Aberrant expression of calcitonin gene-related peptide and its correlation with prognosis in severe childhood pneumonia

5-HT/CGRP pathway and Sumatriptan role in Covid-19

Coronavirus disease 2019 (Covid-19) is a pandemic caused by severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2). In Covid-19, there is uncontrolled activation of immune cells with a massive release of pro-inflammatory cytokines and the development of cytokine storm. These inflammatory changes induce impairment of different organ functions, including the central nervous system (CNS), leading to acute brain injury and substantial changes in the neurotransmitters, including serotonin (5-HT) and calcitonin gene-related peptide (CGRP), which have immunomodulatory properties through modulation of central and peripheral immune responses. In Covid-19, 5-HT neurotransmitters and CGRP could contribute to abnormal and atypical vascular reactivity. Sumatriptan is a pre-synaptic 5-HT (5-HT1D and 5-HT1B) agonist and inhibits the release of CGRP. Both 5-HT and CGRP seem to be augmented in Covid-19 due to underlying activation of inflammatory signaling pathways and hyperinflammation. In virtue of its anti-inflammatory and antioxidant properties with inhibition release of 5-HT and CGRP, Sumatriptan may reduce Covid-19 hyperinflammation. Therefore, Sumatriptan might be a novel potential therapeutic strategy in managing Covid-19. In conclusion, Sumatriptan could be an effective therapeutic strategy in managing Covid-19 through modulation of 5-HT neurotransmitters and inhibiting CGRP.

Clinical Value of Coagulation Function Indicators in Children with Severe Pneumonia

Objective

This study aimed to probe the changes in coagulation function-related indicators (prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB), D-dimer (D-D), and fibrinogen degradation product (FDP)) in severe pneumonia and their clinical significance.

Methods

The levels of coagulation function indicators of all the children were measured within 24 hours of admission. Pearson correlation analysis was utilized to analyze the correlation between PT, APTT, FIB, D-D, FDP and PCIS in children with severe pneumonia. The ROC curve was drawn to assess the power of PT, APTT, FIB, D-D and FDP in diagnosing severe pneumonia and predicting the prognosis of severe pneumonia. A logistic regression analysis was implemented to analyze the factors influencing the prognosis of children with severe pneumonia.

Results

PT, APTT, FIB, FDP, and D-D in the critically severe pneumonia and the extremely severe pneumonia groups were higher versus the common pneumonia group (P < 0.05). FDP and D-D levels in children with severe pneumonia were negatively correlated with PCIS. PT, APTT, FIB, FDP, and D-D of children in the poor prognosis group were higher compared with those in the good prognosis group (P < 0.05). Further logistic regression analysis unveiled that FDP and APTT were influential factors impacting the prognosis of severe pneumonia.

Conclusion

The levels of D-D, FDP, FIB, APTT, and PT in severe pneumonia are increased. Detecting the contents of coagulation function indicators can help clinical judgment of the changes in the condition of severe pneumonia and evaluate prognosis.

The current landscape of microRNAs (miRNAs) in bacterial pneumonia: opportunities and challenges

MicroRNAs (miRNAs), which were initially discovered in Caenorhabditis elegans, can regulate gene expression by recognizing cognate sequences and interfering with the transcriptional or translational machinery. The application of bioinformatics tools for structural analysis and target prediction has largely driven the investigation of certain miRNAs. Notably, it has been found that certain miRNAs which are widely involved in the inflammatory response and immune regulation are closely associated with the occurrence, development, and outcome of bacterial pneumonia. It has been shown that certain miRNA techniques can be used to identify related targets and explore associated signal transduction pathways. This enhances the understanding of bacterial pneumonia, notably for "refractory" or drug-resistant bacterial pneumonia. Although these miRNA-based methods may provide a basis for the clinical diagnosis and treatment of this disease, they still face various challenges, such as low sensitivity, poor specificity, low silencing efficiency, off-target effects, and toxic reactions. The opportunities and challenges of these methods have been completely reviewed, notably in bacterial pneumonia. With the continuous improvement of the current technology, the miRNA-based methods may surmount the aforementioned limitations, providing promising support for the clinical diagnosis and treatment of "refractory" or drug-resistant bacterial pneumonia.

Mammalian Neuropeptides as Modulators of Microbial Infections: Their Dual Role in Defense versus Virulence and Pathogenesis

The regulation of infection and inflammation by a variety of host peptides may represent an evolutionary failsafe in terms of functional degeneracy and it emphasizes the significance of host defense in survival. Neuropeptides have been demonstrated to have similar antimicrobial activities to conventional antimicrobial peptides with broad-spectrum action against a variety of microorganisms. Neuropeptides display indirect anti-infective capacity via enhancement of the host’s innate and adaptive immune defense mechanisms. However, more recently concerns have been raised that some neuropeptides may have the potential to augment microbial virulence. In this review we discuss the dual role of neuropeptides, perceived as a double-edged sword, with antimicrobial activity against bacteria, fungi, and protozoa but also capable of enhancing virulence and pathogenicity. We review the different ways by which neuropeptides modulate crucial stages of microbial pathogenesis such as adhesion, biofilm formation, invasion, intracellular lifestyle, dissemination, etc., including their anti-infective properties but also detrimental effects. Finally, we provide an overview of the efficacy and therapeutic potential of neuropeptides in murine models of infectious diseases and outline the intrinsic host factors as well as factors related to pathogen adaptation that may influence efficacy.