Zinc Finger and BTB Domain-Containing 20: A Newly Emerging Player in Pathogenesis and Development of Human Cancers.

Zinc finger and BTB domain-containing 20 (ZBTB20), which was initially identified in human dendritic cells, belongs to a family of transcription factors (TFs) with an N-terminal BTB domain and one or more C-terminal DNA-binding zinc finger domains. Under physiological conditions, ZBTB20 acts as a transcriptional repressor in cellular development and differentiation, metabolism, and innate immunity. Interestingly, multiple lines of evidence from mice and human systems have revealed the importance of ZBTB20 in the pathogenesis and development of cancers. ZBTB20 is not only a hotspot of genetic variation or fusion in many types of human cancers, but also a key TF or intermediator involving in the dysregulation of cancer cells. Given the diverse functions of ZBTB20 in both health and disease, we herein summarize the structure and physiological roles of ZBTB20, with an emphasis on the latest findings on tumorigenesis and cancer progression.

BACH2-mediated CD28 and CD40LG axes contribute to pathogenesis and progression of T-cell lymphoblastic leukemia.

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive subtype of ALL characterized by its high heterogeneity and unfavorable clinical features. Despite improved insights in genetic and epigenetic landscapes of T-ALL, the molecular mechanisms that drive malignant T-cell development remain unclear. BTB and CNC homology 2 (BACH2) is a lymphoid-specific transcription repressor recognized as a tumor suppressor in B-cell malignancies, but little is known about its function and regulatory network in T-ALL. Here we found extremely low levels of BACH2 in T-ALL clinical samples and cell lines compared to normal T cells. Overexpression of BACH2 in T-ALL cells not only induced cell growth retardation but also inhibited cancer progression and infiltration in xenografts. Further RNA sequencing (RNA-seq) analysis revealed significant alterations in regulation of defense and immune responses in T-ALL cells upon BACH2 overexpression. Strikingly, CD28 and CD40LG, two essential stimulatory molecules on T cells, were for the first time identified as novel downstream targets repressed by BACH2 in T-ALL cells. Interestingly, both CD28 and CD40LG were indispensable for T-ALL survival, since largely or completely silencing CD28 and CD40LG led to rapid cell death, whereas partial knockdown of them resulted in cell-cycle arrest and enhanced apoptosis. More importantly, BACH2-mediated CD28 and CD40LG signals contributed to cell migration and dissemination of T-ALL cells to the bone marrow, thus adding a new layer to the BACH2-mediated tumor immunoregulation in T-cell malignancies.

BACH1 Loss Exerts Antitumor Effects on Mantle Cell Lymphoma Cells via Inducing a Tumor-Intrinsic Innate Immune Response and Cell-Cycle Arrest.

BTB and CNC homology 1 (BACH1) is a transcription repressor that regulates multiple physiological processes, including intracellular heme homeostasis and immune responses. Increasing lines of evidence indicate that BACH1 reshapes metastasis and metabolism of human solid tumors. However, its potential roles in mantle cell lymphoma (MCL) remain largely unknown. Here, we found that silencing BACH1 in MCL cells induced markedly cell-cycle arrest and cell apoptosis, whereas overexpression of BACH1 exhibited the opposite patterns. Increased BACH1 levels not only promoted tumor growth and dispersal in xenografts, but also conferred a long-term poor prognosis in patients with MCL. Interestingly, RNA sequencing analysis revealed noncanonical function of BACH1 in regulation of type I interferon (IFNI) response, DNA replication and repair, and cell cycle. Mechanistically, zinc finger and BTB domain containing 20 (ZBTB20) and HMG-box transcription factor 1 (HBP1) were for the first time identified as two novel downstream targets repressed by BACH1 in MCL cells. Further double-knockdown functional assays confirmed that loss of BACH1 induced ZBTB20-mediated IFNα production and HBP1-mediated cell-cycle arrest, indicating that BACH1-centered regulatory network may be a novel targetable vulnerability in MCL cells. IMPLICATIONS: BACH1 serves as a pleotropic regulator of tumor-intrinsic innate immune response and cell-cycle progression, disruption of which may offer a promising therapeutic strategy for MCL treatment.

Jiawei Yanghe Decoction Regulates Bone-Lipid Balance through the BMP-SMAD Signaling Pathway to Promote Osteogenic Differentiation of Bone Mesenchymal Stem Cells.

Background: The Jiawei Yanghe decoction (JWYHD) is a traditional Chinese medicine formula for the treatment of osteoporosis, but its therapeutic mechanism has not been fully elucidated, and the therapeutic target of the intervention disease needs to be further verified. The dysfunction of bone mesenchymal stem cells (BMSCs) is considered to be an important pathogenesis of postmenopausal osteoporosis (PMOP). The purpose of this study was to explore how JWYHD regulates BMSC differentiation through the BMP-SMAD signal pathway. Methods: In the in vivo study, we used an ovariectomized PMOP rat (n = 36, 2-month-old, 200 ± 20 g) model and femur micro-CT analysis to study the effect of JWYHD on bone loss in rats. By immunofluorescence, the translocation expression of BMP2, a key protein in the pathway, was detected. Serum bone metabolism was detected by an enzyme-linked immunosorbent assay (ELISA). Alkaline phosphatase (ALP) activity was detected by alkaline phosphatase staining (ALPS), osteogenesis and matrix mineralization were detected by alizarin red staining (ARS), the adipogenic ability of BMSCs was detected by oil red staining (ORS), and CFU is used to detect the ability of cells to form colonies. The expression of related proteins was detected by western blotting. Results: In vivo and in vitro, the OP phenotypes of SD rats induced by ovariectomy (OVX) included impaired bone mineral density and microstructure, abnormal bone metabolism, and impaired MSC differentiation potential. JWYHD treatment reversed this trend and restored the differentiation potential of MSCs. JWYHD medicated serum and direct intervention of drugs activated the BMP-SMAD signaling pathway, promoted the osteogenic differentiation of BMSCs, and inhibited their adipogenic differentiation. Conclusions: Our data identified that JWYHD is an effective alternative drug for the treatment of PMOP that functions to stimulate the differentiation of BMSCs into osteoblasts in the BMP-SMAD signaling-dependent mechanism.

Genetic Associations and Architecture of Asthma-COPD Overlap.

BACKGROUND: Some people have characteristics of both asthma and COPD (asthma-COPD overlap), and evidence suggests they experience worse outcomes than those with either condition alone. RESEARCH QUESTION: What is the genetic architecture of asthma-COPD overlap, and do the determinants of risk for asthma-COPD overlap differ from those for COPD or asthma? STUDY DESIGN AND METHODS: We conducted a genome-wide association study in 8,068 asthma-COPD overlap case subjects and 40,360 control subjects without asthma or COPD of European ancestry in UK Biobank (stage 1). We followed up promising signals (P < 5 × 10-6) that remained associated in analyses comparing (1) asthma-COPD overlap vs asthma-only control subjects, and (2) asthma-COPD overlap vs COPD-only control subjects. These variants were analyzed in 12 independent cohorts (stage 2). RESULTS: We selected 31 independent variants for further investigation in stage 2, and discovered eight novel signals (P < 5 × 10-8) for asthma-COPD overlap (meta-analysis of stage 1 and 2 studies). These signals suggest a spectrum of shared genetic influences, some predominantly influencing asthma (FAM105A, GLB1, PHB, TSLP), others predominantly influencing fixed airflow obstruction (IL17RD, C5orf56, HLA-DQB1). One intergenic signal on chromosome 5 had not been previously associated with asthma, COPD, or lung function. Subgroup analyses suggested that associations at these eight signals were not driven by smoking or age at asthma diagnosis, and in phenome-wide scans, eosinophil counts, atopy, and asthma traits were prominent. INTERPRETATION: We identified eight signals for asthma-COPD overlap, which may represent loci that predispose to type 2 inflammation, and serious long-term consequences of asthma.

Lung proteomic biomarkers associated with chronic obstructive pulmonary disease.

Identifying protein biomarkers for chronic obstructive pulmonary disease (COPD) has been challenging. Most previous studies have used individual proteins or preselected protein panels measured in blood samples. Mass spectrometry proteomic studies of lung tissue have been based on small sample sizes. We used mass spectrometry proteomic approaches to discover protein biomarkers from 150 lung tissue samples representing COPD cases and controls. Top COPD-associated proteins were identified based on multiple linear regression analysis with false discovery rate (FDR) < 0.05. Correlations between pairs of COPD-associated proteins were examined. Machine learning models were also evaluated to identify potential combinations of protein biomarkers related to COPD. We identified 4,407 proteins passing quality controls. Twenty-five proteins were significantly associated with COPD at FDR < 0.05, including interleukin 33, ferritin (light chain and heavy chain), and two proteins related to caveolae (CAV1 and CAVIN1). Multiple previously reported plasma protein biomarkers for COPD were not significantly associated with proteomic analysis of COPD in lung tissue, although RAGE was borderline significant. Eleven pairs of top significant proteins were highly correlated (r > 0.8), including several strongly correlated with RAGE (EHD2 and CAVIN1). Machine learning models using Random Forests with the top 5% of protein biomarkers demonstrated reasonable accuracy (0.707) and area under the curve (0.714) for COPD prediction. Mass spectrometry-based proteomic analysis of lung tissue is a promising approach for the identification of biomarkers for COPD.

Heterozygosity of the Alpha 1-Antitrypsin Pi*Z Allele and Risk of Liver Disease.

The serpin family A member 1 (SERPINA1) Z allele is present in approximately one in 25 individuals of European ancestry. Z allele homozygosity (Pi*ZZ) is the most common cause of alpha 1-antitrypsin deficiency and is a proven risk factor for cirrhosis. We examined whether heterozygous Z allele (Pi*Z) carriers in United Kingdom (UK) Biobank, a population-based cohort, are at increased risk of liver disease. We replicated findings in Massachusetts General Brigham Biobank, a hospital-based cohort. We also examined variants associated with liver disease and assessed for gene-gene and gene-environment interactions. In UK Biobank, we identified 1,493 cases of cirrhosis, 12,603 Z allele heterozygotes, and 129 Z allele homozygotes among 312,671 unrelated white British participants. Heterozygous carriage of the Z allele was associated with cirrhosis compared to noncarriage (odds ratio [OR], 1.53; P = 1.1×10-04); homozygosity of the Z allele also increased the risk of cirrhosis (OR, 11.8; P = 1.8 × 10-09). The OR for cirrhosis of the Z allele was comparable to that of well-established genetic variants, including patatin-like phospholipase domain containing 3 (PNPLA3) I148M (OR, 1.48; P = 1.1 × 10-22) and transmembrane 6 superfamily member 2 (TM6SF2) E167K (OR, 1.34; P = 2.6 × 10-06). In heterozygotes compared to noncarriers, the Z allele was associated with higher alanine aminotransferase (ALT; P = = 4.6 × 10-46), aspartate aminotransferase (AST; P = 2.2 × 10-27), alkaline phosphatase (P = 3.3 × 10-43), gamma-glutamyltransferase (P = 1.2 × 10-05), and total bilirubin (P = 6.4 × 10-06); Z allele homozygotes had even greater elevations in liver biochemistries. Body mass index (BMI) amplified the association of the Z allele for ALT (P interaction = 0.021) and AST (P interaction = 0.0040), suggesting a gene-environment interaction. Finally, we demonstrated genetic interactions between variants in PNPLA3, TM6SF2, and hydroxysteroid 17-beta dehydrogenase 13 (HSD17B13); there was no evidence of epistasis between the Z allele and these variants. Conclusion: SERPINA1 Z allele heterozygosity is an important risk factor for liver disease; this risk is amplified by increasing BMI.

Genetic Variation in the Mitochondrial Glycerol-3-Phosphate Acyltransferase Is Associated With Liver Injury.

BACKGROUND AND AIMS: Most of the genetic basis of chronic liver disease remains undiscovered. APPROACH AND RESULTS: To identify genetic loci that modulate the risk of liver injury, we performed genome-wide association studies on circulating levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and total bilirubin across 312,671 White British participants in the UK Biobank. We focused on variants associated with elevations in all four liver biochemistries at genome-wide significance (P < 5 × 10-8 ) and that replicated using Mass General Brigham Biobank in 19,323 European ancestry individuals. We identified a genetic locus in mitochondrial glycerol-3-phosphate acyltransferase (GPAM rs10787429) associated with increased levels of ALT (P = 1.4 × 10-30 ), AST (P = 3.6 × 10-10 ), ALP (P = 9.5 × 10-30 ), and total bilirubin (P = 2.9 × 10-12 ). This common genetic variant was also associated with an allele dose-dependent risk of alcohol-associated liver disease (odd ratio [OR] = 1.34, P = 2.6 × 10-5 ) and fatty liver disease (OR = 1.18, P = 5.8 × 10-4 ) by International Classification of Diseases, 10th Revision codes. We identified significant interactions between GPAM rs10787429 and elevated body mass index in association with ALT and AST (P = 7.1 × 10-9 and 3.95 × 10-8 , respectively), as well as between GPAM rs10787429 and weekly alcohol consumption in association with ALT, AST, and alcohol-associated liver disease (P = 4.0 × 10-2 , 1.6 × 10-2 , and 1.3 × 10-2 , respectively). Unlike previously described genetic variants that are associated with an increased risk of liver injury but confer a protective effect on circulating lipids, GPAM rs10787429 was associated with an increase in total cholesterol (P = 2.0 × 10-17 ), LDL cholesterol (P = 2.0 × 10-10 ), and HDL cholesterol (P = 6.6 × 10-37 ). Single-cell RNA-sequencing data demonstrated hepatocyte-predominant expression of GPAM in cells that co-express genes related to VLDL production (P = 9.4 × 10-103 ). CONCLUSIONS: Genetic variation in GPAM is associated with susceptibility to liver injury. GPAM may represent a therapeutic target in chronic liver disease.

Clinical acupuncture therapy for femur head necrosis: A protocol for systematic review and meta analysis.

BACKGROUND: Femur Head Necrosis (FHN) is a common clinical joint orthopedic-related disease, and its incidence is increasing year by year. Symptoms include dull pain and dull pain in the affected hip joint or its surrounding joints. More severely, it can lead to limited joint movement and inability to walk autonomously. Surgical treatment has many sequelae. The high cost makes it unaffordable for patients, and the side effects of drug treatment are unknown. A large number of clinical studies have shown that acupuncture is effective in treating femoral head necrosis. Therefore, this systematic review aims to explore the safety and effectiveness of acupuncture in the treatment of femoral head necrosis. METHODS: We will conduct a comprehensive literature search in Medline, PubMed, Cochrane Database of Systematic Reviews, Embase, Chinese Biomedical Literatures Database (CBM), China National Knowledge Infrastructure (CNKI), Wang FangDatabase (WF), Chinese Scientific Journal Database (VIP) from inception to May 2021 without any language restriction. In addition, we will retrieve the unpublished studies and the references of initially included literature manually. The two reviewers will identify studies, extract data, and assess the quality independently. The outcomes of interest include: total effective rate; the total nasal symptom score; Hip function (Hip Harris joint score, WOMAC hip score, hip joint Lequesne index score, Merle D 'Aubigne and hip joint Postel score); Adverse events. Randomized clinical trials will be collected, methodological quality will be evaluated using the Cochrane risk-of-bias assessment tool, and the level of evidence will be rated using the Grading of Recommendations, Assessment, Development and Evaluation approach. Meta-analysis will be performed using RevMan 5.4.0 software. The heterogeneity test will be conducted between the studies, P < .1 and I2 > 50% are the thresholds for the tests. We will utilize the fixed effects model or the random effects model according to the size of heterogeneity. RESULTS: The meta-analysis program will systematically evaluate the efficacy and safety of acupuncture in the treatment of FHN patients. CONCLUSION: This study will investigate whether acupuncture can be used as one of the non-surgical and non-pharmacological therapies for the prevention or treatment of FHN. TRIAL REGISTRATION NUMBER: INPLASY202150035.

Integrated Strategy of Network Pharmacological Prediction and Experimental Validation Elucidate Possible Mechanism of Bu-Yang Herbs in Treating Postmenopausal Osteoporosis via ESR1.

Postmenopausal osteoporosis (PMOP) is a type of bone metabolism disease-related to estrogen deficiency with an increasing incidence. Traditional Chinese (TCM) has always been used and showed effectiveness in treating PMOP. In the current study, Bu-Yang herbs were considered to be the most frequently used and efficient TCM herbs in PMOP treatment. However, chemical and pharmacological profiles were not elucidated. Network pharmacology was conducted on representative Bu-Yang herbs (Yin-Yang-Huo. Du-Zhong, Bu-Gu-Zhi, Tu-Si-Zi) to investigate the mechanism of Bu-Yang herbs on PMOP. Chemical compounds, potential targets, and disease related genes were available from the corresponding database. Results showed that Bu-Yang herbs could interact with ESR1 and estrogen signaling pathways. For further validation, the Bu-Yang decoction (BYD), formula consisted of the above-mentioned 4 Bu-Yang herbs was presented for experimental validation. In vivo, BYD significantly reversed ovariectomy (OVX)-induced osteoporosis progress in a dose-dependent manner by up-regulation of bone mineral density and amelioration of bone microarchitecture. In vitro, BYD dramatically improved the proliferation and mineral nodules formation of osteoblasts. Both in vitro and in vivo results illustrated that the phenotype change induced by BYD is correlated with up-regulated of ESR1 and activation of the ß-catenin pathway. Meanwhile, inhibition of ESR1 by ICI182, 780 blocked the osteogenic phenotype and ß-catenin pathway activation induced by BYD. In conclusion, the current study suggested that Bu-Yang herbs are the most useful TCM herbs in treating PMOP. Furthermore, the integrated strategy of network pharmacology prediction with experimental validation suggested that BYD exerted its anti-PMOP via ESR1 and the downstream mechanism might be activation of the ß-catenin signaling pathway.

A systematic analysis of protein-altering exonic variants in chronic obstructive pulmonary disease.

Genome-wide association studies (GWASs) have identified regions associated with chronic obstructive pulmonary disease (COPD). GWASs of other diseases have shown an approximately 10-fold overrepresentation of nonsynonymous variants, despite limited exonic coverage on genotyping arrays. We hypothesized that a large-scale analysis of coding variants could discover novel genetic associations with COPD, including rare variants with large effect sizes. We performed a meta-analysis of exome arrays from 218,399 controls and 33,851 moderate-to-severe COPD cases. All exome-wide significant associations were present in regions previously identified by GWAS. We did not identify any novel rare coding variants with large effect sizes. Within GWAS regions on chromosomes 5q, 6p, and 15q, four coding variants were conditionally significant (P < 0.00015) when adjusting for lead GWAS single-nucleotide polymorphisms A common gasdermin B (GSDMB) splice variant (rs11078928) previously associated with a decreased risk for asthma was nominally associated with a decreased risk for COPD [minor allele frequency (MAF) = 0.46, P = 1.8e-4]. Two stop variants in coiled-coil α-helical rod protein 1 (CCHCR1), a gene involved in regulating cell proliferation, were associated with COPD (both P < 0.0001). The SERPINA1 Z allele was associated with a random-effects odds ratio of 1.43 for COPD (95% confidence interval = 1.17-1.74), though with marked heterogeneity across studies. Overall, COPD-associated exonic variants were identified in genes involved in DNA methylation, cell-matrix interactions, cell proliferation, and cell death. In conclusion, we performed the largest exome array meta-analysis of COPD to date and identified potential functional coding variants. Future studies are needed to identify rarer variants and further define the role of coding variants in COPD pathogenesis.

Chromatin Landscapes of Human Lung Cells Predict Potentially Functional Chronic Obstructive Pulmonary Disease Genome-Wide Association Study Variants.

Genome-wide association studies (GWASs) have identified dozens of loci associated with risk of chronic obstructive pulmonary disease (COPD). However, identifying the causal variants and their functional role in the appropriate cell type remains a major challenge. We aimed to identify putative causal variants in 82 GWAS loci associated with COPD susceptibility and predict the regulatory impact of these variants in lung-cell types. We used an integrated approach featuring statistical fine mapping, open chromatin profiling, and machine learning to identify functional variants. We generated chromatin accessibility data using the Assay for Transposase-Accessible Chromatin with High-Throughput Sequencing (ATAC-seq) for human primary lung-cell types implicated in COPD pathobiology. We then evaluated the enrichment of COPD risk variants in lung-specific open chromatin regions and generated cell type-specific regulatory predictions for >6,500 variants corresponding to 82 COPD GWAS loci. Integration of the fine-mapped variants with lung open chromatin regions helped prioritize 22 variants in putative regulatory elements with potential functional effects. Comparison with functional predictions from 222 Encyclopedia of DNA Elements (ENCODE) cell samples revealed cell type-specific regulatory effects of COPD variants in the lung epithelium, endothelium, and immune cells. We identified potential causal variants for COPD risk by integrating fine mapping in GWAS loci with cell-specific regulatory profiling, highlighting the importance of leveraging the chromatin status in relevant cell types to predict the molecular effects of risk variants in lung disease.

Genome-Wide Association Study: Functional Variant rs2076295 Regulates Desmoplakin Expression in Airway Epithelial Cells.

Rationale: Genetic association studies have identified rs2076295 in association with idiopathic pulmonary fibrosis (IPF). We hypothesized that rs2076295 is the functional variant regulating DSP (desmoplakin) expression in human bronchial epithelial cells, and DSP regulates extracellular matrix-related gene expression and cell migration, which is relevant to IPF development.Objectives: To determine whether rs2076295 regulates DSP expression and the function of DSP in airway epithelial cells.Methods: Using CRISPR (clustered regularly interspaced short palindromic repeat)/Cas9 editing (including regional deletion, indel, CRISPR interference, and single-base editing), we modified rs2076295 and measured DSP expression in edited 16HBE14o- and primary airway epithelial cells. Cellular integrity, migration, and genome-wide gene expression changes were examined in 16HBE14o- single colonies with DSP knockout. The expression of DSP and its relevant matrix genes was measured by quantitative PCR and also analyzed in single-cell RNA-sequencing data from control and IPF lungs.Measurements and Main Results:DSP is expressed predominantly in bronchial and alveolar epithelial cells, with reduced expression in alveolar epithelial cells in IPF lungs. The deletion of the DNA region-spanning rs2076295 led to reduced expression of DSP, and the edited rs2076295GG 16HBE14o- line has lower expression of DSP than the rs2076295TT lines. Knockout of DSP in 16HBE14o- cells decreased transepithelial resistance but increased cell migration, with increased expression of extracellular matrix-related genes, including MMP7 and MMP9. Silencing of MMP7 and MMP9 abolished increased migration in DSP-knockout cells.Conclusions: rs2076295 regulates DSP expression in human airway epithelial cells. The loss of DSP enhances extracellular matrix-related gene expression and promotes cell migration, which may contribute to the pathogenesis of IPF.

Synthesis, nanofeatures, in vitro thrombus lysis activity and in vivo thrombolytic activity of poly-alpha,beta-aspartyl-L-alanine.

AIM: Applying nanoscale assembly to the design of a thrombolytic agent. MATERIALS: poly-alpha,beta-DL-aspartyl-L-alanine (molecular weight: 15726 atomic mass units) from the thermal polycondensation of DL-aspartic acid and the amidation of polysuccimide with L-alanine. METHODS: The correlation of concentration and pH with nanofeatures, the correlation of concentration with in vitro thrombus lysis activity, the correlation of dose with the in vivo thrombolytic activity and the correlation of the dose with nanofeatures are all explained in this article. RESULTS: Poly-alpha,beta-DL-aspartyl-L-alanine was concentration- (6.4 x 10(4,2,-4,-6,-8,-10,-12) nM) and pH-dependently (pH 1.2, 7.4 and 7.6) assembled to various nanospecies, exhibited concentration-dependent (4, 8 and 16 microM) lysis action in vitro and dose-dependent (5, 0.5 and 0.05 micromol/kg) thrombolytic action in vivo. CONCLUSION: Upon entering the stomach, intestinal tract, blood and tissue fluids, poly-alpha,beta-DL-aspartyl-L-alanine assembled to small nanoparticles or nanoblocks to escape the entrapment by macrophages and exhibited desirable thrombolytic action.

3D QSAR of novel estrogen-RGD peptide conjugates: getting insight into structural dependence of anti-osteoporosis activity and side effect of estrogen in ERT.

To explore the structural dependence of the oral potency and side effect of estrogen-RGD peptide conjugates, here six novel conjugates were prepared via introducing RGD-tetrapeptides into both 3- and 17-positions of estradiol, and introducing RGD-octapeptides into 3-position of estrone. In an ovariectomized mouse model they exhibited higher anti-osteoporosis activity and lower side effect than estrogen. For 3D QSAR analysis the anti-osteoporosis activities of nine known conjugates estrogen-RGD tetrapeptide conjugates were also provided. Using Cerius(2) module their 3D QSAR analysis was performed, four equations with high r(2) values were established, and the structural dependence of the oral potency and side effect of them was elucidated.

Synthesis, evaluation and 3D QSAR analysis of novel estradiol-RGD octapeptide conjugates with oral anti-osteoporosis activity.

To enhance the potency, reduce the side effects and improve oral property of estradiol in estrogen replacement therapy (ERT), 6 novel estradiol-RGD octapeptide conjugates have been prepared. In an ovariectomized mouse osteoporotic model, at an oral dosage of 110.3 nmol/kg per day, their anti-osteoporosis activity was significantly higher than that of estradiol and estradiol-RGD tetrapeptide conjugates, and their risks of thrombogenesis and endometrial hyperplasia were significantly lower than that of estradiol and estradiol-RGD tetrapeptide conjugates. Using QSAR module of Cerius2, the 3D QSAR was performed for both femur weights and femur ash weights of estradiol-RGD peptide conjugates receiving mice. The r(2) of the 3D QSAR equations up to 0.995 and 0.988 indicates that they are capable of predicting a comparatively exact anti-osteoporosis activity for a conjugate.

The composition and sequence specificity of Pro-Ala-Lys-OH for the thrombolytic activities of P6A and related oligopeptides.

The in vitro and in vivo thrombolytic activities of Ala-Arg-Pro-Ala-Lys-OH, its analogs and the related peptides were assayed. The results indicate that when (5)Lys of Ala-Arg-Pro-Ala-Lys-OH is changed into (5)Arg, and (3)Lys of Pro-Ala-Lys-OH is changed into (3)Arg the thrombolytic activities are collapsed; when Pro-Ala-Lys-OH is changed into Ala-Pro-Lys-OH, and Ala-Arg-Pro-Ala-Lys-OH is changed into Ala-Arg-Ala-Pro-Lys-OH the thrombolytic activities are also collapsed; when (5)Lys of Ala-Arg-Pro-Ala-Lys-OH is changed into (5)nLeu the thrombolytic activities are again collapsed. All of the results indicate that for the thrombolytic activities of Ala-Arg-Pro-Ala-Lys-OH and the related peptides Pro-Ala-Lys-OH exhibits either amino acid composition specificity or sequence specificity. The composition and sequence specificity of Pro-Ala-Lys-OH reflects its rule as the pharmacophore of P6A and the related peptides.

Identification, synthesis and bioassay for the metabolites of P6A.

The metabolites Ala-Arg-Pro-Ala-OH, Ala-Arg-Pro-OH, Arg-Pro-Ala-Lys-OH and Pro-Ala-Lys-OH were identified by HPLC/ESI/MS from the in vivo blood of Ala-Arg-Pro-Ala-Lys-OH (P6A) received mice. The in vitro incubation of P6A in the blood of mice the same metabolites were also found by use of the Prep LC System. The protective intermediates of these metabolites were prepared via the solution method using the stepwise synthesis in 77.4, 90, 88, and 80% yield, respectively. After deprotection with catalytic hydrogenation the intermediates were converted into the corresponding sequences Arg-Pro-Ala-Lys-OH, Pro-Ala-Lys-OH, Ala-Arg-Pro-Ala-OH, and Ala-Arg-Pro-OH in 90, 95, 85% and 86% yield, respectively. In the thrombolysis in vivo assay the synthetic Ala-Arg-Pro-Ala-OH, and Ala-Arg-Pro-OH exhibited no activity. On the other hand the thrombolytic activity of Arg-Pro-Ala-Lys-OH was comparable to P6A, and an enhanced thrombolytic activity was observed for Pro-Ala-Lys-OH. In the in vitro fibrinolytic lysis tests the approximate results were obtained and an enhanced activity was also observed for Pro-Ala-Lys-OH. In the euglobulin clot lysis time tests P6A, Arg-Pro-Ala-Lys-OH and Pro-Ala-Lys-OH gave significantly shorter time than that given by UK, demonstrating their fast action.