A peptide inhibitor of macrophage migration in atherosclerosis purified from the leech Whitmania pigra

Therapeutic Potentials of Medicinal Leech in Chinese Medicine

The use of medicinal leeches in clinical therapy has been employed for a long time, as it was originally recognized for exerting antithrombin effects. These effects were due to the ability of the leech to continuously suck blood while attached to human skin. According to Chinese Pharmacopoei, leeches used in traditional Chinese medicine mainly consist of Whitmania pigra Whitman, Hirudo nipponia Whitman, and Whitmania acranulata, but the latter two species are relatively scarce. The main constituents of leeches are protein and peptide macromolecules. They can be categorized into two categories based on their pharmacological effects. One group consists of active ingredients that directly target the coagulation system, such as hirudin, heparin, and histamine, which are widely known. The other group comprises protease inhibitor components like Decorsin and Hementin. Among these, hirudin secreted by the salivary glands of the leech is the most potent thrombin inhibitor and served as the sole remedy for preventing blood clotting until the discovery of heparin. Additionally, leeches play a significant role in various traditional Chinese medicine formulations. In recent decades, medicinal leeches have been applied in fields including anti-inflammatory treatment, cardiovascular disease management, antitumor treatment, and many other medical conditions. In this review, we present a comprehensive overview of the historical journey and medicinal applications of leeches in various medical conditions, emphasizing their pharmaceutical significance within traditional Chinese medicine. This review offers valuable insights for exploring additional therapeutic opportunities involving the use of leeches in various diseases and elucidating their underlying mechanisms for future research.

Characterization of the natural peptidome of four leeches by integrated proteogenomics and pseudotargeted peptidomics

Animal-derived drugs are an indispensable part of folk medicine worldwide. However, their chemical constituents are poorly approached, which leads to the low level of the quality standard system of animal-derived drugs and further causes a chaotic market. Natural peptides are ubiquitous throughout the organism, especially in animal-derived drugs. Thus, in this study, we used multi-source leeches, including Hirudo nipponica (HN), Whitmania pigra (WP), Whitmania acranulata (WA), and Poecilobdella manillensis (PM), as a model. A strategy integrating proteogenomics and novel pseudotargeted peptidomics was developed to characterize the natural peptide phenotype and screen for signature peptides of four leech species. First, natural peptides were sequenced against an in-house annotated protein database of closely related species constructed from RNA-seq data from the Sequence Read Archive (SRA) website, which is an open-sourced public archive resource. Second, a novel pseudotargeted peptidomics integrating peptide ion pair extraction and retention time transfer was established to achieve high coverage and quantitative accuracy of the natural peptides and to screen for signature peptides for species authentication. In all, 2323 natural peptides were identified from four leech species whose databases were poorly annotated. The strategy was shown to significantly improve peptide identification. In addition, 36 of 167 differential peptides screened by pseudotargeted proteomics were identified, and about one-third of them came from the leucine-rich repeat domain (LRR) proteins, which are widely distributed in organisms. Furthermore, six signature peptides were screened with good specificity and stability, and four of them were validated by synthetic standards. Finally, a dynamic multiple reaction monitoring (dMRM) method based on these signature peptides was established and revealed that one-half of the commercial samples and all of the Tongxinluo capsules were derived from WP. All in all, the strategy developed in this study was effective for natural peptide characterization and signature peptide screening, which could also be applied to other animal-derived drugs, especially for modelless species that are less studied in protein database annotation.

Review on Extraction, Modification, and Synthesis of Natural Peptides and Their Beneficial Effects on Skin

Peptides, functional nutrients with a size between those of large proteins and small amino acids, are easily absorbed by the human body. Therefore, they are seeing increasing use in clinical medicine and have revealed immunomodulatory and anti-inflammatory properties which could make them effective in healing skin wounds. This review sorted and summarized the relevant literature about peptides during the past decade. Recent works on the extraction, modification and synthesis of peptides were reviewed. Importantly, the unique beneficial effects of peptides on the skin were extensively explored, providing ideas for the development and innovation of peptides and laying a knowledge foundation for the clinical application of peptides.

Study on the regulatory effect of leech peptide HE-D on macrophages in atherosclerosis by transcriptome sequencing

ETHNOPHARMACOLOGICAL RELEVANCE

The incidence of atherosclerotic cardiovascular disease is a serious threat to human health. Leeches are used in traditional Chinese medicine to treat cardiovascular diseases. HE-D is an active peptide extracted and isolated from leeches, which can inhibit the migration of RAW264.7 macrophages.

AIM

This study shows the effects of HE-D on macrophages in atherosclerosis and the mechanism of inhibition on the migration of macrophages based on transcriptome sequencing (RNA-Seq).

MATERIALS AND METHODS

The transwell method was used to detect the activity of HE-D in inhibiting the migration of macrophages. Macrophages were divided into control group, lipopolysaccharide group, and HE-D group. Samples were collected and RNA-Seq performed. The DEseq2 method detected significantly differentially expressed genes (DEGs), GO and KEGG Pathway databases were used to analyze the functions and pathway enrichment of DEGs. Finally, qRT-PCR and Western blotting were used to verify the genes screened by RNA-Seq analyses.

RESULTS

Cell experiments showed that HE-D can inhibit the migration of RAW264.7 macrophages induced by LPS. DEseq2 analyses showed that there were 363 DEGs after HE-D administration in the result of RNA-Seq. The GO function of DEGs was significantly enriched in cell migration and inflammation, and the DEGs related to cell migration were significantly enriched in the NF-κB signaling pathway. qRT-PCR and Western blot analyses, showed that when compared with the LPS group, the related genes IKKα, IKKγ, TRAF6, TLR4, and TRAF5 in the NF-κB pathway were significantly down-regulated in the HE-D group. In addition, it was found that the inflammatory factors iNOS and TNF-α were significantly down-regulated, and Arg-1 and IL-10 were up-regulated.

CONCLUSION

HE-D can inhibit the migration of macrophages by inhibiting IKKα and IKKγ in the NF-κB signaling pathway, and promote the transformation of macrophages from M1to M2 subtypes. Therefore, HE-D can potentially be used as a drug for the treatment of atherosclerosis.

Recent advances in nanomaterials for therapy and diagnosis for atherosclerosis

Atherosclerosis is a chronic inflammatory disease driven by lipid accumulation in arteries, leading to narrowing and thrombosis. It affects the heart, brain, and peripheral vessels and is the leading cause of mortality in the United States. Researchers have strived to design nanomaterials of various functions, ranging from non-invasive imaging contrast agents, targeted therapeutic delivery systems to multifunctional nanoagents able to target, diagnose, and treat atherosclerosis. Therefore, this review aims to summarize recent progress (2017-now) in the development of nanomaterials and their applications to improve atherosclerosis diagnosis and therapy during the preclinical and clinical stages of the disease.

Time to Change Theory; Medical Leech from a Molecular Medicine Perspective Leech Salivary Proteins Playing a Potential Role in Medicine

Followed by developing modern medicine, leeches did not have extensive use as before; however, in the late 19th century, they were still used in most countries all over the world. Thus far, leeches were utilized in treating various diseases like skin disorders, arthritis, and cancer. In Egypt, using leeches for treatment dates back to early 1500 BC. A medical leech’s salivary glands involve over 100 bioactive proteins and the salivary gland secretion contains bacteriostatic, analgesic, and anticoagulation influences; with resolving activity, it causes microcirculation disorders elimination, restoring the hurt vascular permeability of organs and tissues, removing hypoxia, decreasing blood pressure and detoxifying the organism by antioxidant paths. The current work reviews the innovative treatment with medical leech, especially proteins in leech saliva extraction (LSE) with high potential in medicine. The virtue of salivary gland secretions which are proteinaceous enzymes, leech acts on various diseases such as venous congestion in reconstructive and plastic surgery, osteoarthritis, cardiovascular diseases caused by blood coagulation disorders, pain management, priapism, macroglossia, cancer complications, wounds and many other. To confirm the potential therapeutic impacts of leech treatment, more studies are required in more extensive areas with more exact methodologies.