May salivary gland secretory proteins from hematophagous leeches (Hirudo verbana) reach pharmacologically relevant concentrations in the vertebrate host?

Hirudotherapy attenuates arthritic pain in patients with various chronic pain syndromes: A retrospective analysis

OBJECTIVE

Osteoarthritis is a degenerative disease that affects synovial joints. Micro-injuries of articular structures initiate inflammatory processes, leading to persistent pain. Due to various risk factors, osteoarthritis is often diagnosed in multimorbid patients. This makes pain management one of the key challenges, with a consistent need for new therapeutic strategies. Hence, complementary and integrative methods such as hirudotherapy have become increasingly important, even though their mechanisms of action are not entirely understood.

METHODS

We retrospectively analyzed the longitudinal effect of a single leech application on osteoarthritic joints in a heterogenic cohort of 24 cases with various chronic pain syndromes. We assessed articular pain intensity ratings and movability of the treated joint after one-time leeching for up to 12 months. We further investigated the effect of hirudotherapy on the systemic pain status and multimodal treatment strategies of the patients.

RESULTS

There was a significant reduction in pain intensity ratings at the joint of leech application for up to 12 months after treatment. The improvements in pain intensities were independent of the form of osteoarthritis treated. In addition, we saw a considerable enhancement in local movability of the treated joint. Hirudotherapy did not seem to influence the systemic pain status as well as the previously established individualized multimodal treatment model of the patients.

CONCLUSION

Leeching as an adjuvant therapy has a great potential especially in terms of safety and long-term outcome.

Draft genome sequences of Hirudo medicinalis and salivary transcriptome of three closely related medicinal leeches

BACKGROUND

Salivary cell secretion (SCS) plays a critical role in blood feeding by medicinal leeches, making them of use for certain medical purposes even today.

RESULTS

We annotated the Hirudo medicinalis genome and performed RNA-seq on salivary cells isolated from three closely related leech species, H. medicinalis, Hirudo orientalis, and Hirudo verbana. Differential expression analysis verified by proteomics identified salivary cell-specific gene expression, many of which encode previously unknown salivary components. However, the genes encoding known anticoagulants have been found to be expressed not only in salivary cells. The function-related analysis of the unique salivary cell genes enabled an update of the concept of interactions between salivary proteins and components of haemostasis.

CONCLUSIONS

Here we report a genome draft of Hirudo medicinalis and describe identification of novel salivary proteins and new homologs of genes encoding known anticoagulants in transcriptomes of three medicinal leech species. Our data provide new insights in genetics of blood-feeding lifestyle in leeches.

Transcriptomic Analysis of the Influence of Methanol Assimilation on the Gene Expression in the Recombinant Pichia pastoris Producing Hirudin Variant 3

Hirudin and its variants, as strong inhibitors against thrombin, are present in the saliva of leeches and are recognized as potent anticoagulants. However, their yield is far from the clinical requirement up to now. In this study, the production of hirudin variant 3 (HV3) was successfully realized by cultivating the recombinant Pichia pastoris GS115/pPIC9K-hv3 under the regulation of the promoter of AOX1 encoding alcohol oxidase (AOX). The antithrombin activity in the fermentation broth reached the maximum value of 5000 ATU/mL. To explore an effective strategy for improving HV3 production in the future, we investigated the influence of methanol assimilation on the general gene expression in this recombinant by transcriptomic study. The results showed that methanol was partially oxidized into CO₂, and the rest was converted into glycerone-P which subsequently entered into central carbon metabolism, energy metabolism, and amino acid biosynthesis. However, the later metabolic processes were almost all down-regulated. Therefore, we propose that the up-regulated central carbon metabolism, energy, and amino acid metabolism should be beneficial for methanol assimilation, which would accordingly improve the production of HV3.

Marine Leech Anticoagulant Diversity and Evolution

Leeches (Annelida: Hirudinea) possess powerful salivary anticoagulants and, accordingly, are frequently employed in modern, authoritative medicine. Members of the almost exclusively marine family Piscicolidae account for 20% of leech species diversity, and they feed on host groups (e.g., sharks) not encountered by their freshwater and terrestrial counterparts. Moreover, some species of Ozobranchidae feed on endangered marine turtles and have been implicated as potential vectors for the tumor-associated turtle herpesvirus. In spite of their ecological importance and unique host associations, there is a distinct paucity of data regarding the salivary transcriptomes of either of these families. Using next-generation sequencing, we profiled transcribed, putative anticoagulants and other salivary bioactive compounds that have previously been linked to blood feeding from 7 piscicolid species (3 elasmobranch feeders; 4 non-cartilaginous fish feeders) and 1 ozobranchid species (2 samples). In total, 149 putative anticoagulants and bioactive loci were discovered in varying constellations throughout the different samples. The putative anticoagulants showed a broad spectrum of described antagonistic pathways, such as inhibition of factor Xa and platelet aggregation, which likely have similar bioactive roles in marine fish and turtles. A transcript with homology to ohanin, originally isolated from king cobras, was found in Cystobranchus vividus but is otherwise unknown from leeches. Estimation of selection pressures for the putative anticoagulants recovered evidence for both positive and purifying selection along several isolated branches in the gene trees, and positive selection was also estimated for a few select codons in a variety of marine species. Similarly, phylogenetic analyses of the amino acid sequences for several anticoagulants indicated divergent evolution.

Be ready at any time: postprandial synthesis of salivary proteins in salivary gland cells of the haematophagous leech Hirudo verbana

Sanguivorous leeches are ectoparasites having access to body fluids of potential hosts only infrequently. During feeding, salivary proteins are released from unicellular salivary glands into the wound. These substances, among them anti-coagulants, anti-inflammatory or anti-microbial agents, allow these animals proper feeding and long-term storage of host blood in their crops for several months. Using histological, protein biochemical and molecular techniques, we investigated whether synthesis of salivary proteins and refilling of salivary gland cells occur immediately after feeding or later when stored nutrients in the crop are getting scarce. The results of the histological analyses showed that gland cell area was significantly smaller right after feeding when compared with those in unfed animals. This parameter recovered quickly and reached the control level at 1 week after feeding. 2D gel electrophoresis and analysis of the abundance of individual proteins in extracts of leech tissues revealed that a subset of proteins that had been present in extracts of unfed animals virtually disappeared during feeding, but re-appeared within 1 week of feeding (most probably secretory proteins) while another subset did not change during the experimental period (most probably housekeeping proteins). Semi-quantitative PCR analysis of hirudin cDNA prepared from leech RNA samples revealed that the amount of hirudin transcripts increased immediately after feeding, peaked at 5 days after feeding and declined to control values thereafter. Our results indicate that bloodsucking leeches synthesize salivary proteins and refill their salivary gland cell reservoirs within a week of a blood meal to be prepared for another feeding opportunity.

Nao-Xue-Shu Oral Liquid Protects and Improves Secondary Brain Insults of Hypertensive Cerebral Hemorrhage

Aim. To determine one traditional Chinese medicine (TCM) Nao-Xue-Shu oral liquid which protects and improves secondary brain insults (SBI) in hypertensive cerebral hemorrhage (HCH). Methods. 158 patients with HCH were divided into routine clinical medicine plus Nao-Xue-Shu oral liquid (n = 78) as treatment group, and routine clinical medicine (n = 80) only served as the control group. The incidence of SBI and the classification of a favorable prognosis and a bad prognosis using the Glasgow outcome scale (GOS) were assessed to evaluate the clinical effects. The changes of IL-6 and TNF-α levels were determined to study the mechanism of the effects for the TCM. Results. The incidence of SBI at the end of week 2 was 8.97% in the treatment group and 23.75% in the control group, and the difference was significant (P < 0.001). The incidence of a favorable prognosis was 48.72% in the treatment group and 32.72% in the control group, and the difference was significant (P < 0.01) at the end of week 2. These findings indicate clear differences for IL-6 and TNF-α at the end of week 1 and week 2 compared with before treatment for the treatment group and a marked difference at the end of week 2 between the two groups. It also shows a significant difference between the end of week 2 and before treatment for IL-6 and TNF-α for the control group, although the difference was much smaller than the treatment group. Conclusion. Nao-Xue-Shu oral liquid could protect against the occurrence of SBI and improve HCH and SBI patients. It may also decrease the damage and the mass effects of the hematoma by reducing IL-6 and TNF-α to obtain the effects, and thus it is a potentially suitable drug for HCH and SBI.

Why do we study animal toxins?

Venom (toxins) is an important trait evolved along the evolutionary tree of animals. Our knowledges on venoms, such as their origins and loss, the biological relevance and the coevolutionary patterns with other organisms are greatly helpful in understanding many fundamental biological questions, i.e., the environmental adaptation and survival competition, the evolution shaped development and balance of venoms, and the sophisticated correlations among venom, immunity, body power, intelligence, their genetic basis, inherent association, as well as the cost-benefit and trade-offs of biological economy. Lethal animal envenomation can be found worldwide. However, from foe to friend, toxin studies have led lots of important discoveries and exciting avenues in deciphering and fighting human diseases, including the works awarded the Nobel Prize and lots of key clinic therapeutics. According to our survey, so far, only less than 0.1% of the toxins of the venomous animals in China have been explored. We emphasize on the similarities shared by venom and immune systems, as well as the studies of toxin knowledge-based physiological toxin-like proteins/peptides (TLPs). We propose the natural pairing hypothesis. Evolution links toxins with humans. Our mission is to find out the right natural pairings and interactions of our body elements with toxins, and with endogenous toxin-like molecules. Although, in nature, toxins may endanger human lives, but from a philosophical point of view, knowing them well is an effective way to better understand ourselves. So, this is why we study toxins.

Quo vadis venomics? A roadmap to neglected venomous invertebrates

Venomics research is being revolutionized by the increased use of sensitive -omics techniques to identify venom toxins and their transcripts in both well studied and neglected venomous taxa. The study of neglected venomous taxa is necessary both for understanding the full diversity of venom systems that have evolved in the animal kingdom, and to robustly answer fundamental questions about the biology and evolution of venoms without the distorting effect that can result from the current bias introduced by some heavily studied taxa. In this review we draw the outlines of a roadmap into the diversity of poorly studied and understood venomous and putatively venomous invertebrates, which together represent tens of thousands of unique venoms. The main groups we discuss are crustaceans, flies, centipedes, non-spider and non-scorpion arachnids, annelids, molluscs, platyhelminths, nemerteans, and echinoderms. We review what is known about the morphology of the venom systems in these groups, the composition of their venoms, and the bioactivities of the venoms to provide researchers with an entry into a large and scattered literature. We conclude with a short discussion of some important methodological aspects that have come to light with the recent use of new -omics techniques in the study of venoms.