Lipid metabolism is dysregulated in endocrine glands upon autoimmune demyelination.

Disturbance in neuroendocrine signaling has been consistently documented in multiple sclerosis (MS), a chronic autoimmune disorder of the central nervous system (CNS) representing the main cause of non-traumatic brain injury among young adults. In fact, MS patients display altered hormonal levels and psychiatric symptoms along with the pathologic hallmarks of the disease, which include demyelination, neuroinflammation and axonal injury. In addition, we have recently shown that extensive transcriptional changes take place in the hypothalamus of mice upon the MS model experimental autoimmune encephalomyelitis (EAE). We also detected structural and functional aberrancies in endocrine glands of EAE animals. Specifically, we described the hyperplasia of adrenal glands and the atrophy of ovaries at disease peak. To further expand the characterization of these phenotypes, here we profiled the transcriptomes of both glands by means of RNA-seq technology. Notably, we identified fatty acid and cholesterol biosynthetic pathways as the most dysregulated molecular processes in adrenals and ovaries, respectively. Furthermore, we demonstrated that key genes encoding neuropeptides and hormone receptors undergo distinct expression dynamics in the hypothalamus along disease progression. Altogether, our results corroborate the dysfunction of the neuroendocrine system as a major pathological event of autoimmune demyelination and highlight the crosstalk between the CNS and the periphery in mediating such disease phenotypes.

Quinoline Compounds Targeting the c-Ring of ATP Synthase Inhibit Drug-Resistant Pseudomonas aeruginosa.

Pseudomonas aeruginosa (PA) is a Gram-negative, biofilm-forming bacterium and an opportunistic pathogen. The growing drug resistance of PA is a serious threat that necessitates the discovery of novel antibiotics, ideally with previously underexplored mechanisms of action. Due to their central role in cell metabolism, bacterial bioenergetic processes are of increasing interest as drug targets, especially with the success of the ATP synthase inhibitor bedaquiline to treat drug-resistant tuberculosis. Like Mycobacterium tuberculosis, PA requires F1Fo ATP synthase for growth, even under anaerobic conditions, making the PA ATP synthase an ideal drug target for the treatment of drug-resistant infection. In previous work, we conducted an initial screen for quinoline compounds that inhibit ATP synthesis activity in PA. In the present study, we report additional quinoline derivatives, including one with increased potency against PA ATP synthase in vitro and antibacterial activity against drug-resistant PA. Moreover, by expressing the PA ATP synthase in Escherichia coli, we show that mutations in the H+ binding site on the membrane-embedded rotor ring alter inhibition by the reported quinoline compounds. Identification of a potent inhibitor and its probable binding site on ATP synthase enables further development of promising quinoline derivatives into a viable treatment for drug-resistant PA infection.

Bisbenzamidine and Bisbenzguanidine Ureas Act as Antibacterial Agents against Pseudomonas aeruginosa.

Due to the global rise in the number of antibiotic resistant bacterial infections over the past 20 years, there is a dire need for the development of small molecule antibiotics capable of overcoming resistance mechanisms in pathogenic bacteria. Antibiotic development against Gram-negative pathogens, such as Pseudomonas aeruginosa, is especially challenging due to their additional outer membrane which reduces antibiotic entry. Recently, it has been shown that a broad range of nitrogen functionality, including guanidines, amidines, primary amines, imidazolines, and imidazoles, promote antibiotic and adjuvant activity in Gram-negative bacteria, but few of these have been targeted towards Pseudomonas aeruginosa specifically despite this pathogen being deemed a critical threat by the United States Centers for Disease Control and Prevention. Herein, we examined a small series of known and unknown nitrogenous dimers, with guanidine, amidine, dimethyl amine, and pyridine functionality, for antibacterial activity against multidrug resistant Pseudomonas aeruginosa. We found that two, with bisbenzguanidine and bisbenzamidine functionality, are potent against clinical isolates of multidrug resistant and biofilm forming Pseudomonas aeruginosa.

Design and evaluation of poly-nitrogenous adjuvants capable of potentiating antibiotics in Gram-negative bacteria.

Antibiotic resistance has been a growing public health crisis since the 1980s. Therefore, it is essential not only to continue to develop novel antibiotics but also to develop new methods for overcoming resistance mechanisms in pathogenic bacteria so antibiotics can be reactivated towards these resistant strains. One common cause of antibiotic resistance in Gram-negative bacteria is reduced permeability of the tightly packed, negatively charged lipopolysaccharide outer membrane (OM), which dramatically reduces or even prevents antibiotic accumulation within the cell. Adjuvants that promote passive diffusion through the OM, including phenylalanine-arginine-ß-naphthylamide, tobramycin, and pentamidine, have proven useful in potentiating antibiotics against Gram-negative bacteria. Structural evaluation of these adjuvants, which all include multiple nitrogenous groups, indicates that the entry rules developed for improving antibiotic accumulation in Escherichia coli (EC), could also be used to guide adjuvant development. To this end, a series of structurally simple poly-nitrogenous diphenylsuccinamide compounds have been prepared and evaluated for their ability to potentiate a panel of classic antibiotics in wild-type EC and Pseudomonas aeruginosa (PA). Modest adjuvant activity was observed for all compounds surveyed when co-administered with known antibiotics to inhibit either wild-type EC or PA, and all were able to accumulate in both EC and PA.