Research advances in peptide‒drug conjugates

Peptide‒drug conjugates (PDCs) are drug delivery systems consisting of a drug covalently coupled to a multifunctional peptide via a cleavable linker. As an emerging prodrug strategy, PDCs not only preserve the function and bioactivity of the peptides but also release the drugs responsively with the cleavable property of the linkers. Given the ability to significantly improve the circulation stability and targeting of drugs in vivo and reduce the toxic side effects of drugs, PDCs have already been extensively applied in drug delivery. Herein, we review the types and mechanisms of peptides, linkers and drugs used to construct PDCs, and summarize the clinical applications and challenges of PDC drugs.

Arf6 regulates endometriotic epithelial-mesenchymal transition and mitochondrial distribution / 中华妇产科杂志

Objective:To investigate the role of adenosine diphosphate ribosylation factor 6 (Arf6) in the pathogenesis of endometriosis.Methods:Endometrial tissues were sampled from women who were hospitalized in the Affiliated Hospital of Medical School of Ningbo University and Ningbo Women and Children′s Hospital from November 2020 to May 2021 with endometriosis ( n=44, endometriosis group) and without endometriosis ( n=17, control group). The expression of Arf6 protein in the endometrial tissues was detected by western blot. Endometrial epithelial cells from both groups were primary cultured and the distribution of intracellular mitochondria was detected by immunofluorescence. The expression of Arf6 protein was down-regulated by small interference RNA (siRNA), the distribution of mitochondria in cells with decreased Arf6 protein expression was observed, and the expression of mitochondria-related proteins development and differentiation enhancing factor 1 (DDEF1, also called AMAP1), reactive oxygen species 1 (ROS1) and epithelial-mesenchymal transition (EMT)-related proteins E-cadherin, vimentin were detected. Transwell assay was used to detect the changes in the migration ability of the cells. Results:Compared with the control group, ectopic endometrial tissue of endometriosis group showed high expression of Arf6 protein (0.174±0.019 vs 0.423±0.033; t=29.630, P<0.01); and in ectopic endometrial epithelial cells, mitochondria were distributed near the edge of the cell membrane. While Arf6 expression was down-regulated by siRNA, the distribution of mitochondria in ectopic cells returned to natural, close to the control level. In addition, the expression levels of AMAP1 and ROS1 in ectopic cells after Arf6 protein knockdown were significantly decreased. Transwell assay results indicated that knockdown of Arf6 could reduce the migration ability of ectopic epithelial cells [migration cell count: (34.3±7.5) cells]; and immunofluorescence verified low expression of E-cadherin but high expression of vimentin in ectopic epithelial cells, whereas knockdown of Arf6 protein E-cadherin expression increased but vimentin expression decreased. Conclusions:High expression of Arf6 protein in ectopic endometrial epithelial cells leads to the distribution of mitochondria tending to membrane marginalization, while inducing EMT, which are involved in the mechanism of endoheterosis pathogenesis.

Multifunctional oral delivery systems for enhanced bioavailability of therapeutic peptides/proteins

In last few years, therapeutic peptides/proteins are rapidly growing in drug market considering their higher efficiency and lower toxicity than chemical drugs. However, the administration of therapeutic peptides/proteins is mainly limited in parenteral approach. Oral therapy which was hampered by harsh gastrointestinal environment and poorly penetrating epithelial barriers often results in low bioavailability (less than 1%-2%). Therefore, delivery systems that are rationally designed to overcome these challenges in gastrointestinal tract and ameliorate the oral bioavailability of therapeutic peptides/proteins are seriously promising. In this review, we summarized various multifunctional delivery systems, including lipid-based particles, polysaccharide-based particles, inorganic particles, and synthetic multifunctional particles that achieved effective oral delivery of therapeutic peptides/proteins.

Diagnostic value of copeptin and cancer antigen 125 in acute heart failure patients with atrial fibrillation and their correlations with short-term cardiovascular events / 中华危重病急救医学

Objective To evaluate the diagnostic value of copeptin and cancer antigen 125 (Ca-125) in acute heart failure (AHF) patients with atrial fibrillation, and to explore the relationship between copeptin, Ca-125 and short-term cardiovascular events. Methods A total of 376 patients with acute left heart failure or permanent atrial fibrillation admitted to the Department of Cardiology of First Affiliated Hospital of Nanjing Medical University from January 2016 to January 2018 were enrolled as the study group. According to whether having atrial fibrillation or not, 376 patients were divided into atrial fibrillation group (n = 108), AHF group (n = 134) and AHF with atrial fibrillation group (n = 134). 102 healthy persons in the same period were enrolled as healthy control group. Copeptin, Ca-125, N-terminal pro-brain natriuretic peptide (NT-proBNP) within 24 hours after admission or on the day of physical examination were determined, and cardiac function indexes including left atrial diameter (LAD), left ventricular diameter (LVD) and left ventricular ejection fraction (LVEF) at 1 week after admission or on the day of physical examination were determined. Correlation analysis among above indexes was conducted by Pearson correlation analysis. Receiver operating characteristic (ROC) curve was plotted to evaluate the diagnostic value of copeptin and Ca-125 in AHF with atrial fibrillation. Results Compared with the healthy control group, copeptin, Ca-125, NT-proBNP, LAD, and LVD in atrial fibrillation group, AHF group and AHF with atrial fibrillation group showed a tendency of gradual increase [copeptin (pmol/L): 12.43±4.36, 18.77±5.29, 32.82±7.07 vs. 6.68±1.94; Ca-125 (kU/L): 18.82±7.39, 27.97±11.47, 61.37±25.49 vs. 4.43±1.74; NT-proBNP (ng/L): 1 070.87±428.84, 1 734.13±725.09, 2 745.92±709.91 vs. 570.40±213.87; LAD (mm): 37.24±6.35, 41.31±7.94, 46.24±10.96 vs. 33.29±4.53; LVD (mm): 49.46±5.19, 52.51±8.09, 55.96±6.49 vs. 45.99±6.26, all P < 0.05], and LVEF showed a tendency of gradual decrease (0.52±0.11, 0.46±0.10, 0.41±0.09 vs. 0.57±0.08, all P < 0.05), indicating that the deterioration of all indexes in AHF patients with atrial fibrillation was more obvious. Correlation analysis showed that copeptin was positively correlated with LAD (r = 0.479, P = 0.012) and LVD (r = 0.513, P = 0.005), and it was negatively correlated with LVEF (r = -0.626, P < 0.001). Ca-125 was positively correlated with LAD (r = 0.479, P = 0.011) and LVD (r = 0.513, P = 0.028), and it was negatively correlated with LVEF (r = -0.645, P = 0.019). ROC curve analysis showed that the area under ROC curve (AUC) of copeptin, Ca-125, NT-proBNP and copeptin combined with Ca-125 in the diagnosis of AHF with atrial fibrillation was 0.750, 0.623, 0.647 and 0.842, respectively, with diagnostic value on AHF with atrial fibrillation. The diagnostic value of copeptin combined with Ca-125 was the largest, with a sensitivity of 72.64% and a specificity of 92.47%. Compared with the healthy control group, the incidence of cardiovascular events after 3 months of follow-up in the atrial fibrillation group, AHF group and AHF with atrial fibrillation group was significantly increased [6.5% (7/108), 9.0% (12/134), 30.6% (41/134) vs. 1.0% (1/102), χ2 = 56.574, P = 0.000], indicating that patients with AHF and atrial fibrillation were more likely to have cardiovascular events. Copeptin combined with Ca-125 showed a significant positive correlation with short-term cardiovascular events (r = 0.641, P = 0.004). Conclusions The combination of copeptin and Ca-125 has a higher diagnostic accuracy for AHF patients with atrial fibrillation. Copeptin and Ca-125 were positively correlated with short-term cardiovascular events. It may be used to assess the prognosis of AHF patients with atrial fibrillation.

Role of cell adhesion molecule L1 like in the inhibition of the metastasis of esophageal squamous cell carcinoma / 中华消化杂志

Objective To investigate the role of cell adhesion molecule L1 like (CALL) in the genesis and development of esophageal squamous cell carcinoma (ESCC).Methods From July 2007 to December 2010,a total of 100 patients with ESCC who received radical resection of esophageal cancer were enrolled.The ESCC tissues and corresponding tumor-adjacent normal tissues were obtained.The expression of CALl was determined by tissue microarray technology and immunohistochemical staining.The CALL over-expressed esophageal cancer cell line was established.The effects of CALL on cell migration and invasion were detected by wound-healing assay and Transwell assay,respectively.The effects of CALL on actin microfilament was analyzed by filamentous actin (F-actin) staining.Chi square test,Fisher's exact test,multivariate analysis and t test were performed for statistical analysis.Results The positive expression rate of CALL in ESCC tissues was 56 ％ (56/100),which was lower than that of tumor-adjacent normal tissues (95％,95/100),and the difference was statistically significant (x2=41.114,P＜0.01).There were statistically significant differences in CALL expression at protein level among patients with ESCC of different differentiation degree,different pathological T stage,lymph node metastasis and different TNM stage (x2=13.702,5.317,21.453,Fisher's exact test;all P＜ 0.05).The five year disease related survival rate of ESCC patients with down-regulated expression of CALL was 0(0/49),which was lower than those with normal CALL expression (25.5％,13/51),and the difference was statistically significant (x2 =43.338,P＜0.01).The median survival time of CALL expression down-regulated group was 17 months,and that of normal expressed group was 38 months.CALL expression was an independent risk factor of disease special survival rate (hazard ratio (HR) 0.353,95％ confidence interval (CI) 0.188 to 0.666,P=0.001).The results of wound-healing assay showed that the migration ability of CALL overexpressed CALL-k30 cells was lower than that of Vec-k30 cells in control group on 24 hours after wound.The results of Transwell invasion test showed the number of migrating cells penetrating CALL k30 cells attached to the inferior surface of the membrane was 44.000±13.748,which was less than that of the Vec k30 cells (154.333±25.007),and the difference was statistically significant (t=5.136,P=0.036).The results of F-actin staining demonstrated that actin filaments of CALL-k30 cells was 234.667 ± 65.118,which was lower than that of Vec-k30 cells (597.000± 119.929),and the difference was statistically significant (t=4.707,P=0.042).Conclusions CALL lowers the migration and invasion abilities of esophageal cancer cells by inhibiting F-actin microfilaments.Its abnormal expression may play an important role in the genesis,development and prognosis of ESCC.

Nanocarrier-mediated co-delivery of chemotherapeutic drugs and gene agents for cancer treatment

The efficacy of chemotherapeutic drug in cancer treatment is often hampered by drug resistance of tumor cells, which is usually caused by abnormal gene expression. RNA interference mediated by siRNA and miRNA can selectively knock down the carcinogenic genes by targeting specific mRNAs. Therefore, combining chemotherapeutic drugs with gene agents could be a promising strategy for cancer therapy. Due to poor stability and solubility associated with gene agents and drugs, suitable protective carriers are needed and have been widely researched for the co-delivery. In this review, we summarize the most commonly used nanocarriers for co-delivery of chemotherapeutic drugs and gene agents, as well as the advances in co-delivery systems.

Expression and significance of bone sialoprotein(BSP) in esophageal squamous cell carcinoma / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the roll of bone sialoprotein (BSP), a secreted glycoprotein, found in mineralized tissues in the development and progression of human esophageal squamous cell carcimoma (ESCC), and explore its association with clinicopathological characteristics and five-year survival of the patients.</p><p><b>METHODS</b>The expression of BSP was determined in 211 primary ESCC tumors and their paired nontumorous tissues using tissue-array, RT-PCR and immunohistochemistry.</p><p><b>RESULTS</b>Primary ESCC tissues showed a significantly higher expression rate of BSP mRNA than their paired nontumorous tissues (93.8% vs. 16.6%, P < 0.001), the same with BSP protein (56.9% vs. 31.3%, P < 0.001). The expression rate of BSP protein was correlated to lymph node metastasis and TNM stage (P < 0.05). The 5-year survival rate of BSP protein-positive ESCC patients was significantly lower than that of BSP protein-negative ESCC patients (P < 0.05). Multivariate analysis showed that tumor differentiation, TNM staging and BSP protein expression were independent factors affecting the prognosis of ESCC patients (P < 0.05).</p><p><b>CONCLUSIONS</b>The abnormal expression of BSP may play a significant role in the malignant progression and prognosis of ESCC, and BSP might be a marker reflecting the biologial behavior of ESCC.</p>

Analysis of the role of endoscopic retrograde cholangiopancreatography in children with pancreaticobiliary diseases / 中华儿科杂志

<p><b>OBJECTIVE</b>To evaluate the safety and efficacy of endoscopic retrograde cholangiopancreatography (ERCP) in children with pancreaticobiliary diseases and the characteristics of pancreaticobiliary disorders in children.</p><p><b>METHOD</b>Retrospective review was conducted on the data of patients younger than 18 years who underwent ERCP between 2005 and 2012 at West China Hospital. The indications,ERCP findings, ERCP procedures, complications, and clinical outcomes were evaluated.ERCP procedures were performed using standard duodenoscopes under general anaesthesia or sedation, which included all endoscopic treatments, such as endoscopic sphincteropapillotomy, stone extraction, stent treatment and so on.</p><p><b>RESULT</b>One hundred and two ERCPs were performed on 68 patients, and all the procedures were successfully completed in 100% cases. There were 39 girls (57%), and median age at time of procedure was 14.6 years (range, 5-17 years).General anesthesia and sedation were performed in 81% and 19% of procedures, respectively. The ERCP findings were classified as follows:bile duct stone(s) (n = 37, 54%), pancreatic duct stone(s) (n = 8, 12%), bile duct benign stricture (n = 7, 10%) and other nonmalignant pancreaticobiliary diseases (n = 16, 24%).Four cases (4/102, prevalence 4%) were complicated with post-ERCP pancreatitis.Symptoms such as abdominal pain and jaundice were cured obviously after the procedures of ERCP were performed.</p><p><b>CONCLUSION</b>The main characteristics of pancreaticobiliary disorders in children were nonmalignant pancreaticobiliary diseases, such as bile duct stone, pancreatic duct stone, and bile/pancreatic duct benign stricture.When performed by well-trained endoscopists, ERCP is safe and effective in children.</p>

Comparison of expression of growth hormone-releasing hormone and its receptor splice variant 1 in different stages of endometriosis

The present study aims to explore the significance of the expression of growth hormone-releasing hormone [GHRH] and its receptor splice variant 1 [GHRHSV1] in endometriosis [EM]. In this research paper 80 EM patients who received treatment between March 2009 and September 2010 were selected, among which 20 were in stages I, II, III and IV respectively. 50 non-EM patients who underwent hysterectomy because of myoma during the same period comprised the control group. GHRH, GHRH-SV1 and their corresponding mRNA expression in eutopic endometrium and endometriotic tissue as well as ectopic endometrium were detected using immunohistochemical streptavidin-peroxidase [SP] and RT-PCR methods. Analysis of Variance [ANOVA] with Tukey Post Hoc test was used for data analysis and p<0.05 was considered significant. GHRH, GHRH-SV1 and their corresponding mRNA were expressed in eutopic endometrium and endometriotic tissue as well as ectopic endometrium. The mean optical density [OD] values of the GHRH and GHRH-SV1 expression in the experimental group were significantly higher than those in the normal group [p<0.05], and the relative intensity [RI] of GHRH mRNA and GHRH-SV1 mRNA expression in the experimental group was also significantly higher [p<0.05]. The mean OD values of the GHRH and GHRHSV1 expression showed significant differences among endometriotic tissue at different stages of EM [p<0.05], and the RI of GHRH and GHRH-SV1 mRNA expression also showed significant differences [p<0.05]. GHRH and GHRH-SV1 expression levels differ significantly at different stages of endometriosis

Promoter methylation of Wilms' tumor gene on the X- chromosome in gastric cancer / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the changes in methylation levels of the promoters of the tumor suppressor gene Wilms' tumor gene on the X-chromosome (WTX) and its possible role in gastric cancer.</p><p><b>METHODS</b>WTX promoter methylation levels were detected in 20 pairs of specimens of gastric cancer and matched normal tissues and in 3 gastric cancer cell lines (MGC803, SCG7901, and BGC823) using the Sequenom MassARRAY quantitative analysis system. The gastric cancer cell line BGC823 was treated with 5-aza-2'-deoxycytidine (5-aza-dC) for demethylation and the changes in the level of WTX promoter methylation were investigated.</p><p><b>RESULTS</b>WTX promoter methylation levels were very low and showed no significant differences among normal gastric tissues, gastric cancer tissues and the 3 gastric cancer cell lines. In BGC823 cells, treatment with 5-aza-dC did not obviously affect the promoter methylation levels of WTX.</p><p><b>CONCLUSION</b>High methylation levels of WTX promoters are rare in gastric cancer.</p>

Estrogen effects on serum interleukin-8 and interleukin-10 expression in ovariectomized rats with osteoporosis / 中国组织工程研究

10.3969/j.issn.2095-4344.2013.24.004

Analysis of clinical effect of laparoscopy in diagnosis 468 female infertility patients / 中国基层医药

Objective To explore clinical effects of laparoscopy applied in the female patients with infertility. Methods 468 cases of female infertility patients were diagnosed and treated by laparoscopy and 168 cases received follow-up survey. Results Among those infertility patients, the patients of normal pelvic cavity and the abnormal one were 49(10.47% ) and 419( 89.53% ). Among those patients of abnormal pelvic cavity .fallopian tube disease in 276 cases(65.87% ) was at the first place. The constituent ratio of endometriosis,ovary tumor,polycystic ovary,uterine myoma,female genital tract malformation and pelvic tuberculosis was 14. 80% ,5. 97% ,4. 30% ,3. 82% , 3. 34% and 1.91% .respectively. The patients of primary infertility and the secondary ones were 208 and 260 cases. In secondary infertility patients 69.23% (180/260) of patients were caused due to fallopian tube diseases,and the constituent ratio was higher than that in primary infertility 46.15% (96/208) (x2 = 14.05 ,P <0.05),while in primary infertility,the constituent ratio of endometriosis and normal pelvic cavity were 20.19% ,15.38% ,which were higher than that in secondary infertility respectively(x2 = 11. 78,11. 16, all P < 0.05). The pregnancy rate of 168 cases followed-up was 45.24% (76/168).47.37% ,84.21% pregnancy occurred within 6,12 months with laparoscopy. The shortest and longest time of pregnancy was 2 and 30 months, respectively. The median was 8months. Conclusion Laparoscopy playd an important role in diagnosis of infertility and improvement of pregnancy rate.

Technical characters of model establishment of penetrating corneal transplantation in rats / 中国组织工程研究

BACKGROUND: The expression of main histocompatibility antigen in cornea of rats is similar to that of human. It is verified in early experiments that penetrating corneal transplantation in rats is more repetition and reliability, and the operation difficulty is lower than that in mice.OBJECTIVE: To establish rat model of penetrating corneal transplantation and analyze the reasons of complications during model preparation and the corresponding managements and probe into the method for improving the success rate of rat model of corneal transplantation.DESIGN: Randomized controlled experiment was designed.SETTING: Department of Ophthalmology , Union Hospital, Tongji Medical College, Huazhong University of Science and Technology.MATERIALS: The experiment was performed in Department of Ophthalmology in Union Hospital Affiliated to Tongji Medical College of Huazhong University of Science and Technology from March to May 2004. Seventysix outbred female Wistar rats of two months old were employed and randomized into experimental group and control group with 38 rats in each,without eye disease, of clean grade, body mass varied from 180 to 200 g and their right eyes were taken as acceptors. Thirty-eight SD female rats were employed and their both eyes were taken as donors. All of the animals were provided from Experimental Animal Center of Tongji Medical College of Huazhong University of Science and Technology.METHODS: Central penetrating corneal transplantation in situ was adopted and the model was established on the right eye of Wistar rat. Ten minutes before operation, tropicamide eye drops was administrated twice to amplify adequately the pupil of the right eye up to 4.0 mm. According to body mass, general anesthesia was done with abdominal injection of 3.0 mL/kg chloral hydrateand dicaine eye drops was applied twice 5 minutes before the operation with 0.1 volume fraction. Routine sterilization was done on the head of rat, the eyes kept in horizontal level and respiration kept smooth. The clip in dental-ophthalmology department was used to fix the posterior of the operated eye and make it to be semiluxated. The ring driller 3.5 mm in diameter was used to collect corneas of both eyes in SD rat as the implant tissue and place in culture dish with endothelial part upward, covered with methyl cellulose of 20 g/L mass weight concentration. The ring driller, 3.0 mm in diameter was used to collect the cornea of the right eye in Wistar rat to be the graft foreman, and the implant tissue was sutured into the graft foreman on the right eye of Wistar rat with 10-0nylon thread intermittently. Eight stitches were done in corneal transplantation in the experimental group and 6 stitches in the control group. After operation, ofloxacin eye drops was administrated and the operated eye was covered with plaster. Corneal rejection was observed and the evaluation was done in 3 items, named, turbidity, edema and neogenetic vessel. The total score of 3 items was taken as the rejection index on the day. Rejection was determined if the rejection index on the day ≥5 or corneal turbidity reached the 3nd grade. x2 and Fisher definite probability methods were used for statistical examination.plant tissue and corneal rejection.RESULTS: Of 76 Wistar rat acceptors, 5 rats were dropped out, among which, 1 rat was died accidentally after operation in the experimental group, 2 rats were died accidentally after operation in the control and 2 rats were injured cornea on the operated eyes due to fighting. But by supcomplications after corneal transplantation: In the experimental group, the number with anterior adhesion of sclera, non-round pupil; limited wound healing and non-formation of anterior chamber was lower than that in the implant tissue and corneal rejection: the survival time of corneal implant tissue was similar basically in both experimental group and the control [(8.9±2.3), (8.6±2.3) days, P ＞ 0.05]. Rejection presented in both groups in 16 days after corneal transplantation and the incidence of rejection was 100%.CONCLUSION: With stitches maintained and without intervention, the acute rejection is similar in rat corneal transplantation and human corneal transplantation. It is explained in the experiment that 8 stitches in corneal transplantation in which the rat implant tissue of 3.5 mm matches graft foreman of 3.0 mm can reduce the complications of rat corneal transplantation and becomes a satisfactory animal model of corneal transplantation.Skillful microscopic operation techniques, satisfactory operation instruments and adequate amplilfied pupil can reduce to the most extent the postoperation complications in rats.