold-hopping of the diphenylmethane scaffold, pharmacophore displacement strategies, and studies of the structure− metabolism relationship, a new derivative 5a was achieved. Compound 5a showed 100-fold increased potency in the ability to reduce pH IB to pH 6.0 and similarly improved mycobactericidal activity compared with 1 against both Mycobacterium bovis-BCG and Mtb. Compound 5a possessed improved metabolic stability in human liver microsomes and hepatocytes, lower cytotoxicity, higher selectivity index, and similar pK a value to natural 1. This study introduces a novel scaffold to an old drug, resulting in improved mycobactericidal activity through decreasing pH IB , and may contribute to the critical search for new agents to overcome drug resistance and persistence in the treatment of tuberculosis.

Objective. To explore the correlation of serum IL-18, BDNF, and IL-1β with depression and prognosis after acute exacerbation of chronic obstructive pulmonary disease (COPD). Methods. By means of retrospective analysis, the data of 240 patients at the acute exacerbation of COPD treated in our hospital (February 2018-February 2021) were analyzed. All patients received conventional treatment 1 d after admission, patients’ serological indicators were measured before treatment, and after 30 d of follow-up, the patients were divided into the survival group (SG) and death group (DG) according to their clinical outcomes, the Beck’s Depression Inventory (BDI) scores of the surviving patients were investigated, the correlation of IL-18, BDNF, and IL-1β levels with depression was analyzed by R analytics, and the correlation of IL-18, BDNF, and IL-1β levels with prognosis was analyzed by ROC curve analysis. Results. The results of 30 d follow-up showed that 220 patients survived (91.7%) and 20 patients died (8.3%). Among the surviving patients, 95 patients had depression and 125 patients did not have depression; the BDI scores of the depressed subjects and the nondepressed subjects were 10.35 ± 1.25 points and 2.06 ± 0.76 points, respectively; significant differences in IL-18, BDNF, and IL-1β levels between SG and DG were observed ( P < 0.05 ); significant differences in IL-18, BDNF, and IL-1β levels between the depressed subjects and the nondepressed subjects were observed ( 538.43 ± 19.02 vs. 515.32 ± 9.65 , 7.54 ± 0.56 vs. 12.11 ± 2.41 , and 8.70 ± 0.98 vs. 8.12 ± 0.87 ; P < 0.001 ); among the depressed patients, the IL-18 and IL-1β levels were positively correlative with the BDI scores ( r = 0.781 , r = 0.2583 , P < 0.001 , P = 0.012 ), and the BDNF level was negatively correlative with the BDI scores ( r = − 0.3277 , P = 0.001 ) before treatment; according to the ROC analysis, the AUC (95% CI) of IL-18, BDNF, and IL-1β in predicting prognosis was 0.8770 (0.8281-0.9260), 0.7723 (0.6879-0.8567), and 0.7165 (0.6080-0.8250) ( P < 0.05 ), respectively. Conclusion. In regard to the depression in COPD patients after acute exacerbation, IL18 and IL-1β show positive correlation, and BDNF presents negative correlation. All three indicators have predictive value for patient outcome.