Clinical significance of RNA methylation in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a primary liver malignancy with high mortality rates and poor prognosis. Recent advances in high-throughput sequencing and bioinformatic technologies have greatly enhanced the understanding of the genetic and epigenetic changes in liver cancer. Among these changes, RNA methylation, the most prevalent internal RNA modification, has emerged as a significant contributor of the development and progression of HCC. Growing evidence has reported significantly abnormal levels of RNA methylation and dysregulation of RNA-methylation-related enzymes in HCC tissues and cell lines. These alterations in RNA methylation play a crucial role in the regulation of various genes and signaling pathways involved in HCC, thereby promoting tumor progression. Understanding the pathogenesis of RNA methylation in HCC would help in developing prognostic biomarkers and targeted therapies for HCC. Targeting RNA-methylation-related molecules has shown promising potential in the management of HCC, in terms of developing novel prognostic biomarkers and therapies for HCC. Exploring the clinical application of targeted RNA methylation may provide new insights and approaches for the management of HCC. Further research in this field is warranted to fully understand the functional roles and underlying mechanisms of RNA methylation in HCC. In this review, we described the multifaceted functional roles and potential mechanisms of RNA methylation in HCC. Moreover, the prospects of clinical application of targeted RNA methylation for HCC management are discussed, which may provide the basis for subsequent in-depth research on RNA methylation in HCC.

Effects of N6-methyladenosine modification on metabolic reprogramming in digestive tract tumors

N6-methyladenosine (m6A), the most abundant RNA modification within cells, participates in various biological and pathological processes, including self-renewal, invasion and proliferation, drug resistance, and stem cell characteristics. The m6A methylation plays a crucial role in tumors by regulating multiple RNA processes such as transcription, processing, and translation. Three protein types are primarily involved in m6A methylation: methyltransferases (such as METTL3, METTL14, ZC3H13, and KIAA1429), demethylases (such as FTO, ALKBH5), and RNA-binding proteins (such as the family of YTHDF, YTHDC1, YTHDC2, and IGF2BPs). Various metabolic pathways are reprogrammed in digestive tumors to meet the heightened growth demands and sustain cellular functionality. Recent studies have highlighted the extensive impact of m6A on the regulation of digestive tract tumor metabolism, further modulating tumor initiation and progression. Our review aims to provide a comprehensive understanding of the expression patterns, functional roles, and regulatory mechanisms of m6A in digestive tract tumor metabolism-related molecules and pathways. The characterization of expression profiles of m6A regulatory factors and in-depth studies on m6A methylation in digestive system tumors may provide new directions for clinical prediction and innovative therapeutic interventions.

Clinical features of hepatic manifestations among adult patients with hemophagocytic lymphohistiocytosis: a retrospective study

INTRODUCTION Liver dysfunction is common in patients with hemophagocytic lymphohistiocytosis (HLH). However, whether the severity of liver injury is associated with the prognosis of patients with HLH remains to be determined. This study aims to assess the association of the severity of liver involvement with short-term prognosis among adult patients with HLH. METHODS A retrospective study was performed from January 2012 to December 2020, including 150 patients with newly diagnosed HLH and liver injury. RESULTS The majority of our cohort suffered from mild to moderate hepatic damage, presenting with Child-Turcotte-Pugh (CTP) class A (55, 36.7%) or B (74, 49.3%). The prevalence of acute liver failure (ALF) was 9.3% in our cohort. The overall 30-day mortality rate was 49.3% among the study population. HLH patients with ALF showed an extremely adverse prognosis, with a mortality rate as high as 92.9%. In a multivariate analysis, age ≥ 60 years (p = 0.016), BUN ≥ 7 μmol/L (p < 0.001) and malignancy-associated HLH (p < 0.001) at the diagnosis of HLH were identified as being strongly correlated with 30-day prognosis. An excellent predictive power was found. Among the predictive scores used to assess early death of HLH patients with liver injury, the prognostic efficiency of chronic liver failure-sequential organ failure assessment (CLIF-SOFA) (AUROC: 0.936 ± 0.0211) and SOFA score (0.901 ± 0.026) were significantly better than those of the APACHE II (p < 0.001), Model for end-stage liver disease score (p < 0.001) and CTP scores (p < 0.001). The CLIF-SOFA score was slightly better than the SOFA score (p = 0.068). CONCLUSION Patients with old age, elevated BUN and malignancy had inferior survival. CLIF-SOFA and SOFA enables a more accurate prediction of early death in HLH patients with liver injury than other liver-specific and general prognostic models.

Retraction Note: Salinomycin enhances radiotherapy sensitivity and reduces expressions of BIRC5 and NEIL2 in nasopharyngeal carcinoma

The article "Salinomycin enhances radiotherapy sensitivity and reduces expressions of BIRC5 and NEIL2 in nasopharyngeal carcinoma, by Y. Chang, Q. Geng, Q. Bao, P. Hu, published in Eur Rev Med Pharmacol Sci 2020; 24 (11): 6409-6416-DOI: 10.26355/eurrev_202006_21539-PMID: 32572938" has been retracted by the authors. After publication, the article was questioned on PubPeer. Concerns were raised about Figure 3 and the reliability of the published results. The same authors stated that the study was not conducted according to the required standard procedures. The Publisher apologizes for any inconvenience this may cause https://www.europeanreview.org/article/21539.

Identification and analysis of necroptosis-associated signatures for prognostic and immune microenvironment evaluation in hepatocellular carcinoma

Background

Hepatocellular carcinoma remains the third most common cause of cancer-related deaths worldwide. Although great achievements have been made in resection, chemical therapies and immunotherapies, the pathogenesis and mechanism of HCC initiation and progression still need further exploration. Necroptosis genes have been reported to play an important role in HCC malignant activities, thus it is of great importance to comprehensively explore necroptosis-associated genes in HCC.

Methods

We chose the LIHC cohort from the TCGA, ICGC and GEO databases for this study. ConsensusClusterPlus was adopted to identify the necroptosis genes-based clusters, and LASSO cox regression was applied to construct the prognostic model based on necroptosis signatures. The GSEA and CIBERSORT algorithms were applied to evaluate the immune cell infiltration level. QPCR was also applied in this study to evaluate the expression level of genes in HCC.

Results

We identified three clusters, C1, C2 and C3. Compared with C2 and C3, the C1 cluster had the shortest overall survival time and highest immune score. The C1 was samples were significantly enriched in cell cycle pathways, some tumor epithelial-mesenchymal transition related signaling pathways, among others. The DEGs between the 3 clusters showed that C1 was enriched in cell cycle, DNA replication, cellular senescence, and p53 signaling pathways. The LASSO cox regression identified KPNA2, SLC1A5 and RAMP3 as prognostic model hub genes. The high risk-score subgroup had an elevated expression level of immune checkpoint genes and a higher TIDE score, which suggested that the high risk-score subgroup had a lower efficiency of immunotherapies. We also validated that the necroptosis signatures-based risk-score model had powerful prognosis prediction ability.

Conclusion

Based on necroptosis-related genes, we classified patients into 3 clusters, among which C1 had significantly shorter overall survival times. The proposed necroptosis signatures-based prognosis prediction model provides a novel approach in HCC survival prediction and clinical evaluation.

IP3R1/GRP75/VDAC1 complex mediated endoplasmic reticulum stress-mitochondrial oxidative stress in diabetic atrial remodeling

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): National Natural Science Foundation of China

Background

Mitochondrial oxidative stress is an important mechanism of atrial remodeling and atrial fibrillation (AF) in the setting of diabetes. Currently, endoplasmic reticulum (ER) stress is regarded as the key link from homeostasis to dysfunction, and is a central feature of metabolic diseases such as type 2 diabetes. However, the molecular mechanisms underlying these processes have not been fully elucidated.

Objective

To explore the potential role of ER stress-mitochondrial oxidative stress in atrial remodeling and AF induction in diabetes.

Methods

 Mouse atrial cardiomyocytes (HL-1 cells) , type 2 diabetic rats and GRP75 conditional knockout mice were used as models systems. These findings were correlated with biomarker findings in human diabetic patients with confirmed atrial fibrillation.

Results

 In the diabetic rat atria, significant ER stress was observed. Treatment with tunicamycin (TM), an ER stress agonist, mass spectrometry (MS) demonstrated many known ER stress and calmodulin proteins, including Heat shock protein family A (Hsp70) member (Hspa) 5 (GRP78) and Hspa9 (GRP75) and in situ proximity ligation assay (PLA) indicated that TM led to increased protein expression of the IP3R1 (inositol 1,4,5-trisphosphate receptors 1)/GRP75 (glucose-regulated protein 75)/VDAC1 (voltage-dependent anion channel 1) complex in HL-1 cells. Silencing of GRP75 using siRNA in HL-1 cells and GRP75 conditional knockout in our mouse model led to impaired calcium transport from the ER to mitochondria, and alleviated mitochondrial oxidative stress and calcium overload. Moreover, GRP75 deficiency attenuates atrial remodeling and AF progression in Myh6-Cre+/Hspa9flox/flox + TM mice.

Conclusions

 The IP3R1/GRP75/VDAC1 complex mediates endoplasmic reticulum stress-mitochondrial oxidative stress plays an important role in diabetic atrial remodeling. Abstract Figure

[Comparative study on prognosis of neoadjuvant chemotherapy followed by hepatic surgery versus upfront surgery in patients with synchronous colorectal liver metastasis]

Objective: To compare the survival outcome in patients with synchronous colorectal cancer liver metastasis receiving neoadjuvant chemotherapy followed by hepatic surgery versus upfront surgery strategies. Methods: A retrospective cohort study was carried out. Data of patients undergoing surgery at the Department of Hepatopancreatobiliary Surgery Unit I of Peking University Cancer Hospital from January 2008 to December 2018 for initially resectable synchronous colorectal liver metastasis were retrospectively collected. A total of 282 cases were enrolled, including 244 in the neoadjuvant chemotherapy group, 38 in the upfront surgery first group. The overall survival (OS) and progression-free survival (PFS) of the two groups were compared. A propensity score risk adjustment was used to eliminate potential bias between groups, and the covariates including sex, age, location of primary tumor, T stage, clinical risk score (CRS), RAS gene status, adjuvant chemotherapy, and resection margin status were included for adjustment. Results: In the neoadjuvant chemotherapy group, 244 cases received 4 (1-15) cycles of chemotherapy before hepatic resection, among whom 207 cases received oxaliplatin-based regimens, 37 cases received irinotecan-based regimens, and 90 cases received combined targeted agents in the first line treatment. The median follow-up time was 30 (5-134) months, and loss of follow-up was 1%. Before adjustment, Kaplan-Meier survival analysis showed that the 1-year and 3-year OS rates in the neoadjuvant chemotherapy group (95.1% and 66.4%) were better than those in the upfront surgery first group (94.7% and 51.5%, P=0.026); 1-year and 3-year PFS rates in neoadjuvant chemotherapy group (51.0% and 23.4%) were also better than those in surgery first group (39.5% and 11.5%, P=0.039). After propensity score risk adjustment, Cox multivariate analysis indicated that neoadjuvant chemotherapy was an independent protective factor of PFS (HR=0.664, 95% CI: 0.449-0.982, P=0.040), however, neoadjuvant chemotherapy was not an independent protective factor of OS (HR=0.651, 95% CI: 0.393-1.079, P=0.096). Subgroup analysis showed that the 1-year and 3-year OS rates in the patients with response to the first line treatment (194, including complete remission, partial remission and reduction but not partial remission) (96.9% and 67.1%) were better than those in the upfront surgery group (94.7% and 51.5%, P=0.026) after adjustment. However, the 1-year and 3-year OS rates in the patients without response to the first line treatment (50, including tumor progression or enlargement) were 90.0% and 63.3%, respectively, which were not significantly different with 94.7% and 51.5% in the upfront surgery group (P=0.310) after adjustment. Conclusions: For patients with resectable synchronous colorectal cancer liver metastasis, liver resection after neoadjuvant chemotherapy can provide longer PFS than upfront surgery. Although the whole OS benefit is not significant, patients with effective neoadjuvant first-line chemotherapy have better OS than those undergoing upfront surgery.

[Long-term outcomes of patients undergoing hepatectomy for bilateral multiple colorectal liver metastases-a propensity score matching analysis]

Objective: Liver is the most common site of distant metastasis in colorectal cancer patients. Currently, surgical resection of colorectal liver metastasis (CRLM) still remains the most curative therapeutic option which is associated with long-term survival. However, the outcome of CRLM patients with bilobar multiple lesions has been reported to be extremely poor due to the complex techniques of the surgery and the difficulties to achieve a negative resection margin. In this study, postoperative long-term outcome in patients with bilobar versus unilobar multiple CRLM undergoing surgical resection were compared and the prognostic factors of CRLM were analyzed. Methods: A retrospective cohort study was performed. The clinicopathological data were collected retrospectively from patients with multiple CRLM who received liver resection between January 2002 and November 2018 at our department. Inclusion criteria: (1) All CRLM lesions were confirmed by preoperative enhanced CT or MRI and enhanced ultrasonography. (2) All CRLM lesions were resectable either initially or converted by systemic treatments. The CRLM patients were considered as resectable, if their extrahepatic diseases were able to be completely removed. (3) Sufficient remnant liver volume was required to maintain normal liver function, which was defined by the ratio of remnant liver volume to total liver volume (RLV-TLV), of greater than 30% in general or 40% for the patients undergoing chemotherapy. (4) Medical records and follow-up information were intact. Those undergoing multiple operations after recurrence, with R2 resection, or with a single CRLM lesion were excluded. Patients were divided into bilobar and unilobar group according to tumor distribution. One-to-one propensity score matching (PSM) was performed to balance the covariates between the bilobar group and unilobar group. After PSM, the differences in long-term outcomes between the two groups were compared. Results: A total of 491 patients met the inclusion criteria, 344 (69.6%) with bilobar and 147 (30.4%) with unilobar CRLM. In the propensity-score-matched population (bilobar, 143; unilobar, 143), baseline characteristics were similar between the two groups. The 1-, 3-, and 5-year overall survival rates in the bilobar group were 91.6%, 52.1%, and 35.3% respectively, compared with 93.7%, 56.8%, and 43.8% in the unilobar group, and the difference was not statistically significant (P=0.204). The 1-, 3-, and 5-year recurrence-free survival rates in the bilobar group were 45.7%, 33.7%, and 33.7% respectively, compared with 62.5%, 44.1%, and 42.1% in the unilobar group, and the difference was not statistically significant (P=0.075). No significant difference was found in liver-only recurrence (45.6% in bilobar vs. 53.3% in unilobar, P=0.543). Univariate analysis showed that N stage of primary tumor, diameter of the largest liver metastases, carcinoembyonic antigen level, RAS gene status and clinical risk score (CRS) were significantly associated with the prognosis of CRLM (all P<0.05). Multivariate analysis indicated that diameter of largest liver metastases > 5 cm (HR=1.888, 95% CI: 1.251-2.848, P=0.002), CRS≥3 (HR=1.552,95% CI:1.050-2.294, P=0.027) and RAS gene mutation (HR=1.561, 95% CI: 1.102-2.212, P=0.012) were independent risk factors of poor overall survival after hepatectomy. Conclusions: Tumor distribution may not affect the prognosis of multiple CRLM after resection. Surgical removal in patients with bilobar multiple CRLM provides comparable long-term survival to unilobar multiple CRLM.

Mesenchymal stem cell-based cell-free strategies: safe and effective treatments for liver injury

Various hepatoxic factors, such as viruses, drugs, lipid deposition, and autoimmune responses, induce acute or chronic liver injury, and 3.5% of all worldwide deaths result from liver cirrhosis, liver failure, or hepatocellular carcinoma. Liver transplantation is currently limited by few liver donors, expensive surgical costs, and severe immune rejection. Cell therapy, including hepatocyte transplantation and stem cell transplantation, has recently become an attractive option to reduce the overall need for liver transplantation and reduce the wait time for patients. Recent studies showed that mesenchymal stem cell (MSC) administration was a promising therapeutic approach for promoting liver regeneration and repairing liver injury by the migration of cells into liver sites, hepatogenic differentiation, immunoregulation, and paracrine mechanisms. MSCs secrete a large number of molecules into the extracellular space, and soluble proteins, free nucleic acids, lipids, and extracellular vesicles (EVs) effectively repair tissue injury in response to fluctuations in physiological states or pathological conditions. Cell-free-based therapies avoid the potential tumorigenicity, rejection of cells, emboli formation, undesired differentiation, and infection transmission of MSC transplantation. In this review, we focus on the potential mechanisms of MSC-based cell-free strategies for attenuating liver injury in various liver diseases. Secretome-mediated paracrine effects participate in the regulation of the hepatic immune microenvironment and promotion of hepatic epithelial repair. We look forward to completely reversing liver injury through an MSC-based cell-free strategy in regenerative medicine in the near future.

Salinomycin enhances radiotherapy sensitivity and reduces expressions of BIRC5 and NEIL2 in nasopharyngeal carcinoma

OBJECTIVE

The aim of this study was to investigate the effects of salinomycin (Sal) on expressions of baculoviral IAP repeat-containing 5 (BIRC5) and Nei endonuclease VIII-like 2 (NEIL2) and radiotherapy sensitivity of nasopharyngeal carcinoma (NPC).

MATERIALS AND METHODS

Human NPC CNE-2 cell lines were used as research objects in this study. Subsequently, the cells received intervention with Sal at different concentrations, radioactive rays at different doses and Sal combined with radioactive rays. The growth inhibition rate of CNE-2 cells was detected via methyl thiazolyl tetrazolium (MTT) assay. The dose-effect relations of Sal, radioactive rays and combination therapy with the inhibitory effect on CNE-2 cells were obtained. CNE-2 cells receiving intervention with Sal at an appropriate concentration or radioactive rays at an appropriate dose alone and Sal combined with radioactive rays were used as intervention groups (Sal group, Radiation group and Combination group). However, those added with an equal amount of DMSO were set as Control group. Next, the cycle, apoptosis and apoptotic morphology of CNE-2 cells were observed via flow cytometry and Hoechst assay, respectively. Moreover, the expressions of apoptosis-related proteins Caspase-3, B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated X protein (Bax), as well as BIRC5 and NEIL2 proteins in CNE-2 cells were determined using Western blotting.

RESULTS

Under the intervention with Sal or radioactive rays alone, the growth inhibition rate of CNE-2 cells rose in a concentration/dose-dependent manner. With the increase in Sal concentration in combination therapy, the growth inhibition rate of CNE-2 cells significantly increased (p<0.05). Compared with Control group, Sal group, Radiation group, and Combination group exhibited remarkably lower colony formation rate, higher proportion of CNE-2 cells in the G2/M phase, enhanced apoptosis of CNE-2 cells with nuclear fragmentation, increased expressions of pro-apoptotic proteins Caspase-3 and Bax, decreased expression of anti-apoptotic protein Bcl-2, and lower protein expressions of BIRC5 and NEIL2 in cells (p<0.05). Compared with Radiation group, the Combination group had significantly decreased colony formation rate, increased proportion of CNE-2 cells in the G2/M phase, enhanced apoptosis of CNE-2 cells with more nuclear fragmentation and other apoptosis characteristics, increased expressions of pro-apoptotic proteins Caspase-3 and Bax, decreased expression of anti-apoptotic protein Bcl-2, and decreased protein expressions of BIRC5 and NEIL2 in cells (p<0.05).

CONCLUSIONS

Sal enhances the radiotherapy sensitivity of NPC and reduces the protein expressions of BIRC5 and NEIL2 in cells.

Research Note: Effects of the rearing method and stocking density on carcass traits and proximate composition of meat in small-sized meat ducks

The present study was conducted to evaluate the effects of different rearing methods and stocking densities on carcass yield and proximate composition of meat in small-sized meat ducks. A total of 555 one-day-old birds were randomly allocated to six treatment groups (three replicates per treatment, sex ratio 1/1) with a 2 × 3 factorial arrangement of two rearing methods (reared in cage or net) and three stocking densities (5 [low], 7 [medium], or 9 [high] birds/m²) until day 70. Five male and five female birds from each replicate were randomly selected and processed to determine the carcass yield. Proximate composition was determined by proximate analysis using the breast and thigh muscles. There was no interaction effect between the rearing method and stocking density on carcass yield. The rearing method affected the thigh muscle rate, which was higher in the cage groups (P < 0.05). The final BW and abdominal fat rate decreased with increasing density (P < 0.05), whereas the thigh muscle rate increased (P < 0.05). There were significant interaction effects (P < 0.05) between the rearing method and stocking density on the content of protein, fat, and collagen. The content of fat and moisture was greater and lower, respectively, in the cage groups (P < 0.05). The content of moisture, fat, and collagen with a medium density was higher (P < 0.05). In addition, the content of protein and fat was lower in the ducks fed in nets at low and high densities (P < 0.05), respectively; the collagen content of breast and thigh muscle was lower in the ducks fed in cages and nets, respectively, at a low density (P < 0.05). Our findings provide valuable insights into the single and interactive effects of the rearing method and stocking density on duck slaughter performance and proximate composition of meat. The results indicate that a rearing system with a cage pattern and a medium density is better than other arrangements for small-sized meat ducks.

Systematic analysis of copy-number variations associated with early pregnancy loss

OBJECTIVES

Embryonic numerical and structural chromosomal abnormalities are the most common cause of early pregnancy loss. However, the role of submicroscopic copy-number variations (CNVs) in early pregnancy loss is unclear, and little is known about the critical regions and candidate genes for miscarriage, because of the large size of structural chromosomal abnormalities. The aim of this study was to identify potential miscarriage-associated submicroscopic CNVs and critical regions of large CNVs as well as candidate genes for miscarriage.

METHODS

Over a 5-year period, 5180 fresh miscarriage specimens were investigated using quantitative fluorescent polymerase chain reaction/CNV sequencing or chromosomal microarray analysis. Statistically significant submicroscopic CNVs were identified by comparing the frequency of recurrent submicroscopic CNVs between cases and a published control cohort. Furthermore, genes within critical regions of miscarriage-associated CNVs were prioritized by integrating the Residual Variation Intolerance Score and the human gene expression dataset for identification of potential miscarriage candidate genes.

RESULTS

Results without significant maternal-cell contamination were obtained in 5003 of the 5180 (96.6%) cases. Clinically significant chromosomal abnormalities were identified in 59.1% (2955/5003) of these cases. Three recurrent submicroscopic CNVs (microdeletions in 22q11.21, 2q37.3 and 9p24.3p24.2) were significantly more frequent in miscarriage cases, and were considered to be associated with miscarriage. Moreover, 44 critical regions of large CNVs were observed, including 14 deletions and 30 duplications. There were 309 genes identified as potential miscarriage candidate genes through gene-prioritization analysis.

CONCLUSIONS

We identified potential miscarriage candidate CNVs and genes. These data demonstrate the importance of CNVs in the etiology of miscarriage and highlight the importance of ongoing analysis of CNVs in the study of miscarriage. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Variation in the gut microbial community is associated with the progression of liver regeneration

AIM

To highlight a potential dynamic interaction between intestinal bacteria (IB) and metabolites that might contribute to liver regeneration (LR).

METHODS

Male Sprague-Dawley rats were subjected to surgical removal of two-thirds of the liver and samples were collected over a 14-day period. Intestinal community and metabolic profiles were characterized to establish their potential interactions during liver regeneration.

RESULTS

Partial hepatectomy caused fluctuating changes in the gut microbiome, which paralleled the biological processes of LR. Briefly, the enhanced cell proliferation occurring within 30-48 h was associated with a decreased ratio of Firmicutes to Bacteroidetes reflected by a reduction in Ruminococcaceae and Lachnospiraceae, and an increase in Bacteroidaceae, Rikenellaceae, and Porphyromonadaceae, which was indicative of a lean phenotype. The microbiota derived from rats at 12-24 h and 3-14 days were characterized by elevated F/B ratios, suggesting the differing energy extract behaviors of microbiota during the course of LR. Functional changes of the shifted microbiota revealed by PICRUSt software confirmed the pyrosequencing results. The microbiome derived from hour 12 rats showed overpresentation of metabolism-related modules. In contrast, the microbiome derived from day 2 rats was functionally unique in "replication and repair", "amino acid metabolism," and "nucleoid metabolism." Upon examining the dynamic pattern of metabolic response, the specific pathways, including glycerophospholipid metabolism, taurine, and hypotaurine metabolism, were identified to be attributable to the systemic alterations in LR-related metabolism. Moreover, our data indicated that several key functional bacteria were strongly related to perturbations of the above pathways.

CONCLUSION

Gut flora could play a central role in manipulating metabolic responses in LR.

Role of microRNA-124 in cardiomyocyte hypertrophy inducedby angiotensin II

Cardiac hypertrophy is a crucial predictor of heart failure and is regulated by microRNAs. MicroRNA-124 (miR-124) is regarded as a prognostic indicator for outcomes after cardiac arrest. However, whether miR-124 participates in cardiac hypertrophy remains unclear. Therefore, our study aimed to determine the role of miR-124 in angiotensin II(AngII)-induced myocardial hypertrophy and the possible mechanism. Primary cultured rat neonatal cardiomyocytes(NCMs) were transfected with miR-124 mimics or inhibitor, followed by AngII stimulation. Quantitative RT-PCR, western blot analysis and determination of cell surface area of NCMs were used to detect the hypertrophic phenotypes. We observed that miR-124 was elevated in AngII-induced hypertrophic cardiomyocytes. Cell surface area of NCMs and mRNA expression of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and β-myosin heavy chain (β-MHC), indicators of myocardial hypertrophy, were higher in NCMs transfected with miR-124 mimics in the presence of AngII. On the contrary, knockdown of miR-124 by its specific inhibitor could restore these courses. Furthermore, downregulation of miR-124 alleviated the increased protein level of endoplasmic reticulum (ER) stress markers 78-kDa glucose-regulated protein (Grp78) and calreticulin(CRT) in AngII-induced NCMs. In conclusion, our study shows that inhibition of miR-124 effectively suppresses AngII-induced myocardial hypertrophy, which is associated with attenuation of ER stress.

Altered Fecal Microbiota Correlates with Liver Biochemistry in Nonobese Patients with Non-alcoholic Fatty Liver Disease

Increasing evidence suggests a role of intestinal dysbiosis in obesity and non-alcoholic fatty liver disease (NAFLD). But it remains unknown in nonobese NAFLD. This prospective, cross-sectional study sought to characterize differences in fecal microbiota between nonobese adult individuals with and without NAFLD and their potential association with metabolic markers of disease progression. A total of 126 nonobese subjects were enrolled: 43 NAFLD and 83 healthy controls (HC). The microbial community was profiled by denaturing gradient gel electrophoresis and examined by 454 pyrosequencing of the 16S ribosomal RNA V3 region. Lower diversity and a phylum-level change in the fecal microbiome were found in NAFLD. Compared with HC, patients had 20% more phylum Bacteroidetes (p = 0.005) and 24% less Firmicutes (p = 0.002). Within Firmicutes, four families and their 8 genera, which were short-chain fatty acids-producing and 7α-dehydroxylating bacteria, were significantly decreased. Moreover, Gram-negative (G-) bacteria were prevalent in NAFLD (p = 0.008). Furthermore, a significant correlation with metabolic markers was revealed for disturbed microbiota in NAFLD. This novel study indicated that intestinal dysbiosis was associated with nonobese NAFLD and might increase the risk of NAFLD progression.

The Effect of Probiotic Treatment on Patients Infected with the H7N9 Influenza Virus

Background

A novel avian-origin influenza A (H7N9) virus emerged and spread among humans in Eastern China in 2013. Prophylactic treatment with antibiotics and probiotics for secondary infection is as important as antiviral treatment. This study aims to assess the ability of probiotic treatment to restore internal homeostasis under antibiotic pressure and to reduce/ameliorate the risk of secondary infections resulting from infection with the H7N9 virus.

Methods

This is a retrospective study in archival samples. Between April 1 and May 10, 2013, 113 stool, sputum, and blood specimens were collected and analyzed by denaturing gradient gel electrophoresis (DGGE) to determine the composition of the patient microbiomes. Microbial diversity was calculated using Gel-Pro analyzer and Past software. Cluster analysis of DGGE pattern profiles was employed to create a phylogenetic tree for each patient, and multidimensional scaling (MDS) and principal component analysis (PCA) were performed to visualize relationships between individual lanes.

Results

Five patients had secondary infections, including Klebsiella pneumonia, Acinetobacter baumanii and Candida albicans infection. The DGGE profiles of fecal samples obtained at different time points from the same individual were clearly different, particularly for patients with secondary infections. Shannon’s diversity index and evenness index were lower in all infected groups compared to the control group. After B. subtilis and E. faecium or C. butyricum administration, the fecal bacterial profiles of patients who had not been treated with antibiotics displayed a trend of increasing diversity and evenness. C. butyricum failed to reduce/ameliorate secondary infection in H7N9-infected patients, but administration of B. subtilis and E. faecium appeared to reduce/ameliorate secondary infection in one patient.

Conclusion

H7N9 infection might decrease intestinal microbial diversity and species richness in humans. C. butyricum failed to reduce/ameliorate secondary infection in H7N9-infected patients. B. subtilis and E. faecium may also play a role in reducing/ameliorating secondary infection in these patients.

A modified prognostic score for critically ill patients with cirrhosis: An observational study

BACKGROUND AND AIMS

It is controversial whether patients with cirrhosis benefit from the intensive care unit (ICU) management. To identify the patients in whom ICU care may offer recovery, this study aimed to determine specific risk factors and to establish a novel prognostic score for 3-month mortality in critically ill patients with cirrhosis.

METHODS

An observational study was performed from August 2008 to May 2014, encompassing 349 critically ill patients with cirrhosis during their ICU stay (a 70% training and 30% validation set).

RESULTS

The overall 3-month mortality rate was 68.1% in training cohort. Prothrombin time, serum bilirubin, use of vasopressors, hepatic encephalopathy, and systemic inflammatory response syndrome at admission were identified as being strongly correlated with the 3-month prognosis. Based on these five variables, a modified score for critically ill cirrhosis (MSCIC) was developed. An increasing MSCIC was significantly correlated with a reduction in the rate of survival (P < 0.001). Moreover, excellent predictive power was found when the MSCIC was used (area under the receiver operating characteristic curve: 0.856 ± 0.047), which was significantly better than the prognostic efficiency of Acute Physiology and Chronic Health Evaluation II (P < 0.001), Model for End-stage Liver Disease (P = 0.02), Simplified Acute Physiology Score (P = 0.023), and the Child-Turcotte-Pugh score (P = 0.01); the MSCIC score was slightly better than that of Chronic Liver Failure-Sequential Organ Failure Assessment (P = 0.068). The similar result was obtained in validation set.

CONCLUSIONS

The MSCIC is an easily adopted tool with a high prognostic efficacy for patients with advanced cirrhosis; MSCIC may act as a supplement to the clinical judgment of physicians when considering the prognosis.

Optimization of the Energy Window for PETbox4, a Preclinical PET Tomograph With a Small Inner Diameter

Small animal positron emission tomography (PET) systems are often designed by employing close geometry configurations. Due to the different characteristics caused by geometrical factors, these tomographs require data acquisition protocols that differ from those optimized for conventional large diameter ring systems. In this work we optimized the energy window for data acquisitions with PETbox4, a 50 mm detector separation (box-like geometry) pre-clinical PET scanner, using the Geant4 Application for Tomographic Emission (GATE). The fractions of different types of events were estimated using a voxelized phantom including a mouse as well as its supporting chamber, mimicking a realistic mouse imaging environment. Separate code was developed to extract additional information about the gamma interactions for more accurate event type classification. Three types of detector backscatter events were identified in addition to the trues, phantom scatters and randoms. The energy window was optimized based on the noise equivalent count rate (NECR) and scatter fraction (SF) with lower-level discriminators (LLD) corresponding to energies from 150 keV to 450 keV. The results were validated based on the calculated image uniformity, spillover ratio (SOR) and recovery coefficient (RC) from physical measurements using the National Electrical Manufacturers Association (NEMA) NU-4 image quality phantom. These results indicate that when PETbox4 is operated with a more narrow energy window (350-650 keV), detector backscatter rejection is unnecessary. For the NEMA NU-4 image quality phantom, the SOR for the water chamber decreases by about 45% from 15.1% to 8.3%, and the SOR for the air chamber decreases by 31% from 12.0% to 8.3% at the LLDs of 150 and 350 keV, without obvious change in uniformity, further supporting the simulation based optimization. The optimization described in this work is not limited to PETbox4, but also applicable or helpful to other small inner diameter geometry scanners.

Clinical, virological, and histopathological manifestations of fatal human infections by avian influenza A(H7N9) virus

BACKGROUND

Systematic analysis of histopathological and serial virological changes of fatal influenza A(H7N9) cases is lacking.

METHODS

Patients with A(H7N9) infection admitted to our intensive care unit during 10-23 April 2013 were included. Viral loads in the respiratory tract, as inferred from the cycle threshold (Ct) value of reverse transcription polymerase chain reaction (RT-PCR), and the serum hemagglutination inhibition (HAI) antibody titer, were analyzed. Postmortem biopsies of the lung, liver, kidney, spleen, bone marrow, and heart were examined.

RESULTS

Twelve patients (6 deaths, 6 survivors) were included. Median viral load was higher in sputa than the nasopharyngeal swabs for fatal cases (median Ct, 23 vs 30.5; P = .08). RT-PCR for A(H7N9) was positive in stool samples (4/6 [67%]) of fatal cases and (2/6 [33%]) of survivors, but was negative in the cerebrospinal fluid, urine, or blood of all patients. Nosocomial bacterial infections were more common in patients who died than in survivors (83% vs 50%). HAI titers increased by ≥4-fold in those with convalescent sera. Postmortem biopsy for 3 patients showed acute diffuse alveolar damage. Patient 1, who died 8 days after symptom onset, had intra-alveolar hemorrhage. Patients 2 and 3, who died 11 days after symptom onset, had pulmonary fibroproliferative changes. Reactive hemophagocytosis in the bone marrow and lymphoid atrophy in splenic tissues were compatible with laboratory findings of leukopenia, lymphopenia, and thrombocytopenia. Hypoxic and fatty changes of kidney and liver tissues are compatible with impaired renal or liver function.

CONCLUSIONS

Fatal A(H7N9) infection was characterized by viral and secondary bacterial pneumonia with 67% having positive RT-PCR in stool.

Selection of potential probiotic lactobacilli for cholesterol-lowering properties and their effect on cholesterol metabolism in rats fed a high-lipid diet

The objectives of this study were to screen probiotic characteristics of lactobacilli isolated from traditionally homemade koumiss products in Xinjiang and Inner Mongolia of China, and to determine and compare the effect of the Lactobacillus strains in vivo on lipid metabolism in rats fed with a high-lipid diet. Three out of 68 strains of Lactobacillus isolated from the koumiss were screened for bile-salt resistance, acid tolerance, and different hypocholesterolemic properties. The cholesterol-lowering effects of the 3 screened strains were estimated in rats fed a high-lipid diet by determination of serum lipids, liver, and fecal cholesterol, fecal total bile acids, and short-chain fatty acids. After a 4-wk feeding period, in comparison with the control group, the groups LIP-1 and MG9-2 had a significant reduction in serum total cholesterol, triglyceride and low-density lipoprotein cholesterol, and significantly increased high-density lipoprotein, the group E7301 had similar effects on serum lipids, but the change was not significant. The groups LIP-1, MG9-2 and E7301 had a significant reduction in liver cholesterol content and an increase in fecal cholesterol content compared with the control group. Total bile acid excretion was significantly higher in rats fed MG9-2 than the other groups. Rats fed diets containing lactic acid bacteria strains had significantly higher propionic acid and butyric acid concentrations in the feces compared with the control. Results indicated that the 3 screened Lactobacillus strains were able to lower cholesterol in vitro, and reduce cholesterol effectively in vivo. The mechanisms behind the hypocholesterolemic effect of 3 strains are likely to be diverse and will need further investigation.

SU-E-T-386: Gamma Analysis of Normalized and Un-Normalized Dose Distributions

PURPOSE

The gamma index method, as currently implemented in all commercial QA software, calls for selection of a normalization point to evaluate agreement between two dose distributions. The implication of this is that there is an infinite number of possible solutions! Which one to pick? A unique and more relevant solution is obtained only if no normalization point is used.

METHODS AND MATERIALS

The set of test cases suggested by the AAPM TG1 19 were planned using Pinnacle 8.0m and delivered on a Varian 21EX linac for 6 and 18 MV photons. The recommended point and planar dose measurements were obtained using a Pinpoint ion chamber, EDR2 film and MatriXX. The gamma index method using typical 3%, 3 mm criteria with and without a normalization point was used to assess the agreement between calculated and delivered planar dose distributions. The analysis was extended to a set of data for clinically treated patients.

RESULTS

The comparison with the TG119 benchmark data showed that all point dose and planar measurements for 6 MV were within the published range. Similar results, although without published data to compare with, were obtained for 18 MV as well. For all complex tests, the percentage of points passing the gamma criteria of 3%, 3 mm was (95.8±1.6)% and (95.6±1.0)% for 6 MV and 18 MV, respectively. Without a normalization point, however, the same gamma analysis fell to (20.7±6.7)% and (13.9±4.0)% for 6 MV and 18 MV, respectively. The clinical data set showed the same trend, with the gamma passing rate declining from (98.9±0.7)% to (33.4±13.1)%.

CONCLUSION

The gamma index method provides a unique answer for gamma passing rate only without normalizing dose distributions to any particular point. The common gamma criteria of 3%, 3 mm, however, is a very poor metric in that case.

Association of angiotensin I converting enzyme, angiotensin II type 1 receptor and angiotensin I converting enzyme 2 gene polymorphisms with the dyslipidemia in type 2 diabetic patients of Chinese Han origin

OBJECTIVE

To investigate whether the genetic polymorphisms in the angiotensin I converting enzyme (ACE) (insertion/ deletion, or I/D), angiotensin II type 1 receptor (AT1R) (rs5186), and ACE2 (rs2285666) could be associated with dyslipidemia in Type 2 diabetic (T2D) patients of Chinese Han origin.

DESIGN AND METHODS

The above 3 polymorphisms were genotyped in a total of 282 patients with T2D and dyslipidemia (Group A), 182 patients with T2D but without dyslipidemia (Group B), and 324 healthy controls. The association between a certain polymorphism and each group was assessed by an odds ratio (OR).

RESULTS

The D allele of the ACE (I/D) was significantly associated with the risk of T2D accompanying dyslipidemia between group A and controls [OR=1.37, 95% confidence interval (CI)=1.08-1.74; p=0.010], and significant association of the D allele with dyslipidemia was also observed in diabetic patients (OR=1.88, 95% CI=1.40-2.54; p<0.001). Furthermore, the ID genotype had a decreased risk of developing T2D without dyslipidemia as compared with controls (OR=0.52, 95% CI=0.32-0.82; p=0.0060). The distributions of the AT1R (rs5186) and ACE2 (rs2285666) genotypes and alleles did not differ between T2D patients with or without dyslipidemia and the controls.

CONCLUSIONS

This study demonstrates that the ACE (I/D) polymorphism is associated with T2D, regardless of the absence or presence of dyslipidemia. The polymorphisms in the AT1R (rs5186) and ACE2 (rs2285666) seem to play lesser roles in the development of T2D.

Performance Characteristics of BGO Detectors for a Low Cost Preclinical PET Scanner

PETbox is a low-cost benchtop PET scanner dedicated to high throughput preclinical imaging that is currently under development at our institute. This paper presents the design and characterization of the detectors that are used in the PETbox system. In this work, bismuth germanate scintillator was used for the detector, taking advantage of its high stopping power, high photoelectric event fraction, lack of intrinsic background radiation and low cost. The detector block was segmented into a pixelated array consisting of 20 × 44 elements, with a crystal pitch of 2.2 mm and a crystal cross section of 2 mm × 2 mm. The effective area of the array was 44 mm × 96.8 mm. The array was coupled to two Hamamatsu H8500 position sensitive photomultiplier tubes, forming a flat-panel type detector head with a sensitive area large enough to cover the whole body of a typical laboratory mouse. Two such detector heads were constructed and their performance was characterized. For one detector head, the energy resolution ranged from 16.1% to 38.5% full width at half maximum (FWHM), with a mean of 20.1%; for the other detector head, the energy resolution ranged from 15.5% to 42.7% FWHM, with a mean of 19.6%. The intrinsic spatial resolution was measured to range from 1.55 mm to 2.39 mm FWHM along the detector short axis and from 1.48 mm to 2.33 mm FWHM along the detector long axis, with an average of 1.78 mm. Coincidence timing resolution for the detector pair was measured to be 4.1 ns FWHM. These measurement results show that the detectors are suitable for our specific application.

Apoptosome: a platform for the activation of initiator caspases

Apoptosome refers to the adaptor protein complex that mediates the activation of an initiator caspase at the onset of apoptosis. In mammalian cells, caspase-9, caspase-8, and caspase-2 rely on the apoptotic protease-activating factor 1 (Apaf-1)-apoptosome, death-inducing signaling complex (DISC), and PIDDosome, respectively, for activation. In Drosophila, activation of the caspase-9 homolog Dronc requires assembly of an apoptosome comprised of Dark/Hac-1/Dapaf-1. In Caenorhabditis elegans, activation of the caspase CED-3 is facilitated by the CED-4-apoptosome. Recent biochemical and structural investigation revealed significant insights into the assembly and function of the various apoptosomes. Nonetheless, conclusive mechanisms by which the initiator caspases are activated by the apoptosomes remain elusive. Several models have been proposed to explain the activation process. The induced proximity model summarizes the general process of initiator caspase activation. The proximity-driven dimerization model describes how initiator caspases respond to induced proximity and offers an explanation for their activation. Regardless of how initiator caspases are activated, enhanced activity must be correlated with altered active site conformation. The induced conformation model posits that the activated conformation for the active site of a given initiator caspase is attained through direct interaction with the apoptosome or through homo-oligomerization facilitated by the apoptosome.

[The study of human papilloma viruses infection in juvenile pharynlaryngeal papillomatosis by PCR and dot blot hybridization]

OBJECTIVE

To study the relationship between infection of human papillomavirus and juvenile pharynlaryngeal papilloma.

METHODS

Polymerase chain reaction (PCR) and dot blot hybridization were used to detect HPV6,11,16,18,33 DNA of 35 samples of pharynlaryngeal papilloma and 10 samples of vocal nodule.

RESULTS

The positive rate of HPV in pharynlaryngeal papilloma was 91.4% (30/35). Among them the positive rates of HPV6 and HPV11 were 54.2%(19/35) and 25.7%(9/35), the positive rate of multiple types of HPV6 + 11 was 11.4%(4/35). The positive rate of HPV16,18,33 was negative. The positive rate of HPV in vocal nodule was negative and were significantly different from that of the pharynlaryngeal papilloma group.

CONCLUSION

The results suggest that infection with HPV, especially with HPV6, is closely associated with the development of juvenile pharynlaryngeal papilloma in Wenzhou area. HPV-DNA detected by PCR and dot blot hybridization has highly specificity and sensitivity.

Extracellularly truncated desmoglein 1 compromises desmosomes in MDCK cells

The formation and stability of epithelial tissue involves cell adhesion and the connection of the intermediate filaments of contiguous cells, mediated by desmosomes. The cadherin family members Desmocollins (Dsc) and Desmogleins (Dsg) mediate desmosome extracellular adhesion. The main intracellular molecules identified linking Dscs and Dsgs with the intermediate filament network are Plakoglobin (PG), Plakophilins (PPs) and Desmoplakin (DP). Previous studies on desmosome-mediated adhesion have focused on the intracellular domains of Dsc and Dsg because of their capacity to interact with PG, PPs and DP. This study examines the role of the extracellular domain of Dsg1 upon desmosome stability in MDCK cells. Dsg1 was constructed containing an extracellular deletion (Dsg delta 1EC) and was expressed in MDCK cells. A high expressor Dsg delta 1EC/MDCK clone was obtained and analysed for its capacity to form desmosomes in cell monolayers and when growing under mechanical stress in three-dimensional collagen cultures. Phenotypic changes associated with the ectopic expression of Dsg1 delta EC in MDCK cells were: disturbance of the cytokeratin network, a change in the quality and number of desmosomes and impairment of the formation of cysts in suspension cultures. Interestingly, Dsg1 delta EC was not localized in desmosomes, but was still able to maintain its intracytoplasmic interaction with PG, suggesting that the disruptive effects were largely due to PG and/or PP sequestration.

[Exploration of gene expression profiles of CD(34)(+) hematopoietic stem/progenitor cells based on large scale sequencing]

OBJECTIVE

To set up a large scale sequencing system and explore the gene expression profiles of CD(34)(+) hematopoietic stem/progenitor cells (HSPCs).

METHODS

CD(34)(+) cells were isolated from umbilical cord blood and subjected to cDNA library construction. A primary profile of gene expression in HSPCs was emerged by EST sequencing and bioinformatics analyzing.

RESULTS

Among 9,866 ESTs thus obtained, 7 476 meaningful ESTs were clustered into 2,060 unique sequence species (USSs), representing 1,054 known gene species and 1,006 unknown gene fragments. The 1054 known genes were divided into 8 categories: (1) hematopoiesis associated: 73, (2) chromatin structure and cell division/apoptosis: 91, (3) signal transduction and receptors: 111, (4) cell structure/mobility: 48, (5) cell/organism defense/homeostasis: 41; (6) Gene expression (transcription, translation and modification): 265, (7) metabolism: 192; and (8) unclassified: 233.

CONCLUSION

A gene expression profile including 1,054 known genes and 1006 new gene fragments of HSPCs was primarily obtained, which may lay a basis for the further study on the molecular mechanism of hematopoiesis regulation and provide candidates for new gene cloning.

[Ureaplasma urealyticum infection and premature delivery or premature rupture of the membrane]

OBJECTIVE

To evaluate the relationships between ureaplasma urealyticum (UU) infection and premature delivery or premature rupture of the membrane (PROM).

METHODS

The cervical swabs, fetal membrane and umbilical cord from 46 cases of PROM, 7 cases of premature delivery (study group), and 32 normal pregnancies (control group) were cultured for UU. Some of these placenta tissues were examined under electron microscopy, and compared with the purified UU.

RESULTS

The detective rates of UU were both 73.6% (39/53) in the cervix and fetal membrane of the study group, and to compare with the control group (40.6%, 13/32 and 15.6%, 5/32 respectively), significant differences were shown (P < 0.01, P < 0.001). The prevalence rate of perinatal mortality, stillbirth and low birth weight in UU-positive cases (34.1%, 15/44) was significantly higher than that in UU-negative cases (7.3%, 3/41, P < 0.01). Electron microscopy demonstrated that large amount of small multiplicated UU particles deposited around the nuclear membrane of the cytotrophoblasts and in the collagen fibers from the placenta of PROM, and its shape was in consistent with that of the purified UU. In contrast, no UU particles was seen in the normal control group.

CONCLUSION

The results show that UU is responsible for some cases of premature delivery, low birth weight and PROM. The multiplication of UU within the trophoblasts may disrupt cell structure which could interfere the normal fetal development.

Galectin-3 and polarized growth within collagen gels of wild-type and ricin-resistant MDCK renal epithelial cells

Previous studies (Q. Bao and R. C. Hughes (1995) J. Cell Sci., 108, 2791-2800) showed that the beta-galactoside-binding protein, galectin-3, is secreted onto the basolateral surface domains of Madin-Darby canine kidney MDCK cells growing as polarized cysts within a collagen gel. The growth and enlargement of such cysts were shown to be increased significantly when cultured in the presence of antibodies directed against the lectin and were slowed down by addition of exogenous galectin-3. These results suggested a role for galectin-3, interacting with appropriately glycosylated surface receptors, as a negative growth regulator in the development of MDCK cysts, a well-known model for renal epithelial morphogenesis. In the present report we have tested this proposal by use of a ricin-resistant mutant of MDCK cells that is unable to transfer galactose residues during biosynthesis of cellular glycoconjugates and hence lacks extracellular receptors for galectin-3. We find that when grown within collagen gels, the mutant cell cysts grow significantly faster than wild-type cell cysts. Furthermore, they form nonspherical and tubular cysts that are induced in wild-type cell cysts only under the influence of the morphogen, hepatocyte growth factor (HGF).

Galectin-3 modulates rat mesangial cell proliferation and matrix synthesis during experimental glomerulonephritis induced by anti-Thy1.1 antibodies

Galectin-3 is a beta-galactoside-binding protein synthesized by macrophages and other inflammatory cells and expressed in various branching epithelia, including the developing kidney. The expression of galectin-3 has been studied in a rat model of acute mesangial proliferative glomerulonephritis in which a single injection of anti-Thy1.1 antibodies leads to destruction of mesangial cells expressing a Thy1.1 epitope on their surface. The glomerular lesion is characterized by expansion of the mesangial matrix, especially laminin and collagen type IV, and mesangial hypercellularity. Galectin-3 expression, which is sparse in mature rat kidney and confined to the apical face of some distal tubules, is increased within 1-3 days following antibody administration, with the recruitment of glomerular macrophages and pronounced neo-expression in the cytoplasm and at the basal face of distal tubules. At later times, galectin-3 is detected immunohistochemically in the repopulating mesangial cell mass, preceding the extensive mesangial deposition of laminin and collagen type IV. Mesangial cells in culture do not produce appreciable amounts of galectin-3 but do bind and endocytose exogenously added lectin. Addition of galectin-3 to primary cultures of mesangial cells prepared from normal rats induces a 1.5-fold increase in the synthesis of collagen type IV and it also acts in synergy with a quantitatively similar stimulatory effect of transforming growth factor beta (TGF-beta) on matrix synthesis. Exogenous galectin-3 prolongs the survival of mesangial cells in serum-free cultures and also protects these cells against cytotoxic effects of TGF-beta. The data support the notion that the increased expression and secretion of galectin-3 in infiltrating macrophages and in distal tubular epithelia, together with up-regulation of IL-1beta and TGF-beta genes, play a role in mesangial hypercellularity in the progression of one model of inflammatory renal disease.

Epithelial galectin-3 during human nephrogenesis and childhood cystic diseases

Galectin-3 is a beta-galactoside-binding protein with putative roles in development, oncogenesis, and inflammation. Its expression in human nephrogenesis has not been previously reported. This study examines galectin-3 expression in early human embryos by Western blot and immunohistochemistry. This 33-kD protein was detected in the apical domain of distal tubules of the mesonephros and also in the mesonephric duct. In the metanephros, the adult kidney precursor, galectin-3 was detected in the apical domains of ureteric bud branches, and there was intense expression in fetal medullary and papillary collecting ducts in both the cytoplasm and plasma membranes. Low levels of galectin-3 were detected in the cytoplasm of a subset of cells in adult collecting ducts; these were alpha-intercalated cells because they expressed basal band 3 protein. In human multicystic dysplastic kidneys, all diseased epithelia had an embryonic apical expression pattern of galectin-3 and, in addition, all cystic epithelia in autosomal recessive polycystic kidneys expressed this molecule. It is concluded that galectin-3 is expressed by cells of the mesonephric duct/ureteric bud lineage, and it is speculated that the different subcellular locations may be implicated in both the regulation of normal growth and differentiation of this lineage, as well as in the pathogenesis of cystic epithelia.

[Long-term investigation of closed reduction of congenital hip dislocation in children with modified frog-leg cast]

From 1978 to 1983, closed reduction and fixation with frog-leg cast were used to treat congenital hip dislocation in children in our hospital. Sixty-two patients with such hip dislocation were treated by these methods. Among them 38 patients under 3 years of age were followed up for 12 to 16 years (mean 13 years). Encouraging results were obtained and the reduction rate was 97.9%. This treatment revealed that after closed reduction the fixation and the slight movement of the femoral head in the cast under the fixation are a self-remould action that may promote the growth of the acetabulum and the femoral head resulting in normal development of the hip.

Galectin-3 expression and effects on cyst enlargement and tubulogenesis in kidney epithelial MDCK cells cultured in three-dimensional matrices in vitro

Galectin-3 is a member of a closely related family of beta-galactoside-binding soluble proteins found in many vertebrate epithelial and myeloid cell types. The developmentally regulated presence of galectin-3 in tissues, for example kidney, and an affinity for many cell-surface and matrix glycoproteins indicate its importance in extracellular biological processes. Since a polarised expression and secretion of galectin-3 was observed in monolayer-cultured MDCK cells, an understanding of the secretion and distribution of this lectin in a three-dimensional in vitro model would help to uncover its role(s) in the interplay between cell-surface adhesion molecules and extracellular matrix components occurring during cell aggregation and polarisation in tissue formation. In this study, the cellular distribution and secretion of galectin-3 were examined in MDCK cells cultured within a gel matrix. MDCK cells were cultured within type I collagen or Matrigel to obtain multicellular cysts, and tubule formation was induced in collagen gels with hepatocyte growth factor. Immunofluorescent staining of these structures using antibodies against galectin-3 and other cell-surface domain markers was carried out either in situ or on cryosections and was visualised by confocal and conventional epifluorescence microscopy. Our results show that MDCK cells suspended in hydrated collagen gels or Matrigel exhibit differential and polarised galectin-3 expression on the baso-lateral surface domains of cells lining the cysts. The lectin is colocalised with laminin on the basal surface. In tubule-forming cysts, galectin-3 is excluded from the initial spikes and the progressing tips of the tubules although its basolateral expression on the cyst body remains. Galectin-3 added exogenously to cultures, as well as antibodies against laminin subunits and integrin beta 1 subunit, exerted an inhibitory effect on cyst enlargement of MDCK cells in 3-D Matrigel while galectin-3-specific antibodies could promote this process. The results suggest that galectin-3 exerts its effect on MDCK cells in a three-dimensional environment through modulation of both cell-cell and cell-substratum adhesions, and the interplay between these adhesions is important in the growth of multicellular aggregates and extensions occurring during normal kidney tubulogenesis.