1.Effect of preoperative immune checkpoint inhibitors on reducing residual lymph node metastases in patients with gastric cancer: a retrospective study
Xinhua CHEN ; Hexin LIN ; Yuehong CHEN ; Xiaodong WANG ; Chaoqun LIU ; Huilin HUANG ; Huayuan LIANG ; Huimin ZHANG ; Fengping LI ; Hao LIU ; Yanfeng HU ; Guoxin LI ; Jun YOU ; Liying ZHAO ; Jiang YU
Chinese Journal of Gastrointestinal Surgery 2024;27(7):694-701
Objective:To investigate the effect of immune checkpoint inhibitors on reducing residual lymph node metastasis in patients with gastric cancer.Methods:The cohort of this retrospective study comprised patients from Nanfang Hospital of Southern Medical University and the First Affiliated Hospital of Xiamen University who had undergone systemic treatment prior to gastrectomy with D2 lymphadenectomy and had achieved Grade 1 primary tumor regression (TRG1) from January 2014 to December 2023. After exclusion of patients who had undergone preoperative radiotherapy, data of 58 patients (Nanfang Hospital: 46; First Affiliated Hospital of Xiamen University: 12) were analyzed. These patients were allocated to preoperative chemotherapy (Chemotherapy group, N=36 cases) and preoperative immunotherapy plus chemotherapy groups (Immunotherapy group, N=22 cases). There were no significant differences between these groups in sex, age, body mass index, diabetes, tumor location, pathological type, Lauren classification, tumor differentiation, pretreatment depth of invasion by primary tumor, pretreatment lymph node stage, pretreatment clinical stage, mismatch repair protein status, number of preoperative treatment cycles, or duration of preoperative treatment (all P>0.05). The primary outcome measure was postoperative lymph node downstaging. Secondary outcomes included postoperative depth of invasion by tumor, number of lymph nodes examined, and factors affecting residual lymph node metastasis status. Results:Lymph node downstaging was achieved significantly more often in the Immunotherapy group than the Chemotherapy group (pN0: 90.9% [20/22] vs. 61.1% [22/36]; pN1: 4.5% [1/22] vs. 36.1% [13/36]; pN2: 4.5% [1/22) vs. 0; pN3: 0 vs. 2.8% [1/36], Z=-2.315, P=0.021). There were no significant difference between the two groups in number of lymph nodes examined (40.5±16.3 vs. 40.8±17.5, t=0.076, P=0.940) or postoperative depth of invasion by primary tumor (pT1a: 50.0% [11/22] vs. 30.6% [11/36]; pT1b: 13.6% [3/22] vs. 19.4% [7/36]; pT2: 13.6% [3/22] vs. 13.9% [5/36]; pT3: 13.6% [3/22] vs. 25.0% [9/36]; pT4a: 9.1% [2/22] vs. 11.1% [4/36], Z=-1.331, P=0.183). Univariate analysis revealed that both preoperative treatment regimens were associated with residual lymph node metastasis status in patients whose primary tumor regression was TRG1 (χ 2=6.070, P=0.014). Multivariate analysis incorporated the following factors: pretreatment depth of invasion by primary tumor, pretreatment lymph node stage, pretreatment clinical stage, number of preoperative treatment cycles, and preoperative treatment duration. We found that a combination of immunotherapy and chemotherapy administered preoperatively was an independent protective factor for reducing residual lymph node metastases in study patients whose primary tumor regression was TRG1 (OR=0.147, 95%CI: 0.026–0.828, P=0.030). Conclusion:Compared with preoperative chemotherapy alone, a combination of preoperative immunotherapy and chemotherapy achieved greater reduction of residual lymph node metastases in the study patients who achieved TRG1 tumor regression in their primary lesions.
2.Construction of Aβ1-42 plasmid and its binding to calmodulin
Shuang QI ; Xuanxuan SUN ; Qixuan WANG ; Yiting HE ; Jiarui LI ; Jingyang SU ; Liying HAO
Journal of China Medical University 2024;53(6):495-500
Objective To investigate the involvement of calmodulin(CaM)in the pathogenesis of Alzheimer disease(AD)and the mechanism by which CaM binds to amyloid-β(Aβ).Methods The hub genes expressed in AD and predicted to be the target proteins for AD prevention and treatment were obtained using bioinformatics methods.The GST-Aβ1-42 recombinant plasmid was constructed through genetic recombination and was then sequenced.The recombinant plasmids were identified using agarose gel electrophoresis,while the extracted and purified GST-Aβ1-42 fusion protein was confirmed using SDS-PAGE gel electrophoresis.GST pull-down assay was used to detect the interaction between GST-Aβ1-42 protein and CaM,expressed in the plasmid.Results The top 20 hub genes in degree ranking were obtained.The DNA sequencing results of the plasmid proved that the recombinant plasmid was successfully constructed.The agarose gel electrophoresis results indicated that the fragment digested by the enzyme was similar to the molecular weight of the Aβ1-42 gene seg-ments,further proving the successful construction of the recombinant plasmid.Binding of GST-Aβ1-42 protein to CaM in a concentration dependent manner was revealed through the GST pull down experiment.Conclusion The GST-Aβ1-42 recombinant plasmid is success-fully constructed and is shown to bind to CaM.
3.Vector construction and protein preparation of long QT syndrome-related C-terminal lobe of calmodulin mutant E141G
Dongxue SHAO ; Chenyang ZHANG ; Miaomiao YE ; Fan CHEN ; Liying HAO
Journal of China Medical University 2024;53(11):967-971
Objective To construct a prokaryotic expression vector of of the long QT syndrome(LQTS)associated C-terminal lobe of calmodulin(CaM)mutant E141G(C-lobeE141G)and to identify the expression,purification,and activity of C-lobeE141G.Methods A cDNA fragment was inserted into a PGEX-6p-3 plasmid vector and transferred into Escherichia coli BL21 receptor cells,and glutathione-S-trans-ferase(GST)fusion protein was induced by isopropyl thio-β-D galactoside(IPTG).Glutathione-Sepharose 4B beads were used to separate and purify GST-C-lobeE141G.After removing the GST label with protease,the purity and concentration of purified C-lobeE141G were detected using SDS-PAGE and BCA,respectively.The activity of purified C-lobeE141G was detected using the GST pull-down method and patch clamp technique.Results GST-C-lobeE141G fusion protein was highly expressed,and C-lobeE141G with high purity and concentration was obtained.The purified C-lobeE141G protein not only bound to CaV1.2 calcium channels,but also rescued the channel activity from run-down in the ventricular myocytes of rat hearts.Conclusion This study successfully constructed a prokaryotic expression vector of C-lobeE141G,which provides a material basis for the study of the mechanism of LQTS mediated by C-lobe mutations in CaM.
4.Calcium Dyshomeostasis and Alzheimer's Disease
Shuang QI ; Yuan YUAN ; Wen YANG ; Jingyang SU ; Liying HAO
Acta Academiae Medicinae Sinicae 2024;46(4):592-602
Alzheimer's disease(AD)is a common neurodegenerative disease with the main manifesta-tions of progressive cognitive dysfunction,behavioral disorders,and gradual decline of living ability.The etiology of AD is complex,and the pathogenesis of this disease remains controversial.Calcium signaling plays an impor-tant role in regulating neuronal activities,including neurotransmitter release,synaptic plasticity,memory stor-age,and neuronal apoptosis.Increasing studies have shown that neuronal calcium dyshomeostasis is a major path-ological factor in the occurrence and development of AD.This article reviews the role and research progress in in-tracellular calcium dyshomeostasis in AD,including the relationship between calcium homeostasis and amyloidβ,the role of calcium/calmodulin-dependent protein kinases in tau phosphorylation,calcium signaling path-ways,the relationship between calcium homeostasis and mitochondrial function,autophagy,and neuroinflamma-tion.
5.Changes of the meibomian gland in a mouse model of aqueous deficient dry eye
Ziying ZHOU ; Shangkun OU ; Chao HUANG ; Hao JIANG ; Liying ZHANG ; Hao GU
Chinese Journal of Tissue Engineering Research 2024;28(11):1666-1671
BACKGROUND:In recent years,increasing studies have focused on the abnormal proliferation and differentiation of acinous cells in the meibomian gland,suggesting that this process is closely related to the occurrence and development of dry eye.Structural and functional abnormalities such as blockage of the lumen of the meibomian gland and atrophy of the glands can cause or exacerbate dry eye.Therefore,the study of changes in the meibomian glands in dry eyes is important for understanding the pathogenesis of dry eyes in depth and finding new targets for the treatment and prevention of dry eyes. OBJECTIVE:To investigate the changes of the meibomian gland in a mouse model of aqueous deficient dry eyes. METHODS:Thirty-two female C57/B6 mice at 6-8 weeks were selected and randomly divided into experimental and control groups with 16 mice in each group.The mice in the experimental group were constructed by removing both the extra-orbital and intra-orbital lacrimal glands,while those in the control group were not treated.After 2 weeks of normal feeding,the corneal changes of both groups were observed under a slit lamp,and the tear secretion of both groups was measured.The meibomian glands of the two groups of mice were removed after decapitation.The changes in the gross morphology of the meibomian glands were observed and the meibomian glands were made into frozen sections.Hematoxylin-eosin staining was used to observe the structure of the meibomian glands,oil red staining was used to evaluate the function of the meibomian glands,and immunofluorescence staining and RT-qPCR were used to observe the expression of cytokeratin 14,Ki67 and abnormally differentiated small proline-rich protein 1B in the meibomian glands of mice. RESULTS AND CONCLUSION:Two weeks after modeling,lamellar defects were seen in the corneas of the experimental mice,and neovascularization of the limbal corneal was generated and invaded the central cornea.(2)Tear secretion volume was significantly reduced in the experimental group compared with the control group(P<0.05).Microscopic findings showed that the ducts of the meibomian glands in the experimental group were interrupted and atrophied,and their arrangement was disorganized.Hematoxylin-eosin staining results showed a significant increase in lipid vacuoles in the meibomian glands of the experimental mice compared with the control group.Lipid deposition was seen in oil red staining in the experimental group.Immunofluorescence and RT-qPCR results showed a significant increase in the expression of cytokeratin 14,Ki67 and small proline-rich protein 1B in the meibomian glands of mice in the experimental group compared with the control group(P<0.05).To conclude,aqueous deficient dry eye can lead to compensatory hypertrophy,increased proliferation,and abnormal lipid metabolism in the meibomian gland,as well as abnormal differentiation of the meibomian gland.
6.Effect of preoperative immune checkpoint inhibitors on reducing residual lymph node metastases in patients with gastric cancer: a retrospective study
Xinhua CHEN ; Hexin LIN ; Yuehong CHEN ; Xiaodong WANG ; Chaoqun LIU ; Huilin HUANG ; Huayuan LIANG ; Huimin ZHANG ; Fengping LI ; Hao LIU ; Yanfeng HU ; Guoxin LI ; Jun YOU ; Liying ZHAO ; Jiang YU
Chinese Journal of Gastrointestinal Surgery 2024;27(7):694-701
Objective:To investigate the effect of immune checkpoint inhibitors on reducing residual lymph node metastasis in patients with gastric cancer.Methods:The cohort of this retrospective study comprised patients from Nanfang Hospital of Southern Medical University and the First Affiliated Hospital of Xiamen University who had undergone systemic treatment prior to gastrectomy with D2 lymphadenectomy and had achieved Grade 1 primary tumor regression (TRG1) from January 2014 to December 2023. After exclusion of patients who had undergone preoperative radiotherapy, data of 58 patients (Nanfang Hospital: 46; First Affiliated Hospital of Xiamen University: 12) were analyzed. These patients were allocated to preoperative chemotherapy (Chemotherapy group, N=36 cases) and preoperative immunotherapy plus chemotherapy groups (Immunotherapy group, N=22 cases). There were no significant differences between these groups in sex, age, body mass index, diabetes, tumor location, pathological type, Lauren classification, tumor differentiation, pretreatment depth of invasion by primary tumor, pretreatment lymph node stage, pretreatment clinical stage, mismatch repair protein status, number of preoperative treatment cycles, or duration of preoperative treatment (all P>0.05). The primary outcome measure was postoperative lymph node downstaging. Secondary outcomes included postoperative depth of invasion by tumor, number of lymph nodes examined, and factors affecting residual lymph node metastasis status. Results:Lymph node downstaging was achieved significantly more often in the Immunotherapy group than the Chemotherapy group (pN0: 90.9% [20/22] vs. 61.1% [22/36]; pN1: 4.5% [1/22] vs. 36.1% [13/36]; pN2: 4.5% [1/22) vs. 0; pN3: 0 vs. 2.8% [1/36], Z=-2.315, P=0.021). There were no significant difference between the two groups in number of lymph nodes examined (40.5±16.3 vs. 40.8±17.5, t=0.076, P=0.940) or postoperative depth of invasion by primary tumor (pT1a: 50.0% [11/22] vs. 30.6% [11/36]; pT1b: 13.6% [3/22] vs. 19.4% [7/36]; pT2: 13.6% [3/22] vs. 13.9% [5/36]; pT3: 13.6% [3/22] vs. 25.0% [9/36]; pT4a: 9.1% [2/22] vs. 11.1% [4/36], Z=-1.331, P=0.183). Univariate analysis revealed that both preoperative treatment regimens were associated with residual lymph node metastasis status in patients whose primary tumor regression was TRG1 (χ 2=6.070, P=0.014). Multivariate analysis incorporated the following factors: pretreatment depth of invasion by primary tumor, pretreatment lymph node stage, pretreatment clinical stage, number of preoperative treatment cycles, and preoperative treatment duration. We found that a combination of immunotherapy and chemotherapy administered preoperatively was an independent protective factor for reducing residual lymph node metastases in study patients whose primary tumor regression was TRG1 (OR=0.147, 95%CI: 0.026–0.828, P=0.030). Conclusion:Compared with preoperative chemotherapy alone, a combination of preoperative immunotherapy and chemotherapy achieved greater reduction of residual lymph node metastases in the study patients who achieved TRG1 tumor regression in their primary lesions.
7.The effect of pressure therapy on the formation of hypertrophic scar and TGF-β1/Smad signaling pathway
Peng CAO ; Yunwei WANG ; Ming YAO ; Shaohui LI ; Yang CHEN ; Chan ZHU ; Qian LENG ; Liying REN ; Hao GUAN
Chinese Journal of Plastic Surgery 2022;38(7):804-813
Objective:To observe the effect of pressure therapy on the formation of hypertrophic scars(HTS) and transforming growth factor beta 1 (TGF-β1) / Sma and Mad homolog proteins (Smad) signaling pathway.Methods:Twelve adult healthy New Zealand white rabbits(provided by the Animal Experiment Center of the Air Force Military Medical University) were wounded with 1 cm round punch on 4 sites of the ventral side of each ear. Round scalpels were used to make incisions along the marked lines, dissect the skin and perichondrium. The remaining tissue was scraped off to expose the wound surface. Scar formation was observed on the 28th day after surgery. After the establishment of rabbit ear HTS models, the right ears were used as self-controls, while the left ears were set as the experimental group. Two hypertrophic scars were randomly selected from each rabbit ear, 24 per group. Experimental group: 4-0 nylon silk thread was used to sew the pressure pad on the circular NdFeB magnets pad with a diameter of 1.5 cm to the rabbit ear cartilage. Flexiforce pressure sensor was used to measure the pressure, and the pads were adjusted to maintain a pressure of 20-25 mmHg (1 mmHg=0.133 kPa) for more than 23 h per day. Control group: no treatment. On the 40th day of pressure therapy, the general morphology of rabbit ear scars were observed, and the tissues were harvested for hematoxylin and eosin (HE) staining and Masson’s Trichrome staining for histological study. The scar elevation index (SEI), the number of fibroblasts, and the thickness of the stratum corneum were calculated. The relative mRNA expression levels of TGF-β1, Smad3, collagen type (Collagen )Ⅰ, Collagen Ⅲ, α-smooth muscle actin (α-SMA) were measured with qPCR; Western blotting was used to detect the relative protein expression levels of TGF-β1, Collagen Ⅰ, Collagen Ⅲ, α-SMA and the phosphorylation level of Smad3 (the ratio of p-Smad3 and Smad3 proteins). Statistical analysis was performed with Excel 2019 and GraphPad Prism 8.0. The measurement data conformed to normal distribution and was expressed as Mean±SD. Student’s t-test was used for the comparison between two groups. P<0.05 was considered statistically significant. Results:A total of 96 wounds were formed in 12 rabbits, 27 wounds had no obvious hyperplasia, and the remaining 69 wounds formed hypertrophic scar tissue blocks with a prominent skin surface, firm texture, and dark red appearance. The scars formation rate was 71.9% (69/96). On the 40th day after the application of pressure, the scars in the experimental group were significantly reduced, softer, and the color was slightly lighter compared with the control group. The results of HE staining and Masson’s Trichrome staining showed that the thickness of the stratum corneum, SEI, and the number of fibroblasts were (69.33±6.03) μm, 1.30±0.08, and (236.30±14.64) cells/field, respectively, which were significantly lower than those in the control group [(114.00±10.15) μm, 1.72±0.05, (320.30±14.57) cells/field] (all P<0.01). Abundance in capillaries, inflammatory cells, and fibroblasts were not observed in the dermal layer. The collagen fibers were orderly arranged and sparse. The results of fluorescence quantitative PCR showed that the relative expression levels of TGF-β1, Smad3, Collagen Ⅰ, Collagen Ⅲ, and α-SMA mRNA in the experimental group were 0.48±0.08, 0.58±0.05, 0.04±0.01, 0.15±0.02, 0.31±0.03, respectively, lower than those of the control group(1.00±0.07, 1.00±0.05, 1.00±0.08, 1.00±0.10, 1.00±0.06) (all P<0.01). The results of Western blotting showed that the relative protein expression of TGF-β1, Collagen Ⅰ, Collagen Ⅲ, α-SMA and the phosphorylation level of Smad3 in the experimental group were 0.65±0.03, 0.07±0.01, 0.43±0.03, 0.53±0.03, 0.54±0.03, all lower than the control group’s 1.02±0.06, 0.93±0.05, 0.92±0.03, 0.82±0.03, 0.92±0.03 (all P<0.01). Conclusions:Pressure therapy can significantly inhibit the hyperplasia of scars, improve the structure of HTS tissue, facilitate the normal arrangement of collagen fiber, and reduce the excessive deposition of collagen. Pressure therapy may inhibit scar proliferation by regulating the TGF-β1/Smad signaling pathway.
8.The effect of pressure therapy on the formation of hypertrophic scar and TGF-β1/Smad signaling pathway
Peng CAO ; Yunwei WANG ; Ming YAO ; Shaohui LI ; Yang CHEN ; Chan ZHU ; Qian LENG ; Liying REN ; Hao GUAN
Chinese Journal of Plastic Surgery 2022;38(7):804-813
Objective:To observe the effect of pressure therapy on the formation of hypertrophic scars(HTS) and transforming growth factor beta 1 (TGF-β1) / Sma and Mad homolog proteins (Smad) signaling pathway.Methods:Twelve adult healthy New Zealand white rabbits(provided by the Animal Experiment Center of the Air Force Military Medical University) were wounded with 1 cm round punch on 4 sites of the ventral side of each ear. Round scalpels were used to make incisions along the marked lines, dissect the skin and perichondrium. The remaining tissue was scraped off to expose the wound surface. Scar formation was observed on the 28th day after surgery. After the establishment of rabbit ear HTS models, the right ears were used as self-controls, while the left ears were set as the experimental group. Two hypertrophic scars were randomly selected from each rabbit ear, 24 per group. Experimental group: 4-0 nylon silk thread was used to sew the pressure pad on the circular NdFeB magnets pad with a diameter of 1.5 cm to the rabbit ear cartilage. Flexiforce pressure sensor was used to measure the pressure, and the pads were adjusted to maintain a pressure of 20-25 mmHg (1 mmHg=0.133 kPa) for more than 23 h per day. Control group: no treatment. On the 40th day of pressure therapy, the general morphology of rabbit ear scars were observed, and the tissues were harvested for hematoxylin and eosin (HE) staining and Masson’s Trichrome staining for histological study. The scar elevation index (SEI), the number of fibroblasts, and the thickness of the stratum corneum were calculated. The relative mRNA expression levels of TGF-β1, Smad3, collagen type (Collagen )Ⅰ, Collagen Ⅲ, α-smooth muscle actin (α-SMA) were measured with qPCR; Western blotting was used to detect the relative protein expression levels of TGF-β1, Collagen Ⅰ, Collagen Ⅲ, α-SMA and the phosphorylation level of Smad3 (the ratio of p-Smad3 and Smad3 proteins). Statistical analysis was performed with Excel 2019 and GraphPad Prism 8.0. The measurement data conformed to normal distribution and was expressed as Mean±SD. Student’s t-test was used for the comparison between two groups. P<0.05 was considered statistically significant. Results:A total of 96 wounds were formed in 12 rabbits, 27 wounds had no obvious hyperplasia, and the remaining 69 wounds formed hypertrophic scar tissue blocks with a prominent skin surface, firm texture, and dark red appearance. The scars formation rate was 71.9% (69/96). On the 40th day after the application of pressure, the scars in the experimental group were significantly reduced, softer, and the color was slightly lighter compared with the control group. The results of HE staining and Masson’s Trichrome staining showed that the thickness of the stratum corneum, SEI, and the number of fibroblasts were (69.33±6.03) μm, 1.30±0.08, and (236.30±14.64) cells/field, respectively, which were significantly lower than those in the control group [(114.00±10.15) μm, 1.72±0.05, (320.30±14.57) cells/field] (all P<0.01). Abundance in capillaries, inflammatory cells, and fibroblasts were not observed in the dermal layer. The collagen fibers were orderly arranged and sparse. The results of fluorescence quantitative PCR showed that the relative expression levels of TGF-β1, Smad3, Collagen Ⅰ, Collagen Ⅲ, and α-SMA mRNA in the experimental group were 0.48±0.08, 0.58±0.05, 0.04±0.01, 0.15±0.02, 0.31±0.03, respectively, lower than those of the control group(1.00±0.07, 1.00±0.05, 1.00±0.08, 1.00±0.10, 1.00±0.06) (all P<0.01). The results of Western blotting showed that the relative protein expression of TGF-β1, Collagen Ⅰ, Collagen Ⅲ, α-SMA and the phosphorylation level of Smad3 in the experimental group were 0.65±0.03, 0.07±0.01, 0.43±0.03, 0.53±0.03, 0.54±0.03, all lower than the control group’s 1.02±0.06, 0.93±0.05, 0.92±0.03, 0.82±0.03, 0.92±0.03 (all P<0.01). Conclusions:Pressure therapy can significantly inhibit the hyperplasia of scars, improve the structure of HTS tissue, facilitate the normal arrangement of collagen fiber, and reduce the excessive deposition of collagen. Pressure therapy may inhibit scar proliferation by regulating the TGF-β1/Smad signaling pathway.
9.Diabetes mellitus promoted lymph node metastasis in gastric cancer: a 15-year single-institution experience
Xinhua CHEN ; Yuehong CHEN ; Tao LI ; Weiqi LIANG ; Huilin HUANG ; Hongtao SU ; Chuyang SUI ; Yanfeng HU ; Hao CHEN ; Tian LIN ; Tao CHEN ; Liying ZHAO ; Hao LIU ; Guoxin LI ; Jiang YU
Chinese Medical Journal 2022;135(8):950-961
Background::Previous studies have revealed that diabetes mellitus (DM) promotes disease progress of gastric cancer (GC). This study aimed to further investigating whether DM advanced lymph nodes (LNs) metastasis in GC.Methods::The clinicopathologic data of GC patients with >15 examined LN (ELN) between October 2004 and December 2019 from a prospectively maintained database were included. The observational outcomes included the number (N3b status) and anatomical distribution (N3 stations) of metastatic LN (MLN).Results::A total of 2142 eligible patients were included in the study between October 2004 and December 2019. N3 stations metastasis (26.8% in DM vs. 19.3% in non-DM, P = 0.026) and N3b status (18.8% in DM vs. 12.8% in non-DM, P = 0.039) were more advanced in the DM group, and multivariate logistic regression analyses confirmed that DM was an independent factor of developing N3 stations metastasis (odds ratio [OR] = 1.771, P= 0.011) and N3b status (OR= 1.752, P= 0.028). Also, multivariate analyses determined DM was independently associated with more MLN (β = 1.424, P = 0.047). The preponderance of N3 stations metastasis (DM vs. non-DM, T1-2: 2.2% vs. 4.9%, T3: 29.0% vs. 20.3%, T4a: 38.9% vs. 25.8%, T4b: 50.0% vs. 36.6%; ELN16-29: 8.6% vs. 10.4%, ELN30-44: 27.9% vs. 20.5%, ELN ≥ 45: 37.7% vs. 25.3%), N3b status (DM vs. non-DM, T1-2: 0% vs. 1.7%, T3: 16.1% vs. 5.1%, T4a: 27.8% vs. 19.1%, T4b: 44.0% vs. 28.0%; ELN16-29: 8.6% vs. 7.9%, ELN30-44: 18.0% vs. 11.8%, ELN ≥ 45: 26.4% vs. 17.3%), and the number of MLN (DM vs. non-DM, T1-2: 0.4 vs. 1.1, T3: 8.6 vs. 5.2, T4a: 9.7 vs. 8.6, T4b: 17.0 vs. 12.8; ELN16-29: 3.6 vs. 4.6, ELN30-44: 5.8 vs. 5.5, ELN ≥ 45: 12.0 vs. 7.7) of DM group increased with the advancement of primary tumor depth stage and raising of ELN. Conclusions::DM was an independent risk factor for promoting LN metastasis. The preponderance of LN involvement in the DM group was aggravated with the advancement of tumor depth.
10.Effects of mechanical tension on the formation of hypertrophic scars in rabbit ears and transforming growth factor-β 1/Smad signaling pathway
Peng CAO ; Yunwei WANG ; Hao GUAN ; Yunshu YANG ; Shaohui LI ; Yang CHEN ; Chan ZHU ; Yu WAN ; Liying REN ; Ming YAO
Chinese Journal of Burns 2022;38(12):1162-1169
Objective:To explore the effects of mechanical tension on the formation of hypertrophic scars in rabbit ears and transforming growth factor-β 1 (TGF-β 1)/Smad signaling pathway. Methods:The experimental research method was adopted. Six New Zealand white rabbits, male or female, aged 3-5 months were used and 5 full-thickness skin defect wounds were made on the ventral surface of each rabbit ear. The appearance of all rabbit ear wounds was observed on post surgery day (PSD) 0 (immediately), 7, 14, 21, and 28. On PSD 28, the scar formation rate was calculated. Three mature scars in the left ear of each rabbit were included in tension group and the arch was continuously expanded with a spiral expander. Three mature scars in the right ear of each rabbit were included in sham tension group and only the spiral expander was sutured without expansion. There were 18 scars in each group. After mechanical tension treatment (hereinafter referred to as treatment) for 40 days, the color and texture of scar tissue in the two groups were observed. On treatment day 40, the scar elevation index (SEI) was observed and calculated; the histology was observed after hematoxylin eosin staining, and the collagen morphology was observed after Masson staining; mRNA expressions of TGF-β 1, Smad3, collagen Ⅰ, collagen Ⅲ, and α-smooth muscle actin (α-SMA) in scar tissue were detected by real-time fluorescence quantitative reverse transcription polymerase chain reaction; and the protein expressions of TGF-β 1, collagen Ⅰ, collagen Ⅲ, and α-SMA, and phosphorylation level of Smad3 in scar tissue were detected by Western blotting. The number of samples of each group in the experiments was 3. Data were statistically analyzed with independent sample t test. Results:On PSD 0, 5 fresh wounds were formed on all the rabbit ears; on PSD 7, the wounds were scabbed; on PSD 14, most of the wounds were epithelialized; on PSD 21, all the wounds were epithelialized; on PSD 28, obvious hypertrophic scars were formed. The scar formation rate was 75% (45/60) on PSD 28. On treatment day 40, the scar tissue of rabbit ears in tension group was more prominent than that in sham tension group, the scar tissue was harder and the color was more ruddy; the SEI of the scar tissue of rabbit ears in tension group (2.02±0.08) was significantly higher than 1.70±0.08 in sham tension group ( t=5.07, P<0.01). On treatment day 40, compared with those in sham tension group, the stratum corneum of scar tissue became thicker, and a large number of new capillaries, inflammatory cells, and fibroblasts were observed in the dermis, and collagen was more disordered, with nodular or swirling distribution in the scar tissue of rabbit ears in tension group. On treatment day 40, the mRNA expressions of TGF-β 1, Smad3, collagen Ⅰ, collagen Ⅲ, and α-SMA in the scar tissue of rabbit ears in tension group were respectively 1.81±0.25, 5.71±0.82, 7.86±0.56, 4.35±0.28, and 5.89±0.47, which were significantly higher than 1.00±0.08, 1.00±0.12, 1.00±0.13, 1.00±0.14, and 1.00±0.14 in sham tension group (with t values of 5.36, 9.82, 20.60, 18.26, and 17.13, respectively, all P<0.01); the protein expressions of TGF-β 1, collagen Ⅰ, collagen Ⅲ, and α-SMA, and phosphorylation level of Smad3 in the scar tissue of rabbit ears in tension group were respectively 0.865±0.050, 0.895±0.042, 0.972±0.027, 1.012±0.057, and 0.968±0.087, which were significantly higher than 0.657±0.050, 0.271±0.029, 0.631±0.027, 0.418±0.023, and 0.511±0.035 in sham tension group (with t values of 5.08, 21.27, 15.55, 16.70, and 8.40, respectively, all P<0.01). Conclusions:Mechanical tension can inhibit the regression of hypertrophic scars in rabbit ears through stimulating the hyperplasia of scars, inhibiting the normal arrangement of dermal collagen fibers, and intensifying the deposition of collagen fibers, and the mechanism may be related to the activation of TGF-β 1/Smad signaling pathway by mechanical tension.

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