Therapeutic utility of human umbilical cord-derived mesenchymal stem cells-based approaches in pulmonary diseases: Recent advancements and prospects.

Pulmonary diseases across all ages threaten millions of people and have emerged as one of the major public health issues worldwide. For diverse disease conditions, the currently available approaches are focused on alleviating clinical symptoms and delaying disease progression but have not shown significant therapeutic effects in patients with lung diseases. Human umbilical cord-derived mesenchymal stem cells (UC-MSCs) isolated from the human UC have the capacity for self-renewal and multilineage differentiation. Moreover, in recent years, these cells have been demonstrated to have unique advantages in the treatment of lung diseases. We searched the Public Clinical Trial Database and found 55 clinical trials involving UC-MSC therapy for pulmonary diseases, including coronavirus disease 2019, acute respiratory distress syndrome, bronchopulmonary dysplasia, chronic obstructive pulmonary disease, and pulmonary fibrosis. In this review, we summarize the characteristics of these registered clinical trials and relevant published results and explore in depth the challenges and opportunitiesfaced in clinical application. Moreover, the underlying molecular mechanisms involved in UC-MSC-based therapy for pulmonary diseases are also analyzed in depth. In brief, this comprehensive review and detailed analysis of these clinical trials can be expected to provide a scientific reference for future large-scale clinical application.

High-risk human papillomavirus distribution in different cytological classification women.

High-risk human papillomavirus (HR-HPV) infection is a major cause of infection-related cancer worldwide. 3101 HR-HPV-positive females were retrospectively analyzed and grouped using the cervical cytological screening (ThinPrep cytological test, TCT) evaluations combined with colposcopy. The HPV16 infection rate is the highest in all groups. HPV16 was the most frequent in each group, with significant differences between the four groups (χ2 = 23.41, P = 0.0001). The distribution of HPV16 and HPV33 correlated with the pathologic stage in each group. The mixed infection rate of mRNA testing differs significantly between groups (P < 0.01, χ2 = 17.44, P = 0.002). HR-HPV infection duration of less than six months accounted for 87.65%, 6 and 12 months of persistent infection (28.28%), and more than one year of continuous infection accounted for only 16.48%. The top three HPV types in a group with a duration of more than 12 months were HPV52 (3.03%), HPV16 (2.55%), and HPV39 (1.58%). The least clearance types were HPV39 (63.48%), 56 (69.54%), and 52 (71.44%) more than 12 months. This study revealed the region's primary pathogenic subtypes on different cervical lesions and provided the basis for diagnosing and treating HPV infection.

High-risk HPV prevalence and genotype distribution among women in Liaocheng, Shandong Province, China from 2016 to 2022.

Human papilloma virus (HPV) infection and its associated disease are major problems affecting millions of individuals around the world. The distribution of HPV genotypes is specific to different areas and different populations. Therefore, understanding the prevalence and genotype distribution of HPV in different populations in different geographical regions is essential to optimize HPV vaccination strategies and to maximize vaccine effects. In this study, 34,076 women from January 2016 to July 2022 were retrospectively analyzed at Liaocheng People's Hospital. Of these, 7540 women were high-risk HPV positive and the infection rate was 22.13%. The top ten genotypes were as follows in descending order: HPV16, HPV52, HPV58, HPV53, HPV39, HPV59, HPV66, HPV51, HPV18, and HPV56 and the least frequent genotypes were, in order, HPV 26, HPV45, and HPV82. The HPV16 positive infection rate was 25.37% and was reduced with the increase in the number of individuals who had undergone HPV screening. The HPV52 infection rate increased with increasing numbers of individuals undergoing HPV screening, and then remained unchanged. The proportion of 20-29-year-olds among all positive women began to decrease since the vaccine was available in 2018. The 30-39-year-old group accounted for the highest percentage of positive women, and the 50-59-year-old group of HPV-positive women with cervical cancer accounted for most infections. This study confirmed that HPV16, HPV52, HPV 58, and HPV53 is widely distributed in this population and the total HR-HPV infection rate remains high in this region. Our findings indicate that prevention of HPV infection in this region still faces important challenges.

Down regulation of G protein-coupled receptor 137 expression inhibits proliferation and promotes apoptosis in leukemia cells.

BACKGROUND: G protein-coupled receptors (GPR) are involved in a wide range of physiological processes, some of which, however, can be hijacked by tumor cells. Over-expression of G protein-coupled receptors 137 (GPR137) are associated with the growth of tumor cells, but under-expression of GPR137 has shown to inhibit cell proliferation in several different types of cancers. Currently, the role of GPR137 in leukemia is still unclear. In this study, the effect of under-expression of GPR137 on inhibiting the proliferation of leukemia cells is explored, to identify a novel target for leukemia treatment. MATERIALS AND METHODS: In this study, lentivirus-mediated RNA interference (RNAi) was employed to investigate the role of GPR137 in two leukemia cell lines K562 and HL60. The gene expression of GPR137 was analyzed by RT-PCR and its protein expression was determined by Western blot. Flow cytometry and Annexin V/7-AAD Apoptosis Detection Kit was used respectively in cell cycle and apoptosis analysis. The protein expression of CyclinD1, CDK4, BCL-2 and caspase-3 were also determined. RESULTS: There was high level of constitutive expression of GPR137 in leukemia cancer cell lines K562 and HL60. Lentivirus-mediated RNAi could significantly down-regulate gene and protein expression of GPR137 in both cell lines. Down regulation of GPR137 was associated with the reduction in proliferation rate and colony forming capacity. In addition, down regulation of GPR137 arrested cells in the G0/G1 phase of cell cycle and induced apoptosis in both leukemia cell lines K562 and HL60. CONCLUSIONS: The expression of GPR137 is associated with the proliferation of leukemia cell lines. Down regulation of GPR137 could inhibit proliferation and promote apoptosis in leukemia cells, which makes it a promising bio-marker and therapeutic target to treat patients with leukemia.

Integrin alpha5beta1 suppresses rBMSCs anoikis and promotes nitric oxide production.

BACKGROUND: Cell based therapy has been heralded as a novel, promising therapeutic strategy for cardiovascular diseases including pulmonary arterial hypertension (PAH). However, the low survival rate after transplantation due to cell death via anoikis is a major obstacle in stem cell therapy. Cells adhesion via Integrin alpha5beta1 (ITGA5B1) has a tendency to exert higher maximum forces. The present study aimed to evaluate the potential protective effect of ITGA5B1 on rat bone marrow mesenchymal stem cells (rBMSCs) from anoikis. METHODS: Mononuclear cells were isolated by density gradient centrifugation with Ficoll, and rBMSCs cell surface markers were evaluated by flow cytometry. Osteogenic and adipocyte differentiation was determined by Alizarin Red S and Oil Red O staining respectively. The expression of Integrin A5 (ITGA5), Integrin B1 (ITGB1), eNOS and actived-caspase-3 mRNA or protein was confirmed by qPCR and western-blot. Cell adhesion, cell viability, anoikis and the migration of rBMSCs were also evaluated. Nitric oxide (NO) production was detected by the greiss assay. RESULTS: Co-infected with Integrin A5 and B1 lentivirus to rBMSCs increased ITGA5 and ITGB1 mRNA and protein expression. ITGA5B1 enhanced the cell adhesion, cell viability, cell migration and NO production but reduced the cell anoikis in rBMSCs/ITGA5B1 groups. CONCLUSION: Transduction of rat rBMSCs with ITGA5B1 lentivirus could prevent cell anoikis and increase NO production.

Effectiveness and safety of chemotherapy combined with cytokine-induced killer cell /dendritic cell-cytokine-induced killer cell therapy for treatment of gastric cancer in China: A systematic review and meta-analysis.

BACKGROUND: Currently, cytokine-induced killer cells (CIK)/dendritic cell (DC)-CIK-mediated immunotherapy is widely used to treat gastric cancer. However, limited information regarding clinical trials on CIK/DC-CIK therapy is available. Therefore, systemic evaluation of the efficacy and safety of the combination therapy is necessary. METHODS: A meta-analysis involving 1735 patients with gastric cancer was conducted. Before analysis, the study quality and heterogeneity were evaluated. The effects of chemotherapy combined with CIK/DC-CIK on gastric cancer were compared with the effects observed when chemotherapy alone was used. Pooled analysis was performed using RevMan version 5.2 from random or fixed-effect models. RESULTS: Seventeen trials were included. First, the analysis showed that the combination therapy significantly increased the overall survival rate and disease-free survival rate compared with those in patients treated using chemotherapy alone. The overall response rate (P = 0.002), disease control rate (P = 0.0007), and quality of life improved rate (P = 0.0008) were significantly improved in patients who received combined treatment than in patients who received chemotherapy alone. Second, the percentage of lymphocyte subsets (CD3(+), CD4(+) and CD3(-)CD56(+), CD3(+)CD56(+); P <0.01) and the levels of interleukin-12 and interferon-γ, which reflect immune function, were significantly increased (P <0.05) after the CIK/DC-CIK therapy. Further, carbohydrate antigen tumor markers were significantly reduced compared with the pre-therapy levels. Immunotherapy with CIK/DC-CIK obviously alleviated the adverse events caused by chemotherapy. CONCLUSION: The combination of CIK/DC-CIK therapy and chemotherapy was superior in prolonging the survival time, enhancing immune function and alleviating the adverse events caused by chemotherapy.

The stimulatory effects of eNOS/F92A-Cav1 on NO production and angiogenesis in BMSCs.

BACKGROUND: Nitric oxide (NO) is generated in endothelial cells by endothelial nitric oxide synthase (eNOS). Caveolin-1 (Cav1) inhibits eNOS function and NO production. Modifying Cav1 scaffold domain, in particular Phenylalanine at position 92 (F92) is critical for the inhibitory actions of Cav1 toward eNOS. The aims of this study were to investigate the effect of enhanced NO production in term of in vitro angiogenesis on rat bone marrow derived mesenchymal stem cells (BMSCs) transduced with a novel bicistronic lentiviral vector co-expressing eNOS and mutant Cav1 (F92A). METHODS: A bicistronic eNOS/F92-Cav1 lentiviral vector was constructed, and used to transduce rat BMSCs. The expression of eNOS and VEGF protein were confirmed by western-blot. NO production was detected by the greiss assay and in vitro angiogenesis was assessed by matrigel assisted capillary tube formation. The cell viability was evaluated using a Cell Counting Kit (CCK)-8. RESULTS: The bicistronic eNOS/F92A-Cav1 lentiviral vector increased eNOS and VEGF protein expression, NO production compared to controls. In vitro capillary formation was increased in eNOS-F92A transduced cells and cell viability was not affected by transduction. CONCLUSION: Transduction of rat BMSCs with an eNOS-F92A-Cav1 lentiviral vector can increase NO production by enhancing eNOS protein expression. The increased NO production did not reduce cell viability. This study demonstrates that genetic modification of BMSCs to enhance NO producton could be applied in stem cell based therapeutic approaches to treat diseases such as pulmonary arterial hypertension (PAH) which is characterized by decreased endothelial NO release.

Effect of diabetic osteoblasts on osteogenic differentiation of human umbilical cord mesenchymal stem cells.

BACKGROUND: This study was aimed to investigate whether osteoblasts from diabetic patients have a promoting effect on osteogenesis of human umbilical cord mesenchymal stem cells (HUMSCs). METHODS: HUMSCs were co-cultured with osteoblasts of diabetic and non-diabetic patients. Morphological appearance and cytochemical characteristics of the non-diabetic osteoblasts and diabetic osteoblasts were observed by hematoxylin-eosin staining, type I collagen protein expression, alkaline phosphatase (ALP) staining and Alizarin Red S staining. Cell viability, type I collagen protein expression, ALP activity and osteocalcin mRNA expression in HUMSCs were investigated. RESULTS: Compared with negative control group, the cell proliferation, type I collagen protein expression, ALP activity and osteocalcin mRNA were increased in HUMSCs co-cultured with diabetic and non-diabetic osteoblasts (P<0.05). There was no statistically significant difference in the HUMSCs cell proliferation, type I collagen protein expression, ALP activity and osteocalcin mRNA between the non-diabetic and diabetic group (P >0.05). CONCLUSIONS: Similar to osteoblasts from non-diabetic patients, osteoblasts from diabetic patients also have the ability to promote HUMSCs proliferation, and leading to HUMSCs exhibit some characteristic of osteoblasts.

Upregulated ROS production induced by the proteasome inhibitor MG-132 on XBP1 gene expression and cell apoptosis in Tca-8113 cells.

Exposure of Tca-8113 cells to proteasome inhibitor carbobenzoxy-Leu-Leu-leucinal (MG-132) causing apoptosis is associated with endoplasmic reticulum (ER) stress. X-box-binding protein-1 (XBP1) is an important regulator of a subset of genes active during ER stress, which is related to cell survival and is required for tumor growth. The present study is to evaluate the effect of MG-132 on ROS production, XBP1 gene expression, tumor necrosis factor receptor-associated factor 2 (TRAF2), ASK1 and c-jun protein expression in tongue squamous cell carcinoma cell line Tca-8113 cells. ROS production was measured by reactive oxygen species assay. X-box binding protein-1 (XBP1) mRNA was analyzed by real-time-PCR, TRAF2, ASK1 and c-jun protein were investigated by western blot and immunocytochemistry respectively. The result indicated that ROS production, TRAF2, ASK1 and c-jun were elevated in MG-132 treated cells. Giving ROS scavenger N-acetyl-L-cysteine (NAC) largely prevented the effects of MG-132. Furthermore, treating with MG-132 lead to decreased XBP1 mRNA expression but could not completely block the expression of XBP1. Taken together, these findings provide the evidence that MG-132 induced ER stress lead to Tca-8113 cells apoptosis through ROS generation and TRAF2-ASK1-JNK signal pathway activation.

Lentivirus-based RNA silencing of Nemo-like kinase (NLK) inhibits the CAL 27 human adenosquamos carcinoma cells proliferation and blocks G0/G1 phase to S phase.

BACKGROUND: The Nemo-like kinase (NLK) is a serine/threonine-protein kinase that involved in a number of signaling pathways regulating cell fate. Variation of NLK has been shown to be associated with the risk of cancer. However, the function of NLK in oral adenosquamous carcinoma cells line CAL-27 is unknown. METHODS: In this study, we evaluated the function of NLK in CAL-27 cells by using lentivirus-mediated RNA silence. The targeted gene expression, cell proliferation and cell cycle are investigated by RT-PCR, western-blot, MTT method, colony forming assay and flow cytometry analysis respectively. RESULTS: After NLK silencing, the number of colonies was significantly reduced (54 ± 5 colonies/well compared with 262 ± 18 colonies/well in non-infected or 226 ± 4 colonies/well in negative control group (sequence not related to NLK sequence with mismatched bases). Using crystal violet staining, we also found that the cell number per colony was dramatically reduced. The RNA silencing of NLK blocks the G0/G1 phase to S phase progression during the cell cycle. CONCLUSIONS: These results suggest that NLK silencing by lentivirus-mediated RNA interference would be a potential therapeutic method to control oral squamous carcinoma growth.

Increased active von Willebrand factor during disease development in the aging diabetic patient population.

Type 2 diabetes is known to cause endothelial activation resulting in the secretion of von Willebrand factor (VWF). We have shown that levels of VWF in a glycoprotein Ib-binding conformation are increased in specific clinical settings. The aim of the current study is to investigate whether active VWF levels increase during aging and the development of diabetes within the population of patients suffering from type 2 diabetes. Patients and controls were divided into two groups based on age: older and younger than 60 years of age. VWF antigen, VWF propeptide, VWF activation factor and total active VWF were measured. Patients older than 60 years of age had increased levels of total active VWF, VWF activation factor and VWF propeptide compared to younger patients and controls. All measured VWF parameters were associated with age in diabetic patients. Total active VWF and VWF propeptide correlated with the period of being diagnosed with diabetes. Regression analyses showed that especially the VWF activation factor was strongly associated with diabetes in patients older than 60 years of age. In conclusion, we found that the conformation of VWF could be involved in the disease process of diabetes and that the VWF in a glycoprotein Ib-binding conformation could play a role as risk marker during the development of diabetes in combination with an increase in age. Our study shows that the active quality of VWF was more important than the quantity.

Effect of short hairpin RNA-induced CXCR4 silence on ovarian cancer cell.

This study was aimed to investigate the effect of down-regulating the CXC chemokine receptor-4 (CXCR4) expression on cell proliferation, invasion and migration of human ovarian cancer cell line SW626. The CXCR4 specific short hairpin RNA (shRNA) plasmid vector was constructed and then transfected into the SW626 cells. The expression of CXCR4 mRNA and protein was detected by real-time RT-PCR and western blot respectively. Cell proliferation was detected by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Cell invasion and migration was assayed in Biocoat Matrigel invasion chambers. The expression level of CXCR4 in SW626 cell transfected with CXCR4-siRNA was inhibited, leading to significant decrease in SW626 cell proliferation, invasion and migration. We conclude that CXCR4 is essential for tumor cell proliferation and invasion. The CXCR4 molecule is a potential therapeutic target to control ovarian cancer cell growth or metastasis.

The protective effect of 17ß-estradiol against hydrogen peroxide-induced apoptosis on mesenchymal stem cell.

This study was designed to investigate the function of 17ß-estradiol (17ß-E2) against oxidative stress on the cell death of mice bone marrow mesenchymal stem cells (BMSCs) induced by hydrogen peroxide (H2O2). BMSCs were treated with 17ß-E2 for 24h and then treated with 100µM H2O2 for 1h. Cell viability, apoptosis, caspase-9 mRNA, JNKs (Jun N-terminal kinases) and c-Jun protein expression in BMSCs were evaluated. Cell apoptosis of BMSCs were increased in a dose-dependent manner after treated with H2O2 compared to control group. But pretreatment with 17ß-E2 can inhibit apoptosis of BMSCs, preserve the mitochondrial transmembrane potential, decrease caspase-9 mRNA, JNK1/2 and c-Jun protein expression. In conclusion, 17ß-E2 exerts antiapoptotic effects in BMSCs which related to the mitochondria death pathway and JNKs pathway. The study revealed that 17ß-E2 can reduce the donor stem cells damage.

ß-radiation reduces the reactivity of extracellular matrix proteins in intravascular brachytherapy (IVBT), resulting in decreased platelet adhesion.

BACKGROUND: Intravascular Brachytherapy as a tool to reduce restenosis is thought to alter vascular wall biology and vessel wall protein function. Platelet accumulation is also indeed important in the genesis of restenosis. We examine the in vitro effects of beta-radiation on the certain vessel wall extra cellular matrix proteins. We hypothesized that vessel wall (proteins) had become less prone to thrombosis. METHODS: We examined platelet adhesion to 20-Gy beta radiation treated extra cellular matrix proteins under flow conditions. Platelet flow adhesion was evaluated or quantified by image analysis, aggregation size analysis using the Watershed program and real-time fluorescence images of thrombus formation. The effect of beta radiation on vWF was further showing by measuring the binding of domain-specific antibodies to radiation treated vWF. RESULTS: 20-Gy beta radiation significantly decreased platelet adhesion to extra cellular matrix protein; vWF and collagen Type III and had no effect on the adhesion upon fibrinogen and fibronectin. The beta-radiation affected mostly the AI, A2 and A3 domains of the vWF molecule on the surface, whereas the D'-D3 and B-C1 domains on the surface remain unaffected and suggesting a significant decrease in vWF binding capacity to the GPIb, heparin and collagen ligands. CONCLUSION: Beta radiation treatment can alter the reactivity of the certain vessel wall extra cellular matrix proteins, in particular vWF and collagen. The vessel wall may become less prone to platelet adhesion, which results in decrease thrombus formation. It might help to reduce the onset of acute coronary occlusion after the intervention.

Apoptotic effect of MG-132 on human tongue squamous cell carcinoma.

The aim of this study was to investigate the apoptotic effect of a proteasome inhibitor MG-132 on Tca-8113, a cell line of human tongue squamous cell carcinoma. Tca-8113 cells were treated with 10, 20, and 30µM of MG-132, or 5µM thapsigargin. Apoptosis rate was determined with annexin V/propidium iodide double staining. Expression of E3ubiquitin-protein ligase was determined by ELISA, and Grp78 and caspase-12 mRNA, and Grp78 and caspase-12 protein was assessed by RT-PCR and Western blot, respectively. Apoptosis was observed 18h after MG-132 treatment. The apoptotic rate in the 10, 20, and 30µM MG-132 group was 13.5, 19.6 and 34.7%, respectively, which was higher than in the thapsigargin (8.5%, P<0.01) or control group (0.5%, P<0.01). The expression of E3 ubiquitin-protein ligase in the 10, 20, and 30µM MG-132 group was 28.75±2.28, 18.16±0.65, 8.85±0.72, respectively, which was lower than in the thapsigargin (38.96±0.33, P<0.05 or 0.01) or control (40.88±4.52, P<0.05 or 0.01) group. The levels of Grp78 and capase-12 mRNA, Grp78 and caspase-12 protein in the MG-132 groups were higher than in the control group (P<0.01). In conclusion, MG-132 induces apoptosis in Tca-8113 cells in a concentration-dependent manner. The MG-132-induced apoptosis may involve downregulation of E3 ubiquitin ligase, and upregulation of Grp78 and caspase-12.

[Apoptosis induced by MG-132 in Tca-8113 cells].

PURPOSE: To explore the apoptotic effect of ubiquitin-proteasome inhibitor (PI) MG-132 on human tongue squamous cell carcinoma cell line (Tca-8113 cell) through endoplasmic reticulum stress. METHODS: Tca-8113 cells were cultured in RPMI 1640 medium supplemented with 10% fetal calf serum, the exponential cells were divided into 5 groups.The cell culture medium was added to 1640 (negative control group), thapsigargin 5 µmol/L (positive control group), and 10,20,30 µmol/L (MG-132 group). After 24 h, the following experiments were carried out: morphological change of apoptotic cells was observed by Hoechst 33258 fluorescent staining under fluorescent microscope, apoptotic rate of cells was determined with annexin V-FITC/PI double staining by flow cytometry, the GRP78 mRNA level was determined by RT-PCR, the expression of caspase-12 protein was evaluated by Western blot, the human ubiquitin-protein ligase E3 concentration was detected by ELISA. The data was analyzed using SPSS16.0 software package. RESULTS: Typical morphological change of apoptosis in Tca-8113 cells was observed 24 hours after treating with 10.0, 20.0, 30.0 µmol/L MG-132 and positive control group; The apoptotic rate of MG-132 groups gradually increased with MG-132 concentration; The GRP78 mRNA level was up-regulated; The expression of caspase-12 increased was demonstrated by Western blot; The expression of the human ubiquitin-protein ligase E3 in MG-132 groups was 28.75 ± 2.28, 18.16 ± 0.65 and 8.85 ± 0.72. CONCLUSIONS: MG-132 can induce apoptosis of Tca-8113 cells through endoplasmic reticulum stress; MG-132 can inhibit the expression of human ubiquitin ligase E3.

Expression of the Golgi phosphoprotein-3 gene in human gliomas: a pilot study.

The oncogene Golgi phosphoprotein 3 (GOLPH3) has been found in several solid cancers, but its expression in glioma tumor tissues is unknown. Reverse transcription polymerase chain reaction and Western blot was used to investigate expression of GOLPH3 mRNA and protein, respectively, in 76 patients with glioma. Non-cancerous brain issues and lung cancer cells were used as controls. There were 45 males and 31 females (mean age 50.7 ± 12.8 years). Astrocytoma was found in 65 patients and glioblastoma in 11. No GOLPH3 expression was found in the non-cancerous brain tissues, but positive GOLPH3 protein was found in lung cancer cells. GOLPH3 mRNA and protein expression were identified in 40 patients with glioma (52.6%). Positive expression of GOLPH3 mRNA or protein was similar in patients with astrocytoma grades I-III and glioblastoma (P > 0.05). The highest mean value of GOLPH3 mRNA and protein was found in patients with glioblastoma (P < 0.01) whereas the lowest mean values were found in those with grade I astrocytoma (P < 0.01). We concluded that, in this pilot study, GOLPH3 expression was present in more than half of the patients with glioma. The amount of GOLPH3 expression in the glioma was associated with the severity of the tumor. Whether positive GOLPH3 gene expression can be used as a predictor for prognosis of the patients or as a therapeutic target for glioma requires further investigation.

MAP kinase phosphatase-1, a critical negative regulator of the innate immune response.

Mitogen-activated protein (MAP) kinase cascades are crucial signal transduction pathways in the regulation of the host inflammatory response to infection. MAP kinase phosphatase (MKP)-1, an archetypal member of the MKP family, plays a pivotal role in the deactivation of p38 and JNK. In vitro studies using cultured macrophages have provided compelling evidence for a central role of MKP-1 in the restraint of pro-inflammatory cytokine biosynthesis. Studies using MKP-1 knockout mice have strengthened the findings from in vitro studies and defined the critical importance of MKP-1 in the regulation of pro-inflammatory cytokine synthesis in vivo during the host response to bacterial cell wall components. Upon challenge with Toll-like receptor ligands MKP-1 knockout mice produced dramatically greater amounts of inflammatory cytokines, developed severe hypotension and multi-organ failure, and exhibited a remarkable increase in mortality. More recent investigations using intact bacteria confirmed these observations and further revealed novel functions of MKP-1 in host defense against bacterial infection. These studies demonstrate that MKP-1 is an essential feedback regulator of the innate immune response, and that it plays a critical role in preventing septic shock and multi-organ dysfunction during pathogenic infection. In this review, we will summarize the studies on the function of MKP-1 in innate immune responses and discuss the regulation of this novel protein phosphatase.

Effect of a seashell protein Haishengsu on cell growth and expression of apoptosis genes in leukemia K562 cells.

OBJECTIVES: To investigate the effect of a seashell protein Haishengsu (HSS), an extract from a shellfish Tegillarca granosa, on cell growth and the expression of apoptosis genes in leukemia K562 cells. METHODS: Cultured K562 cells were treated with HSS at various concentrations (10-40 mg/L). The cell cycle, cell growth and the expression of apoptosis suppressor gene bcl-2 and apoptosis promoting gene bax were evaluated. RESULTS: HSS, 20mg/L, inhibited cell cycle in the G0/G1 and S phases. HSS, 20mg/L, also inhibited the growth of K562 cells over time. Expression of bcl-2 gene in the HSS 20mg/L (58.8%+/-4.7%) and HSS 40 mg/L group (26.6%+/-2.1%) were lower than in the control group (91.0+/-8.7%, P < 0.01). Expression of bax gene in the HSS 20mg/L (77.7+/-3.6%) and 40 mg/L group (90.6+/-3.7%) were higher than in the control group (10.9+/-6.6%, P < 0.01). CONCLUSION: HSS suppresses leukemia K562 cell growth by inhibiting the G0/G1 and S phases of the cell cycle. It also induces apoptosis in these leukemia cells by reducing the expression of apoptosis suppressor gene bcl-2, and increasing the expression of apoptosis promoting gene bax. Further studies are required to investigate the clinical efficacy of HSS in leukemia.