Antibacterial Activities of the Algal Bromophenol Methylrhodomelol Against Pseudomonas aeruginosa.

Methylrhodomelol (1: ) is a bromophenol from the red alga Vertebrata lanosa that has been associated with antimicrobial properties. The aim of the current study was, therefore, to assess the antimicrobial potential of this compound in more detail against the gram-negative pathogen Pseudomonas aeruginosa. 1: exerted weak bacteriostatic activity against different strains when grown in minimal medium, whereas other phenolics were inactive. In addition, 1: (35 and 10 µg/mL) markedly enhanced the susceptibility of multidrug-resistant P. aeruginosa toward the aminoglycoside gentamicin, while it did not affect the viability of Vero kidney cells up to 100 µM. Finally, pyoverdine release was reduced in bacteria treated at sub-inhibitory concentration, but no effect on other virulence factors was observed. Transcriptome analysis of treated versus untreated P. aeruginosa indicated an interference of 1: with bacterial carbon and energy metabolism, which was corroborated by RT-qPCR and decreased ATP-levels in treated bacteria. In summary, the current study characterized the antibacterial properties of methylrhodomelol, revealed its potential as an adjuvant to standard antibiotics, and generated a hypothesis on its mode of action.

CRP/Neopterin Ratio and Neuropsychiatric Symptoms in Patients with Different Forms of Pneumonia: Results of a Pilot Study.

BACKGROUND: Pneumonia is one of the most common infectious diseases, mostly caused by viruses or bacteria. In response to bacteria or viruses which are different but which also are partly overlapping, innate and adaptive immune responses are induced, which can be quantified using the determination of specific biomarkers. Among these, C-reactive protein (CRP) has been established as a marker of innate immune function, whereas Neopterin, which is mainly produced upon stimulation with interferon-gamma, reflects cellular immune activation. AIM: We investigated inflammation markers in patients with microbiologically confirmed viral or bacterial pneumonia, and studied the potential of CRP, Neopterin, and the CRP/Neopterin ratio to distinguish between viral and bacterial pathogenesis. Furthermore, we examined, how often neuropsychiatric symptoms occur in patients suffering from different kinds of pneumonia. PATIENTS AND METHOD: A total of 194 patients diagnosed with either coronavirus disease 2019 (COVID-19) (n = 63), bacterial pneumonia (n = 58), Influenza infection (n = 10), Influenza and a bacterial superinfection (n = 9), and COVID-19 patients with a bacterial superinfection (n = 54) were included in our pilot study. Clinical as well as laboratory parameters were determined shortly after admission. RESULTS: We found significantly higher CRP/Neopterin ratios in patients with bacterial pneumonia (median: 0.34) and lower CRP/Neopterin ratios in patients hospitalized with COVID-19 infection (median: 0.03; p < 0.001). Both in men and in women, the CRP/Neopterin ratio was able to distinguish between viral and bacterial pathogens, but also was able to detect bacterial super-infection (BSI) in subjects with initial viral pneumonia (p < 0.001). Patients with BSI presented with significantly lower CRP/Neopterin ratios (median 0.08) than patients with bacterial infection only (median 0.34; p < 0.001). Interestingly, COVID-19 patients had a decreased physical functioning (as reflected in the ECOG score) and a higher frequency of fatigue (84.1%) and neurological symptoms (54.8%) than patients with pneumonia, due to other underlying pathogens. Patients that reported fatigue during viral and bacterial pneumonia presented with lower CRP concentrations than patients without it. CONCLUSIONS: The CRP/Neopterin ratio is useful to differentiate between viral and bacterial pathogenesis. The occurrence of neuropsychiatric symptoms in pneumonia appears to depend on the kind of pathogen causing the infection. Lower CRP concentrations at admission appear to be related to fatigue during acute viral and bacterial infection.

Laboratory parameters related to disease severity and physical performance after reconvalescence of acute COVID-19 infection.

Research into the molecular basis of disease trajectory and Long-COVID is important to get insights toward underlying pathophysiological processes. The objective of this study was to investigate inflammation-mediated changes of metabolism in patients with acute COVID-19 infection and throughout a one-year follow up period. The study enrolled 34 patients with moderate to severe COVID-19 infection admitted to the University Clinic of Innsbruck in early 2020. The dynamics of multiple laboratory parameters (including inflammatory markers [C-reactive protein (CRP), interleukin-6 (IL-6), neopterin] as well as amino acids [tryptophan (Trp), phenylalanine (Phe) and tyrosine (Tyr)], and parameters of iron and vitamin B metabolism) was related to disease severity and patients' physical performance. Also, symptom load during acute illness and at approximately 60 days (FU1), and one year after symptom onset (FU2) were monitored and related with changes of the investigated laboratory parameters: During acute infection many investigated laboratory parameters were elevated (e.g., inflammatory markers, ferritin, kynurenine, phenylalanine) and enhanced tryptophan catabolism and phenylalanine accumulation were found. At FU2 nearly all laboratory markers had declined back to reference ranges. However, kynurenine/tryptophan ratio (Kyn/Trp) and the phenylalanine/tyrosine ratio (Phe/Tyr) were still exceeding the 95th percentile of healthy controls in about two thirds of our cohort at FU2. Lower tryptophan concentrations were associated with B vitamin availability (during acute infection and at FU1), patients with lower vitamin B12 levels at FU1 had a prolonged and more severe impairment of their physical functioning ability. Patients who had fully recovered (ECOG 0) presented with higher concentrations of iron parameters (ferritin, hepcidin, transferrin) and amino acids (phenylalanine, tyrosine) at FU2 compared to patients with restricted ability to work. Persistent symptoms at FU2 were tendentially associated with IFN-γ related parameters. Women were affected by long-term symptoms more frequently. Conclusively, inflammation-mediated biochemical changes appear to be related to symptoms of patients with acute and Long Covid.

A Novel AMPK Inhibitor Sensitizes Pancreatic Cancer Cells to Ferroptosis Induction.

Cancer cells must develop strategies to adapt to the dynamically changing stresses caused by intrinsic or extrinsic processes, or therapeutic agents. Metabolic adaptability is crucial to mitigate such challenges. Considering metabolism as a central node of adaptability, it is focused on an energy sensor, the AMP-activated protein kinase (AMPK). In a subtype of pancreatic ductal adenocarcinoma (PDAC) elevated AMPK expression and phosphorylation is identified. Using drug repurposing that combined screening experiments and chemoproteomic affinity profiling, it is identified and characterized PF-3758309, initially developed as an inhibitor of PAK4, as an AMPK inhibitor. PF-3758309 shows activity in pre-clinical PDAC models, including primary patient-derived organoids. Genetic loss-of-function experiments showed that AMPK limits the induction of ferroptosis, and consequently, PF-3758309 treatment restores the sensitivity toward ferroptosis inducers. The work established a chemical scaffold for the development of specific AMPK-targeting compounds and deciphered the framework for the development of AMPK inhibitor-based combination therapies tailored for PDAC.