Effect of IFN-α on KC and LIX expression: role of STAT1 and its effect on neutrophil recruitment to the spleen after lipopolysaccharide stimulation

The spleen is a crucial lymphoid organ. It is involved in the recruitment of various immunocytes to their correct locations using specific chemokines, but little is known concerning the role of type-I interferon (IFN) in the regulation of chemokines. In this study, we first used protein microarrays to assess the expression of keratinocyte-derived chemokine (KC) and lipopolysaccharide-induced CXC chemokine (LIX) in murine spleens. Both expressions were smoothly enhanced by IFN-α pretreatment after LPS injection. Then, we focused on the IFN-α regulation of KC, LIX, and their target cells, neutrophils, using an IFN-α neutralizing antibody and fludarabine (specific signal transducers and activators of transcription 1 - STAT1 inhibitor). Next, LPS was found to attenuate the production of KC and LIX in spleen. Even the elevated production of chemokines caused by exogenous IFN-α was found to be attenuated by fludarabine pretreatment. We later determined that the marginal zone and red pulp are the main sites of KC and LIX production. Last, we determined that the number of neutrophils was slightly increased by IFN-α treatment and diminished by IFN-α neutralization or fludarabine treatment. Further, the elevated neutrophils due to exogenous IFN-α were partially reversed by fludarabine pretreatment. In this way, these results indicate that IFN-α facilitates KC and LIX expression in mouse spleens after an LPS challenge. This effect was found to be mainly dependent upon the activation of STAT1, it may be involved in the recruitment of neutrophils to the spleen for the clearance of pathogens.

Partial splenic embolization has beneficial effects for the management of gastroesophageal variceal hemorrhage

BACKGROUND/AIMS

Partial splenic embolization (PSE) is used in the management of gastroesophageal variceal hemorrhage (GEVH). However, it is uncertain whether it has beneficial effects for GEVH patients in preventing variceal recurrence and variceal hemorrhage, as well as promoting overall survival (OS), when it is combined with conventional therapies.

MATERIALS AND METHODS

The databases including PubMed, EMBASE, Web of Science, Google scholar, and Cochrane Central Register of Controlled Trials were searched up to 11th of November, 2015. Meta-analyses were performed by using Review Manager 5.3 software for analyzing the risk of bias, Newcastle-Ottawa Scale for assessing the bias of cohort studies, and GRADEprofiler software for assessing outcomes obtained from the meta-analyses.

RESULTS

A total of 1505 articles were reviewed, and 1 randomized controlled trial and 5 cohort studies with 244 participants were eligible for inclusion. The pooled hazard ratio (HR) of variceal recurrence is 0.50 (95% confidence interval (CI) 0.37, 0.68; P< 0.00001; I2 = 0%). The pooled HR of variceal hemorrhage is 0.24 (95% CI 0.15, 0.39; P< 0.00001; I2 = 0%). The pooled HR of OS is 0.50 (95% CI 0.33, 0.67; P< 0.00001; I2 = 0%). Meta-analyses demonstrated statistically significant superiority of combinational therapies over conventional therapies in preventing variceal recurrence and variceal hemorrhage and prolonging OS. The complications related to PSE were mild or moderate and nonfatal.

CONCLUSIONS

The results indicate that PSE has beneficial effects for GEVH patients, however, future investigation with a larger number of subjects in clinical trials is warranted.

Enhanced autophagy by everolimus contributes to the antirestenotic mechanisms in vascular smooth muscle cells

OBJECTIVE

The present study aims to investigate the underlying mechanisms accounting for the activities of everolimus to inhibit the growth of vascular smooth muscle cells (VSMCs), which contributes to restenosis.

METHODS

Primary VSMCs were cultured in media containing smooth muscle growth supplements and incubated with testing agents. Cell proliferation, cell cycle distribution, apoptosis and autophagy, and the key molecules involved, were examined.

RESULTS

Everolimus inhibited the proliferation of VSMCs by inhibiting the activation of ribosomal protein S6 kinase and phosphorylation of eukaryotic translation initiation factor 4E-binding protein 1, and downregulating proliferating cellular nuclear antigen. Everolimus induced cell cycle arrest at the G1 phase by downregulating cyclin D1 and upregulating p27, and increased apoptosis by downregulating Bcl-2, upregulating Bad and activating capsase-3 and poly ADP ribose polymerase. Everolimus enhanced autophagy by increasing the conversion of microtubule-associated protein 1 light chain 3 (LC3)-I to LC3-II, and upregulating Beclin 1. Specific autophagy inhibitors, 3-methyladenine and bafilomycin A1, significantly attenuated the inhibition of cell proliferation, the increased apoptosis and the altered expression of the above key proteins induced by everolimus.

CONCLUSIONS

Enhanced autophagy by everolimus contributes to its antirestenotic activity and its abilities to inhibit cell proliferation and to induce apoptosis of VSMCs.

Gene transfer of interleukin-4 delays acute rejection of splenic allografts in rats

Spleen transplantation is the treatment of choice for some diseases, such as hemophilia A. However, the risk and intensity of rejection after spleen transplantation is greater and more difficult to control than other types of transplant. In the present study, we demonstrated that perfusion of IL-4 expression plasmids into donor spleens pretransplantation led to overexpression of IL-4 and downregulation of IFN-gamma in situ, associated with delayed acute rejection of the allograft. Gene transfer of IL-4 may represent a potential therapeutic approach to induce tolerance to splenic allografts.

Expression of immunoreactive inducible nitric oxide synthase in pancreatic islet cells from newly diagnosed and long-term type 1 diabetic donors is heterogeneous and not disease-associated

Exposure of isolated human islets to proinflammatory cytokines leads to up-regulation of inducible nitric oxide synthase (iNOS), raised NO, and beta cell toxicity. These findings have led to increasing interest in the clinical utility of iNOS blockade to mitigate beta cell destruction in human type 1 diabetes (T1D). However, recent studies show that iNOS-derived NO may also confer beta cell protection. To investigate this dichotomy, we compared islet cell distributions and intensity of iNOS immunostaining in pancreatic sections, co-stained for insulin and glucagon, from new-onset T1D donors (group 1), with non-diabetic autoantibody-negative (group 2), non-diabetic autoantibody-positive (group 3) and long-term diabetic donors (group 4). The cellular origins of iNOS, its frequency and graded intensities in islets and number in peri-islet, intra-islet and exocrine regions were determined. All donors showed iNOS positivity, irrespective of disease and presence of beta cells, had variable labelling intensities, without significant differences in the frequency of iNOS-positive islets among study groups. iNOS was co-localised in selective beta, alpha and other endocrine cells, and in beta cell-negative islets of diabetic donors. The number of peri- and intra-islet iNOS cells was low, being significantly higher in the peri-islet area. Exocrine iNOS cells also remained low, but were much lower in group 1. We demonstrate that iNOS expression in islet cells is variable, heterogeneous and independent of co-existing beta cells. Its distribution and staining intensities in islets and extra-islet areas do not correlate with T1D or its duration. Interventions to inactivate the enzyme to alleviate disease are currently not justified.

PEA‑15 contributes to the clinicopathology and AKT‑regulated cisplatin resistance in gastric cancer

Phosphoprotein enriched in astrocytes 15 (PEA‑15) plays an important role in controlling biological behaviors of cancer cells. In the present study, we demonstrated that PEA‑15 was overexpressed in gastric cancer tissues and associated with tumor staging, differentiation, pathological types and the prognosis of patients. Gastric cancer cells expressed variable levels of PEA‑15 and its bi‑phosphorylation forms, p‑PEA‑15 (Ser104) and p‑PEA‑15 (Ser116). To gain insight into the functional role of PEA‑15, we generated cells stably depleted of PEA‑15 and resistant to cisplatin (CDDP) from human gastric cancer cells. PEA‑15 depletion inhibited cell proliferation by reducing cyclin D1 expression through the extracellular signal‑regulated kinase (ERK) pathway, resulting in cell cycle arrest at the G1 phase, and induced apoptosis by activating caspase‑8. PEA‑15 depletion also enhanced the inhibitory effect of CDDP that caused cell cycle arrest at the S phase and also enhanced the pro‑apoptotic activity of CDDP in vitro and in animal models of tumorigenesis and therapeutic effects. PEA‑15 and its phosphorylated forms were overexpressed in CDDP‑resistant cells, which had higher levels of p‑AKT. Specific inhibition of AKT by MK2206 reduced the expression of p‑PEA‑15 at the Ser116 residue, resulting in sequential downregulation of p‑ERK1/2, cyclin D1 and caspase‑8 activation. However, depletion of PEA‑15 had little effect on AKT expression or phosphorylation, or its downstream factors including p27, glycogen synthase kinase 3β and caspase‑9, indicating that the regulatory effects between PEA‑15 and AKT were unidirectional. In summary, the results indicated that PEA‑15 expression was associated with clinicopathology and prognosis in gastric cancer and was regulated by AKT to participate in CDDP resistance, indicating that it may be a potential target for overcoming CDDP resistance in the treatment of gastric cancer.

Castleman disease presenting with jaundice: A case report and review of literature

BACKGROUND

Castleman disease (CD) is a rare lymphoproliferative disorder that presents with various symptoms. CD accompanied with jaundice is uncommon since there are only 11 cases reported in the literature.

CASE SUMMARY

Here we report a 62-year-old woman who was admitted to the hospital with signs and symptoms of intermittent jaundice. Biochemical tests showed higher serum levels of total and direct bilirubin, and normal serum levels of tumor markers and interleukin-6. Contrast-enhanced computed tomography detected a 6 cm × 4 cm × 2.5 cm mass between the hepatoduodenal ligament and the inferior vena cava. The mass was successfully excised and the patient had a complete resolution of symptoms. A diagnosis of idiopathic unicentric CD was made based upon histological examination, which demonstrated the pathological features of CD of mixed type, including hyperplasia of follicular lymphoids with abundant plasma cells, degenerative germinal centers, interfollicular vascularity and hyaline degeneration. The diagnosis was corroborated by immunohistochemical analysis which detected multiple biomarkers.

CONCLUSION

This is the first study that describes the clinicopathological features of CD presenting with jaundice, which may deepen and extend our understanding of this disease.

Solanum nigrum Linn.: Advances in anti-cancer activity and mechanism in digestive system tumors

Cancer has currently become a serious public health issue in many countries worldwide, and tumors of the digestive system have attracted an increasing number of researchers' due to their numerous types, high proportion and wide area of occurrence. While tumors of the digestive system suffer from high mortality rates, leading to untimely diagnosis and a poor prognosis, making it necessary to update current treatment approaches such as surgery, radiation therapy, and chemotherapy. This highlights the importance of exploring novel therapeutic ideas and targets. Traditional Chinese medicine has a long history of clinical use due to its low toxicity and multi-factor targeting of multiple pathways. As a kind of traditional Chinese herb, S. nigrum Linn. is highly regarded for its proven antitumor activity. The aim of this study was to comprehensively recapitulate and analyze the anti-cancer effects and molecular mechanisms of treatment of gastrointestinal tumors with S. nigrum Linn. extracts and related compounds, including classical signaling pathways mediated by them as well as noncoding RNA pathways associated with tumor suppression. Components that have been found to be responsible for the anti-cancer activity of S. nigrum Linn. include solanine, solasonine, solamargine, a-L-rhhamnopyranose, uttroside B, degalactotigonin, glycoprotein, and other compounds. The underlying mechanisms of anti-cancer activity reflected in this study include apoptosis, cell cycle arrest, autophagy, anti-angiogenesis, suppression of metastasis and invasion, immune escape, and increased sensitivity to radiotherapy. S. nigrum Linn. has great potential in the treatment of tumors of the digestive system, and through further clinical trials and pharmacological mechanisms it has the potential to become a uniform and standardized anti-tumor drug.

Beta7 integrins contribute to skin graft rejection

BACKGROUND

Because integrins alpha4beta7 and alphaEbeta7 contribute to epidermotropism of T-cells during skin inflammation, we sought to study their role in skin allograft rejection.

METHODS

Wild-type (WT) (beta7+/+) and beta7 gene knockout (beta7-/-) C57BL/6 (H-2(b)) mice and SJL/J (H-2(s)) mice served as donors and recipients of allogeneic skin grafts. An anti-integrin beta7 subunit mAb (FIB504.64) was used to treat WT beta7+/+ C57BL/6 recipients of skin grafts from SJL/J mice.

RESULTS

WT C57BL/6 recipients acutely rejected skin from SJL/J mice in 13 days. In contrast, the survival of SJL/J skin on either beta7-/- gene knockout or WT C57BL/6 recipients treated with anti-beta7 subunit mAb, was prolonged by 6 to 7 additional days (P<0.01). The survival of skin allografts from either beta7-/- or beta7+/+ C57BL/6 mice received by SJL/J recipients was not prolonged (P >0.05).

CONCLUSIONS

Beta7 integrins contribute to skin graft rejection, in accord with their role in mediating the epidermotropism of T-cells during skin inflammation.

Gene transfer of antisense B7.1 attenuates acute rejection against splenic allografts in rats

Blockade of CD80-CD28 costimulatory pathway induces unresponsiveness of T cells to alloantigens and protects allografts against immune rejection in numerous animal models. The aim of this study was to investigate whether blocking expression of B7.1 (CD80) on donor splenocytes by an antisense technique protected splenic allografts against immune rejection. Splenic grafts from Wistar-Furth rats were intra-arterially transfused with an antisense B7.1 expression vector, before they were transplanted into Sprague-Dawley rats. The rats were sacrificed at scheduled times, and the splenic allografts histologically examined. Antisense gene transfer resulted in marked down-regulation of B7.1 in donor spleens, hyporesponsiveness of recipient T cells, and attenuated acute immune rejection against splenic allografts. No obvious damage to skin, liver, or gut due to graft-versus-host disease was detected in the recipients. In conclusion, blocking expression of B7.1 in donor spleens by antisense gene therapy represented a potential alloantigen-specific immunosuppressive strategy to inhibit acute rejection against splenic allografts.

Analysis of risk factors of stage IV gastric cancer from the SEER database

INTRODUCTION

Gastric cancer is the fourth most common cancer in the world. By the time the patients are diagnosed with stage IV gastric cancer, many patients already have distant metastases. There is no unified systemic treatment plan in existence. The use of gastrectomy is ambiguous in patients with stage IV gastric cancer. The objective of this study was to evaluate the beneficial outcome of gastrectomy in patients with stage IV gastric cancer.

METHODS

Clinical information of patients with gastric cancer from 2000 to 2010 in the Surveillance, Epidemiology, and End Results database were extracted and analysed. The risk factors for stage IV gastric cancer were also analysed.

RESULTS

We observed that the median survival time for patients after surgery was greater than that for patients not treated surgically. The five-year survival rate for chemotherapy patients was higher than that of non-chemotherapeutic patients. Patients who receive both chemotherapy and surgery could achieve a more significant survival benefit. The risks following gastrectomy (partial, subtotal, hemi-) were lower than those of other surgical procedures, which provided guidance on the choice of surgical method. The numbers of regional lymph node metastasis were found to be related to prognosis.

CONCLUSIONS

In patients with stage IV gastric cancer, gastrectomy (partial, subtotal or hemi) should be selected when surgery is necessary. The number of regional lymph node metastasis could be considered as a prognostic factor for patients with stage IV gastric cancer and lymph node dissection could reduce the risk of patients undergoing surgery.

Distribution of insulin mRNA transcripts within the human body

Here we sought evidence for the existence of insulin mRNA-producing cells outside the human pancreas. Commercially available complementary DNA (cDNA) arrays prepared from 72 different types of adult human tissues were screened by PCR for transcripts encoding insulin, and other classic pancreatic hormones. Insulin mRNA transcripts were detected by standard PCR in the pancreas, stomach, pylorus region of the stomach, and the duodenum; and additionally by nested PCR in the jejunum, ileum and cecum, but not in other body tissues including the brain and colon. Most of these tissues also variably expressed mRNA transcripts for amylase α2B, amylin, glucagon, somatostatin, and pancreatic polypeptide. In summary, using sensitive PCR methods we have provided evidence for the presence of rare insulin mRNA-expressing cells within the stomach, small intestine, and cecum. Their role at these sites may be to support classical enteroendocrine cells as sentinels to sense and monitor gastric contents passing into and through the bowel.

Gene transfer of antisense B7.1 attenuates acute rejection against liver allografts in rats

OBJECTIVE

Blockade of CD80-CD28 costimulatory pathway induces unresponsiveness of T cells to alloantigens and protects allografts against immune rejection. The aim of this study was to investigate whether downregulating the expression of B7.1 (CD80) in the donor livers by antisense B7.1 gene transfer could attenuate the acute immune rejection against liver allografts in rats.

METHODS

The liver grafts from 60 Dark Agouti rats were intraportally perfused with antisense B7.1 expression vector, before they were transplanted into Lewis rats. Empty vector pcDNA3 served as control to be perfused into livers of another group of 60 Dark Agouti rats. The orthotopic liver transplantation was performed. The rats were randomly sacrificed at scheduled time points to collect liver allografts, or monitored to record the survival rate. The livers were histologically examined to calculate Banff rejection activity index, or subjected to Western blot analysis or immunohistochemistry for examining the expression of B7.1, or counting CD4+ and CD8+ cells.

RESULTS

Antisense gene transfer resulted in markedly downregulation of B7.1 in the donor livers, attenuated acute immune rejection against liver allografts, prolonged the survival time of rats, and decreased the number of infiltrating CD4+ and CD8+ cells in livers.

CONCLUSIONS

Blocking expression of B7.1 in liver by antisense gene therapy may represent a potential strategy to attenuate acute rejection against liver allografts.

Modified method of hepatic portal choledochoplasty to treat benign strictures of hilar biliary ducts

BACKGROUND AND AIM

Roux-en-Y hepaticojejunostomy (RYHJ) is usually used to treat benign strictures of hilar bile ducts. However, RYHJ might also induce ascending cholangitis and recurrent hepatolithiasis. The present study aims to introduce a modified hepatic portal choledochoplasty with a pedicled graft of gallbladder (HPC) to treat this disease.

METHODS

One hundred and forty-nine patients, who had undergone HPC or RYHJ from January 1997 to January 2006 in our institutions, were included in this study, and the clinical data were retrospectively collected and analyzed.

RESULTS

The incidences of perioperative bile leakage and inflammatory ileus in patients treated with HPC were slightly lower than RYHJ without significant difference (1.89% vs 2.08% and 3.77% vs 5.21%, both P > 0.05). However, in a long-term follow up, patients treated with HPC had significantly lower incidences of cholangitis and recurrent hepatolithiasis (5.66% and 3.77%, respectively) than those treated with RYHJ (cholangitis, 21.88%; hepatolithiasis, 16.67%; both P < 0.05).

CONCLUSION

Compared to RYHJ, HPC is a safer and more efficient method to treat benign strictures of hilar biliary ducts. It preserves the sphincter of Oddi and normal biliary duct pressure, thus avoiding bile reflux into the bile duct.

Antiangiogenesis and damaging blood flow by antisense vascular endothelial growth factor oligodeoxynucleotides to suppress lung cancers

Angiogenesis plays a key role in the growth and metastasis of lung cancers, and vascular endothelial growth factor (VEGF) is one of the major angiogenic factors. The study aims to investigate whether phosphoro thioate-modified antisense VEGF oligodeoxynucleo tides (ASODN) formulated in cationic liposome could inhibit the growth of Lewis lung carcinoma (LLC) tumors by antiangiogenesis. The study demonstrated that ASODN downregulated the expression of VEGF in LLC cells at levels of protein and mRNA in vitro and in vivo. The conditioned media obtained from LLC cells treated with ASODN significantly inhibited the proliferation of bovine aortic endothelial cells. The ASODN therapy significantly suppressed the growth of established subcutaneous LLC tumors in mice by inhibiting angiogenesis and damaging the blood flow of tumors. In conclusion, our results suggest that ASODN targeting VEGF presents a potent therapeutic strategy to combat lung cancers.

A novel in situ model of liver cold ischemia-reperfusion in rats

BACKGROUND

Orthotopic liver transplantation (OLT) is being used for studying cold ischemia reperfusion (I/R)-induced injury in experimental animals, but the technique is complicated and it does not accurately reflect the pathophysiology. Here, we report a novel model, termed "in situ liver cold ischemia (ISLCI)", in Wistar rats.

METHODS

ISLCI was achieved in rats by establishing a portal-jugular shunt and a cannula shunt in inferior vena cava, and the liver was continuously perfused with lactate Ringer's solution at a speed of 150 mL/h through the portal vein for 60 min. Portal venous pressure, serum levels of total bilirubin, alkaline phosphatase, alanine aminotransferase and γ-glutamyl transpeptidase (GGT), and hepatic histopathology were examined, and compared with rats undergoing OLT, in which the donor liver was subjected to a 60 min cold ischemia.

RESULTS

Livers from ISLCI and OLT rats showed histopathologic changes characteristic of I/R-induced injury when examined on days 1 and 7, with complete recovery 14 d after reperfusion. Compared with OLT rats, ISLCI rats had significantly lower levels of portal venous pressure 1 and 10 min after porta hepatis clamping. They suffered a milder degree of I/R-induced hepatic injury, reflected by significantly lower levels of GGT, alanine aminotransferase, and alkaline phosphatase on day 1, and a significant lower level of GGT and a lower histopathologic score on day 7 after reperfusion.

CONCLUSIONS

Our preliminary results indicate that the ISLCI model is reliable and technically easier, and is superior to OLT for studying cold I/R injury.

Opposite effects of donor apoptotic versus necrotic splenocytes on splenic allograft tolerance

BACKGROUND

Apoptotic cells have immunosuppressive activity, whereas necrotic cells activate immune response, indicating they might have different effects on immune rejection against splenic allografts. The aim of this study was to determine whether administration of apoptotic or necrotic splenocytes of donor origin could impact the acute rejection of splenic allografts.

MATERIALS AND METHODS

Apoptotic or necrotic splenocytes derived from donor rats were induced by irradiation or freeze thaw, respectively. Heterotopic vascularized spleen transplantation was performed from Wistar-Furth (donor) to Sprague-Dawley (recipient) rats, and splenocytes were intravenously injected into the recipients. At different time points, the recipients were sacrificed and the splenic allografts underwent histological examination. The interferon-gamma (IFN-gamma) and transforming growth factor-beta1 (TGF-beta1) in sera, spleens of recipients, and donor splenocytes before administration were measured. Mixed leukocyte reaction (MLR) was detected with recipient splenocytes as effectors and donor splenocytes as stimulators.

RESULTS

Exposure to gamma-irradiation at dose of 10,000 rad caused over 80% splenocytes to become apoptotic. The levels of TGF-beta1 released by apoptotic splenocytes in vitro were significantly higher than that by untreated splenocytes, whereas there was almost no TGF-beta1 detected in necrotic splenocytes culture medium. Administration of apoptotic splenocytes significantly attenuated acute rejection of splenic allografts, evidenced by less severe splenic histological alteration and reduction of histological scores compared with control; whereas necrotic splenocytes exacerbated the acute rejection. Apoptotic splenocytes inhibited production of IFN-gamma but increased the levels of TGF-beta1, whereas necrotic splenocytes showed opposite activity in production of those cytokines. Administration of apoptotic splenocytes inhibited MLR, and necrotic splenocytes promoted MLR.

CONCLUSIONS

The apoptotic and necrotic splenocytes exhibited opposite effects on acute rejection against splenic allografts, and IFN-gamma and TGF-beta1 have been involved in the effects.

Identification of a robust functional subpathway signature for pancreatic ductal adenocarcinoma by comprehensive and integrated analyses

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy and its mortality continues to rise globally. Because of its high heterogeneity and complex molecular landscapes, published gene signatures have demonstrated low specificity and robustness. Functional signatures containing a group of genes involved in similar biological functions may display a more robust performance.

METHODS

The present study was designed to excavate potential functional signatures for PDAC by analyzing maximal number of datasets extracted from available databases with a recently developed method of FAIME (Functional Analysis of Individual Microarray Expression) in a comprehensive and integrated way.

RESULTS

Eleven PDAC datasets were extracted from GEO, ICGC and TCGA databases. By systemically analyzing these datasets, we identified a robust functional signature of subpathway (path:00982_1), which belongs to the drug metabolism-cytochrome P450 pathway. The signature has displayed a more powerful and robust capacity in predicting prognosis, drug response and chemotherapeutic efficacy for PDAC, particularly for the classical subtype, in comparison with published gene signatures and clinically used TNM staging system. This signature was verified by meta-analyses and validated in available cell line and clinical datasets with chemotherapeutic efficacy.

CONCLUSION

The present study has identified a novel functional PDAC signature, which has the potential to improve the current systems for predicting the prognosis and monitoring drug response, and to serve a linkage to therapeutic options for combating PDAC. However, the involvement of path:00982_1 subpathway in the metabolism of anti-PDAC chemotherapeutic drugs, particularly its biological interpretation, requires a further investigation. Video Abstract.

[Expression of heme oxygenase-1 and GFP gene mediated by recombinant adeno-associated-virus in transplanted liver in rats]

OBJECTIVE

To construct and purify heme oxygenase-1, GFP gene mediated by recombinant adeno-associated-virus and identify expression rate of GFP in transplanted liver in rats.

METHODS

Heme oxygenase-1 gene of rat was cloned and subcloned to rAAV vector, the gene sequence was confirmed correct by restriction enzyme and DNA sequencing. The rAAV-HO-1 was then cotransfected into 293 cell line with accessory plasmid virus helper and AAV-cap-rep through CaCl2 coprecipitation. Virus particles were purified by heparin column chromatography and titre were detected by Real-time PCR. An orthotopic liver transplantation model by Wistar to Wistar was set up using Kamada's two cuff technique. Purified rAAV-GFP was injected into portal vein and incubated for 2 hours at the donor liver cold preserved stage, and then performed OLT. Recipients were killed and visceral organs were sampled at 1 and 3 months after operation respectively, frozen section (3-5 microm) were prepared and gene expression rate in different tissues was examined under fluorescence microscope.

RESULTS

The inserted segment of HO-1 was identified through restriction enzyme cutting followed with electrophoresis, the result of DNA sequencing was in accordance with which found in Genbank. The GFP expression rate was over 80% in allograft at 1 and 3 month after transfection whereas there was no GFP expression in heart, lung, spleen, kidney and small bowel.

CONCLUSIONS

High titre rAAV carried HO-1 and GFP were constructed successfully. Steady and effective expression of GFP mediated by rAAV was demonstrated in liver allograft in rats.