Metabolic remodeling in tumor-associated macrophages contributing to antitumor activity of cryptotanshinone by regulating TRAF6-ASK1 axis.

Dampening tumor growth by converting tumor-associated macrophages (TAMs) from M2/repair-types to M1/kill-types is of high interest. Here, we show that cryptotanshinone (CPT) can function as an antitumor immune modulator that switches TAMs from an M2 to an M1 phenotype, leading to tumor regression. An orthotopic triple-negative breast cancer (TNBC) implantation model was used to determine the role and mechanism of CPT in suppressing M1-to-M2 repolarization of TAMs. Co-culturing TNBC cells with CPT-treated macrophages reduced TNBC proliferation and motility, while in TNBC orthotopic mouse models, CPT treatment inhibited breast tumor formation. Moreover, we identified that CPT inhibits mitochondrial oxidative phosphorylation and mitochondrial fusion via autophagy and transcriptional activation of the apoptosis signal-regulating kinase 1 (ASK1) pathway. Suppression of ASK1 downregulates autophagy and abolishes CPT-induced effects upon TAMs. In addition, CPT inhibits M2 macrophage differentiation and causes TRAF6 auto-ubiquitination-dependent activation of the ASK1, leading to M1 polarization. On the contrary, in M1 macrophage, CPT increases interaction of ASK1 and TRAF6 which induces ASK1 ubiquitination and degradation. Intriguingly, CPT plays opposite roles in the M1 and M2 phenotype. Our findings help to illuminate a previously unrecognized antitumor mechanism of CPT and suggest that this natural compound offers a macrophage-based approach for cancer immunotherapy.

Improved Wound Healing by Naringin Associated with MMP and the VEGF Pathway.

This study aims to investigate the wound-healing effectiveness of the phenolic compound, naringin, both in vitro and in vivo. Male mice were shaved on their dorsal skin under isoflurane, a biopsy punch was made in four symmetrical circular resection windows (6 mm) to induce a wound. These excision wounds were used to study the topical effects of naringin in terms of various biochemical, molecular, and histological parameters. We observed a significant recovery in the wound area. Increased levels of MMP-2, 9, 14, TIMP-2, VEGF-A, and VEGF-R1 were induced by naringin in the HaCaT cells. The time course experiments further revealed that levels of VEGF-A and B increased within 36 h; whereas levels of VEGF-C decreased. In line with this, VEGF-R3 levels, but not VEGF-R1 and 2 levels, increased soon after stimulation; although the increase subsided after 36 h. Additionally, naringin cream upregulated wound healing in vitro. The blockage of VEGF by Bevacizumab abolished the function of naringin cream on cell migration. Histological alterations in the wounded skin were restored by naringin cream, which accelerated wound healing via upregulated expression of growth factors (VEGF-A, B, and C and VEGF-R3), and thus increased MMP-2, 9, 14 expressions.