Mitogenicity of the earthworm's (Eisenia foetida) insulin-like proteins

Dilong: role in peripheral nerve regeneration

Dilong, also known as earthworm, has been widely used in traditional Chinese medicine (TCM) for thousands of years. Schwann cell migration and proliferation are critical for the regeneration of injured nerves and Schwann cells provide an essentially supportive role for neuron regeneration. However, the molecular mechanisms of migration and proliferation induced by dilongs in Schwann cells remain unclear. Here, we discuss the molecular mechanisms that includes (i) migration signaling, MAPKs (mitogen-activated protein kinases), mediated PAs and MMP2/9 pathway; (ii) survival and proliferative signaling, IGF-I (insulin-like growth factor-I)-mediated PI3K/Akt pathways and (iii) cell cycle regulation. Dilong stimulate RSC96 cell proliferation and migration. It can induce phosphorylation of ERK1/2 and p38, but not JNK, and activate the downstream signaling expression of PAs (plasminogen activators) and MMPs (matrix metalloproteinases) in a time-dependent manner. In addition, Dilong stimulated ERK1/2 and p38 phosphorylation was attenuated by pretreatment with chemical inhibitors (U0126 and SB203580), and small interfering ERK1/2 and p38 RNA, resulting in migration and uPA-related signal pathway inhibition. Dilong also induces the phosphorylation of IGF-I-mediated PI3K/Akt pathway, activates protein expression of PCNA (proliferating cell nuclear antigen) and cell cycle regulatory proteins (cyclin D1, cyclin E and cyclin A) in a time-dependent manner. In addition, it accelerates G₁-phase progression with earlier S-phase entry and significant numbers of cells entered the S-phase. The siRNA-mediated knockdown of PI3K that significantly reduces PI3K protein expression levels, resulting in Bcl₂ survival factor reduction, revealing a marked blockage of G₁ to S transition in proliferating cells. These results reveal the unknown RSC96 cell migration and proliferation mechanism induced by dilong, which find use as a new medicine for nerve regeneration.

RSC96 Schwann Cell Proliferation and Survival Induced by Dilong through PI3K/Akt Signaling Mediated by IGF-I

Schwann cell proliferation is critical for the regeneration of injured nerves. Dilongs are widely used in Chinese herbal medicine to remove stasis and stimulate wound-healing functions. Exactly how this Chinese herbal medicine promotes tissue survival remains unclear. The aim of the present study was to investigate the molecular mechanisms by which Dilong promote neuron regeneration. Our results show that treatment with extract of Dilong induces the phosphorylation of the insulin-like growth factor-I (IGF-I)-mediated phosphatidylinositol 3-kinase/serine-threonine kinase (PI3K/Akt) pathway, and activates protein expression of cell nuclear antigen (PCNA) in a time-dependent manner. Cell cycle analysis showed that G₁ transits into the S phase in 12–16 h, and S transits into the G₂ phase 20 h after exposure to earthworm extract. Strong expression of cyclin D1, cyclin E and cyclin A occurs in a time-dependent manner. Small interfering RNA (siRNA)-mediated knockdown of PI3K significantly reduced PI3K protein expression levels, resulting in Bcl₂ survival factor reduction and a marked blockage of G₁ to S transition in proliferating cells. These results demonstrate that Dilong promotes the proliferation and survival of RSC96 cells via IGF-I signaling. The mechanism is mainly dependent on the PI3K protein.

Schwann Cell Migration Induced by Earthworm Extract via Activation of PAs and MMP2/9 Mediated through ERK1/2 and p38

The earthworm, which has stasis removal and wound-healing functions, is a widely used Chinese herbal medicine in China. Schwann cell migration is critical for the regeneration of injured nerves. Schwann cells provide an essentially supportive activity for neuron regeneration. However, the molecular migration mechanisms induced by earthworms in Schwann cells remain unclear. Here, we investigate the roles of MAPK (ERK1/2, JNK and p38) pathways for earthworm-induced matrix-degrading proteolytic enzyme (PAs and MMP2/9) production in Schwann cells. Moreover, earthworm induced phosphorylation of ERK1/2 and p38, but not JNK, activate the downstream signaling expression of PAs and MMPs in a time-dependent manner. Earthworm-stimulated ERK1/2 and p38 phosphorylation was attenuated by pretreatment with U0126 and SB203580, resulting in migration and uPA-related signal pathway inhibition. The results were confirmed using small interfering ERK1/2 and p38 RNA. These results demonstrated that earthworms can stimulate Schwann cell migration and up-regulate PAs and MMP2/9 expression mediated through the MAPK pathways, ERK1/2 and p38. Taken together, our data suggests the MAPKs (ERK1/2, p38)-, PAs (uPA, tPA)-, MMP (MMP2, MMP9) signaling pathway of Schwann cells regulated by earthworms might play a major role in Schwann cell migration and nerve regeneration.

Effect of earthworm (G-90) extract on formation and lysis of clots originated from venous blood of dogs with cardiopathies and with malignant tumors

The stability of homeostasis is important to keep a balance between coagulation and fibrinolysis. A disorder of homeostasis leads to different physiological changes and causes different diseases such as cardiopathies and malignant tumors. Cardiopathies is characterized by a hypercoagulation. In the malignant tumors, besides the hypercoagulation due to plasminogen activators (PA) formed inside the tumor, a disorder of homeostasis leads also to acceleration of the fibrinolysis. The variety of internal and external factors in both cases determine the deviation of time for the clots formation, as well as the lyses of blood and fibrin clots. In this study the venous blood as well as the blood and the fibrin clots, derived from healthy dogs, the dogs with cardiopathies and with malignant tumors, were examined for the time of coagulation and fibrinolysis by adding different substances. In these experiments we used a glycolipoprotein extract from earthworm tissue homogenate (G-90) and the proteolytic enzymes P I and P II, isolated from G-90. The efficacy of the tested substances was comparable with the clinically administered anticoagulants. The most significant differences in clotting time among the three tested groups of dogs were obtained by application of the original G-90. The results suggest a possibility that G-90, along with the fibrinolytic enzymes and other biologically active factors, also contains a factor that decelerates the formation of clot in a specific medium, such as the blood from the dogs with malignant tumors.

Adhesins of immunoglobulin-like superfamily from earthworm Eisenia foetida

1. From the biologically active extract (G-90) isolated from the tissue homogenate of Eisenia foetida immunoglobulin-like structures were isolated and named G-90/4. 2. G-90/4 in nanogram concentrations stimulated cell proliferation more than did the original G-90. It lyses cells in microgram concentrations. 3. G-90/4 acts as an adhesion molecule between the receptors of adjacent cells. 4. The increase in proliferative activity was accompanied by the elevation of cytoplasmic protein containing tyrosine. 5. Immunohistochemical analyses confirm immunoglobulin-like transmembrane structures in the connective and muscular tissues of E. foetida.

Fibrinolytic and anticoagulative activities from the earthworm Eisenia foetida

Biologically active glycolipoprotein complex (G-90) isolated from whole earthworm tissue extract shows anticoagulative and fibrinolytic activities. We isolated two tyrosine like serine peptidases with molecular masses of 34 kDa (P I) and 23 kDa (P II), respectively. P I peptidase is autocatalytically degraded to P II. Both peptidases exhibit fibrinolytic and anticoagulative activities. The activity of P I is much higher. P I in concentration of 10(5) ng ml-1 of plasma shortened the physiological time of fibrin clot lysis by 54% and completely inhibited blood clotting at a concentration of 10(3) ng ml-1 of venous blood.

Identification of insulin-like peptides in cerebral ganglia neurosecretory cells of the mussel Mytilus edulis

The immunostaining patterns of cerebral ganglia sections from the mussel Mytilus edulis with monoclonal antibodies raised against cerebral ganglia (CG) extracts were compared to those obtained with various polyclonal anti-insulin-like antibodies. One of the monoclonal antibodies (MAB 46) revealed clusters of positive cells in localization comparable to those revealed by the polyclonal antibodies. The nature of the antigen recognized by MAB 46 and the polyclonal antibodies was compared by gel filtration-HPLC of a cerebral ganglia extract. Similar peaks were revealed by the monoclonal and polyclonal antibodies. MAB 46 significantly inhibited the cerebral ganglia induced stimulation of amino-acid incorporation by mantle edge cell suspensions, suggesting that the antigen recognized by MAB 46 is involved in the control of growth.