Hypoxic preconditioning BMSCs-exosomes inhibit cardiomyocyte apoptosis after acute myocardial infarction by upregulating microRNA-24

OBJECTIVE

To elucidate the regulatory effect of hypoxic preconditioning bone marrow mesenchymal stem cells (BMSCs)-exosomes on cardiomyocyte apoptosis in acute myocardial infarction (AMI) rats.

MATERIALS AND METHODS

BMSCs-derived exosomes were extracted by Exoquick method. Expressions of exosome surface markers were determined by Western blot. The AMI model in rats was established by LAD ligation. Rats were randomly assigned into sham group, AMI group, AMI+H-exo group and AMI+N-exo group. MicroRNA-24 expression in rat myocardium was detected at different time points. Subsequently, hypoxic preconditioning or normoxic preconditioning BMSCs-exosomes were intramyocardially injected into rats. Infarct size was calculated through TTC (triphenyltetrazolium chloride) staining. Cardiomyocyte apoptosis was accessed with Terminal Deoxynucleotidyl Transferase dUTP Nick-end Labeling (TUNEL). Heart function of AMI rats was evaluated by echocardiography. Protein expressions of apoptotic genes in rat myocardium were detected by Western blot.

RESULTS

The mRNA level of microRNA-24 was higher in H-exo group than N-exo group. Injection of hypoxic preconditioning BMSCs-exosomes markedly upregulated microRNA-24 level, reduced infarct size and improved cardiac function in AMI rats. Protein expressions of Bax, caspase-3 and cleaved-caspase-3 were downregulated by BMSCs-exosomes treatment. H9c2 cells showed upregulated microRNA-24 level and decreased apoptotic rate after incubation with hypoxic preconditioning BMSCs-exosomes. The above cellular performances were partially reversed by transfection of microRNA-24 inhibitor.

CONCLUSIONS

Hypoxic preconditioning BMSCs-exosomes inhibit cardiomyocyte apoptosis in AMI rats by upregulating microRNA-24.

Research Advances on Matrine

Matrine is an alkaloid extracted from traditional Chinese herbs including Sophora flavescentis, Sophora alopecuroides, Sophora root, etc. It has the dual advantages of traditional Chinese herbs and chemotherapy drugs. It exhibits distinct benefits in preventing and improving chronic diseases such as cardiovascular disease and tumors. The review introduced recent research progresses on extraction, synthesis and derivatization of Matrine. The summary focused on the latest research advances of Matrine on anti-atherosclerosis, anti-hypertension, anti-ischemia reperfusion injury, anti-arrhythmia, anti-diabetic cardiovascular complications, anti-tumor, anti-inflammatory, anti-bacterium, anti-virus, which would provide new core structures and new insights for new drug development in related fields.

G-MDSC-derived exosomes mediate the differentiation of M-MDSC into M2 macrophages promoting colitis-to-cancer transition

BACKGROUNDS

In inflammatory bowel disease microenvironment, transdifferentiation of myeloid-derived suppressor cells (MDSCs) and M2 macrophage accumulation are crucial for the transition of colitis-to-cancer. New insights into the cross-talk and the underling mechanism between MDSCs and M2 macrophage during colitis-to-cancer transition are opening new avenues for colitis-associated cancer (CAC) prevention and treatment.

METHODS

The role and underlying mechanism that granulocytic MDSCs (G-MDSCs) or exosomes (Exo) regulates the differentiation of monocytic MDSCs (M-MDSCs) into M2 macrophages were investigated using immunofluorescence, FACS, IB analysis, etc, and employing siRNA and antibodies. In vivo efficacy and mechanistic studies were conducted with dextran sulfate sodium-induced CAC mice, employed IL-6 Abs and STAT3 inhibitor.

RESULTS

G-MDSCs promote the differentiation of M-MDSC into M2 macrophages through exosomal miR-93-5 p which downregulating STAT3 activity in M-MDSC. IL-6 is responsible for miR-93-5 p enrichment in G-MDSC exosomes (GM-Exo). Mechanistically, chronic inflammation-driven IL-6 promote the synthesis of miR-93-5 p in G-MDSC via IL-6R/JAK/STAT3 pathway. Early use of IL-6 Abs enhances the effect of STAT3 inhibitor against CAC.

CONCLUSIONS

IL-6-driven secretion of G-MDSC exosomal miR-93-5 p promotes the differentiation of M-MDSC into M2 macrophages and involves a STAT3 signaling mechanism that promote colitis-to-cancer transition. Combining STAT3 inhibitors with strategies that inhibit IL-6-mediated G-MDSC exosomal miR-93-5 p production is beneficial for the prevention and treatment of CAC.

Association between serum NPTX2 and cognitive function in patients with vascular dementia

OBJECTIVE

Neuronal Pentraxin 2 (NPTX2) has recently been widely reported as a novel biomarker for Alzheimer's disease (AD), but its correlation with vascular dementia (VaD) has not been elucidated. This study aimed to explore the correlation between NPTX2 and the cognitive function of VaD patients.

METHODS

112 VaD patients and 76 healthy controls were included in the study. Upon admission, clinical baseline data for all subjects were collected. Serum NPTX2 levels were determined using enzyme-linked immunosorbent assay (ELISA). At the same time, the Montreal cognitive assessment (MoCA) scale was used to measure cognitive function. Multivariate regression analysis was used to determine the relationship between serum NPTX2 level and the cognitive function of VaD patients.

RESULTS

Compared with healthy controls, VaD patients had lower serum NPTX2 levels (p < .001). The results of Spearman's correlation analysis showed that serum NPTX2 levels in VaD patients were positively correlated with MoCA scores (r = .347, p = .042). The results of multivariate regression analysis showed that after adjusting for common risk factors, serum NPTX2 levels in VaD patients were still significantly associated with MoCA scores (β = 0.346, p = .039).

CONCLUSIONS

Serum NPTX2 level was independently associated with cognitive function in patients with VaD. Serum NPTX2 level may be a novel predictor for cognitive function in VaD.

Sulfatide-tenascin interaction mediates binding to the extracellular matrix and endocytic uptake of liposomes in glioma cells

Tenascin-C is an extracellular matrix glycoprotein, whose expression is highly restricted in normal adult tissues, but markedly up-regulated in a range of tumors, and therefore serves as a potential receptor for targeted anticancer drug or gene delivery. We describe here a liposomal carrier system in which the targeting ligand is sulfatide. Experiments with tenascin-C-expressing glioma cells demonstrated that binding of liposomes to the extracellular matrix relied essentially on the sulfatide-tenascin-C interaction. Following binding to the extracellular matrix, the sulfatide-containing liposomes were internalized via both caveolae/lipid raft- and clathrin-dependent pathways, which would ensure direct cytoplasmic release of the cargoes carried in the liposomes. Such natural lipid-guided intracellular delivery targeting at the extracellular matrix glycoproteins of tumor cells thus opens a new direction for development of more effective anticancer chemotherapeutics in future.

Different Effects of Tacrolimus on Innate and Adaptive Immune Cells in the Allograft Transplantation

While tacrolimus (FK506) is currently used as immunosuppression therapy in transplant recipient, the immunological mechanism remains unknown. Herein, the immunoregulatory effects of FK506 were investigated in the physiological status and allogeneic skin transplantation. FK506 cannot significantly alter the functions of innate immune cells (macrophages and neutrophils) and adaptive immune cells (T cells) in the physiological status. However, it can effectively delay allogeneic skin-graft rejection through ameliorating the T cell responses, but not myeloid-derived innate immune cell responses. Importantly, it did not affect the allograft recipient macrophage innate immune defence capacity to bacteria. In clinics, FK506 treatment can significantly control the cytokine production in T cells, but not non-T cells. This study shows targeting calcineurin signalling, FK506, to be essential in inducing allograft tolerance, but not to damage the innate defence capacity, validating the immune cell phenotypes as a potential marker in transplantation following FK506 treatment.

DNA hypermethylation contributes to colorectal cancer metastasis by regulating the binding of CEBPB and TFCP2 to the CPEB1 promoter

Background

Aberrant DNA methylation has been firmly established as a factor contributing to the pathogenesis of colorectal cancer (CRC) via its capacity to silence tumour suppressor genes. However, the methylation status of multiple tumour suppressor genes and their roles in promoting CRC metastasis are not well characterised.

Methods

We explored the methylation and expression profiles of CPEB1 (the gene encoding cytoplasmic polyadenylation element-binding protein 1), a candidate CRC tumour suppressor gene, using The Cancer Genome Atlas (TCGA) database and validated these results in both CRC cell lines and cells from Han Chinese CRC patients (n = 104). The functional role of CPEB1 in CRC was examined in experiments performed in vitro and in vivo. A candidate transcription factor capable of regulating CPEB1 expression was predicted in silico and validated by luciferase reporter, DNA pull-down, and electrophoretic mobility shift assays.

Results

Hypermethylation and decreased expression of CPEB1 in CRC tumour tissues were revealed by TCGA database. We also identified a significant inverse correlation (Pearson’s R = − 0.43, P < 0.001) between promoter methylation and CPEB1 expression. We validated these results in CRC samples and two CRC cell lines. We also demonstrated that up-regulation of CPEB1 resulted in significantly decreased tumour growth, migration, invasion, and tumorigenicity and promoted tumour cell apoptosis both in vitro and in vivo. We identified the transcription factors CCAAT enhancer-binding protein beta (CEBPB) and transcription factor CP2 (TFCP2) as critical regulators of CPEB1 expression. Hypermethylation of the CPEB1 promoter resulted in a simultaneous increase in the capacity for TFCP2 binding and a decreased likelihood of CEBPB binding, both of which led to diminished expression of CPEB1.

Conclusions

Our results identified a novel tumour-suppressive role of CPEB1 in CRC and found that hypermethylation of the CPEB1 promoter may lead to diminished expression due to decreased chromatin accessibility and transcription factor binding. Collectively, these results suggest a potential role for CPEB1 in the diagnosis and treatment of CRC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-021-01071-z.

Research Advances on Anti-Cancer Natural Products

Malignant tumors seriously threaten people's health and life worldwide. Natural products, with definite pharmacological effects and known chemical structures, present dual advantages of Chinese herbs and chemotherapeutic drug. Some of them exhibit favorable anti-cancer activity. Natural products were categorized into eight classes according to their chemical structures, including alkaloids, terpenoids and volatile oils, inorganic salts, phenylpropanoids, flavonoids and isoflavones, quinone, saponins and polysaccharides. The review focused on the latest advances in anti-cancer activity of representative natural products for every class. Additionally, anti-cancer molecular mechanism and derivatization of natural products were summarized in detail, which would provide new core structures and new insights for anti-cancer new drug development.

Mutants of human choriogonadotropin lacking N-glycosyl chains in the alpha-subunit. 1. Mechanism for the differential action of the N-linked carbohydrates

Analogs of human choriogonadotropin (hCG) lacking N-glycosyl chains at alpha52Asn and alpha78Asn were purified from the culture media of insect cells by immunoaffinity chromatography using a monoclonal antibody column. As previously reported, while analogs lacking carbohydrate at alpha52Asn and alpha78Asn had similar receptor binding activities compared with the wild type recombinant hCG (hCGwt), they differed in their signal transduction properties. The mutant lacking carbohydrate at alpha78Asn had 20% less cAMP-stimulating activity than hCGwt, but the absence of glycosylation at alpha52Asn resulted in the reduction of cAMP accumulation by 90-95%. A similar effect of the mutations was observed on the stimulation of steroidogenesis. Circular dichroism spectra of the two mutants showed significant differences. The mutant lacking carbohydrate at alpha52Asn had a much higher negative mean residue ellipticity (MRE) at 200 nm and a lower negative MRE at 220 nm than that lacking carbohydrate at alpha78Asn and hCGwt. The dissociation rates of the alpha52Asn and alpha78Asn carbohydrate deficient mutants at pH 3 and room temperature, measured by using 1-anilino-8-naphthalenesulfonate, were 9.4 x 10(-5) and 3.8 x 10(-5) s-1, respectively, as compared with 1.5 x 10(-5) s-1 for hCGwt. The results of both CD measurements and dissociation studies strongly suggest that the absence of carbohydrate at alpha52Asn results in conformational changes in the mutant which might explain the loss in its signal transduction function. This is further supported by indirect evidence from two other lines of experimentation. Unlike the mutant lacking carbohydrate at alpha78Asn, the one lacking carbohydrate at alpha52Asn cross-reacted with the two subunit specific monoclonal antibodies, anti-hCGalpha and anti-hCGbeta, which normally did not cross-react with the native or the hCGwt. Also, polyclonal anti-hCGbeta but not anti-hCGalpha was able to restore the cAMP-producing activity of the alpha52Asn carbohydrate deficient mutant. From all the data taken together, it appears that the loss of second messenger-producing activity of hCG with the absence of the glycosyl chain at alpha52Asn was probably due to a conformational change in the heterodimer rather than due to the loss of the alpha52Asn-carbohydrate-receptor interaction.

Surgical treatment for upper or middle esophageal carcinoma occurring after gastrectomy: a study of 52 cases

Fifty-two patients presenting with upper or middle esophageal carcinoma after gastrectomy between 1980 and 2003 were analyzed retrospectively. Among them, there were five cases of total gastrectomy, six cases of proximal partial gastrectomy and 41 cases of distal subtotal gastrectomy. The interval between gastrectomy and the diagnosis of esophageal carcinoma ranged from 2 to 22 years. Surgical procedures included resection of the esophageal lesion with esophageal replacement using non-reversed or reversed gastric tubes (2 and 3 cases respectively), and short or long segment colon (5 and 40 cases respectively); two cases underwent a palliative procedure (jejunostomy). Complications included cervical anastomotic leaks (3 cases), pulmonary infection (3 cases), atelectasis (2 cases) and cordis arrhythmia (5 cases), all of which responded to treatment. In our group, resection of the esophageal lesions and reconstruction of the esophagus was performed in 45 cases (86.5%), exclusion and bypass procedure of esophageal carcinoma and following radiotherapy and chemotherapy in four (7.7%), eternal jejunostomy for intestinal nutrition in two (3.9%) and death occurred in one case (1.9%) due to multiple organ dysfunction syndrome (MODS). Esophageal resection combined with lymph node dissection is indicated for the treatment of upper or middle esophageal carcinoma following gastrectomy. While esophageal substitutes can include non-reversed or reversed gastric tubes as well as short or long segment colon interpositions, we usually recommend the use of colon interposition. The 1-, 3- and 5-year survival rate of cases with resection of the esophageal lesions and reconstruction of the esophagus was 84.6%, 57.7% and 26.7% respectively.

Transcription of promoter from the human APRIL gene regulated by Sp1 and NF-kB

A proliferation-inducing ligand (APRIL) which stimulates the cell proliferation is abundantly expressed in colorectal cancer (CRC) tumors. In this report, the promoter region of the APRIL gene was determined and the major transcription factor was investigated for the first time. Deletion analysis of 5'-flanking region of the human APRIL gene and transient transfection revealed that a 538 bp region (from -1539 to -1001) was essential for promoter activation of the APRIL gene. The data from electrophoretic mobility shift assays (EMSA) indicated that the 538 bp promoter region was responsive to the specificity protein 1 (Sp1) and nuclear factor kappa B (NF-kB). Overexpression of Sp1 or NF-kB increased the activity of the APRIL promoter. Mithramycin A (inhibitor of Sp1) and Bay11-7082 (inhibitor of NF-kB) exhibited an inhibitory activity to APRIL promoter. Our results will benefit to the APRIL gene regulation investigation and contribute to discover new drug target for the APRIL gene therapy of CRC.

Diffusion of tellurium at nickel grain boundaries: a first-principles study

The atomic structures, stabilities, segregation behaviors and diffusion barriers of Te are studied for the bulk, surfaces and four kinds of GBs of nickel. Te behavior is found to be very sensitive to the GB type. The effect of strain on diffusion is strong for different GBs.

Effect of modification of all loop regions in the alpha- and beta-subunits of human choriogonadotropin on its signal transduction activity

Human choriogonadotropin (hCG), according to its three dimensional structure as determined by X-ray diffraction, has three beta-hairpin loops each in the alpha and beta subunit designated as alpha 1, alpha 2 alpha 3 and beta 1 beta 2 and beta 3, respectively. Since similar beta-hairpin loops in NGF and TNF beta have been implicated in their direct interaction with the receptor, it prompted the present investigation to determine the role of such loops in receptor binding and post-receptor signaling events in hCG. Based on the three dimensional structure of hCG, radical mutations were introduced in the alpha loops by replacing hydrophobic alpha 18Phe and alpha 74Phe by hydrophilic Thr residues in the alpha 1 and alpha 3 loops, respectively, and positively charged alpha 45Lys by negatively charged Asp in the helical segment in the alpha 2 loop. The beta loops were mutated by replacement of the beta 1, beta 2 and beta 3 sequences with the corresponding hFSH sequences. These replacements included beta 22Gly, beta 24Pro and beta 25Val with Glu, Arg and Phe in beta 1, 45Leu Gln Gly Val Leu Pro Ala Leu Pro53 with Tyr Lys Asn Pro Ala Arg Pro Leu Ile in beta 2 and 73Pro Arg Gly with Ala His His in the beta 3 loop. Six mutants, hCG alpha 1 beta, hCG alpha 2 beta and hCG alpha 3 beta and hCG alpha beta 1, hCG alpha beta 2 and h CG alpha beta 3, were obtained by co-infection of the insect High-Five cells with baculovirus containing mutant alpha or beta cDNAs and that containing complimentary wild type beta or alpha cDNAs. The mutants were almost completely secreted in the culture medium and were over expressed at levels ranging between 4.5 to 29 micrograms/ml indicating that mutations had no effect on the secretion or subunit assembly of hCG. In order to remove any contaminating beta-subunit, the culture medium was passed through a column of an hCG beta-specific monoclonal antibody, B158. The receptor binding activity of the mutant hCG alpha 1 beta, in which alpha 18Phe was replaced with Thr, increased almost 200% relative to rehCG. Similarly, increase in the cAMP and progesterone stimulation by the mutant ranged between 150 to 200%. This increase is believed to be due to a short range conformational change in the mutant as a result of the mutation rather than direct involvement of alpha 18Phe in the receptor binding. The evidence in support of this was derived from the fact that the affinity or interaction between the two subunits was impaired as indicated by the first order rate constant of hCG alpha 1 beta (km = 4.1 x 10(-2) min-1) at pH 3.0 at 23 degrees C which is one order of magnitude greater relative to rehCG (kw = 4.6 x 10(-3) min-1). All other mutations had no effect on the receptor binding or signal transduction of hCG indicating that, unlike NGF or TNF beta, beta-hairpin loops in hCG were not directly involved in receptor binding or post-receptor signaling events. However, since the mutation in the alpha 1 loop affects the receptor binding site, its presence in the vicinity of the alpha 1 loop is highly likely.

Construction and optimization of an efficient amplification method of a random ssDNA library by asymmetric emulsion PCR

Construction of a random ssDNA sublibrary is an important step of the aptamer screening process. The available construction methods include asymmetric PCR, biotin–streptavidin separation, and lambda exonuclease digestions, in which PCR amplification is a key step. The main drawback of PCR amplification is overamplification increasing nonspecific hybridization among different products and by‐products, which may cause the loss of potential high‐quality aptamers, inefficient screening, and even screening failure. Cycle number optimization in PCR amplification is the main way to avoid overamplification but does not fundamentally eliminate the nonspecific hybridization, and the decreased cycle number may lead to insufficient product amounts. Here, we developed a new method, “asymmetric emulsion PCR,” which could overcome the shortcomings of conventional PCR. In asymmetric emulsion PCR, different templates were separated by emulsion particles, allowing single‐molecule PCR, in which each template was separately amplified, and the nonspecific hybridization was avoided. Overamplification or formation of by‐products was not observed. The method is so simple that direct amplification of 40 or more cycles can provide a high‐quality ssDNA library. Therefore, the asymmetric emulsion PCR would improve the screening efficiency of systematic evolution of ligands by exponential enrichment.

Targeted Bisulfite Sequencing Reveals DNA Methylation Changes in Zinc Finger Family Genes Associated With KRAS Mutated Colorectal Cancer

Background: Colorectal cancer (CRC) is a leading cause of cancer death, and early diagnosis of CRC could significantly reduce its mortality rate. Previous studies suggest that the DNA methylation status of zinc finger genes (ZFGs) could be of potential in CRC early diagnosis. However, the comprehensive evaluation of ZFGs in CRC is still lacking. Methods: We first collected 1,426 public samples on genome-wide DNA methylation, including 1,104 cases of CRC tumors, 54 adenomas, and 268 para-tumors. Next, the most differentially methylated ZFGs were identified and validated in two replication cohorts comprising 218 CRC patients. Finally, we compared the prediction capabilities between the ZFGs and the SEPT9 in all CRC patients and the KRAS + and KRAS- subgroup. Results: Five candidate ZFGs were selected: ESR1, ZNF132, ZNF229, ZNF542, and ZNF677. In particular, ESR1 [area under the curve (AUC) = 0.91] and ZNF132 (AUC = 0.93) showed equivalent or better diagnostic capability for CRC than SEPT9 (AUC = 0.91) in the validation dataset, suggesting that these two ZFGs might be of potential for CRC diagnosis in the future. Furthermore, we performed subgroup analysis and found a significantly higher diagnostic capability in KRAS + (AUC ranged from 0.97 to 1) than that in KRAS- patients (AUC ranged from 0.74 to 0.86) for all these five ZFGs, suggesting that these ZFGs could be ideal diagnostic markers for KRAS mutated CRC patients. Conclusion: The methylation profiles of the candidate ZFGs could be potential biomarkers for the early diagnosis of CRC, especially for patients carrying KRAS mutations.

High expression of nuclear factor of activated T cells in Chinese primary non-small cell lung cancer tissues

PURPOSE

Nuclear factor of activated T cells (NFAT) has been reported to be involved in the development of various types of cancer including adenocarcinoma of the breast. This research was the first to investigate NFAT protein expression in primary non-small cell lung cancer (NSCLC) tissues from Chinese patients.

METHODS

NFAT protein expression was determined in 130 surgically resected primary NSCLC and matched normal tissues by immunohistochemical analysis. The association between NFAT expression and clinical categorical variables was further analyzed with the SPSS software.

RESULTS

We found that NFAT expression was much higher in 85 tumor tissues (65.4%) and lower in 45 tumor tissues (34.6%) compared with the matched normal tissues. Further statistical analysis by the chi-square test showed that high expression of NFAT proteins was significantly associated with tumor differentiation (p=0.045), invasion (p=0.031), histology (p<0.0001), tumor size (p=0.038) and cigarette smoking history (p=0.024). However, there was no correlation between the expression of NFAT proteins and pTNM classification, and no difference in 5-year survival rate between patients with high or low expression of NFAT proteins. Multivariate logistic regression analysis for the correlation between NFAT protein expression levels and various characteristics showed a significant association with histology (p=0.008, OR=0.273).

CONCLUSION

Our results revealed that high NFAT expression was present in Chinese NSCLCs and that NFAT expression might be involved in the process of human lung cancer development.

Increased expression of paxillin is found in human oesophageal squamous cell carcinoma: a tissue microarray study

Oesophageal cancer is one of the most common cancers worldwide. Currently, the tumour, node, metastasis (TNM) staging system is the primary method for determining its extent and prognosis, however, data suggest this system does not predict prognosis accurately. Research has, therefore, concentrated on searching for specific biomarkers. Paxillin has been shown to play an important role in controlling cell spread and migration. Its over-expression is considered to correlate with the prognosis of some types of cancers, however, the relationship between paxillin expression and clinical outcome in oesophageal cancer has not been investigated. This study determined the expression of paxillin by immunohistochemistry on the tissue microarray of 100 oesophageal squamous cell cancer patients followed up for a mean of 55 months. Paxillin was over-expressed in tumours in 27/100 cases, compared with 6/100 cases for adjacent non-tumoural cells. No correlation occurred between expression of paxillin and overall patient survival, hence paxillin is not an effective prognostic marker in these patients.

Effect of modification of the beta-hairpin and long loops simultaneously in both alpha- and beta-subunits on the function of human choriogonadotropin: part II

According to the X-ray diffraction, human choriogonadotropin has four beta-hairpin and two long loops, equally distributed in each of the alpha and beta subunits. Radical mutations such as the replacement of alpha 18Phe and alpha 74Phe with Thr in the alpha1 and alpha3 loops respectively and the replacement of alpha 45Lys with Asp in the alpha2 loop in the alpha-subunit were introduced while the loop sequences in the beta-subunit were replaced with the corresponding sequences in hFSH beta. Nine different double mutants with simultaneous mutations in both the alpha and beta loops including hCG alpha1 beta1, hCG alpha1 beta2, hCG alpha1 beta3, hCG alpha2 beta1, hCG alpha2 beta2, hCG alpha2 beta3, hCG alpha3 beta1, hCG alpha3 beta2 and hCG alpha3 beta3 were partially purified from insect High-Five cells. As previously reported (Shao et al., 1996, Mol. Cell. Endocrinol. 122, 173-182), the mutation in the alpha1 loop in the mutant, hCG alpha1 beta, the mutants hCG alpha1 beta1 and hCG alpha1 beta3 caused 200%, increase in the receptor binding, cAMP and progesterone stimulation. The mutant, hCG alpha1 beta2 and all other mutants behaved like the recombinant hCG (rehCG) in the receptor binding and post-receptor signaling activities. The molecular cause for this increase is probably due to a conformational change in the heterodimers caused by the mutation in the alpha1 loop. This conclusion is based on the results of the dissociation studies of the mutants heterodimers which indicated a decreased affinity between the subunits. The first order rate constants for the dissociation of the mutants hCG alpha1 beta1, hCG alpha1 beta2 and hCG alpha beta3 were 3.7 x 10(-2) min(-1), 1.4 x 10(-2) min(-1) and 4.6 x 10(-2) min(-1) respectively, as compared with 4.6 x 10(-3) min(-1) for the rehCG. It seems from the data that alpha 18Phe is located in, or in proximity to the receptor binding site and probably plays a critical role in maintaining either directly or indirectly its conformational integrity.

High Expression of Nuclear Factor of Activated T Cells in Chinese Primary Non-Small Cell Lung Cancer Tissues

Purpose

Nuclear factor of activated T cells (NFAT) has been reported to be involved in the development of various types of cancer including adenocarcinoma of the breast. This research was the first to investigate NFAT protein expression in primary non-small cell lung cancer (NSCLC) tissues from Chinese patients.

Methods

NFAT protein expression was determined in 130 surgically resected primary NSCLC and matched normal tissues by immunohistochemical analysis. The association between NFAT expression and clinical categorical variables was further analyzed with the SPSS software.

Results

We found that NFAT expression was much higher in 85 tumor tissues (65.4%) and lower in 45 tumor tissues (34.6%) compared with the matched normal tissues. Further statistical analysis by the chi-square test showed that high expression of NFAT proteins was significantly associated with tumor differentiation (p=0.045), invasion (p=0.031), histology (p<0.0001), tumor size (p=0.038) and cigarette smoking history (p=0.024). However, there was no correlation between the expression of NFAT proteins and pTNM classification, and no difference in 5-year survival rate between patients with high or low expression of NFAT proteins. Multivariate logistic regression analysis for the correlation between NFAT protein expression levels and various characteristics showed a significant association with histology (p=0.008, OR=0.273).

Conclusion

Our results revealed that high NFAT expression was present in Chinese NSCLCs and that NFAT expression might be involved in the process of human lung cancer development.

Effect of individual N-glycosyl chains in the beta-subunit on the conformation of human choriogonadotropin

Human choriogonadotropin is a heterodimeric glycoprotein hormone comprised of noncovalently associated alpha- and beta-subunits. Each of the subunits has two N-glycosyl chains. In our previous communication, we investigated the role of individual carbohydrate chains in the alpha-subunit on the signal transduction function and conformation of the hormone. This paper deals with the effect of individual or both N-glycosyl chains in the beta-subunit on the function and conformation of the monomer as well as of the heterodimer. Three mutants each of hCGbeta and hCG lacking N-glycosyl chains at beta13Asn, beta30Asn and beta13,30Asn were prepared by site-directed mutagenesis by replacing Thr residues in the recognition triplet sequence at beta15 and beta32 positions with Gln. All mutant heterodimers had receptor binding and cAMP and progesterone stimulating activities comparable to wild type hCG. While the loss of carbohydrate at beta13Asn or beta13,30Asn in the case of hCGbeta monomer resulted in a 4-6%, decrease in the ordered structure, the loss of the glycosyl chain at beta 30Asn did not alter the conformation as compared with the wild type hCGbeta. Similarly, all carbohydrate deficient hCG heterodimers had a decrease of 6-8%) in the ordered structure as compared with hCG. Thus, while the individual N-glycosyl chains did not affect the function of the hormone, they did have marked effect on its conformation but the conformational changes were localized and did not perturb the receptor binding and signal transduction sites.

Disseminated Rhizopus microsporus infection following allogeneic hematopoietic stem cell transplantation in a child with severe aplastic anemia

Disseminated Rhizopus microsporus infections are uncommon in children and are resistant to echinocandin and azole antifungal agents. We describe a child with severe aplastic anemia who developed disseminated R. microsporus infection following allogeneic hematopoietic stem cell transplantation. R. microsporus was identified microscopically in the hepatic drain culture and was confirmed on the basis of 18S rRNA and 28S rRNA sequence analyses. The patient was treated successfully with hepatic drainage and amphotericin B deoxycholate.

3D knife-edge characterization of two-photon absorption volume in silicon for integrated circuit testing

We have performed three-dimensional characterization of the TPA effective laser spot size in silicon using an integrated knife-edge sensor. The TPA-induced response of a CMOS integrated circuit is analyzed based on these results and compared to simulation; we have found that the charge injection capacity in IC's active layer could be influenced by irradiance energy and focus depth.

Role of amino acid residues at the interface of alpha52asparginyl-N-glycosyl chain of human choriogonadotropin

Of all the four N-glycosyl chains present in hCG, only one of them at alpha52Asn is located at the alpha/beta subunit interface and is crucial for the biological function of the hormone. The other three are exposed on the surface of the molecule and play only a minor role in the function of the hormone. The alpha52Asn oligosaccharide interacts with five amino acid residues in the beta-subunit, Tyr59, Val62, Phe64, Ala83, and Thr97. The present studies were undertaken to determine the role of the residues at the alpha52Asn-oligosaccharide and the beta-subunit interface in the mechanism of subunit association and downstream signaling events. Ten mutants, two of the alpha-subunit by the replacement of Asn52 and Thr80 with Gln and eight of the beta-subunit by multiple or single amino acid mutations, were prepared. These mutants included, hCGbeta59,62,64,97Ala, hCGbeta59,62,64Ala, hCGbeta62,64Ala, hCGbeta59Phe, hCGbeta62Ala or Thr, hCGbeta83Ile and hCGbeta97Ala. The mutation of the Asn52 to Gln resulted in a drastic change in its conformation and as a consequence in its weak affinity with the wild type beta as compared with that of the wild type hCGalpha and hCGalpha80Gln. The mutants with mutations in the four or three amino acids as well as both mutants of hCGbeta62Val almost failed to combine with hCGalpha again as a result of conformational changes shown by circular dichroism (CD) analysis and not due to their direct involvement in the subunit association. The double mutant combined with hCGalpha and the heterodimer behaved more like the wild type hCG. The mutation of Tyr to Phe resulted in a drop of 20% in the receptor binding and cAMP stimulation although Tyr is considered to be involved directly in subunit association. HCGbeta with mutations in the other amino acids, Phe64, Ala83, and Thr97, combined with the alpha subunit forming heterodimers with biological activity comparable to that of the wild type hCG. Thus, it appears that among the five amino acids in the vicinity of alpha52Asn carbohydrate, only beta59Tyr and beta62Val may be involved directly or indirectly in the alpha/beta beta dimer formation.