Dual dose-related effects evoked by CCL4 on thermal nociception after gene delivery or exogenous administration in mice.

As recently described, the administration of extremely low doses (pg/kg) of CCL4 (Macrophage inflammatory protein 1ß, MIP-1ß) can induce antinociceptive effects in mice (García-Domínguez et al., 2019b). We describe here that hydrodynamic delivery of a plasmid containing CCL4 cDNA provokes a biphasic response consisting in an initial thermal hyperalgesic reaction for 8 days followed by analgesia at days 10-12, being both responses blocked after the administration of the CCR5 antagonist DAPTA. Both the luminiscence evoked in liver after the administration of a plasmid containing CCL4 and luciferase cDNAs and the hepatic concentration of CCL4 measured by ELISA were maximal 4 days after plasmid administration and markedly diminished at day 10. A dose-effect curve including a wide dose range of exogenous CCL4 revealed thermal analgesia after the administration of 10-100 pg/kg whereas 1000 times higher doses (30-100 ng/kg) induced, instead, thermal hyperalgesia inhibited by DAPTA. This hyperalgesia was absent in mice with reduced white blood cells after cyclophosphamide treatment, thus supporting the involvement of circulating leukocytes. A multiarray bioluminescent assay revealed increased plasma levels of IL-1α, CCL2, CXCL1, CXCL13, IL-16 and TIMP-1 in mice treated with 100 ng/kg of CCL4. The hyperalgesic response evoked by CCL4 was prevented by IL-1R, CXCR2 or CCR2 antagonists or by the neutralization of CXCL13 or IL-16, but not TIMP-1, with selective antibodies. The administration of the anti-IL-16 antibody was the unique treatment able to convert hyperalgesia evoked by 100 ng/kg of CCL4 in an analgesic effect. The ability of IL-16 to evoke hypernociception was confirmed by studying the response to its exogenous administration (10-30 ng/kg). In summary, the present results demonstrate that CCL4 induces a dual modulation of nociception and describe some mechanisms involved in the hyperalgesic response evoked by this chemokine.

Nanostructured recombinant cytokines: A highly stable alternative to short-lived prophylactics.

Cytokines have been widely used as adjuvants and therapeutic agents in treatments of human diseases. Despite their recognized potential as drugs, the medical use of cytokines has considerable drawbacks, mainly related to their low stability and short half-life. Such intrinsic limitations imply the administration of high doses, often prompting toxicity, undesirable side effects and greater production costs. Here, we describe a new category of mechanically stable nanostructured cytokines (TNFα and CCL4/MIP-1ß) that resist harsh physicochemical conditions in vitro (pH and temperature), while maintaining functionality. These bio-functional materials are produced in recombinant cell factories through cost-effective and fully scalable processes. Notably, we demonstrate their prophylactic potential in vivo showing they protect zebrafish from a lethal infection by Pseudomonas aeruginosa.

Bone morphogenetic protein 7 suppresses the progression of hepatic fibrosis and regulates the expression of gremlin and transforming growth factor ß1.

Bone morphogenetic protein 7 (BMP-7), a member of the transforming growth factor (TGF)-ß superfamily, counteracts the effect of TGF-ß through different signaling pathways, and gremlin is considered as one of the antagonists of BMP-7. The aim of this study was to investigate the antifibrotic effect of BMP-7, and to clarify the expression patterns of gremlin and TGF-ß1 in the progression of hepatic fibrosis after treatment with BMP-7. A mouse liver fibrosis model was induced by hypodermic injection of CCL4 and all the liver and blood samples were preserved for further study. Reverse transcription-polymerase chain reaction was used for detecting mRNA expression, and protein levels and localization were measured by western blotting and immunohistochemistry, respectively. The improvement of liver function and the regression of hepatic fibrosis were demonstrated by the parameters of a liver test and a histopathological assay, owing to the downregulated expression of COL-I, α-SMA, TIMP-2 and upregulated MMP-2. Moreover, exogenous BMP-7 appeared to suppress the expression of TGF-ß1 and increase the levels of gremlin. In conclusion, hepatic fibrosis was ameliorated by the administration of BMP-7, and the expression of gremlin and TGF-ß1 were regulated by BMP-7. The identification of the dynamic expression pattern of gremlin may yield a novel biomarker for assessing the degree of hepatic fibrosis.