Cloning, Expression and Effects of P. americana Thymosin on Wound Healing

Abstract

The American cockroach (Periplaneta americana) is a medicinal insect. Its extract is used clinically to promote wound healing and tissue regeneration, but the effective medicinal components and mechanisms are not yet clear. It has been reported that human thymosin beta 4 (Tβ4) may accelerate skin wound healing, however, the role of P. americana thymosin (Pa-THYs) is still poorly understood. In the present study, we identify and analyze the DNA sequences of Pa-THYs by bioinformatics analysis. Then we clone, express, and purify the Pa-THYs proteins and evaluate the activity of recombinant Pa-THYs proteins by cell migration and proliferation assays in NIH/3T3 cells. To elucidate the role of Pa-THYs in wound healing, a mouse model is established, and we evaluate wound contraction, histopathological parameters, and the expressions of several key growth factors after Pa-THYs treatment. Our results showed that three THY variants were formed by skipping splicing of exons. Pa-THYs could promote fibroblast migration, but have no effect on fibroblast proliferation. In wound repair, Pa-THYs proteins could effectively promote wound healing through stimulating dermal tissue regeneration, angiogenesis, and collagen deposition. On the molecular mechanism, Pa-THYs also stimulated the expression of several key growth factors to promote wound healing. The data suggest that Pa-THYs could be a potential drug for promoting wound repair.

Spatiotemporal expression patterns of thymosin and its immune regulation after bacterial stimulation in American cockroach (Periplaneta americana)

“…At present, many thymosins had been identified from invertebrates, but their functions were still not fully understood (Saelee et al 2013). The result of this study, combined with that of our previous study (Sun et al 2019), showed that the expression levels of THY1, THY2, and THY3 were significantly up-regulated during the eclosion period, revealing that thymosin of P. americana might play an important role in the emergence period of P. americana. Eclosion was a critical period for the development of gradual insects (Judd 2018).…”

“…Three subtype proteins expressed by E. coli BL21 could promote wound healing in mice (Jin et al 2006). The expression pattern of THY3 in P. americana had been reported (Sun et al 2019).…”

“…Some functions of thymosins are highly similar to that of the Kangfuxin Liquid extracted from P. americana. The thymosin gene had been annotated in P. americana genome database and found that it contained three different splices named THY1 (MK573540), THY2 (MK573541), and THY3 (MK573542) by Jing et al (2019) based on transcriptome analysis. Three subtype proteins expressed by E. coli BL21 could promote wound healing in mice (Jin et al 2006).…”

Unraveling the role of male reproductive tract and haemolymph in cantharidin-exuding Lydus trimaculatus and Mylabris variabilis (Coleoptera: Meloidae): a comparative transcriptomics approach

“…These repairing functions could also be performed by thymosines, whose domains were highly represented in the haemolymph of the two analysed species (Table 5 ). Thymosin β4, in particular, is associated with tissue repair and cell migration in vertebrates [ 101 ], albeit still scarcely characterized in insects [ 102 ]. Thymosines are also known to regulate haemopoietic stem cell proliferation and differentiation in crustaceans [ 103 ].…”

Development of microparticles for oral administration of Periplaneta americana extract to treat ulcerative colitis

“…The dry cockroach body is recorded as a traditional Chinese medicine in ‘Shennong Materia Medica Classic’, which is commonly used for infantile malnutrition, sore throat, insect and snake bite, sore carbuncle, ulcer of digestive tract, etc (Chen et al, 2019 ). Studies have shown that the Periplaneta americana extract (PAE) promotes the growth of new granulation tissue and repairing ulcer wounds (Jing et al, 2019 ; Li et al, 2019 ), which can be used to treat gastric ulcers (Ma et al, 2018 ; Lu et al, 2019 ). PAE can be delivered to treat UC intravenously or subcutaneously in mice by increasing epidermal growth factor, which significantly reduces the lesion area (Xue et al, 2020 ).…”