ABSTRACT
ObjectiveThis study aims to investigate the effect of modified Baitouwengtang （MBTWD） on tumor growth and the number of tumor-associated macrophages （TAMs） in tumor tissue of MC38 cell tumor-bearing mice with colorectal cancer and explores whether MBTWD mediates the remodeling of TAM phenotype to play an immunologically antitumor effect. MethodFirstly， The C57BL/6 mouse tumor model grafted subcutaneously was established， and then model mice were classified into a model group， positive control group（3 mg·kg-1）， and MBTWD groups with high and low dosages（23.43、46.86 g·kg-1）， with 10 mice in each group. In addition， 10 healthy mice were set as the blank group， and the changes in body weight， tumor volume， and survival status of mice in each group were observed. Tumor tissue， spleen， and peripheral blood were collected to calculate the tumor volume change， tumor inhibition rate， and spleen mass. Hematoxylin-eosin （HE） staining was used to observe the morphological changes of tumor tissue， and an immunofluorescence assay was used to detect the expression levels of CD4， CD8， and CD206 in tumor tissues of tumor-bearing mice. The secretion levels of transforming growth factor （TGF）-β， interleukin （IL）-6， and chemokine （C-C Motif） ligand 2 （CCL2） in peripheral serum were measured by using enzyme-linked immunosorbent assay （ELISA）. Secondly， a co-culture model induced by IL-4 in vitro of MC38 cells and murine monocytic macrophage RAW264.7 cells was established. Cell proliferation and activity assay （CCK-8） was used to detect the inhibitory effect of MBTWD containing serum on cell proliferation. A transwell experiment was used to detect the effect of IL-4-induced M2 macrophages on the invasion of MC38 cells. Flow cytometry was used to detect the expression of CD86 on the membrane of M2 macrophages induced by IL-4 with MBTWD containing serum. Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was used to detect the effect of MBTWD containing serum on the mRNA expression levels of M1 macrophage-related polarization factors CD86， nitric oxide synthase （iNOS）， and IL-12， as well as M2 macrophage-related polarization factors CD206， CD163， and IL-10 after co-cultivation. Finally， the protein expression levels of colony-stimulating factor 1 receptor （CSF1R）， stimulator of interferon genes （STING）， and TANK binding kinase 1 （TBK1） in tumor tissues of tumor-bearing mice were detected by Western blot. ResultIn vivo experimental results show that compared with the model group， the MBTWD can significantly inhibit the tumor growth of tumor-bearing mice. Immunofluorescence experiments show that the MBTWD can increase the number of CD8+ T cell infiltration in tumor tissue of tumor-bearing mice， reduce the number of CD206+ TAMs infiltration， and down-regulate the secretion levels of cytokines IL-6， TGF-β， and CCL2 in peripheral blood of tumor-bearing mice. The results of in vitro experiments show that the MBTWD containing serum has no obvious inhibitory effect on cell proliferation， but the cell supernatant after co-cultivation with RAW264.7 cells can inhibit the proliferation activity of MC38 cells， and the invasion ability of MC38 cells is enhanced by IL-4-induced M2 macrophages. However， this effect can be inhibited in a concentration-dependent manner by the MBTWD containing serum. At the same time， the results of Real-time PCR show that the MBTWD containing serum can up-regulate the mRNA expression levels of M1 macrophage-related polarization factors CD86， iNOS， and IL-12 and down-regulate those of M2 macrophage-related polarization factors CD206， CD163， and IL-10. Flow cytometry results also confirm that the MBTWD containing serum can increase the number of repolarized CD86+ M1 macrophages， indicating that MBTWD can induce M2 macrophages to repolarized M1 macrophages to play an anti-tumor growth role. Finally， Western blot results show that MBTWD can down-regulate the expression of CSF1R protein and up-regulate that of STING and TBK1 proteins in tumor tissue of tumor-bearing mice. ConclusionMBTWD can down-regulate the infiltration number of CD206+ TAMs and increase the infiltration of CD8+ T cells， thereby playing an immunologically antitumor effect on the growth inhibition of colorectal cancer， which may be related to regulating CSF1R signaling and then activating STING/TBK1 signaling pathway to induce phenotypic remodeling of TAMs.
ABSTRACT
Background Diabetic complication is associated with lipid peroxidation.Aldehyde dehydrogenases (ALDH) catalyze the irreversible oxidation of a variety of biological aldehydes,including lipid-derived aldehydes (LDAs),and thus protect organs and tissues from toxic LDAs.Understanding the activity of ALDH in different ocular tissues in diabetic subjects is very important for prevention and treatment of diabetic ocular complications.Objective This research aimed to investigate the activity and expression of ALDH in different ocular tissues in diabetic rats and to explore the mechanism of ALDH in diabetes-induced eye disease.Methods Twenty-eight healthy SPF male Sprague-Dawley(SD) rats weighted 170-180 g were randomly divided into the normal control group and diabetic group.The diabetic animal model was established by intraperitonial injection of 4％ streptozotocin at 65 mg/kg.Isometric citric acid buffer was injected in the rats of the normal control group.The rats were sacrificed in each group 2 and 4 months after the establishment of the diabetic models,and eyeballs were obtained for the preparation of corneal,lens and retinal homogenates.ALDH activity was detected using a multifunctional microplate reader SpectraMax M5,and ALDH content was measured by ELISA at the wavelength of 450 nm with the SpectraMax M5 ELISA reader.Results The blood glucose level in diabetic rats was significantly elevated at various time points compared with the normal control group(P=0.000),and body weights were evidently lower in the diabetic group than in the normal group (P =0.000).The activities of ALDH (A340) in corneal,lens and retinal tissues in the diabetic group were increased in comparison with the normal control group (F =396.601,P=0.000),and showed an enhancement with the lapsing of time (F =53.139,P =0.000).In addition,the highest level of ALDH was found in the cornea and the lowest level in the lens(F =6973.000,P=0.000).The expression level of ALDH in the corneal,lens and retinal homogenates was significantly higher in the diabetic group compared with the normal control group (F=312.985,P =0.000) and showed a considerable increase over the course (F =19.203,P=0.000).The highest expression level was seen in the cornea and the lowest was in the lens,with a significant difference among these three kinds of tissues (F =3243.000,P =0.000).Conclusions ALDH can protect ocular tissue from the damage of lipid peroxidation.Thess results suggest that ALDH plays a role in preventing diabetes-related ocular complications.