Objective To explore the role and mechanism of mammalian target of rapamycin (mTOR) in oxidized low-density lipoprotein (oxLDL)-induced ferroptosis in vascular smooth muscle cells (VSMCs). Methods A model of oxLDL-induced VSMC ferroptosis was established. VSMCs were co-treated with either the mTOR inhibitor rapamycin or the autophagy inducer carbonyl cyanide m-chlorophenylhydrazone (CCCP), followed by detection of autophagy and ferroptosis-related indexes. Quantitative real-time PCR and Western blot were used respectively to analyze the expression of mTOR, glutathione peroxidase 4 (GPX4), sequestosome 1 (p62), and microtubule-associated protein 1 light chain 3 (LC3). Flow cytometry was employed to assess VSMC death. C11 BODIPY fluorescent staining was used to measure cellular lipid peroxidation levels. Colorimetric assays were performed to determine the contents of malondialdehyde (MDA), ferrous ion (Fe²⁺) and glutathione (GSH). Results oxLDL significantly upregulated mTOR expression in VSMCs, while increasing p62 expression and reducing LC3 expression, thereby suppressing VSMC autophagy. Compared with oxLDL treatment alone, rapamycin co-treatment reversed oxLDL-induced VSMC ferroptosis, as characterized by reduced VSMC death, increased GPX4 expression and GSH contents, along with decreased MDA content, Fe²⁺ content and lipid peroxidation levels. Similarly, CCCP co-treatment activated autophagy characterized by reduced p62 expression and elevated LC3 expression, which subsequently alleviated oxLDL-induced ferroptosis, showing reduced VSMC death, increased GPX4 expressions and GSH contents, and decreased MDA content, Fe²⁺ content and lipid peroxidation levels. Moreover, mTOR inhibition by rapamycin significantly reversed the oxLDL-induced upregulation of p62 and downregulation of LC3. Conclusion mTOR may promote oxLDL-induced VSMC ferroptosis by suppressing autophagy.
Ferroptosis/drug effects* ; Lipoproteins, LDL/metabolism* ; TOR Serine-Threonine Kinases/physiology* ; Autophagy/drug effects* ; Muscle, Smooth, Vascular/metabolism* ; Animals ; Rats ; Myocytes, Smooth Muscle/cytology* ; Cells, Cultured ; Lipid Peroxidation/drug effects* ; Sequestosome-1 Protein/genetics* ; Phospholipid Hydroperoxide Glutathione Peroxidase/metabolism* ; Microtubule-Associated Proteins/genetics* ; Sirolimus/pharmacology*

OBJECTIVES: To investigate the effect of a variety of kidney-tonifying Chinese medicines on thymus regeneration after acute degeneration in mice. METHODS: Forty-eight 8-week-old male BALB/c mice were randomly divided into normal control group, model control group, negative control group, positive control group, the fructus of Cnidium monnieri (L.) Cuss. group, the fructus of Psoralea corylifolia (L.) group, the fructus of Rubus chingii Hu group, and the tuber onion seed group, with 6 mice in each group. Except for the normal control group, mice in the other groups received intraperitoneal injections of rapamycin (1 mg·kg^－1·d^－1) for 5 consecutive days followed by 14 h of starvation to induce acute thymus degeneration. After successful modeling, in treatment groups ethanol extract of the fructus of Cnidium monnieri (L.) Cuss. (0.78 g·kg^－1·d^－1), fructus of Psoralea corylifolia (L.) (0.39 g·kg^－1·d^－1), fructus of Rubus chingii Hu (0.78 g·kg^－1·d^－1) or the tuber onion seed(0.39 g·kg^－1·d^－1) was intraperitoneally injected once a day for 5 days; while the negative control group was given equal volume of normal saline, and the positive control group was given metformin (300 mg·kg^－1·d^－1). The grip strength was measured with a grip tester 2 h after the last administration. The pathological changes of thymus were observed by hematoxylin and eosin (HE) staining. The structure and distribution of thymic epithelial cells were observed by multiple immunofluorescence method. The proportion of T cell subsets in thymus and peripheral blood was analyzed by flow cytometry. The level of T cell receptor excision circles (TREC) in the genomic DNA of mouse spleen mononuclear cells was detected by quantitative polymerase chain reaction (PCR) for evaluation of thymic output function. The expression of thymus aging- and function-related factors in the thymus tissue were detected by quantitative reverse transcription PCR. The expression of cyclin-dependent kinase inhibitor 1A (p21) and tumor protein 53 (p53) were verified by immunohistochemistry. RESULTS: Rapamycin induced thymic atrophy and significantly reduced limb grip strength in mice (P<0.01). Compared with the negative control group, the limb grip strength of mice in the fructus of Psoralea corylifolia (L.) group, the fructus of Rubus chingii Hu group and the tuber onion seed group was significantly enhanced (all P<0.05), and the level of TREC in spleen of the mice in each administration group was reduced (all P<0.05). Among Chinese herb medicine-treatment groups, the recovery of thymus function and tissue structure in the tuber onion seed group was most obvious. Further study showed that compared with the negative control group, the proportion of CD4 single positive cells (CD3⁺TCR-β⁺CD4⁺CD8^－) in the thymus of the tuber onion seed group was significantly increased (P<0.01), and the proportion of CD3⁺CD28⁺ T cell and CD3⁺CD8⁺CD28⁺ T cell in peripheral blood was significantly increased (all P<0.01). The mRNA levels of IL-1α, IL-6, p21 and p53 in thymocytes were decreased (all P<0.05). The results of immunohistochemistry further confirmed the decrease in p21 and p53 expression. In normal mice, tuber onion seed was observed to enhance limb grip strength (P<0.01), while suppressing thymus output and change the distribution of T cell subsets, and there was no significant effect on thymus weight and the expression of Foxn1, SIRT1, p21, CXCL2 and PTMα. CONCLUSIONS The tuber onion seed and other kidney-tonifying traditional Chinese medicines can accelerate the regeneration process of mouse thymus after acute degeneration induced by rapamycin in mice, and the tuber onion seed exhibits the most pronounced therapeutic effect.
Animals ; Mice ; Male ; Mice, Inbred BALB C ; Thymus Gland/physiology* ; Drugs, Chinese Herbal/pharmacology* ; Sirolimus/adverse effects* ; Regeneration/drug effects*

OBJECTIVE: To investigate the effects of knocking down nucleostemin ( NS) combined with rapamycin (RAPA) on autophagy and apoptosis in HL-60 cells , and to explore its role in HL-60 cells . METHODS: The expression of NS protein was detected using Western blot , after transfection of HL-60 cells was achieved by the recombinant lentviral vector NS -RNAi-GV248 . Flow cytometry was used to detect changes in cells apoptosis after NS silencing/ rapamycin for 24 , 48 hours , and the expressions of NS , LC3 , p62 , BCL-2 and Bax proteins in cells were detected by Western blot. RESULTS: The expression of NS in HL-60 cells was successfully down-regulated by recombinant lentiviral vector. After treatment with rapamycin for 24 and 48 h , the apoptosis rate of cells in each group increased (P < 0.05) , and the apoptosis was more obvious at 48 hours . Compared with the NS silencing group or rapamycin group , after treated with NS down-regulation combined with rapamycin for 48 hours , the apoptosis of HL-60 cells was significantly increased ( P < 0.05 ) , LC3 -II/LC3 -I ratio was significantly increased ( P < 0.05 ) , p62 protein expression was significantly decreased (P < 0.05) , and BCL-2/Bax ratio was significantly decreased ( P < 0.05) . CONCLUSION NS down-regulation combined with rapamycin can enhance the apoptosis and autophagy of HL-60 cells , and the induction of apoptosis of HL-60 cells may be related to the expression of BCL-2 and Bax proteins .
Humans ; HL-60 Cells ; Sirolimus/pharmacology* ; bcl-2-Associated X Protein ; Autophagy ; Apoptosis

OBJECTIVE: To investigate the effect of emodin on high glucose (HG)-induced podocyte apoptosis and whether the potential anti-apoptotic mechanism of emodin is related to induction of adenosine-monophosphate-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR)-mediated autophagy in podocytes (MPC5 cells) in vitro. METHODS: MPC5 cells were treated with different concentrations of HG (2.5, 5, 10, 20, 40, 80 and 160 mmol/L), emodin (2, 4, 8 µ mol/L), or HG (40 mmol/L) and emodin (4 µ mol/L) with or without rapamycin (Rap, 100 nmol/L) and compound C (10 µ mol/L). The viability and apoptosis of MPC5 cells were detected using cell counting kit-8 (CCK-8) assay and flow cytometry analysis, respectively. The expression levels of cleaved caspase-3, autophagy marker light chain 3 (LC3) I/II, and AMPK/mTOR signaling pathway-related proteins were determined by Western blot. The changes of morphology and RFP-LC3 fluorescence were observed under microscopy. RESULTS: HG at 20, 40, 80 and 160 mmol/L dose-dependently induced cell apoptosis in MPC5 cells, whereas emodin (4 µ mol/L) significantly ameliorated HG-induced cell apoptosis and caspase-3 cleavage (P<0.01). Emodin (4 µ mol/L) significantly increased LC3-II protein expression levels and induced RFP-LC3-containing punctate structures in MPC5 cells (P<0.01). Furthermore, the protective effects of emodin were mimicked by rapamycin (100 nmol/L). Moreover, emodin increased the phosphorylation of AMPK and suppressed the phosphorylation of mTOR. The AMPK inhibitor compound C (10 µ mol/L) reversed emodin-induced autophagy activation. CONCLUSION Emodin ameliorated HG-induced apoptosis of MPC5 cells in vitro that involved induction of autophagy through the AMPK/mTOR signaling pathway, which might provide a potential therapeutic option for diabetic nephropathy.
Emodin/pharmacology* ; AMP-Activated Protein Kinases/metabolism* ; Podocytes ; Caspase 3/metabolism* ; TOR Serine-Threonine Kinases/metabolism* ; Signal Transduction ; Apoptosis ; Sirolimus/pharmacology* ; Glucose/metabolism* ; Autophagy

Objective To explore the role of autophagy, apoptosis of neutrophils and neutrophils extracellular traps (NET) formation in systemic lupus erythematosus (SLE). Methods Thirty-six patients with SLE were recruited as research subjects, and 32 healthy controls matched accordingly were enrolled as control subjects. The expression levels of microtubule associated protein 1 light chain 3B (LC3B), autophagy-related gene5(ATG5), P62, B-cell lymphoma 2(Bcl2), Bcl2-related X protein (BAX) in neutrophils were detected by Western blot analysis. Flow cytometry was employed to analyze the expression of LC3B on neutrophils. The expression level of myeloperoxidase(MPO) in plasma was estimated by ELISA. Furthermore, neutrophils were cultured in vitro and stimulated by 100 nmol/L rapamycin and 10 μg/mL lipopolysaccharide (LPS) for 6 hours, respectively. And then, the expression levels of LC3B, ATG5, P62, Bcl2 and BAX in neutrophils were detected by Western blot analysis. The level of MPO in culture supernatant was detected by ELISA. The change of fluorescence intensity of NET in culture supernatant was assayed by Sytox^TM Green staining combined with fluorescence spectrophotometry. Results Compared with healthy controls, the levels of autophagy and apoptosis of neutrophils and NET formation in SLE patients were increased. The level of apoptosis and NET formation was positively associated with neutrophil autophagy. The level of autophagy showed an increase but had no effect on apoptosis and NET formation for neutrophil stimulated by rapamycin. The levels of autophagy and NET formation also increased with no significant effect on apoptosis for neutrophil induced by LPS. Conclusion The autophagy, apoptosis and NET formation of neutrophils increase in SLE patients. The activation of autophagy and NET in neutrophils possibly result from the inflammatory internal environment in SLE patients.
Humans ; Neutrophils ; Extracellular Traps/metabolism* ; Lipopolysaccharides/pharmacology* ; bcl-2-Associated X Protein/metabolism* ; Sirolimus/pharmacology* ; Lupus Erythematosus, Systemic ; Autophagy

Mammalian target of rapamycin (mTOR) controls cellular anabolism, and mTOR signaling is hyperactive in most cancer cells. As a result, inhibition of mTOR signaling benefits cancer patients. Rapamycin is a US Food and Drug Administration (FDA)-approved drug, a specific mTOR complex 1 (mTORC1) inhibitor, for the treatment of several different types of cancer. However, rapamycin is reported to inhibit cancer growth rather than induce apoptosis. Pyruvate dehydrogenase complex (PDHc) is the gatekeeper for mitochondrial pyruvate oxidation. PDHc inactivation has been observed in a number of cancer cells, and this alteration protects cancer cells from senescence and nicotinamide adenine dinucleotide (NAD^+‍) exhaustion. In this paper, we describe our finding that rapamycin treatment promotes pyruvate dehydrogenase E1 subunit alpha 1 (PDHA1) phosphorylation and leads to PDHc inactivation dependent on mTOR signaling inhibition in cells. This inactivation reduces the sensitivity of cancer cells' response to rapamycin. As a result, rebooting PDHc activity with dichloroacetic acid (DCA), a pyruvate dehydrogenase kinase (PDK) inhibitor, promotes cancer cells' susceptibility to rapamycin treatment in vitro and in vivo.
Humans ; Sirolimus/pharmacology* ; Dichloroacetic Acid/pharmacology* ; Pyruvate Dehydrogenase Complex ; TOR Serine-Threonine Kinases ; Mechanistic Target of Rapamycin Complex 1 ; Neoplasms/drug therapy*

Objective: To investigate the effects of low-dose photodynamic therapy on the proliferation, regulation, and secretion functions of human adipose mesenchymal stem cells (ADSCs) and the related mechanism, so as to explore a new method for the repair of chronic wounds. Methods: The experimental research methods were adopted. From February to April 2021, 10 patients (5 males and 5 females, aged 23 to 47 years) who underwent cutaneous surgery in the Department of Dermatology of the First Affiliated Hospital of Army Medical University (the Third Military Medical University) donated postoperative waste adipose tissue. The cells were extracted from the adipose tissue and the phenotype was identified. Three batches of ADSCs were taken, with each batch of cells being divided into normal control group with conventional culture only, photosensitizer alone group with conventional culture after being treated with Hemoporfin, irradiation alone group with conventional culture after being treated with red light irradiation, and photosensitizer+irradiation group with conventional culture after being treated with Hemoporfin and red light irradiation, with sample number of 3 in each group. At culture hour of 24 after the treatment of the first and second batches of cells, the ADSC proliferation level was evaluated by 5-ethynyl-2'-deoxyuridine staining method and the migration percentage of HaCaT cells cocultured with ADSCs was detected by Transwell experiment, respectively. On culture day of 7 after the treatment of the third batch of cells, the extracellular matrix protein expression of ADSCs was detected by immunofluorescence method. The ADSCs were divided into 0 min post-photodynamic therapy group, 15 min post-photodynamic therapy group, 30 min post-photodynamic therapy group, and 60 min post-photodynamic therapy group, with 3 wells in each group. Western blotting was used to detect the protein expressions and calculate the phosphorylated mammalian target of rapamycin complex (p-mTOR)/mammalian target of rapamycin (mTOR), phosphorylated p70 ribosomal protein S6 kinase (p-p70 S6K)/p70 ribosomal protein S6 kinase (p70 S6K) ratio at the corresponding time points after photodynamic therapy. Two batches of ADSCs were taken, and each batch was divided into normal control group, photodynamic therapy alone group, and photodynamic therapy+rapamycin group, with 3 wells in each group. At culture minute of 15 after the treatment, p-mTOR/mTOR and p-p70 S6K/p70 S6K ratios of cells from the first batch were calculated and detected as before. On culture day of 7 after the treatment, extracellular matrix protein expression of cells from the second batch was detected as before. Data were statistically analyzed with one-way analysis of variance and least significant difference test. Results: After 12 d of culture, the cells were verified as ADSCs. At culture hour of 24 after the treatment, the ADSC proliferation level ((4.0±1.0)% and (4.1±0.4)%, respectively) and HaCaT cell migration percentages (1.17±0.14 and 1.13±0.12, respectively) in photosensitizer alone group and irradiation alone group were similar to those of normal control group ((3.7±0.6)% and 1.00±0.16, respectively, P>0.05), and were significantly lower than those of photosensitizer+irradiation group ((34.2±7.0)% and 2.55±0.13, respectively, P<0.01). On culture day of 7 after the treatment, compared with those in normal control group, the expression of collagen Ⅲ in ADSCs of photosensitizer alone group was significantly increased (P<0.05), and the expressions of collagen Ⅰ and collagen Ⅲ in ADSCs of irradiation alone group were significantly increased (P<0.01). Compared with those in photosensitizer alone group and irradiation alone group, the expressions of collagen Ⅰ, collagen Ⅲ, and fibronectin of ADSCs in photosensitizer+irradiation group were significantly increased (P<0.01). Compared with those in 0 min post-photodynamic therapy group, the ratios of p-mTOR/mTOR and p-p70 S6K/p70 S6K of ADSCs in 15 min post-photodynamic therapy group were significantly increased (P<0.01), the ratios of p-p70 S6K/p70 S6K of ADSCs in 30 min post-photodynamic therapy group and 60 min post-photodynamic therapy group were both significantly increased (P<0.01). At culture minute of 15 after the treatment, compared with those in normal control group, the ratios of p-mTOR/mTOR and p-p70 S6K/p70 S6K of ADSCs in photodynamic therapy alone group were significantly increased (P<0.05 or P<0.01). Compared with those in photodynamic therapy alone group, the ratios of p-mTOR/mTOR and p-p70 S6K/p70 S6K of ADSCs in photodynamic therapy+rapamycin group were significantly decreased (P<0.05). On culture day of 7 after the treatment, compared with those in normal control group, the expressions of collagen Ⅰ, collagen Ⅲ, and fibronectin of ADSCs in photodynamic therapy alone group were significantly increased (P<0.01). Compared with those in photodynamic therapy alone group, the expressions of collagen Ⅰ, collagen Ⅲ, and fibronectin of ADSCs in photodynamic therapy+rapamycin group were significantly decreased (P<0.01). Conclusions: Low-dose photodynamic therapy can promote the proliferation of ADSCs, improve the ability of ADSCs to regulate the migration of HaCaT cells, and enhance the secretion of extracellular matrix protein by rapidly activating mTOR signaling pathway.
Adipose Tissue ; Female ; Fibronectins ; Humans ; Male ; Mesenchymal Stem Cells ; Photochemotherapy ; Photosensitizing Agents/pharmacology* ; Sirolimus/pharmacology* ; TOR Serine-Threonine Kinases

Cabozantinib, mainly targeting cMet and vascular endothelial growth factor receptor 2, is the second-line treatment for patients with advanced hepatocellular carcinoma (HCC). However, the lower response rate and resistance limit its enduring clinical benefit. In this study, we found that cMet-low HCC cells showed primary resistance to cMet inhibitors, and the combination of cabozantinib and mammalian target of rapamycin (mTOR) inhibitor, rapamycin, exhibited a synergistic inhibitory effect on the in vitro cell proliferation and in vivo tumor growth of these cells. Mechanically, the combination of rapamycin with cabozantinib resulted in the remarkable inhibition of AKT, extracellular signal-regulated protein kinases, mTOR, and common downstream signal molecules of receptor tyrosine kinases; decreased cyclin D1 expression; and induced cell cycle arrest. Meanwhile, rapamycin enhanced the inhibitory effects of cabozantinib on the migration and tubule formation of human umbilical vascular endothelial cells and human growth factor-induced invasion of cMet inhibitor-resistant HCC cells under hypoxia condition. These effects were further validated in xenograft models. In conclusion, our findings uncover a potential combination therapy of cabozantinib and rapamycin to combat cabozantinib-resistant HCC.
Anilides/pharmacology* ; Animals ; Carcinoma, Hepatocellular/drug therapy* ; Cell Line, Tumor ; Cell Proliferation ; Endothelial Cells/metabolism* ; Humans ; Liver Neoplasms/drug therapy* ; Pyridines/pharmacology* ; Sirolimus/pharmacology* ; Xenograft Model Antitumor Assays

BACKGROUND: Pulmonary microvascular endothelial cells (PMVECs) were not complex, and the endothelial barrier was destroyed in the pathogenesis progress of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS). Previous studies have demonstrated that hepatocyte growth factor (HGF), which was secreted by bone marrow mesenchymal stem cells, could decrease endothelial apoptosis. We investigated whether mTOR/STAT3 signaling acted in HGF protective effects against oxidative stress and mitochondria-dependent apoptosis in lipopolysaccharide (LPS)-induced endothelial barrier dysfunction and ALI mice. METHODS: In our current study, we introduced LPS-induced PMEVCs with HGF treatment. To investigate the effects of mammalian target of rapamycin (mTOR)/signal transducer and activator of transcription 3 (STAT3) pathway in endothelial oxidative stress and mitochondria-dependent apoptosis, mTOR inhibitor rapamycin and STAT3 inhibitor S3I-201 were, respectively, used to inhibit mTOR/STAT3 signaling. Moreover, lentivirus vector-mediated mTORC1 (Raptor) and mTORC2 (Rictor) gene knockdown modifications were introduced to evaluate mTORC1 and mTORC1 pathways. Calcium measurement, reactive oxygen species (ROS) production, mitochondrial membrane potential and protein, cell proliferation, apoptosis, and endothelial junction protein were detected to evaluate HGF effects. Moreover, we used the ALI mouse model to observe the mitochondria pathological changes with an electron microscope in vivo. RESULTS: Our study demonstrated that HGF protected the endothelium via the suppression of ROS production and intracellular calcium uptake, which lead to increased mitochondrial membrane potential (JC-1 and mitochondria tracker green detection) and specific proteins (complex I), raised anti-apoptosis Messenger Ribonucleic Acid level (B-cell lymphoma 2 and Bcl-xL), and increased endothelial junction proteins (VE-cadherin and occludin). Reversely, mTOR inhibitor rapamycin and STAT3 inhibitor S3I-201 could raise oxidative stress and mitochondria-dependent apoptosis even with HGF treatment in LPS-induced endothelial cells. Similarly, mTORC1 as well as mTORC2 have the same protective effects in mitochondria damage and apoptosis. In in vivo experiments of ALI mouse, HGF also increased mitochondria structural integrity via the mTOR/STAT3 pathway. CONCLUSION In all, these reveal that mTOR/STAT3 signaling mediates the HGF suppression effects to oxidative level, mitochondria-dependent apoptosis, and endothelial junction protein in ARDS, contributing to the pulmonary endothelial survival and barrier integrity.
Animals ; Apoptosis ; Calcium/metabolism* ; Endothelial Cells/metabolism* ; Endothelium/metabolism* ; Hepatocyte Growth Factor/metabolism* ; Lipopolysaccharides/pharmacology* ; Mammals/metabolism* ; Mechanistic Target of Rapamycin Complex 1/metabolism* ; Mechanistic Target of Rapamycin Complex 2/metabolism* ; Mice ; Mitochondria/metabolism* ; Oxidative Stress ; Reactive Oxygen Species/metabolism* ; Respiratory Distress Syndrome ; Sirolimus/pharmacology* ; TOR Serine-Threonine Kinases/metabolism*

Objective: To investigate the role and mechanism of Vγ4 T cells in impaired wound healing of rapamycin-induced full-thickness skin defects in mice. Methods: The experimental research methods were applied. Eighty-six C57BL/6J male mice (hereinafter briefly referred to as wild-type mice) aged 8-12 weeks were selected for the following experiments. Vγ4 T cells were isolated from axillary lymph nodes of five wild-type mice for the following experiments. Intraperitoneal injection of rapamycin for 42 mice was performed to establish rapamycin-treated mice model for the following experiments. Eighteen wild-type mice were divided into normal control group without any treatment, trauma only group, and trauma+CC chemokine ligand 20 (CCL20) inhibitor group according to the random number table (the same grouping method below), with 6 mice in each group. The full-thickness skin defect wound was made on the back of mice in the latter two groups (the same wound model below), and mice in trauma+CCL20 inhibitor group were continuously injected subcutaneously with CCL20 inhibitor at the wound edge for 3 days after injury. Another 6 rapamycin-treated mice were used to establish wound model as rapamycin+trauma group. On post injury day (PID) 3, the epidermal cells of the skin tissue around the wound of each trauma mice were extracted by enzyme digestion, and the percentage of Vγ4 T cells in the epidermal cells was detected by flow cytometry. In normal control group, the epidermal cells of the normal skin tissue in the back of mice were taken at the appropriate time point for detection as above. Five wild-type mice were used to establish wound models. On PID 3, the epidermal cells were extracted from the skin tissue around the wound. The cell populations were divided into Vγ4 T cells, Vγ3 T cells, and γδ negative cells by fluorescence-activated cell sorter, which were set as Vγ4 T cell group, Vγ3 T cell group, and γδ negative cell group (with cells in each group being mixed with B16 mouse melanoma cells), respectively. B16 mouse melanoma cells were used as melanoma cell control group. The expression of interleukin-22 (IL-22) mRNA in cells of each group was detected by real-time fluorescence quantitative reverse transcription polymerase chain reaction (RT-PCR), with the number of samples being 6. Thirty rapamycin-treated mice were used to establish wound models, which were divided into Vγ4 T cell only group and Vγ4 T cell+IL-22 inhibitor group performed with corresponding injections and rapamycin control group injected with phosphate buffer solution (PBS) immediately after injury, with 10 mice in each group. Another 10 wild-type mice were taken to establish wound models and injected with PBS as wild-type control group. Mice in each group were injected continuously for 6 days. The percentage of wound area of mice in the four groups was calculated on PID 1, 2, 3, 4, 5, and 6 after injection on the same day. Six wild-type mice and 6 rapamycin-treated mice were taken respectively to establish wound models as wild-type group and rapamycin group. On PID 3, the mRNA and protein expressions of IL-22 and CCL20 in the peri-wound epidermis tissue of mice in the two groups were detected by real-time fluorescence quantitative RT-PCR and Western blotting, respectively. The Vγ4 T cells were divided into normal control group without any treatment and rapamycin-treated rapamycin group. After being cultured for 24 hours, the mRNA and protein expressions of IL-22 of cells in the two groups were detected by real-time fluorescence quantitative RT-PCR and Western blotting, respectively, with the number of samples being 6. Data were statistically analyzed with independent sample t test, analysis of variance for repeated measurement, one-way analysis of variance, Bonferroni method, Kruskal-Wallis H test, and Wilcoxon rank sum test. Results: The percentage of Vγ4 T cells in the epidermal cells of the skin tissue around the wound of mice in trauma only group on PID 3 was 0.66% (0.52%, 0.81%), which was significantly higher than 0.09% (0.04%, 0.14%) in the epidermal cells of the normal skin tissue of mice in normal control group (Z=4.31, P<0.01). The percentages of Vγ4 T cells in the epidermal cells of the skin tissue around the wound of mice in rapamycin+trauma group and trauma+CCL20 inhibitor group on PID 3 were 0.25% (0.16%, 0.37%) and 0.24% (0.17%, 0.35%), respectively, which were significantly lower than that in trauma only group (with Z values of 2.27 and 2.25, respectively, P<0.05). The mRNA expression level of IL-22 of cells in Vγ4 T cell group was significantly higher than that in Vγ3 T cell group, γδ negative cell group, and melanoma cell control group (with Z values of 2.96, 2.45, and 3.41, respectively, P<0.05 or P<0.01). Compared with that in wild-type control group, the percentage of wound area of mice in rapamycin control group increased significantly on PID 1-6 (P<0.01), the percentage of wound area of mice in Vγ4 T cell+IL-22 inhibitor group increased significantly on PID 1 and PID 3-6 (P<0.05 or P<0.01). Compared with that in rapamycin control group, the percentage of wound area of mice in Vγ4 T cell only group decreased significantly on PID 1-6 (P<0.05 or P<0.01). Compared with that in Vγ4 T cell only group, the percentage of wound area of mice in Vγ4 T cell+IL-22 inhibitor group increased significantly on PID 3-6 (P<0.05 or P<0.01). On PID 3, compared with those in wild-type group, the expression levels of IL-22 protein and mRNA (with t values of -7.82 and -5.04, respectively, P<0.01) and CCL20 protein and mRNA (with t values of -7.12 and -5.73, respectively, P<0.01) were decreased significantly in the peri-wound epidermis tissue of mice in rapamycin group. After being cultured for 24 hours, the expression levels of IL-22 protein and mRNA in Vγ4 T cells in rapamycin group were significantly lower than those in normal control group (with t values of -7.75 and -6.04, respectively, P<0.01). Conclusions: In mice with full-thickness skin defects, rapamycin may impair the CCL20 chemotactic system by inhibiting the expression of CCL20, leading to a decrease in the recruitment of Vγ4 T cells to the epidermis, and at the same time inhibit the secretion of IL-22 by Vγ4 T cells, thereby slowing the wound healing rate.
Animals ; Male ; Melanoma ; Mice ; Mice, Inbred C57BL ; RNA, Messenger ; Sirolimus/pharmacology* ; T-Lymphocytes ; Wound Healing