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1.
J Am Coll Surg ; 237(2): 259-269, 2023 08 01.
Article in English | MEDLINE | ID: mdl-36919936

ABSTRACT

BACKGROUND: Acute traumatic coagulopathy (ATC) has many phenotypes and varying morbidity and mortality. The MA-R ratio, calculated from the admission thromboelastogram, serves as a biomarker to identify 1 phenotype of ATC and has previously been associated with significant derangements in the inflammatory response. This study evaluates outcomes related to abnormal MA-R ratios, including inflammatory responses, in a heterogeneous patient population. STUDY DESIGN: Patients from the Pragmatic, Randomized Optimal Platelet and Plasma Ratios (PROPPR) dataset were included. The MA-R ratio was calculated from admission thromboelastography, with a CRITICAL ratio defined as 11 or less. Key inflammatory mediators were identified as a priori. Cytokine expression was assessed during 24 hours using multivariable logistic regression. RESULTS: Significant elevations in the proinflammatory cytokines IL-1b, IL-6, and IL-8, as well as in the chemokines eotaxin, IFN-γ-induced protein 10, monocyte chemoattractant protein-1, and macrophage inflammatory protein-1ß, persisted during the first 24 hours. CRITICAL patients had significantly lower survival at 1, 3, 6, 12, and 18 hours and demonstrated significantly increased ARDS (odds ratio [OR] 1.817, 95% CI 1.082 to 3.051, p = 0.0239). CRITICAL patients had fewer ICU-free days (CRITICAL, 10 days, interquartile range [IQR] 0 to 25; vs NORMAL, 22 days, IQR 4 to 26, p < 0.0001) and fewer ventilator-free days (CRITICAL, 15 days, IQR 0 to 28; vs NORMAL, 26 days, IQR 9 to 28, p < 0.0001). CRITICAL patients were protected against systemic inflammatory response (OR 0.521, 95% CI 0.322 to 0.816, p = 0.0044). CONCLUSIONS: The subtype of ATC identified by the low MA-R ratio is associated with significant elevations in multiple proinflammatory cytokines at admission. Early mortality remains elevated in the CRITICAL group, in part due to coagulopathy. The MA-R ratio at admission is associated with a particularly morbid type of coagulopathy, associated with significant alterations in the inflammatory response after severe injury in heterogeneous patient populations.


Subject(s)
Blood Coagulation Disorders , Thrombelastography , Humans , Blood Coagulation Disorders/diagnosis , Blood Coagulation Disorders/etiology , Blood Platelets , Cytokines , Inflammation/etiology
2.
Oncogene ; 30(7): 822-31, 2011 Feb 17.
Article in English | MEDLINE | ID: mdl-20956939

ABSTRACT

MicroRNAs are gene regulators that work through a posttranscriptional repression mechanism. Dysregulation of microRNA expression could lead to a variety of disorders, in particular, human cancer, and has also been implicated in antihormone therapy resistance. However, little is known whether microRNAs have a role in estrogen-independent growth, leading to tamoxifen resistance in estrogen receptor (ER)-positive tumors. In this study, we use an in vivo selection system against a microRNA library using the MCF-7 model and demonstrate that miR-101 promotes estrogen-independent growth and causes the upregulation of phosphorylated Akt (pAkt) without impacting the ER level or activity. Importantly, although miR-101 suppresses cell growth in normal estradiol (E2)-containing medium, it promotes cell growth in E2-free medium. Moreover, estrogen deprivation greatly enhances miR-101-mediated Akt activation. Finally, we show that MAGI-2 (membrane-associated guanylate kinase), a scaffold protein required for PTEN (phosphatase and tensin homolog) activity, is a direct target for miR-101; suppression of MAGI-2 by miR-101 reduces PTEN activity, leading to Akt activation. Taken together, these results not only establish a role for miR-101 in estrogen-independent signaling but also provide a mechanistic link between miR-101 and Akt activation.


Subject(s)
Estrogens/metabolism , MicroRNAs/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Adaptor Proteins, Signal Transducing , Adenocarcinoma/drug therapy , Adenocarcinoma/metabolism , Antineoplastic Agents, Hormonal/pharmacology , Breast Neoplasms/drug therapy , Breast Neoplasms/metabolism , Carrier Proteins/metabolism , Cell Line, Tumor , Cell Proliferation/drug effects , Drug Resistance, Neoplasm , Female , Guanylate Kinases , Humans , PTEN Phosphohydrolase/metabolism , Receptors, Estrogen/metabolism , Tamoxifen/pharmacology , Up-Regulation
3.
Schizophr Res ; 77(1): 1-9, 2005 Sep 01.
Article in English | MEDLINE | ID: mdl-16005380

ABSTRACT

BACKGROUND: Despite the effectiveness of anti-psychotic pharmacotherapy, residual hallucinations and delusions do not completely resolve in some medicated patients. Additional cognitive behavioral therapy (CBT) seems to improve the management of positive symptoms. Despite promising results, the efficacy of CBT is still unclear. The present study addresses this issue taking into account a number of newly published controlled studies. METHOD: Fourteen studies including 1484 patients, published between 1990 and 2004 were identified and a meta-analysis of their results performed. RESULTS: Compared to other adjunctive measures, CBT showed significant reduction in positive symptoms and there was a higher benefit of CBT for patients suffering an acute psychotic episode versus the chronic condition (effect size of 0.57 vs. 0.27). DISCUSSION: CBT is a promising adjunctive treatment for positive symptoms in schizophrenia spectrum disorders. However, a number of potentially modifying variables have not yet been examined, such as therapeutic alliance and neuropsychological deficits.


Subject(s)
Cognitive Behavioral Therapy/methods , Schizophrenia/therapy , Schizophrenic Psychology , Adult , Combined Modality Therapy , Female , Follow-Up Studies , Humans , Male , Randomized Controlled Trials as Topic , Retrospective Studies , Treatment Outcome
4.
J Cardiovasc Pharmacol ; 35(4): 595-605, 2000 Apr.
Article in English | MEDLINE | ID: mdl-10774791

ABSTRACT

A murine model of vascular injury-induced neointimal hyperplasia was developed by using a photoactive dye, rose bengal. Photoactivation of rose bengal induced vascular injury to the femoral arteries of C57B1/6 mice and resulted in an occlusive neointimal hyperplasia after 4 weeks. The cellular elements of the hyperplastic neointima were found to be alpha-actin-positive vascular smooth muscle cells expressing epidermal growth factor (EGF) receptor at high levels. EGF-Gen, an EGF-R-specific inhibitor with potent anticancer activity, suppressed the formation of hyperplastic neointima. Morphometric analysis of serial tissue sections at 4 weeks after vascular injury showed that in 75% of the EGF-Gen-treated mice, the maximal stenosis index was only 0.44 +/- 0.13, whereas in 75% of phosphate-buffered saline (PBS)-treated mice, the maximal stenosis index was 1.20 +/- 0.25. The mean neointima/media ratios for areas of maximum neointimal hyperplasia were 0.59 +/- 0.16 (n = 24) for the EGF-Gen-treated group, 0.99 +/- 16 (n = 45) for the PBS group (EGF-Gen vs. PBS, p = 0.0017), and 1.03 +/- 18 (n = 8) for group treated with unconjugated genistein (EGF-Gen vs. Gen, p = 0.0088). EGF-Gen treatment of mice with vascular injury to the left femoral artery was not associated with any clinical signs of toxicity or histopathologic lesions in any of the organs, including the uninjured right femoral artery. EGF-Gen also inhibited VSMC migration in vitro, without affecting VSMC proliferation and viability, suggesting that EGF-Gen is blocking neointima formation by inhibiting cellular migration to vascular injury sites. In conclusion, EGF-Gen may be useful as a nontoxic prophylactic agent for prevention of restenosis in clinical settings.


Subject(s)
Antineoplastic Agents/pharmacology , Epidermal Growth Factor/pharmacology , ErbB Receptors/antagonists & inhibitors , Genistein/pharmacology , Tunica Intima/pathology , Vascular Diseases/prevention & control , Animals , Antineoplastic Agents/chemistry , Cell Movement , Constriction, Pathologic , Disease Models, Animal , Epidermal Growth Factor/chemistry , ErbB Receptors/genetics , ErbB Receptors/metabolism , Genistein/chemistry , Hyperplasia/prevention & control , Male , Mice , Mice, Inbred C57BL , Muscle, Smooth, Vascular/cytology , Muscle, Smooth, Vascular/physiology , Protein-Tyrosine Kinases/antagonists & inhibitors , Recombinant Proteins/chemistry , Recombinant Proteins/pharmacology , Tunica Intima/drug effects , Up-Regulation , Vasoconstriction/drug effects
5.
J Cardiovasc Pharmacol ; 35(2): 179-88, 2000 Feb.
Article in English | MEDLINE | ID: mdl-10672848

ABSTRACT

We identified a novel organic compound, 4-(3'-bromobenzoyl)-6,7-dimethoxyquinazoline (compound WHI-P164), as a potent inhibitor of triglyceride (TG) synthesis. In an in vitro model of lipid synthesis, WHI-P164 (but not any one of the three structurally similar control dimethoxyquinazoline compounds) inhibited the accumulation of TG-rich intracellular lipid droplets in Caco-2 human intestinal cells in a concentration-dependent fashion. WHI-P164 caused no acute toxicity associated with morbidity or mortality in mice when administered at dose levels ranging from 0.5 to 80 mg/kg. In pharmacokinetic studies in mice, WHI-P164 was rapidly eliminated from plasma with a terminal elimination half-life of 26.1 +/- 1.3 min after intraperitoneal administration and 33.3 +/- 11.3 min after intravenous administration. Treatment with 40 mg/kg WHI-P164 (but not one of three structurally similar control dimethoxyquinazoline compounds) administered intraperitoneally once daily for 7 consecutive treatment days blocked the in vivo hepatic TG synthesis in both apoE-deficient and wild-type C57B1/6 mice. In apoE-deficient mice maintained on a high-fat/high-cholesterol Western diet, WHI-P164 substantially reduced the lipid accumulation in the liver after 7 days of treatment and the lipid accumulation in the aorta after 1 month of treatment. Our results in apoE-deficient mice show that lipid accumulation in hepatocytes and foam cells are related events, and inhibiting TG synthesis with WHI-P164 offers an effective means to treat atherosclerosis.


Subject(s)
Aorta/pathology , Apolipoproteins/deficiency , Arteriosclerosis/drug therapy , Enzyme Inhibitors/therapeutic use , Lipid Metabolism , Quinazolines/therapeutic use , Triglycerides/biosynthesis , Animals , Aorta/drug effects , Arteriosclerosis/etiology , Caco-2 Cells , Chromatography, High Pressure Liquid/methods , Dietary Fats , Dose-Response Relationship, Drug , Enzymes/blood , Humans , Hypercholesterolemia/pathology , Liver/drug effects , Liver/metabolism , Liver/pathology , Mice , Mice, Inbred C57BL , Quinazolines/blood , Quinazolines/toxicity , Time Factors , Triglycerides/blood
6.
Biochem Biophys Res Commun ; 268(3): 835-41, 2000 Feb 24.
Article in English | MEDLINE | ID: mdl-10679292

ABSTRACT

Apolipoprotein E (apoE)-deficient mice exhibit neuronal abnormalities similar to those in Alzheimer's disease and enhanced sensitivity to stroke-associated injuries. Here, we show that apoE deficiency results in impaired microglia/macrophage recruitment and accumulation after cerebral infarct. Astrogliosis and apolipoprotein D (apoD) expression are unaffected, suggesting that the neurological abnormalities of apoE-deficient mice could be due to impaired microglia/macrophage recruitment/accumulation, which is important for the clearance of neurodegenerative products via reverse cholesterol transport. To our knowledge, the results presented herein provide the first experimental evidence that brain microglia/macrophage recruitment/accumulation is affected by apoE deficiency. The insights gained from this study should facilitate the elucidation of the role of apoE in neurological disorders such as dementia with stroke and Alzheimer's disease.


Subject(s)
Apolipoproteins E/deficiency , Apolipoproteins E/metabolism , Apolipoproteins/metabolism , Oxygen/toxicity , Stroke/chemically induced , Stroke/metabolism , Alzheimer Disease/etiology , Animals , Apolipoproteins D , Disease Models, Animal , Humans , Immunohistochemistry , Macrophages/drug effects , Macrophages/metabolism , Macrophages/pathology , Mice , Mice, Inbred C57BL , Mice, Knockout , Microglia/drug effects , Microglia/metabolism , Microglia/pathology , Singlet Oxygen , Stroke/pathology
7.
Biochem Biophys Res Commun ; 267(1): 22-5, 2000 Jan 07.
Article in English | MEDLINE | ID: mdl-10623568

ABSTRACT

Amyotrophic lateral sclerosis (ALS) is a progressive, fatal neurodegenerative disorder involving the motor neurons of cortex, brain stem, and spinal cord. About 10% of all ALS patients are familial cases (FALS), of which 20% have mutations in the Cu, Zn-superoxide dismutase (SOD1) gene. The murine model for FALS, which overexpresses a FALS variant of the SOD1 gene, exhibits progressive limbic paralysis followed by death. Treatment of FALS mice with WHI-P131, a specific inhibitor of Janus kinase 3 (JAK3), increased survival by more than two months, suggesting that specific inhibitors of JAK3 may be useful in the treatment of human ALS. These results uniquely establish JAK3 as a novel molecular target for the treatment of FALS.


Subject(s)
Antioxidants/pharmacology , Enzyme Inhibitors/therapeutic use , Genistein/therapeutic use , Motor Neuron Disease/drug therapy , Motor Neuron Disease/genetics , Neuroprotective Agents/therapeutic use , Protein-Tyrosine Kinases/antagonists & inhibitors , Quinazolines/therapeutic use , Superoxide Dismutase/genetics , Animals , Disease Models, Animal , Genetic Variation , Genistein/pharmacology , Heterozygote , Humans , Janus Kinase 3 , Male , Mice , Mice, Inbred BALB C , Mice, Transgenic , Paralysis , Quinazolines/pharmacology
8.
Bioorg Med Chem Lett ; 10(1): 87-90, 2000 Jan 03.
Article in English | MEDLINE | ID: mdl-10636251

ABSTRACT

In a systematic search for novel dual function antioxidants with potent anti-HIV activity, we evaluated 9 rationally designed non-nucleoside inhibitors (NNI) of HIV-1 RT for antioxidant and anti-HIV activities. Our lead phenethyl-5-bromopyridyl thiourea (PEPT) compounds, N-[2-(2-methoxyphenylethyl)]-N'-[2-(5-bromopyridyl)]-thioure a (2) and N-[2-(2-chlorophenylethyl)]-N'-[2-(5-bromopyridyl)]-thiourea (9), inhibited the oxidation of ABTS to ABTS*+ by metmyoglobin in the presence of hydrogen peroxide with EC50 values of 79 and 75 microM, respectively. Both compounds effectively inhibited the oxidation-induced green fluorescence emission from the free radical-sensitive indicator dye 2',7'-dichlorodihydrofluorescein diacetate in CEM human T-cells and Nalm-6 human B-cells exposed to hydrogen peroxide. To our knowledge, compounds 2 and 9 are the first NNI of HIV-1 RT with potent anti-oxidant activity. Furthermore, the activity center was defined as the sulfhydryl group since alkylated PEPT derivatives were inactive. The presence of a free thiourea group was also essential for the anti-HIV activity of the PEPT compounds.


Subject(s)
Anti-HIV Agents/chemistry , Anti-HIV Agents/pharmacology , Antioxidants/chemistry , Antioxidants/pharmacology , Pyridines/chemistry , Pyridines/pharmacology , Thiourea/pharmacology , B-Lymphocytes/drug effects , B-Lymphocytes/metabolism , Crystallography, X-Ray , Flow Cytometry , Fluorescence , Free Radical Scavengers/chemistry , Free Radical Scavengers/pharmacology , HIV Reverse Transcriptase/antagonists & inhibitors , Humans , Hydrogen Peroxide/toxicity , Structure-Activity Relationship , T-Lymphocytes/drug effects , T-Lymphocytes/metabolism , Thiourea/analogs & derivatives
9.
Radiat Res ; 152(5): 508-16, 1999 Nov.
Article in English | MEDLINE | ID: mdl-10523874

ABSTRACT

We evaluated the in vivo antioxidant activity of genistein in a mouse model of singlet oxygen-induced cerebral stroke. Cerebral stroke was induced in male BALB/c mice through extensive microvessel damage caused by photoactivated rose bengal dye. The photoactivation of the intravenously administered rose bengal was achieved by transcranial illumination with green light. Genistein was more active than its analogs and other antioxidants that were used as control agents. At a dose of 16 mg/kg genistein administered every 6 h from 24 h prior to irradiation until 24 h after irradiation, the average size of the cerebral lesion of genistein-treated mice was significantly smaller than that in control mice treated with the carrier DMSO (8.1 +/- 1.0 mm(2) compared to 14.6 +/- 0.7 mm(2), P < 0.001). Our findings provide experimental evidence that genistein could be useful for the prevention of cerebral stroke and other pathological conditions caused by reactive oxygen species.


Subject(s)
Antioxidants/pharmacology , Genistein/pharmacology , Neuroprotective Agents/pharmacology , Reactive Oxygen Species , Stroke/drug therapy , Animals , Antioxidants/therapeutic use , Disease Models, Animal , Genistein/therapeutic use , Male , Mice , Mice, Inbred BALB C , Neuroprotective Agents/therapeutic use , Stroke/etiology
10.
Biochem Biophys Res Commun ; 258(3): 685-8, 1999 May 19.
Article in English | MEDLINE | ID: mdl-10329446

ABSTRACT

Amyotrophic lateral sclerosis (ALS), whether sporadic or familial (FALS), is a progressive, fatal neurodegenerative disorder involving the motor neurons of the cortex, brain stem, and spinal cord. In some studies, the male/female ratio of ALS patients was as high as 2 to 1. In FALS mice, disease onset and mortality were earlier among males than among females. This sexual dimorphism was due to estrogen, as treatment with genistein, a phytoestrogen, eliminated the observed sexual dimorphism in FALS mice. Genistein treatment also protected against oxygen singlet-induced cerebral damage in vivo. However, sexual dimorphism was not observed in this model of stroke; and genistein was equally effective in males and females. These data suggest that genistein has both estrogen-dependent and estrogen-independent neuroprotective activities and it should be investigated as a prophylactic agent against pathologic conditions such as ALS and stroke.


Subject(s)
Amyotrophic Lateral Sclerosis/drug therapy , Cerebrovascular Disorders/drug therapy , Genistein/therapeutic use , Neuroprotective Agents/therapeutic use , Amyotrophic Lateral Sclerosis/genetics , Animals , Cerebrovascular Disorders/genetics , Disease Models, Animal , Female , Male , Mice , Mice, Inbred BALB C , Mice, Transgenic
11.
Biochem Biophys Res Commun ; 257(3): 714-8, 1999 Apr 21.
Article in English | MEDLINE | ID: mdl-10208849

ABSTRACT

Lipoprotein (a) [Lp(a)] is a LDL-like particle with one apolipoprotein(a) [apo(a)] covalently bound to apolipoprotein B, the structural protein of Low Density Lipoprotein (LDL). Lewis Lung Carcinoma (LL/2) cells exhibited delayed growth and reduced angiogenesis in apo(a) transgenic mice, expressing a recombinant apo(a) [r-apo(a)] with 18 kringle 4 repeats. The mean microvessel density of subcutaneous LL/2 tumors from apo(a) transgenic mice was significantly lower than that of tumors from control wild type mice. CHO cells secreting a truncated apo(a) protein with only six kringle 4 repeats did not exhibit delayed tumor growth nor did it impair angiogenesis. These data point to an unappreciated role of human apo(a) in angiogenesis and cancer biology. As angiogenesis is necessary for reendothelialization following vascular injury, suppression of angiogenesis by apo(a) may also contribute to the atherogenicity of apo(a). The differences between the truncated apo(a) and r-apo(a) are consistent with the higher atherogenicity of higher molecular weight isoforms.


Subject(s)
Apolipoproteins A/metabolism , Arteriosclerosis/pathology , Carcinoma, Lewis Lung/blood supply , Neovascularization, Pathologic , Animals , Apolipoproteins A/chemistry , Apolipoproteins A/genetics , CHO Cells , Carcinoma, Lewis Lung/pathology , Cell Division , Cricetinae , Gene Deletion , Gene Expression , Humans , Immunohistochemistry , Kringles/genetics , Mice , Mice, Inbred C57BL , Mice, SCID , Mice, Transgenic , Neoplasm Transplantation , Recombinant Proteins/biosynthesis , Recombinant Proteins/chemistry , Recombinant Proteins/metabolism , Transfection , Tumor Cells, Cultured
12.
Biochem Biophys Res Commun ; 255(2): 377-81, 1999 Feb 16.
Article in English | MEDLINE | ID: mdl-10049716

ABSTRACT

An inverse relationship has been reported between cancer risk and cholesterol level, prompting the hypothesis that hypercholesterolemia may be protective against cancer. We tested this hypothesis by evaluating the growth of Lewis lung carcinoma in three different murine models of hypercholesterolemia: Pluronic treated mice, apolipoprotein E (ApoE) deficient mice, and low density lipoprotein receptor (LDL-R) deficient mice. Only the accumulation of LDL-cholesterol in LDL-R deficient mice suppressed tumor growth. Accumulation of chylomicrons, very low density lipoproteins (VLDL), and cholesterol-enriched remnants in the Pluronic treated mice and ApoE deficient mice did not inhibit tumor growth, even though mice in all three models were equally hypercholesterolemic. Taken together, the experimental evidence from our studies indicate that high plasma cholesterol in the form of LDL-cholesterol could have a beneficial effect against cancer in vivo.


Subject(s)
Carcinoma, Lewis Lung/prevention & control , Cholesterol, LDL/pharmacology , Growth Inhibitors/pharmacology , Hypercholesterolemia/genetics , Hypercholesterolemia/metabolism , Receptors, LDL/deficiency , Animals , Antineoplastic Agents/pharmacology , Carcinoma, Lewis Lung/etiology , Carcinoma, Lewis Lung/metabolism , Humans , Mice , Mice, Inbred C57BL , Mice, Knockout , Mice, Transgenic , Neoplasm Transplantation , Neovascularization, Pathologic/complications , Receptors, LDL/genetics , Tumor Cells, Cultured
13.
Biochem Biophys Res Commun ; 251(1): 356-9, 1998 Oct 09.
Article in English | MEDLINE | ID: mdl-9790960

ABSTRACT

Lipoprotein (a) [Lp(a)], a risk factor for coronary artery disease, is a LDL-like particle with apolipoprotein (a) [apo(a)] covalently linked to apolipoprotein B (apoB). Apo(a) has many repeats of kringle 4-like domain, classified as type 1 through type 10 (T1-T10). Deletion analysis was performed to define the functional modules of human apo(a). We found that T7 has an affinity for cell surfaces and is required for Lp(a) formation. Cell surface binding was inhibited by L-proline, KI = 4.7 +/- 3.6 mM (n=3). We also found that T8 has an affinity for subendothelial extracellular matrix (ECM). ECM binding was inhibited modestly by L-proline (KI = 6.1 +/- 1.9 mM, n=3), and more effectively by L-lysine (KI = 2.7 +/- 1.0 mM, n=3) and its analogue, 6-aminohexanoic acid (KI = 0.35 +/- 0.13 mM, n=3). These data point to T7 and T8 as important functional modules of apo(a).


Subject(s)
Lipoprotein(a)/chemistry , Lipoprotein(a)/physiology , Animals , Apolipoproteins A/chemistry , Apolipoproteins A/metabolism , Apolipoproteins A/physiology , CHO Cells , Cricetinae , Extracellular Matrix Proteins/metabolism , Humans , Kringles/physiology , Lipoprotein(a)/metabolism , Membrane Proteins/metabolism , Protein Binding , Protein Isoforms/chemistry , Protein Isoforms/metabolism , Protein Isoforms/physiology , Tumor Cells, Cultured
14.
Biochem Biophys Res Commun ; 247(2): 277-9, 1998 Jun 18.
Article in English | MEDLINE | ID: mdl-9642116

ABSTRACT

Hypertension is more common among African Americans than Americans of European descent. However, the genetic etiology has not been defined. Similarly, lipoprotein (Lp) (a), an independent risk factor for cardiovascular disease, is higher among African Americans. To explore the relationship between Lp (a) and hypertension, we measured the blood pressure of transgenic mice expressing apolipoprotein(a), the unique protein moiety of lipoprotein(a). As controls, we also determined blood pressure for apoE deficient mice, low density lipoprotein-receptor (LDL-R) deficient mice, and wild type C57Bl/6 mice. Apo(a) expression was not associated with hypertension. Surprisingly, LDL-R deficient mice exhibited male-associated hypertension. This observation could explain the higher incidence of atherosclerosis in male LDL-R deficient mice and human familial hypercholesterolemia (FH) patients. LDL-R deficient mice were more sensitive to photochemically induced cerebral stroke. However, this hypersensitivity was only modestly associated with sexual dimorphism. The presented data suggest that LDL-R deficiency results in hitherto unrecognized changes in the vascular tone.


Subject(s)
Apolipoproteins/genetics , Hypertension/etiology , Lipoprotein(a) , Receptors, LDL/deficiency , Animals , Apolipoproteins E/deficiency , Apoprotein(a) , Blood Pressure , Cerebrovascular Disorders/etiology , Disease Models, Animal , Female , Humans , Hypertension/genetics , Hypertension/physiopathology , Male , Mice , Mice, Inbred C57BL , Mice, Transgenic , Sex Characteristics
15.
Biochem J ; 309 ( Pt 3): 899-904, 1995 Aug 01.
Article in English | MEDLINE | ID: mdl-7639708

ABSTRACT

Lipoprotein(a) [Lp(a)] is a risk factor for coronary artery disease. It is composed of lipids and apolipoprotein(a) [apo(a)] linked to apolipoprotein B (apoB) by a disulphide bond between Cys-4057 of apo(a)'s kringle 36 and possibly Cys-3734 of apoB. We call this the covalent apo(a): apoB-Lp interaction, to distinguish it from the non-covalent apo(a)/Lp(a): apoB-Lp interaction, which is probably mediated by apo(a)'s kringle 33 and residues 3304-3317 of apoB. The non-covalent interaction could be the initial interaction which brings apo(a) and apoB together prior to covalent linkage and Lp(a) formation. The non-covalent apo(a)/Lp(a)-binding site on apoB is evolutionarily more ancient than the covalent apo(a)-binding site on apoB. Both human and non-human low-density lipoproteins (LDLs) bind non-covalently to human apo(a)/Lp(a); however, only rabbit and human LDLs bind covalently to human apo(a). The non-covalent interaction between mouse LDL and human apo(a)/Lp(a) has a Kd of (1.7 +/- 1.33) x 10(-7) M (n = 3). This explains the co-localization of human apo(a) and mouse apoB in the atherosclerotic lesions of human apo(a) transgenic mice and supports our hypothesis that the non-covalent interaction is a contributing factor to apo(a) atherogenicity.


Subject(s)
Apolipoproteins/metabolism , Lipoprotein(a) , Lipoproteins, LDL/metabolism , Animals , Apolipoproteins/genetics , Apoprotein(a) , CHO Cells , Cells, Cultured , Chickens , Cloning, Molecular , Cricetinae , Humans , Mice , Mice, Transgenic , Protein Binding , Rabbits , Species Specificity
16.
J Biol Chem ; 270(26): 15471-4, 1995 Jun 30.
Article in English | MEDLINE | ID: mdl-7797538

ABSTRACT

Lipoprotein(a) (Lp(a)), a risk factor for coronary artery disease, is a LDL-like particle with apolipoprotein(a) (apo(a)) covalently linked to apolipoprotein B (apoB), the main protein component of LDL. Apo(a) is highly homologous to plasminogen and its gene probably arose by duplication of the plasminogen gene. It has many repeats of kringle-4-like domain, classified as type 1 through type 10 (T1-T10). T9 is responsible for the covalent linkage between apo(a) and LDL. However, we found that T9 has no affinity for LDL. Therefore, an initial noncovalent interaction between apo(a) and LDL is necessary to bring T9 and LDL together. T6 and possibly T7 of apo(a) were identified as the kringles which mediate this initial interaction. With these findings, a two-step model for Lp(a) formation is proposed. This model should be useful in the design of Lp(a) formation inhibitors. These inhibitors are potential antihyperlipoprotein(a) drugs.


Subject(s)
Lipoprotein(a)/biosynthesis , Amino Acid Sequence , Binding Sites , Cells, Cultured , Lipoprotein(a)/chemistry , Lipoproteins, LDL/metabolism , Models, Biological , Molecular Sequence Data
17.
Biochem Biophys Res Commun ; 211(3): 754-60, 1995 Jun 26.
Article in English | MEDLINE | ID: mdl-7598703

ABSTRACT

A plasmid directing the expression of preapolipoprotein C-III fused to beta-galactosidase was constructed. Escherichia coli harboring this construct produced the hybrid, with full beta-galactosidase activity, at 0.6% of total cellular protein. Purified preapoC-III-beta-galactosidase hybrid exhibited specific binding to very low density lipoproteins, which was inhibited by purified apoC-III. No binding to low density lipoproteins was observed. Binding was mediated by the phospholipids of very low density lipoproteins, as the hybrid had a specific affinity for phospholipids and no detectable affinity for triglycerides, cholesteryl esters, or cholesterol. The differential binding suggests that there are differences between the phospholipids of very low density lipoproteins and the phospholipids of low density lipoproteins.


Subject(s)
Apolipoproteins C/metabolism , Lipoproteins, LDL/metabolism , Lipoproteins, VLDL/metabolism , Phospholipids/metabolism , Protein Precursors/metabolism , Amino Acid Sequence , Apolipoprotein C-III , Apolipoproteins C/genetics , Base Sequence , Escherichia coli/genetics , Lipoproteins , Molecular Sequence Data , Protein Binding , Protein Precursors/genetics , Recombinant Fusion Proteins/metabolism , beta-Galactosidase/genetics
18.
Biochem J ; 307 ( Pt 1): 17-22, 1995 Apr 01.
Article in English | MEDLINE | ID: mdl-7717972

ABSTRACT

Lipoprotein (a) [Lp(a)] is a risk factor for coronary artery disease. It is characterized by apolipoprotein (a) [apo(a)] disulphide linked to apolipoprotein B (apoB), by Cys4057 of apo(a) and possibly Cys3734 of apoB. We call this the covalent apo(a):apoB-Lp interaction, to distinguish it from the non-covalent Lp(a):apoB-Lp interaction, mediated by the proline-binding kringle-4-like domain(s) of Lp(a). The Lp(a):apoB-Lp interaction was inhibited by an apoB peptide spanning residues 3304-3317. This peptide was found by a computerized search for sites on apoB similar to the plasminogen's kringle-4-binding site of alpha 2-antiplasmin. It probably constitutes part of the Lp(a)-binding site on apoB because: (1) it corresponds to the alpha 2-antiplasmin minimum binding domain for plasminogen's kringle-4; (2) the competitive nature of inhibition [KI = (1.5 +/- 0.7) x 10(-4) M, n = 5] suggested that it and apoB-Lp bound to Lp(a) by the same mechanism at the same site; and (3) it specifically bound Lp(a) and not apoB-Lp, and the bound Lp(a) was dissociated by inhibitors of the Lp(a):apoB-Lp interaction, 6-aminohexanoic acid and L-proline. Inhibition was independent of its proline residue, suggesting that proline in the context of a peptide is not a ligand for the kringle(s) which mediated the binding of Lp(a) to apoB-Lp.


Subject(s)
Apolipoproteins B/metabolism , Apolipoproteins B/pharmacology , Lipoprotein(a)/metabolism , Peptide Fragments/pharmacology , Amino Acid Sequence , Apolipoproteins B/chemistry , Binding Sites , Binding, Competitive , Chromatography, Affinity , Depression, Chemical , Humans , Immunodiffusion , Kringles , Molecular Sequence Data , Proline/chemistry , Protein Binding/drug effects , Recombinant Proteins/metabolism , Sequence Alignment , Sequence Homology, Amino Acid , alpha-2-Antiplasmin/chemistry
19.
Chem Phys Lipids ; 67-68: 105-13, 1994 Jan.
Article in English | MEDLINE | ID: mdl-8187204

ABSTRACT

We found a significantly reduced incidence of increased lipoprotein(a) (Lp(a)) levels in subjects with triglycerides (TG) greater than 150 mg/dl compared with those with TG levels lower than 150 mg/dl. This was the case in patients with angiographically documented coronary artery disease (CAD) and in subjects with no CAD. We explored the potential role of lipoprotein lipase (LPL) in mediating this relationship. Lp(a) and LDL2 exhibited a minimal effect on the rate constant for degradation of VLDL-TG by LPL (13% inhibition). Binding analyses indicated no differences between VLDL and LDL with respect to Lp(a) binding, and lipolysis only reduced binding by 30% at 75% degradation of VLDL-TG. Our study indicates that the inverse relationship between elevated plasma TG and Lp(a) levels is not caused by activation of LPL by Lp(a) either due to failure of Lp(a) to bind to VLDL or its lipolytic remnants. It is hypothesized that this relationship could stem from the enhanced clearance of TG-rich lipoproteins in individuals with higher levels of Lp(a) by receptor-mediated events.


Subject(s)
Lipoprotein(a)/blood , Lipoproteins/blood , Triglycerides/blood , Adult , Aged , Coronary Disease/blood , Enzyme Activation , Female , Humans , Hypertriglyceridemia/blood , In Vitro Techniques , Lipolysis , Lipoprotein Lipase/blood , Lipoproteins, LDL/blood , Lipoproteins, VLDL/blood , Male , Middle Aged , Protein Binding
20.
Gene ; 134(2): 267-70, 1993 Dec 08.
Article in English | MEDLINE | ID: mdl-7916724

ABSTRACT

The nucleotide sequence of the swine apoA-I gene (encoding apolipoprotein) has been determined. The structure of the gene is similar to that of the human gene, and the exons exhibit a high degree of homology with those of the human gene. The porcine apoA-I gene is located adjacent to the apoC-III gene, as in humans.


Subject(s)
Apolipoprotein A-I/genetics , Amino Acid Sequence , Animals , Base Sequence , Cloning, Molecular , DNA , Humans , Molecular Sequence Data , Restriction Mapping , Swine
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