Therapeutic Interventions of Gut-Brain Axis as Novel Strategies for Treatment of Alcohol Use Disorder Associated Cognitive and Mood Dysfunction.

Alcohol use disorders (AUD) is characterized by persistent or intermittent alcohol cravings and compulsive drinking. The functional changes in the central nervous system (CNS) after alcohol consumption are alcohol-associated cognitive impairment and mood disorders, which are major health issues reported in AUDs. Studies have shown that transferring the intestinal microbiota from AUDs patients to germ-free animals causes learning and memory dysfunction, depression and anxiety-like behavior, indicating the vital role of intestinal microbiota in development of neuropsychiatric disorders in AUD. Intestinal flora composition of AUD patients are significantly different from normal people, suggesting that intestinal flora imbalance orchestrate the development of neuropsychiatric disorders in AUD. Studies suggests that gut microbiome links bidirectional signaling network of the enteric nervous system (ENS) to central nervous system (CNS), forming gut-microbe-brain axis (brain-gut axis). In this review, we discussed pathogenesis and possible treatment of AUD-induced cognitive deficits, anxiety, and depression disorders. Further, we described the mechanism of intestinal flora imbalance and dysfunction of hippocampus-amygdala-frontal cortex (gut-limbic circuit system dysfunction). Therefore, we postulate therapeutic interventions of gut-brain axis as novel strategies for treatment of AUD-induced neuropsychiatric disorders.

Diagnostic value of FeNO and MMEF for predicting cough variant asthma in chronic cough patients with or without allergic rhinitis.

OBJECTIVE: To evaluate the diagnostic value of fractional exhaled nitric oxide (FeNO) and maximum mid-expiratory flow (MMEF) for differentiating cough variant asthma (CVA) from chronic cough in patients with or without allergic rhinitis. METHODS: In total, 328 patients with chronic cough who underwent spirometry and FeNO testing were consecutively included in the retrospective analysis. Patients were divided into the CVA (n = 125) or NCVA (n = 203) groups according to the diagnostic criteria of CVA. Receiver operating characteristic (ROC) curves were established to assess the diagnostic efficiency and optimal cutoff points of FeNO and MMEF for the prediction of CVA. RESULTS: The optimal cutoff values of FeNO and MMEF to discriminate CVA from chronic cough were 24.5 ppb (AUC, 0.765; sensitivity, 69.60%; specificity 72.91%; PPV, 61.27%; NPV, 79.57%) and 66.2% (AUC, 0.771; sensitivity, 67.20%; specificity 78.33%; PPV, 65.63%; NPV, 79.50%). The optimal cutoff values of combining FeNO with MMEF to discriminate CVA from chronic cough were >22 ppb for FeNO and <62.6% for MMEF (AUC, 0.877). In patients with and without allergic rhinitis, the optimal cutoff point of FeNO to discriminate CVA from chronic cough was 24.5 ppb (AUC, 0.820) and 33.5 ppb (AUC, 0.707), respectively. CONCLUSIONS: FeNO and MMEF might have greater value as negative parameters for differentiating CVA from chronic cough. Combining FeNO and MMEF provided a significantly better prediction than either alone. The diagnostic accuracy of FeNO for predicting CVA in chronic cough patients with allergic rhinitis was higher than in chronic cough patients without allergic rhinitis.

Pleomorphic adenoma of the trachea: A case report and review of the literature.

BACKGROUND: Pleomorphic adenoma (PA) is the most common benign tumor that occurs in the salivary glands; however, tracheobronchial PA is rarely observed. To the best of our knowledge, fewer than 50 cases have been reported in the literature. We report a 49-year-old woman who had been treated for asthma for 2 years before being diagnosed with PA of the trachea. CASE SUMMARY: A 49-year-old woman was referred to our hospital due to dyspnea upon exertion and chronic cough with wheezing for 2 years. Laboratory tests showed an elevated white blood cell count, absolute neutrophil count, and percentage of neutrophils. A chest computerized tomography scan showed a well-defined, soft-tissue density lesion measuring 2.4 cm × 2.1 cm in the lower trachea. Flexible bronchoscopy revealed that nearly 90% of the tracheal lumen was obstructed. The histopathological and immunohistochemistry features suggested PA of the trachea. Furthermore, we review the characteristics of 29 patients with tracheobronchial PA over the last 30 years. CONCLUSION: Tracheobronchial PA occurs without gender predominance, mostly in the lower or upper trachea, and has a low recurrence rate. The median age at diagnosis is 48 years. The most common symptoms are cough, stridor, dyspnea, and wheezing.

The relationship between steps of 6MWT and COPD severity: a cross-sectional study.

BACKGROUND AND OBJECTIVE: The distance of 6-minute walk test (D6MWT) has been widely used in the assessment of functional status in patients with COPD, while very little attention has been paid to the role of steps of 6-minute walk test (S6MWT). The purpose of this study was to investigate the relationship between S6MWT and other physiologic parameters of COPD. PATIENTS AND METHODS: Seventy patients with stable COPD were enrolled consecutively in this cross-sectional study. Pulmonary function tests, including spirometry, impulse oscillometry (IOS) and the single-breath diffusing capacity of the lungs for carbon monoxide (DLCO), were carried out at rest. Quality of life was assessed by health-related quality of life (HRQoL) questionnaires, including modified Medical Research Council dyspnea scale (mMRC), St George's Respiratory Questionnaire, Chronic Obstructive Pulmonary Disease Assessment Test (CAT) and Clinical Chronic Obstructive Pulmonary Questionnaire. Both steps and distance were measured in the following 6-minute walk test (6MWT). RESULTS: Both S6MWT and D6MWT showed significant correlation with spirometry, IOS, DLCO parameters and HRQoL questionnaires score. Both pre- and post-6MWT inspiratory capacity showed significant correlation with S6MWT (ρ=0.338, P=0.004; ρ=0.359, P=0.002, respectively), whereas did not correlate with D6MWT (ρ=0.145, P=0.230; ρ=0.160, P=0.189, respectively). In stepwise multiple regression analysis, mMRC grade, age and CAT score remained as significant predictors in the final model for D6MWT (adjusted R 2=0.445, P<0.01). DLCO and CAT score remained as significant predictors in the final model for S6MWT (adjusted R 2=0.417, P<0.01). CONCLUSION: S6MWT is efficient in the evaluation of functional status and quality of life in COPD and has significant correlation with various parameters indicating disease severity. Additionally, S6MWT might be better in predicting lung hyperinflation in COPD compared with D6MWT.

Associations between NBS1 Polymorphisms and Colorectal Cancer in Chinese Population.

As the central protein of the double strand breaks (DSB)-induced DNA repair pathway, NBS1 participates in detecting the DSBs and plays an essential role in maintaining genomic stability. Single nucleotide polymorphisms (SNPs) in NBS1 gene were commonly tested that associated with the susceptibility to multiple cancers, but the results remained controversial. Thus, we conducted two independent hospital-based case-control studies comprising 1,072 colorectal cancer patients and 1,263 controls to evaluate the association between four NBS1 SNPs and colorectal cancer risk. The result showed that rs2735383C/G polymorphism in the 3'-untranslated region (UTR) of NBS1 was significantly associated with risk of colorectal cancer using logistic regression (P<10(-4)). Furthermore, we observed that rs2735383CC genotype was associated with substantially increased risk of colorectal cancer (odds ratio=1.55, 95% confidence interval=1.27-1.94), compared with the rs2735383GC+GG genotypes. Further functional experiments demonstrated that the rs2735383C allele in the NBS1 disrupted the binding affinity of has-miR-509-5p to the NBS1 3'-UTR in colorectal cancer cells, affecting the NBS1 transcriptional activity and expression level. In conclusion, current evidence suggests that the rs2735383C/G polymorphism might contribute to the risk for colorectal cancer.

Furazolidone-based triple and quadruple eradication therapy for Helicobacter pylori infection.

AIM: To evaluate the efficacy of furazolidone-based triple and quadruple therapy in eradicating Helicobacter pylori (H. pylori) in a multi-center randomized controlled trial. METHODS: A total of 720 H. pylori positive patients with duodenal ulcer disease were enrolled at 10 different hospitals in Jiangxi province in China. The patients were randomly assigned to four treatment groups as follows: patients in Groups 1 and 3 received rabeprazole (10 mg), amoxicillin (1000 mg) and furazolidone (100 mg) twice daily for 7 and 10 d, respectively; patients in Groups 2 and 4 received rabeprazole (10 mg), bismuth (220 mg), amoxicillin (1000 mg) and furazolidone (100 mg) twice daily for 7 and 10 d, respectively. The primary outcome measure was H. pylori eradication rate 4 wk after treatment by intention-to-treat and per protocol analysis, while the secondary outcome measures were symptom and sign changes at the end of treatment and 4 wk after the end of treatment, as well as the proportion of patients who developed adverse events. RESULTS: The demographic data of the four groups were not significantly different. Overall, 666 patients completed the scheme and were re-assessed with the (13)C-urea breath test. The intention-to-treat analysis of the H. pylori eradication rates in Groups 1, 2, 3 and 4 were 74.44%, 82.78%, 78.89% and 86.11%, respectively. The H. pylori eradication rate in Group 4 was significantly higher than that in Group 1. According to the per protocol analysis, the H. pylori eradication rates in Groups 1, 2, 3 and 4 were 81.21%, 89.22%, 85.54% and 92.26%, respectively. The H. pylori eradication rate in Group 4 was significantly higher than that in Group 1. The number of adverse events was 15 (8.3%), 16 (8.9%), 15 (8.3%) and 17 (9.4%) in Groups 1, 2, 3 and 4, respectively, including dizziness, vomiting, diarrhea, nausea, skin rash, itchy skin, and malaise. The symptoms were relieved without special treatment in all of the patients. CONCLUSION: Both 7- and 10-d quadruple furazolidone-based therapies achieve satisfactory H. pylori eradication rates.

Curcumin protects neurons against oxygen-glucose deprivation/reoxygenation-induced injury through activation of peroxisome proliferator-activated receptor-γ function.

The turmeric derivative curcumin protects against cerebral ischemic injury. We previously demonstrated that curcumin activates peroxisome proliferator-activated receptor-γ (PPARγ), a ligand-activated transcription factor involved in both neuroprotective and anti-inflammatory signaling pathways. This study tested whether the neuroprotective effects of curcumin against oxygen-glucose deprivation/reoxygenation (OGD/R)-induced injury of rat cortical neurons are mediated (at least in part) by PPARγ. Curcumin (10 µM) potently enhanced PPARγ expression and transcriptional activity following OGD/R. In addition, curcumin markedly increased neuronal viability, as evidenced by decreased lactate dehydrogenase release and reduced nitric oxide production, caspase-3 activity, and apoptosis. These protective effects were suppressed by coadministration of the PPARγ antagonist 2-chloro-5-nitrobenzanilide (GW9662) and by prior transfection of a small-interfering RNA (siRNA) targeting PPARγ, treatments that had no toxic effects on healthy neurons. Curcumin reduced OGD/R-induced accumulation of reactive oxygen species and inhibited the mitochondrial apoptosis pathway, as indicated by reduced release of cytochrome c and apoptosis-inducing factor and maintenance of both the mitochondrial membrane potential and the Bax/Bcl-2 ratio. Again, GW9662 or PPARγ siRNA transfection mitigated the protective effects of curcumin on mitochondrial function. Curcumin suppressed IκB kinase phosphorylation and IκB degradation, thereby inhibiting nuclear factor-κ B (NF-κB) nuclear translocation, effects also blocked by GW9662 or PPARγ siRNA. Immunoprecipitation experiments revealed that PPARγ interacted with NF-κB p65 and inhibited NF-κB activation. The present study provides strong evidence that at least some of the neuroprotective effects of curcumin against OGD/R are mediated by PPARγ activation.

[Effect of vascular endothelial growth factor C and collagen triple helix repeat containing 1 expression on prognosis of rectal carcinoma patients].

OBJECTIVE: To explore the relationship of vascular endothelial growth factor C (VEGF-C) and collagen triple helix repeat containing 1 (CTHRC1) expression with the carcinogenesis and prognosis of rectal cancer. METHODS: Cancer tissue samples from 120 rectal cancer patients confirmed by pathology in the People's Hospital of Yichun City from September 2005 to September 2010 were included in the study. Expressions of CTHRC1 and VEGF-C were examined by immunohistochemistry and their correlations with clinicopathological features and prognosis were analyzed. RESULTS: The expression of VEGF-C was positively correlated with tumor size (r=0.943), TNM stages (r=0.784) and tumor differentiation (r=0.773) (all P<0.05). Similarly, the expression of CTRHC1 was also positively correlated with tumor size (r=0.829), TNM stages (r=0.632) and tumor differentiation (r=0.532) (all P<0.05). Rectal cancer patients with low expression of VEGF-C and CTHRC1 had significantly longer survival than those with high expression of VEGF-C and CTHRC1 [(40.0±1.3) vs. (35.4±0.5) months, P<0.01, (39.0±0.5) vs. (35.0±0.5) months, P=0.014]. CONCLUSION: VEGF-C and CTHRC1 may synergistically promote the invasion and metastasis of human rectal cancer, and provide evidence in predicting the prognosis of patients.

[Inhibition of lipopolysaccharide-induced myeloid-derived suppressor cells in the proliferation of spleen T lymphocytes].

OBJECTIVE: To explore the effects of lipopolysaccharide (LPS)-induced myeloid-derived suppressor cells (MDSCs) on the proliferation of spleen T lymphocytes. METHODS: BALB/c mice were randomly divided into two groups: LPS group and normal control group. They were injected intraperitoneally with LPS and normal saline solution respectively. MDSCs were separated with CD11b immunomagnetic beads from the spleen extract of mice. The morphological characteristics of MDCSs were observed by Wright-Giemsa staining and the characteristic molecules on cell surface identified by flow cytometry. And the effects of MDSCs on the in vitro proliferation of T cells were determined by methyl-thiazolyl-tetrazolium bromide (MTT). RESULTS: The proportion of MDSCs in the spleen of the LPS group was much more than that of the normal control group (27.4% ± 6.6% vs 5.1% ± 3.8%; t = 5.06, P = 0.007). CD11b(+)Gr-1(+)MDSCs could be separated by CD11b immunomagnetic beads from the spleen of mice injected with LPS at a high purity of 84.0% ± 4.2%. MTT method showed that the proliferation of T cells decreased significantly after a co-cultivation with CD11b(+)MDSCs versus the control group. And it was positively correlated with the number of MDSCs (F = 46.26, P = 0.000). CONCLUSIONS: A high purity of LPS-induced myeloid-derived suppressor cells may be separated with CD11b immunomagnetic beads. And it has dose-dependent inhibitory effects on the proliferation of the spleen T lymphocytes.

[Effect and mechanism of lipopolysaccharides-induced myeloid-derived suppressor cells on airway inflammation in asthmatic mice].

OBJECTIVE: To explore the effect and mechanism of lipopolysaccharides (LPS)-induced CD11b⁺Gr-1⁺ myeloid-derived suppressor cells (MDSCs) on airway inflammation in asthmatic mice. METHODS: A total of 34 female BALB/c mice were selected. Among them, 4 mice received an intraperitoneal injection of LPS for inducing the accumulation of MDSCs. And the MDSCs were separated with CD11b immunomagnetic beads from spleen extract. Another 30 mice were randomly divided into normal control, asthmatic and cell treatment groups. The mice in the asthmatic and cell treatment groups were sensitized with ovalbumin by a combination of intraperitoneal injection and challenges to establish the murine asthmatic model. At Days 14 and 21 post-sensitization, the mice in cell treatment group received an intravenous injection of LPS-induced MDSCs. At 24 hours after the last allergen challenge, the number of inflammatory cells were counted and morphological identification of leucocytes in bronchoalveolar lavage fluid (BALF) was performed to analyze the degree of airway inflammation in conjunctions with pathological sections. The BALF and serum levels of interleukin-13 were measured by enzyme-linked immunosorbent assay (ELISA). The number of CD4⁺CD25⁺Foxp3⁺ regulatory T cells (Tregs) in peripheral blood was measured by flow cytometry. RESULTS: The total number of cells, the percentage of neutrophils and eosinophils of BALF in the cell treatment group [(17.0 ± 8.3)×104/ml, 11.1% ± 2.0%, 9.8% ± 2.9%] were significantly lower than those in the asthmatic group [(36.0 ± 15.9)×104/ml, 20.8% ± 4.0%, 14.1% ± 4.2%] (P = 0.000, 0.000, 0.011). Compared to the asthmatic group, the BALF and serum levels of IL-13 were significantly lower [(34.7 ± 7.1) vs (105.0 ± 9.0) ng/L, (34.0 ± 4.7) vs (48.1 ± 6.1) ng/L] (both P = 0.000) and the number of CD4⁺CD25⁺Foxp3⁺ regulatory T cells increased in peripheral blood (8.0% ± 1.3% vs 5.1% ± 2.1%, P = 0.002) and airway inflammation was significantly relieved in the cell treatment group. CONCLUSION: LPS-induced MDSCs may improve airway inflammation through up-regulating Tregs in peripheral blood and suppressing Th2 effector function in asthmatic mice.

[Pathogenic mechanism of CD8(+)CD28(-)T cell and the effect of dexamethasone in asthmatic mouse].

OBJECTIVE: To explore whether or not CD8(+)CD28(-)T cell play a pathogenic role in asthma and detect the effects of dexamethasone (DXM). METHODS: A total of 30 mice were randomly divided into 3 groups: asthmatic group, DXM group and control group (n = 10 each). The asthmatic and DXM groups were sensitized twice and inhaled ovalbumin. The DXM Group received an intraperitoneal injection of DXM 1mg/kg before inhaling ovalbumin. After successful modeling, 3 mice were selected randomly from each group to measure the airway responsiveness. Also a bronchoalveolar lavage cytological study was performed and lung tissue sections were prepared for histopathologic examination to evaluate the airway inflammation. The content of IgE in bronchoalveolar lavage fluid (BALF) was detected with a murine IgE ELISA kit. And the fractions of CD8(+)CD28(-)T cell of peripheral blood and BALF were tested by flow cytometry to analyze the correlation between IgE, eosinophils (EOS) of BALF and CD8(+)CD28(-)T cell of blood. RESULTS: The airway hyperresponsiveness in asthmatic and DXM groups were significantly higher than that in the control group. The number of total cells and EOS of BALF in the asthmatic group [(5.56 ± 4.06) × 10(2)/L; (3.29 ± 2.23) × 10(2)/L] were significantly higher than that in control group [(0.91 ± 0.65) × 10(2)/L, P = 0.003; (0.43 ± 0.37) × 10(2)/L, P = 0.001] and DXM group [(2.59 ± 1.69) × 10(2)/L, P = 0.044; (1.11 ± 0.73) × 10(2)/L, P = 0.008]; while the DXM group was insignificantly higher than the control group (P = 0.234, P = 0.363). There were significant differences in the contents of IgE of BALF for the asthmatic, DXM and control groups [(23.85 ± 5.97) g/L, (13.15 ± 2.22) g/L, (6.54 ± 1.03) g/L, F = 38.558, P = 0.000]. The percentages of CD8(+)CD28(-)T cell in peripheral blood in asthmatic and DXM groups [(18.68 ± 4.12)% and (13.43 ± 2.91)%] were significantly higher than those in control mice [(8.43 ± 4.60)%, both P < 0.05]. The percentages of CD8(+)CD28(-)T cell of BALF in asthmatic group and DXM group [(1.25 ± 0.40)% and (0.66 ± 0.49)%] were also significantly higher than those in control mice [(0.21 ± 0.19)%, both P < 0.05]. The percentages of CD8(+)CD28(-)T cell of blood and BALF in the DXM mice were significantly lower than those in asthmatic group. The correlations between IgE (r = 0.864, P = 0.012), EOS (r = 0.804, P = 0.029) and CD8(+)CD28(-)T cell were significant. CONCLUSION: The fraction of CD8(+)CD28(-)T cell is closely correlated with the inflammation of asthmatic airway. The airway hyperresponsiveness and inflammation in asthmatic mice may be relieved by DXM through its effect of inhibiting the expression of CD8(+)CD28(-) T cell.

N-Glycosylation is required for secretion-competent human plasma phospholipid transfer protein.

Human plasma phospholipid transfer protein (PLTP) contains six potential N-glycosylation sites (Asn-X-Ser). To study the role of these sites on PLTP structure and function, seven variants in which asparagine (N) residues were converted to glycine (G) were prepared by site-directed mutagenesis. These were N(47)G, N(77)G, N(100)G, N(126)G, N(228)G, N(381)G and N(47, 77, 100, 126, 228, 381)G (N(null)G). These variants and wild-type (WT) PLTP were expressed in COS-7 cells. Intracellular and secreted PLTP mass was analyzed by Western blots and quantitative enzyme-linked immunosorbent assay; PLTP activities in cellular lysates and media were based on the transfer of [(3)H]dipalmitoylphosphatidylcholine from phospholipid single bilayer vesicles to HDL. N(null)G was not detected intracellularly. N(381)G was similar to WT PLTP with respect to specific activity and secretion efficiency. The specific activities of N(47)G, N(77)G, N(100)G, N(126)G, N(228)G and N(381)G were similar in cell lysate (range = 67-90% WT) and medium (range = 65-77% WT). Intracellular masses of these PLTP variants were similar to that of WT (Mean = 103% WT); mean secreted mass was 88% WT. These results suggest that secretion-competent PLTP requires glycosylation but that no single glycosylation site is required.

[Rapid detection of Streptococcus pneumoniae and Haemophilus influenzae with DNA probes].

OBJECTIVE: To establish a method for rapid molecular detection of Streptococcus pneumoniae and Haemophilus influenzae in the early stage of infection. METHODS: Specific DNA probes for Streptococcus pneumoniae and Haemophilus influenzae and 16 S rRNA universal probe of bacteria were synthesized by polymerase chain reaction (PCR) and labeled with biotin. The DNA of the bacteria, virus and fungi were hybridized with these probes respectively prior to application for examination of the clinical samples. RESULTS: The DNA probes of 263, 351, and 370 bp were amplified by PCR. Streptococcus pneumoniae and Haemophilus influenzae reacted only with their corresponding probes, and no cross reaction of the bacterial universal probe with virus and fungi was noted. The method could detect bacterial DNA in as small amount as 1 ng. Of the 100 sputum specimens, 11 were found to be positive for Streptococcus pneumoniae and 8 for Haemophilus influenzae, with a positivity rate greater than that by sputum culture. CONCLUSION: DNA probe detection is simple, rapid, and specific for clinical examination of Streptococcus pneumoniae and Haemophilus influenzae.

[Detection of oprI gene of Pseudomonas aeruginosa by reverse dot-blot hybridization].

OBJECTIVE: To establish a rapid method for detecting Pseudomonas aeruginosa at the early stage of infection. METHODS: Specific primers were designed according to oprI gene sequence of Pseudomonas aeruginosa, and the specific probe was synthesized by PCR. After photosensitive biotin labeling of the bacterial DNA, reverse dot-blot hybridization was used to detect Pseudomonas aeruginosa. RESULTS: The probe synthesized was highly specific to Pseudomonas aeruginosa without cross reaction with other bacteria, viruses or fungi. The method was capable of detecting 100 ng bacteria DNA. CONCLUSION: Reverse dot-blot hybridization possesses the merits of speediness and specificity in the detection of Pseudomonas aeruginosa in the early stage of infection.

The 15-lipoxygenase-1 product 13-S-hydroxyoctadecadienoic acid down-regulates PPAR-delta to induce apoptosis in colorectal cancer cells.

Diminished apoptosis, a critical event in tumorigenesis, is linked to down-regulated 15-lipoxygenase-1 (15-LOX-1) expression in colorectal cancer cells. 13-S-hydroxyoctadecadienoic acid (13-S-HODE), which is the primary product of 15-LOX-1 metabolism of linoleic acid, restores apoptosis. Nonsteroidal antiinflammatory drugs (NSAIDs) transcriptionally up-regulate 15-LOX-1 expression to induce apoptosis. Peroxisome proliferator-activated receptors (PPARs) are nuclear receptors for linoleic and arachidonic acid metabolites. PPAR-delta promotes colonic tumorigenesis. NSAIDs suppress PPAR-delta activity in colon cancer cells. The mechanistic relationship between 15-LOX-1 and PPAR-delta was previously unknown. Our current study shows that (i) 13-S-HODE binds to PPAR-delta, decreases PPAR-delta activation, and down-regulates PPAR-delta expression in colorectal cancer cells; (ii) the induction of 15-LOX-1 expression is a critical step in NSAID down-regulation of PPAR-delta and the resultant induction of apoptosis; and (iii) PPAR-delta is an important signaling receptor for 13-S-HODE-induced apoptosis. The in vivo relevance of these mechanistic findings was demonstrated in our tumorigenesis studies in nude mouse xenograft models. Our findings indicate that the down-regulation of PPAR-delta by 15-LOX-1 through 13-S-HODE is an apoptotic signaling pathway that is activated by NSAIDs.

Structural and functional determinants of human plasma phospholipid transfer protein activity as revealed by site-directed mutagenesis of charged amino acids.

Human plasma phospholipid transfer protein (PLTP) exchanges phospholipids between lipoproteins and remodels high-density lipoproteins (HDLs). We determined phospholipid transfer activity and HDL binding ability in wild-type PLTP and in 16 PLTP variants created by replacing 12 charged amino acids by site-directed mutagenesis. The data were analyzed in relation to the structure of a member of the same gene family, bactericidal/permeability-increasing protein, which is a boomerang-shaped molecule containing two symmetrical, hydrophobic pockets that bind phospholipid molecules. When expressed in COS-7 cells, wild-type and all mutant PLTPs accumulated intracellularly to nearly the same extent. Relative to wild-type PLTP, substitution(s) for amino acids with a lateral position totally exposed to the solvent produced reductions in transfer activity proportional to the reductions in the level of HDL binding. Variants containing substitutions for charged amino acids on the concave surface of PLTP did not affect binding to HDL or specific transfer activity. A mutation in the C-terminal pocket (E270R) led to a decrease in both the specific transfer activity and the level of binding to HDLs, whereas mutations in the N-terminal pocket (R25E and D231R) resulted in a large decrease in specific transfer activity without affecting HDL binding. The data support a model of transfer in which N- and C-terminal pockets have different roles in HDL binding and transfer activity. The N-terminal pocket may be critical to PLTP transfer activity but may have no involvement in binding to lipoproteins, whereas amino acid substitutions in the C-terminal pocket might reduce PLTP activity by decreasing PLTP's affinity for HDLs.