Skin repair properties of d-Limonene and perillyl alcohol in murine models.

The orange-peel derived terpene d-Limonene, probably through its metabolite, perillyl alcohol (POH), has been reported to have tissue-repair properties. Two murine models of respectively 12-O-Tetradecanoylphorbol-13-Acetate (TPA)-induced dermatitis and mechanical skin lesion were used here to assess the efficacy of d-Limonene or POH applied topically. Macroscopic and microscopic evaluation of skin lesions was performed as well as that of P-selectin expression, together with measurements of serum concentrations of IL-1ß, IL-6 and TNF-α in the first model. Healing and angiogenesis around the scar were examined in the second model. Because differences in angiogenesis were noted, the effect of both d-Limonene and POH was further tested on an in vitro model of endothelial microtubules formation. Both d-Limonene and POH reduced the severity and extension of TPA-induced skin lesions with significantly lowered macroscopic and microscopic scores (p<0.04 in both cases). Moreover, the expression of P-selectin induced by TPA was abrogated by POH and significantly lower serum concentrations of IL-6 and TNF-α were observed in d-Limonene- and POH-treated mice (p<0.04 and 0.03). In the second model, tissue regeneration was improved, especially by POH, and was clearly associated with reduced neovascularization. This surprising anti-angiogenic effect was confirmed in the matrigel model of endothelial microtubules formation. These studies show that d-Limonene and POH demonstrate significant anti-inflammatory effects in murine dermal inflammation and wound-healing. The decreased systemic cytokine production as well as a consistent inhibition of endothelial P-selectin expression and neo-vascularization induced by these terpenic compounds contribute to their healing effects on the epidermal barrier.

Whole blood clots are more resistant to lysis than plasma clots--greater efficacy of rivaroxaban.

INTRODUCTION: Defective thrombolysis, a thrombotic risk factor, can be attributed to the formation of a compact clot poorly accessible to fibrinolytic enzymes. Venous thrombi, rich in red blood cells (RBCs), and arterial thrombi containing various amounts of RBCS, plasma and whole blood (WB) clot permeability and degradability were compared. The effect of rivaroxaban, a potent direct factor Xa inhibitor, was also evaluated. MATERIALS AND METHODS: Fibrin permeability was determined by flow measurement through the clot. Clot degradability was evaluated by the amount of D-dimer generated by clot perfusion with plasminogen and tissue plasminogen activator. Fibrin clot structure was assessed by confocal microscopy. RESULTS: WB clot permeability (KS) and degradability were 6.7- and 38-fold lower, respectively, compared with plasma clots. This is attributed to 1) occlusion of fibrin pores by RBCs and 2) a consistent increase in thrombin generation due to platelets and RBCs inducing formation of a tighter clot. Rivaroxaban added to plasma or WB before clotting, in reducing thrombin generation, led to the formation of a looser clot that is more degradable by fibrinolytic enzymes. Permeability and degradability of whole blood clots formed in the presence of rivaroxaban were very similar to those of plasma clots. CONCLUSION: The resistance to fibrinolysis of WB clots was reduced considerably when clots were formed with rivaroxaban. These results may have implications for the development of antithrombotic agents.

The BH3-only protein Noxa is stimulated during apoptosis of chronic lymphocytic leukemia cells triggered by M2YN, a new plant-derived extract.

Deficiency of apoptosis is a hallmark of chronic lymphocytic leukemia (CLL) cells. M2Yn is a natural extract from plants of central Asia, identified for its antiangiogenic properties and its ability to block the migration of malignant cells. Here, we report that in vitro treatment of cells derived from CLL patients with M2Yn results in internucleosomal DNA fragmentation, phosphatidylserine externalization, mitochondrial membrane depolarization, caspase-3 activation and cleavage of the caspase substrate PARP-1. The extents of these effects depend on the patients and are mostly comparable to those of flavopiridol or hyperforin, two known plant-derived apoptosis inducers of CLL cells. M2Yn does not modulate Mcl-1 expression, while downregulation of this antiapoptotic protein is involved in the action of flavopiridol. By contrast, M2Yn, like hyperforin, upregulates the Noxa protein, possibly by inhibiting proteasomal activity. This BH3-only protein is known to trigger the activation of the pro-apoptotic protein Bak through displacement of the Mcl-1/Bak complex at the mitochondrial membrane, as actually observed here in M2Yn-treated cells. Our data, therefore, show that M2Yn can induce the caspase-dependent mitochondrial pathway of apoptosis in CLL cells via a mechanism resembling that of hyperforin. Our data also confirm that the BH3-only protein Noxa is a relevant target for CLL therapy.

Tumor associated mesenchymal stem cells protects ovarian cancer cells from hyperthermia through CXCL12.

Hyperthermic intraperitoneal chemotherapy (HIPEC) has shown promise in treatment of ovarian carcinosis. Despite its efficiency for the treatment of peritoneal carcinosis from digestive tract neoplasia, it has failed to demonstrate significant benefit in ovarian cancers. It is therefore essential to understand the mechanism underlying resistance to HIPEC in ovarian cancers. Mesenchymal stem cells (MSC) play an important role in the development of ovarian cancer metastasis and resistance to treatments. A recent study suggests that MSCs may be cytotoxic for cancer cells upon heat shock. In contrast, we describe the protective role of MSC against hyperthermia. Using cytokine arrays we determined that the tumor associated MSC (TAMC) secrete pro-tumoral cytokines. We studied the effect of hyperthermia in co-culture setting of TAMC or BM-MCS associated with ovarian cancer cell lines (SKOV3 and CaOV3) with polyvariate flow cytometry. We demonstrate that hyperthermia does not challenge survival of TAMC or bone marrow derived MSC (BM-MSC). Both TAMC and BM-MSC displayed strong protective effect inducing thermotolerance in ovarian cancer cells (OCC). Transwell experiments demonstrated the role of secreted factors. We showed that CXCL12 was inducing thermotolerance and that inhibition of CXCL12/CXCR4 interaction restored cytotoxicity of hyperthermia in co-culture experiments. Contrary to the previous published study we demonstrated that TAMC and BM-MSC co-cultured with OCC induced thermotolerance in a CXCL12 dependant manner. Targeting the interaction between stromal and cancer cells through CXCL12 inhibition might restore hyperthermia sensitivity in ovarian cancers, and thus improve HIPEC efficiency.

The mineralocorticoid receptor in rodent retina: ontogeny and molecular identity.

PURPOSE: Mineralocorticoid hormones contribute to ion-water balance in all cell types. In this study, we investigated the presence of mineralocorticoid receptors in rat and bovine ocular tissues and during retinal development. METHODS: Isolated photoreceptors and/or intact retina, retinal pigment epithelium (RPE) cells, and ciliary body were analyzed for the expression of MR (Mineralocorticoid Receptor) using the polymerase chain reaction (PCR) technique. Since aldosterone can stimulate the expression of epithelial Na+ channels (ENaC), expression of this gene in RPE was measured under basal and aldosterone-induced level. RESULTS: MR was expressed in rat photoreceptors and in the inner retina (inner nuclear layer and ganglion cell layer) even one day after birth, almost hundred percent identity was observed between rat retina and kidney MR gene products. The expression was also present in the RPE and in the ciliary body. ENaC gene was expressed in RPE and generated a predicted band at 520 bp following RT-PCR amplification which was 95% homology to that of ENaC mRNA from bovine kidney. The incubation of RPE cells in vitro with aldosterone increased the mRNA level of ENaC. CONCLUSIONS: MR expression in the mammalian retina, RPE, and ciliary body extends the potential field of action for mineralocorticoid hormones. Results on RPE cells are consistent with the idea that steroid hormones may regulate the physiology of these tissues by modulating ENaC expression. This study provides new light on the potential effect of mineralocorticoid in this area of the nervous system.