Immunization with neural-derived peptides as a neuroprotective therapy for spinal cord injury

Spinal cord injury (SCI) induces several destructive events that develop immediately after the primary insult. These phenomena increase tissue damage; that is why, numerous therapeutic approaches are studied in order to neutralize these destructive mechanisms. In line with this, several studies indicate that after injury, neural tissue could be protected by an adaptive immune response directed against self-antigens. Immunization with neural-derived peptides (INDP) reduces secondary degeneration of neurons after spinal cord insult and promotes a significant motor recovery. The combination of antioxidants or other immunomodulatory peptides after SCI can improve the protective effect induced by INDP. INDP in acute SCI is a promising strategy, so further studies should be addressed to be able to formulate the best strategy.

Construction of Unified Human Antimicrobial and Immunomodulatory Peptide Database and Examination of Antimicrobial and Immunomodulatory Peptides in Alzheimer’s Disease Using Network Analysis of Proteomics Datasets

The reanalysis of genomics and proteomics datasets by bioinformatics approaches is an appealing way to examine large amounts of reliable data. This can be especially true in cases such as Alzheimer’s disease, where the access to biological samples, along with well-defined patient information can be challenging. Considering the inflammatory part of Alzheimer’s disease, our aim was to examine the presence of antimicrobial and immunomodulatory peptides in human proteomic datasets deposited in the publicly available proteomics database ProteomeXchange (http://www.proteomexchange.org/). First, a unified, comprehensive human antimicrobial and immunomodulatory peptide database, containing all known human antimicrobial and immunomodulatory peptides was constructed and used along with the datasets containing high-quality proteomics data originating from the examination of Alzheimer’s disease and control groups. A throughout network analysis was carried out, and the enriched GO functions were examined. Less than 1% of all identified proteins in the brain were antimicrobial and immunomodulatory peptides, but the alterations characteristic of Alzheimer’s disease could be recapitulated with their analysis. Our data emphasize the key role of the innate immune system and blood clotting in the development of Alzheimer’s disease. The central role of antimicrobial and immunomodulatory peptides suggests their utilization as potential targets for mechanistic studies and future therapies.

Damage-Associated Molecular Patterns (DAMPs) in Plant Innate Immunity: Applying the Danger Model and Evolutionary Perspectives

Danger signals trigger immune responses upon perception by a complex surveillance system. Such signals can originate from the infectious nonself or the damaged self, the latter termed damage-associated molecular patterns (DAMPs). Here, we apply Matzinger's danger model to plant innate immunity to discuss the adaptive advantages of DAMPs and their integration into pre-existing signaling pathways. Constitutive DAMPs (cDAMPs), e.g., extracellular ATP, histones, and self-DNA, fulfill primary, conserved functions and adopt a signaling role only when cellular damage causes their fragmentation or localization to aberrant compartments. By contrast, immunomodulatory peptides exclusively function as signals and, upon damage, are activated as inducible DAMPs (iDAMPs). Dynamic coevolutionary processes between the signals and their emerging receptors and shared co-receptors have likely linked danger recognition to preexisting, conserved downstream pathways. Expected final online publication date for the Annual Review of Phytopathology, Volume 59 is August 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Detection of Antimicrobial Peptides in Stratum Corneum by Mass Spectrometry

Antimicrobial and immunomodulatory peptides (AMPs) are considered as the key players in the maintenance of skin barrier functions. Here, we developed a novel approach for the examination of AMPs in the outermost layer of the epidermis, namely stratum corneum (SC). The SC sample collection by tape stripping was coupled with detection by highly specific and sensitive parallel reaction monitoring (PRM)-based mass spectrometry. We found that hexane-free processing of SC samples produced higher protein yield compared to hexane-based extraction. Of the 18 investigated peptides, 9 could be detected either in healthy or in inflamed skin specimens. Regarding the amount of S100A8, LCN2, LACRT and LYZ significant topographical differences were described among gland poor (GP), sebaceous gland rich (SGR) and apocrine gland rich (AGR) healthy skin regions. We applied a minimally invasive, reproducible approach for sampling, which can be assessed for research and diagnostic purposes and for monitoring the effectiveness of therapies in skin diseases.

Purification and characterization of immunomodulatory peptides from enzymatic hydrolysates of duck egg ovalbumin

Duck egg white (DEW) is considered as an abandoned protein resource.

Exploring Potential Bioactive Peptides in Fermented Bactrian Camel’s Milk and Mare’s Milk Made by Mongolian Nomads

To date, bioactive proteins and peptides from minor livestock milks and their fermented products have been scarcely reported. In Mongolia, nomads are commonly rearing five livestock animal species (i.e., cow, camel, goat, horse, and sheep) for milking and other purposes. In this study, we analyzed the peptide composition in fermented milks of Bactrian camels (Camelus bactrianus) and horses, produced by Mongolian nomads for self-consumption. Peptides from skimmed fermented milks were separated by ultrafiltration and reverse-phase high-performance liquid chromatography. Then, their amino acid sequences were determined by matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry. Consequently, eleven peptides were identified in the fermented camel’s milk including four from β-casein (β-CN), three from αs1-CN, and two from both κ-CN and lactophorin. On the other hand, twenty-four peptides were identified in the fermented mare’s milk including nineteen from β-CN, three from αs1-CN, and one from both κ-CN and αs2-CN. According to previous reports on the bioactivities of milk-derived peptides, antibacterial and antihypertensive activities were promising in both the fermented camel’s milk and mare’s milk. In addition, potential antioxidant activity was conjectured in the fermented camel’s milk. Further investigations are currently needed to clarify the potential role of immunomodulatory peptides in the two fermented milks.

Aminopeptidases in Cardiovascular and Renal Function. Role as Predictive Renal Injury Biomarkers

Aminopeptidases (APs) are metalloenzymes that hydrolyze peptides and polypeptides by scission of the N-terminus amino acid and that also participate in the intracellular final digestion of proteins. APs play an important role in protein maturation, signal transduction, and cell-cycle control, among other processes. These enzymes are especially relevant in the control of cardiovascular and renal functions. APs participate in the regulation of the systemic and local renin–angiotensin system and also modulate the activity of neuropeptides, kinins, immunomodulatory peptides, and cytokines, even contributing to cholesterol uptake and angiogenesis. This review focuses on the role of four key APs, aspartyl-, alanyl-, glutamyl-, and leucyl-cystinyl-aminopeptidases, in the control of blood pressure (BP) and renal function and on their association with different cardiovascular and renal diseases. In this context, the effects of AP inhibitors are analyzed as therapeutic tools for BP control and renal diseases. Their role as urinary biomarkers of renal injury is also explored. The enzymatic activities of urinary APs, which act as hydrolyzing peptides on the luminal surface of the renal tubule, have emerged as early predictive renal injury biomarkers in both acute and chronic renal nephropathies, including those induced by nephrotoxic agents, obesity, hypertension, or diabetes. Hence, the analysis of urinary AP appears to be a promising diagnostic and prognostic approach to renal disease in both research and clinical settings.