Targeting myeloperoxidase to stabilize unruptured aneurysm: an imaging-guided approach.

Inflammation plays a key role in pathogenesis and rupture of aneurysms. Non-invasively and dynamically monitoring aneurysm inflammation is critical. This study evaluated myeloperoxidase (MPO) as an imaging biomarker and therapeutic target for aneurysm inflammation using an elastase-induced rabbit model treated with or without 4-aminobenzoic acid hydrazide (ABAH), an irreversible inhibitor of MPO. Myeloperoxidase-sensitive magnetic resonance imaging (MRI) using Mn-TyrEDTA, a peroxidase activity-dependent contrast agent, revealed weak contrast enhancement in contralateral arteries and decreased contrast enhancement in aneurysm walls with ABAH treatment, indicating MPO activity decreased and inflammation mitigated. This was supported by reduced immune cell infiltration, matrix metalloproteinases (MMP-2 and - 9) activity, ROS production and arterial wall destruction on histology. Finally, the aneurysm expansion rate remained < 50% throughout the study in the ABAH(+) group, but increased gradually in the ABAH(-) group. Our results suggest that inhibition of MPO attenuated inflammation and expansion of experimental aneurysm and MPO-sensitive MRI showed promise as a noninvasive tool for monitoring aneurysm inflammation.

A New OATP-Mediated Hepatobiliary-Specific Mn(II)-Based MRI Contrast Agent for Hepatocellular Carcinoma in Mice: A Comparison With Gd-EOB-DTPA.

BACKGROUND: Growing concerns about the safety of gadolinium (Gd)-based contrast agents have reinforced the need for the development of Gd-free MRI contrast agents (CAs) that are effective in imaging liver tumors. PURPOSE: To evaluate the ability of Mn-BnO-TyEDTA MRI CA to detect hepatocellular carcinoma in a mouse model of implanted liver tumor. STUDY TYPE: Prospective. ANIMAL MODEL: Thirteen orthotopically implanted liver tumor mice. FIELD STRENGTH/SEQUENCE: 3.0 T/precontrast and postcontrast T1-weighted fast spoiled gradient recalled echo and T2-weighted fast recovery fast spin-echo imaging with fat suppression. ASSESSMENT: The relative enhancement ratio was calculated and statistically compared. Lesion detection in postcontrast images was analyzed by calculations of area under the curve (AUC, the increases in liver-to-tumor contrast-to-noise ratio [∆CNR] vs. time curve). Mn or Gd levels were measured in the liver and tumoral tissues by inductively coupled plasma-mass spectrometry. Tumor specimens were stained with hematoxylin and eosin (H&E) and the expression of organic anion transfer peptide (OATP)1B1 was evaluated by immunofluorescence (IF) staining and mean fluorescence intensity (MFI) was calculated. STATISTICAL TESTS: Unpaired t-test and two-tailed paired t-test. P < 0.05 was considered statistical significance. RESULTS: Mn-BnO-TyEDTA and Gd-EOB-DTPA demonstrated nearly identical enhancement patterns in the liver, tumor, and psoas muscle and no difference in lesion detection (AUC10-30, Mn  = 851 ∆CR·min, AUC10-30, Gd  = 823 ∆CR·min). A Significant higher concentration of metal (Mn or Gd) was found in the liver compared to the tumor ([Mn]liver  = 0.88 ± 0.07 µmmol/g, [Mn]tumor  = 0.49 ± 0.05 µmmol/g, [Gd]liver  = 0.65 ± 0.07 µmmol/g, [Gd]tumor  = 0.27 ± 0.04 µmmol/g). IF staining showed significantly decreased expression of OATP1B1 in the tumor core compared to the liver (MFItumor  = 5.28 ± 1.54, MFIliver  = 25.49 ± 3.41). DATA CONCLUSION: Mn-BnO-TyEDTA can provide comparable hepatobiliary tumor contrast enhancement to Gd-EOB-DTPA. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 1.

Myeloperoxidase-Sensitive Magnetic Resonance Imaging Assesses Inflammatory Activation State in Experimental Mouse Acute Gout.

BACKGROUND: A novel myeloperoxidase-activatable manganese-based (MPO-Mn) MRI probe may enable the activation state of inflammatory foci to be detected and monitored noninvasively. PURPOSE: To evaluate the inflammatory response in a mouse model of acute gout using MPO as an imaging biomarker and a potential therapeutic target. STUDY TYPE: Prospective. ANIMAL MODEL: A total of 40 male Swiss mice with monosodium urate crystals induced acute gout. FIELD STRENGTH/SEQUENCE: A 3.0 T/T1-weighted imaging with 2D fast spoiled gradient recalled echo and T2-weighted imaging with fast recovery fast spin-echo sequences. ASSESSMENT: The difference in contrast-to-noise ratio between left hind limb (lesion) and right hind limb (internal reference) (ΔCNR), and normalized signal-to-noise ratio (nSNR) on the right hind limb were calculated and compared. The expression level and activity of myeloperoxidase (MPO) were analyzed using western blotting and spectrophotometric quantitation activity assay. MPO-positive cell infiltration and lesion volume were evaluated using immunofluorescence staining and T2-weighted images, respectively. STATISTICAL TESTS: Student's t test. A P-value less than 0.05 was considered to be statistically significant. RESULTS: MPO-Mn resulted in a significantly higher ΔCNR than Gd-DTPA (22.54 ± 1.86 vs. 13.90 ± 2.22) but lower nSNR on the reference right hind limb (1.08 ± 0.07 vs. 1.21 ± 0.08). Compared to the nontreatment group, MPO-inhibition resulted in a significantly reduced contrast enhancement at the lesion (17.81 ± 1.58 vs. 22.96 ± 3.12), which was consistent with a remission of the inflammatory response, as evidenced by a substantial reduction of lesion volume (0.55 ± 0.16 mm3 /g vs. 1.14 ± 0.15 mm3 /g), myeloperoxidase expression level (0.98 ± 0.09 vs. 1.48 ± 0.19) and activity (0.75 ± 0.12 vs. 1.12 ± 0.07), and inflammatory cell recruitment. DATA CONCLUSION: MPO-Mn MRI has potential to evaluate the activation state of inflammatory foci in the experimental model of acute gout. EVIDENCE LEVEL: 1. TECHNICAL EFFICACY: Stage 1.

Accuracy of multiparametric MRI in distinguishing the breast malignant lesions from benign lesions: a meta-analysis.

BACKGROUND: The sensitivity of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for detecting breast cancer was high and the specificity was relatively low. However, diffusion-weighted imaging (DWI) has a high specificity in the diagnosis of malignant lesions. PURPOSE: To evaluate the accuracy of the multiparametric MRI (mp-MRI) in distinguishing the breast malignant lesions from the benign lesions. MATERIAL AND METHODS: A comprehensive search of the PubMed, Embase, and Cochrane Library electronic databases was conducted up to March 2020. Data were analyzed for the following indexes: pooled sensitivity and specificity; positive likelihood ratio; negative likelihood ratio; diagnostic odds ratio; and the area under the curve. RESULTS: A total of 2356 patients with 1604 malignant and 967 benign breast lesions were included from 22 studies. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and area under the curve for mp-MRI were 0.93, 0.85, 6.3, 0.08, 81, and 0.96, respectively. The pooled sensitivity, specificity, and area under the curve for DCE-MRI alone were 0.95, 0.71, and 0.92, respectively. The pooled sensitivity, specificity, and area under the curve for DWI alone were 0.88, 0.84, and 0.93, respectively. CONCLUSION: The mp-MRI did not improve the sensitivity but increased the specificity for the diagnosis of breast malignant lesions.

Streptozotocin-induced diabetic cardiomyopathy in rats: ameliorative effect of PIPERINE via Bcl2, Bax/Bcl2, and caspase-3 pathways.

The objective of present investigation was to appraise the effects of piperine on STZ-induced diabetic cardiomyopathy in rats. Diabetes was induced in Sprague-Dawley rats with intraperitoneal STZ injection, and the rats were assigned to seven groups. Electrocardiograph, hemodynamic, various biochemical, molecular, and histological parameters were examined. Treatment with piperine significantly (p < 0.05) restored altered myocardial functions, inhibited cardiac marker, and restored electrocardiogram and hemodynamic alterations. The elevated level of cardiac oxido-nitrosative stress and decreased cardiac Na-K-ATPase concentration, after STZ administration, were significantly (p < 0.05) attenuated by piperine treatment. Piperine also considerably (p < 0.05) increased myocardial mitochondrial enzyme activity. STZ-induced alteration in heart ANP, BNP, cTn-I, Bcl2, Bax/Bcl2, and caspase3 mRNA expression was significantly (p < 0.05) restored by piperine treatment. Piperine administration reduced histopathological aberrations induced by STZ. In conclusion, the present investigation suggests that piperine ameliorates STZ-induced diabetic cardiomyopathy via modulation of caspase-3, Bcl2, Bax/Bcl2 pathways. Abbreviations: ACE: Angiotensin-Converting Enzyme; ANOVA: Analysis of Variance; ANP: Atrial Natriuretic Peptide; APAF: Apoptotic Protease-Activating Factor; ARB: Angiotensin Receptor Blockers; ATP: Adenosine Triphosphate; Bax: Bcl-2-associated X protein; Bcl2: B-cell lymphoma 2; BPM: Beats Per Minute; BNP: brain natriuretic peptide; CAD: Caspase-3-Activated DNase; cDNA: Complementary DNA; CK-MB: Creatine Kinase-MB; CPCSEA: Committee for the Purpose of Control And Supervision of Experiments on Animals; cTn-I: cardiac troponin I; DBP: Diastolic Blood Pressure; DCM: Diabetic Cardiomyopathy; DNA: Deoxyribonucleic Acid; DPX: DisterenePhthalate Xylene; ECG: Electrocardiogram; ETC: Electron Transport Chain; GOD-POD: Glucose Oxidase Peroxidase; GSH: Glutathione; IAEC: Institutional Animal Ethics Committee; IL-6: Interleukin-6; IL-1b: Interleukin-1b; LDH: Lactate Dehydrogenase; LV: Left Ventricle; LVEDP: left ventricular end-diastolic Pressure; MABP: Mean Arterial Blood Pressure; MDA: Malondialdehyde; mRNA: Messenger Ribonucleic Acid; MTT: 3- (4,5-Dimethylthiazol-2-yl)-2,5-DiphenyltetrazoliumBromide; NADH: Nicotinamide Adenine Dinucleotide Phosphate; NADPH: Nicotinamide Adenine Dinucleotide Phosphate Hydrogen; NO: nitric oxide; NP: Natriuretic Peptides; OXPHOS: Oxidative Phosphorylation; p.o.: per os; PCR: Polymerase Chain Reaction; RT-PCR: Reverse Transcriptionpolymerase Chain Reaction; PPAR: Peroxisome Proliferator-Activated Receptor Gamma; RAS: Renin-Angiotensin System; RNA: Ribonucleic Acid; ROS: Reactive Oxygen Species; SBP: Systolic Blood Pressure; SDH: Succinate Dehydrogenase; SEM: Standard Error Means; SOD: superoxide dismutase: STZ: Streptozotocin; TNF: Tumor Necrosis Factor Alpha; TnI: Troponin I.

[The cytotoxic effect and the effect of permeability with OmpA like protein Loa22 from Leptospira interrogans serovar].

OBJECTIVE: To study the toxic effect and the change of permeability on human umbilical vein endothelia (HUVE) of the Loa22 protein from virulent serovar Lai. Leptaspira interrogans by expressing its protein. METHODS: In this study, the pGEX-Loa22 peptide prokaryotic recombinant plasmid of Leptospira interrogans serovar Lai preserved in our laboratory was used to express Loa22 fusion protein with GST lable. Then the target fusion protein was obtained by using affinity chromatography with the GST-Trap FF Column. The purified Loa22 fusion protein was detected by SDS-PAGE and confirmed by Western blot assay using the mouse anti-GST tag monoclonal anti-body. pGEX-Loa22 protein was administered to culture with human umbilical vein endothelial cells (HUVEC) to elucidate the cytotoxic role and the change of permeability of leptospiral outer membrane proteins. RESULTS: The recombiant plasmid with Loa22 mature peptide was expressed successfully and the protein was purfied. Significant higher level of apoptosis ratio, lower CCK-8 aborntion, and increasing permeability on HUVEC were observed after treated the HUVEC with the expressed fusion protein. CONCLUSION: The purified Loa22 fusion protein have obvious toxic effects on vascular endothelial cells, and also it can increase permeability of HUVEC.

Transcutaneous Electrical Acupoint Stimulation Improves Postoperative Cognitive Function in Senior Patients Undergoing Video-Assisted Thoracoscopic Surgery: A Randomized Controlled Trial.

OBJECTIVE: To evaluate the effectiveness and safety of transcutaneous electrical acupoint stimulation (TEAS) for improving postoperative cognitive function in senior patients undergoing video-assisted thoracoscopic surgical (VATS). METHODS: From January to December 2020, 97 participants were randomly assigned to the TEAS group (49 cases) and the control group (48 cases) by a random number table. The patients in the TEAS group received TEAS, at the bilateral Neiguan (PC 6) and Zusanli (ST 36) acupoints. The control group received sham TEAS. The stimulation was started from 30 min before surgery until the end of the operation. The primary outcome was the incidence of pstoperative cognitive dysfunction (POCD), diagnosed based on the changes in the Mini-Mental Status Examination (MMSE) and Montreal Cognitive Assessment (MoCA) scores. The secondary outcomes were plasma levels of S100ß protein and neuron-specific enolase (NSE). RESULTS: The incidence of POCD on day 1 and 3 after surgery in the TEAS group was significantly lower than that in the control group [day 1 after surgery: 28.3% (13/46) vs. 52.3% (23/44), P=0.028; day 3 after surgery: 21.7% (10/46) vs. 40.9% (18/44), P=0.043]. Compared with baseline, the MMSE and MoCA scores decreased to various extents in both groups. The MMSE scores on day 1, 3, and 5 after surgery and MoCA scores on day 1, 3, 5, and 7 after surgery in the TEAS group were higher than those in the control group (all P<0.05) in both groups. Compared with baseline, the plasma levels of S100ß and NSE were significantly increased at 4, 8, 12, 24 h after surgery (all P<0.05). Compared with the control group, the plasma levels of S100ß and NSE were lower in the TEAS group at 4, 8, 12, and 24 h after surgery (all P<0.05). No obvious adverse events were found during the trial. CONCLUSION: Application of TEAS in senior patients after VATS could reduce incidence of POCD and improve postoperative cognitive function.

An activatable Mn(II) MRI probe for detecting peroxidase activity in vitro and in vivo.

Myeloperoxidase (MPO), a hallmark of the function and activation of innate immune cells, can act as a 'double-edged sword', contributing to clear infection as well as causing tissue oxidizing damage in various inflammatory diseases. In this study, an activatable Mn(II) chelate-based magnetic resonance imaging (MRI) contrast agent (CA), Mn-TyEDTA (TyEDTA = tyrosine derived ethylenediaminetetraacetic acid) structurally featuring a phenol group as the electron-donor, was developed to sense the activity of peroxidase in vitro and in vivo. Mn-TyEDTA demonstrated a peroxidase activity-dependent relaxivity in the presence of horseradish peroxidase (HRP)/H2O2 with more than a 2.6-fold increase in water proton relaxivity produced (HRP, 500 U; H2O2, 4.5 eq). A mechanism of peroxidase-mediated Mn(II) monomer radical polymerization was confirmed with those oligomers of Mn-TyEDTA such as dimer, trimer and tetramer were found in the LC-MS study. Dynamic MR imaging of normal mice revealed rapid blood clearance and mixed renal and hepatobiliary elimination of Mn-TyEDTA. Furthermore, compared to liver-specific and non-specific extracellular contrast agents (Mn-BnO-TyEDTA (BnO-TyEDTA = benzyl tyrosine-derived ethylenediaminetetraacetic acid) and Gd-DTPA (DTPA = diethylene triamine penta-acetic acid)), MRI on a monosodium urate (MSU) crystal-induced acute mice model of arthritis showed that inflamed tissues could be selectively enhanced by Mn-TyEDTA, suggesting that this peroxidase-activatable Mn(II) MRI probe could potentially be used for noninvasive detection of MPO activity in vivo.

Mn(II) Complex of Lipophilic Group-Modified Ethylenediaminetetraacetic Acid (EDTA) as a New Hepatobiliary MRI Contrast Agent.

Liver-specific contrast agents (CAs) can improve the Magnetic resonance imaging (MRI) detection of focal and diffuse liver lesions by increasing the lesion-to-liver contrast. A novel Mn(II) complex, Mn-BnO-TyrEDTA, with a lipophilic group-modified ethylenediaminetetraacetic acid (EDTA) structure as a ligand to regulate its behavior in vivo, is superior to Gd-EOB-DTPA in terms of a liver-specific MRI contrast agent. An MRI study on mice demonstrated that Mn-BnO-TyrEDTA can be rapidly taken up by hepatocytes with a combination of hepatobiliary and renal clearance pathways. Bromosulfophthalein (BSP) inhibition imaging, biodistribution, and cellular uptake studies confirmed that the mechanism of hepatic targeting of Mn-BnO-TyrEDTA is the hepatic uptake of the amphiphilic anion contrast agent mediated by organic anion transporting polypeptides (OATPs) expressed by functional hepatocytes.