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1.
J Biol Chem ; 299(11): 105299, 2023 11.
Article in English | MEDLINE | ID: mdl-37777156

ABSTRACT

Microbes living in the intestine can regulate key signaling processes in the central nervous system that directly impact brain health. This gut-brain signaling axis is partially mediated by microbe-host-dependent immune regulation, gut-innervating neuronal communication, and endocrine-like small molecule metabolites that originate from bacteria to ultimately cross the blood-brain barrier. Given the mounting evidence of gut-brain crosstalk, a new therapeutic approach of "psychobiotics" has emerged, whereby strategies designed to primarily modify the gut microbiome have been shown to improve mental health or slow neurodegenerative diseases. Diet is one of the most powerful determinants of gut microbiome community structure, and dietary habits are associated with brain health and disease. Recently, the metaorganismal (i.e., diet-microbe-host) trimethylamine N-oxide (TMAO) pathway has been linked to the development of several brain diseases including Alzheimer's, Parkinson's, and ischemic stroke. However, it is poorly understood how metaorganismal TMAO production influences brain function under normal physiological conditions. To address this, here we have reduced TMAO levels by inhibiting gut microbe-driven choline conversion to trimethylamine (TMA), and then performed comprehensive behavioral phenotyping in mice. Unexpectedly, we find that TMAO is particularly enriched in the murine olfactory bulb, and when TMAO production is blunted at the level of bacterial choline TMA lyase (CutC/D), olfactory perception is altered. Taken together, our studies demonstrate a previously underappreciated role for the TMAO pathway in olfactory-related behaviors.


Subject(s)
Olfactory Perception , Animals , Mice , Bacteria/metabolism , Choline/metabolism , Methylamines/metabolism , Female , Mice, Inbred C57BL
2.
J Lipid Res ; 64(4): 100349, 2023 04.
Article in English | MEDLINE | ID: mdl-36806709

ABSTRACT

We previously demonstrated that antisense oligonucleotide-mediated knockdown of Mboat7, the gene encoding membrane bound O-acyltransferase 7, in the liver and adipose tissue of mice promoted high fat diet-induced hepatic steatosis, hyperinsulinemia, and systemic insulin resistance. Thereafter, other groups showed that hepatocyte-specific genetic deletion of Mboat7 promoted striking fatty liver and NAFLD progression in mice but does not alter insulin sensitivity, suggesting the potential for cell autonomous roles. Here, we show that MBOAT7 function in adipocytes contributes to diet-induced metabolic disturbances including hyperinsulinemia and systemic insulin resistance. We generated Mboat7 floxed mice and created hepatocyte- and adipocyte-specific Mboat7 knockout mice using Cre-recombinase mice under the control of the albumin and adiponectin promoter, respectively. Here, we show that MBOAT7 function in adipocytes contributes to diet-induced metabolic disturbances including hyperinsulinemia and systemic insulin resistance. The expression of Mboat7 in white adipose tissue closely correlates with diet-induced obesity across a panel of ∼100 inbred strains of mice fed a high fat/high sucrose diet. Moreover, we found that adipocyte-specific genetic deletion of Mboat7 is sufficient to promote hyperinsulinemia, systemic insulin resistance, and mild fatty liver. Unlike in the liver, where Mboat7 plays a relatively minor role in maintaining arachidonic acid-containing PI pools, Mboat7 is the major source of arachidonic acid-containing PI pools in adipose tissue. Our data demonstrate that MBOAT7 is a critical regulator of adipose tissue PI homeostasis, and adipocyte MBOAT7-driven PI biosynthesis is closely linked to hyperinsulinemia and insulin resistance in mice.


Subject(s)
Hyperinsulinism , Insulin Resistance , Non-alcoholic Fatty Liver Disease , Animals , Mice , Acylation , Adipocytes/metabolism , Arachidonic Acid/metabolism , Diet, High-Fat/adverse effects , Glucose/metabolism , Homeostasis , Hyperinsulinism/genetics , Hyperinsulinism/metabolism , Insulin Resistance/genetics , Mice, Inbred C57BL , Mice, Knockout , Non-alcoholic Fatty Liver Disease/metabolism
3.
BMC Surg ; 22(1): 232, 2022 Jun 17.
Article in English | MEDLINE | ID: mdl-35715794

ABSTRACT

BACKGROUND: The traditional approach for occipital migraine surgery encompasses three separate surgical incisions in the posterior neck to decompress the greater occipital nerves (GON), lesser occipital nerves (LON), and third occipital nerves (TON). Other incisions have been investigated, including singular transverse incisions. We sought to evaluate a single, vertical midline incision approach for decompression of all six occipital nerves. METHODS: Using 10 cadaveric hemi-sides (5 fresh cadaver head and necks). Anatomic landmarks and the location of the bilateral GON, LON, and TON were marked according to previous anatomic studies. A single, midline 9-cm incision was made, and lateral skin flaps were raised to decompress or avulse all six nerves. RESULTS: Through the midline incision, the GON and TON were identified at 3.5 and 6.2 cm, respectively, inferior to a line bisecting the external auditory canal (EAC) and 1.5 cm lateral to the midline. The LON was identified as 6-cm inferior and 6.5-cm medial to a line bisecting the EAC in the plane just above the investing layer of the deep cervical fascia until the posterior border of the sternocleidomastoid was encountered. The LON had the greatest amount of variation but was identified lateral to the posterior border of the SCM. CONCLUSIONS: A single midline incision approach allows for successful identification and decompression of all six occipital nerves in migraine surgery.


Subject(s)
Migraine Disorders , Surgical Wound , Cadaver , Cervical Plexus , Decompression , Humans , Migraine Disorders/surgery , Spinal Nerves/anatomy & histology , Spinal Nerves/surgery
4.
Am J Physiol Heart Circ Physiol ; 318(6): H1474-H1486, 2020 06 01.
Article in English | MEDLINE | ID: mdl-32330092

ABSTRACT

The gut microbe-derived metabolite trimethylamine-N-oxide (TMAO) has recently been linked to cardiovascular disease (CVD) pathogenesis, prompting the development of therapeutic strategies to reduce TMAO. Previous work has shown that experimental alteration of circulating TMAO levels via dietary alterations or inhibition of the host TMAO producing enzyme flavin containing monooxygenase 3 (FMO3) is associated with reorganization of host cholesterol and bile acid metabolism in mice. In this work, we set out to understand whether recently developed nonlethal gut microbe-targeting small molecule choline trimethylamine (TMA) lyase inhibitors also alter host cholesterol and bile acid metabolism. Treatment of mice with the mechanism-based choline TMA lyase inhibitor, iodomethylcholine (IMC), increased fecal neutral sterol loss in the form of coprostanol, a bacteria metabolite of cholesterol. In parallel, IMC treatment resulted in marked reductions in the intestinal sterol transporter Niemann-pick C1-like 1 (NPC1L1) and reorganization of the gut microbial community, primarily reversing choline supplemented diet-induced changes. IMC also prevented diet-driven hepatic cholesterol accumulation, causing both upregulation of the host hepatic bile acid synthetic enzyme CYP7A1 and altering the expression of hepatic genes critical for bile acid feedback regulation. These studies suggest that the gut microbiota-driven TMAO pathway is closely linked to both microbe and host sterol and bile acid metabolism. Collectively, as gut microbe-targeting choline TMA lyase inhibitors move through the drug discovery pipeline from preclinical models to human studies, it will be important to understand how these drugs impact both microbe and host cholesterol and bile acid metabolism.NEW & NOTEWORTHY The gut microbe-dependent metabolite trimethylamine-N-oxide (TMAO) has been strongly associated with cardiovascular mortality, prompting drug discovery efforts to identify points of therapeutic intervention within the microbe host TMAO pathway. Recently, mechanism-based small molecule inhibitors of the major bacterial trimethylamine (TMA) lyase enzymes have been developed, and these drugs show efficacy as anti-atherothrombotic agents. The novel findings of this study are that small molecule TMA lyase inhibition results in beneficial reorganization of host cholesterol and bile acid metabolism. This study confirms previous observations that the gut microbial TMAO pathway is intimately linked to host cholesterol and bile acid metabolism and provides further rationale for the development of small molecule choline TMA lyase inhibitors for the treatment of cardiometabolic disorders.


Subject(s)
Bile Acids and Salts/metabolism , Cholesterol/metabolism , Gastrointestinal Microbiome/physiology , Intestinal Mucosa/metabolism , Animals , Choline/metabolism , Lipid Metabolism , Liver/metabolism , Male , Mice
5.
J Nutr ; 150(4): 775-783, 2020 04 01.
Article in English | MEDLINE | ID: mdl-31851339

ABSTRACT

BACKGROUND: Hepatocellular carcinoma (HCC) is the third most common cause of cancer-related death in the world. Choline deficiency has been well studied in the context of liver disease; however, less is known about the effects of choline supplementation in HCC. OBJECTIVE: The objective of this study was to test whether choline supplementation could influence the progression of HCC in a high-fat-diet (HFD)-driven mouse model. METHODS: Four-day-old male C57BL/6J mice were treated with the chemical carcinogen, 7,12-dimethylbenz[a]anthracene, and were randomly assigned at weaning to a cohort fed an HFD (60% kcal fat) or an HFD with supplemental choline (60% kcal fat, 1.2% choline; HFD+C) for 30 wk. Blood was isolated at 15 and 30 wk to measure immune cells by flow cytometry, and glucose-tolerance tests were performed 2 wk prior to killing. Overall tumor burden was quantified, hepatic lipids were measured enzymatically, and phosphatidylcholine species were measured by targeted MS methods. Gene expression and mitochondrial DNA were quantified by quantitative PCR. RESULTS: HFD+C mice exhibited a 50-90% increase in both circulating choline and betaine concentrations in the fed state (P ≤ 0.05). Choline supplementation resulted in a 55% decrease in total tumor numbers, a 67% decrease in tumor surface area, and a 50% decrease in hepatic steatosis after 30 wk of diet (P ≤ 0.05). Choline supplementation increased the abundance of mitochondria and the relative expression of ß-oxidation genes by 21% and ∼75-100%, respectively, in the liver. HFD+C attenuated circulating myeloid-derived suppressor cells at 15 wk of feeding (P ≤ 0.05). CONCLUSIONS: Choline supplementation attenuated HFD-induced HCC and hepatic steatosis in male C57BL/6J mice. These results suggest a therapeutic benefit of choline supplementation in blunting HCC progression.


Subject(s)
Choline/administration & dosage , Diet, High-Fat/adverse effects , Liver Neoplasms, Experimental/prevention & control , Liver Neoplasms/prevention & control , Animals , Betaine/blood , Choline/blood , DNA, Mitochondrial/analysis , Dietary Supplements , Fatty Liver/prevention & control , Gene Expression/drug effects , Lipid Metabolism/genetics , Liver/chemistry , Liver/pathology , Liver Neoplasms/etiology , Liver Neoplasms/pathology , Liver Neoplasms, Experimental/etiology , Liver Neoplasms, Experimental/pathology , Male , Mice , Mice, Inbred C57BL , Myeloid-Derived Suppressor Cells/pathology , Organ Size/drug effects
6.
Arterioscler Thromb Vasc Biol ; 38(1): 218-231, 2018 01.
Article in English | MEDLINE | ID: mdl-29074585

ABSTRACT

OBJECTIVE: Human genetic variants near the FADS (fatty acid desaturase) gene cluster (FADS1-2-3) are strongly associated with cardiometabolic traits including dyslipidemia, fatty liver, type 2 diabetes mellitus, and coronary artery disease. However, mechanisms underlying these genetic associations are unclear. APPROACH AND RESULTS: Here, we specifically investigated the physiological role of the Δ-5 desaturase FADS1 in regulating diet-induced cardiometabolic phenotypes by treating hyperlipidemic LDLR (low-density lipoprotein receptor)-null mice with antisense oligonucleotides targeting the selective knockdown of Fads1. Fads1 knockdown resulted in striking reorganization of both ω-6 and ω-3 polyunsaturated fatty acid levels and their associated proinflammatory and proresolving lipid mediators in a highly diet-specific manner. Loss of Fads1 activity promoted hepatic inflammation and atherosclerosis, yet was associated with suppression of hepatic lipogenesis. Fads1 knockdown in isolated macrophages promoted classic M1 activation, whereas suppressing alternative M2 activation programs, and also altered systemic and tissue inflammatory responses in vivo. Finally, the ability of Fads1 to reciprocally regulate lipogenesis and inflammation may rely in part on its role as an effector of liver X receptor signaling. CONCLUSIONS: These results position Fads1 as an underappreciated regulator of inflammation initiation and resolution, and suggest that endogenously synthesized arachidonic acid and eicosapentaenoic acid are key determinates of inflammatory disease progression and liver X receptor signaling.


Subject(s)
Aorta/enzymology , Aortic Diseases/enzymology , Atherosclerosis/enzymology , Dyslipidemias/enzymology , Fatty Acid Desaturases/metabolism , Inflammation Mediators/metabolism , Inflammation/enzymology , Lipogenesis , Animals , Aorta/pathology , Aortic Diseases/genetics , Aortic Diseases/pathology , Arachidonic Acid/metabolism , Atherosclerosis/genetics , Atherosclerosis/pathology , Cells, Cultured , Delta-5 Fatty Acid Desaturase , Disease Models, Animal , Dyslipidemias/genetics , Dyslipidemias/pathology , Eicosapentaenoic Acid/metabolism , Fatty Acid Desaturases/genetics , Inflammation/genetics , Inflammation/pathology , Liver/metabolism , Liver X Receptors/metabolism , Macrophage Activation , Macrophages, Peritoneal/enzymology , Macrophages, Peritoneal/pathology , Mice, Inbred C57BL , Mice, Knockout , Oligonucleotides, Antisense/genetics , Oligonucleotides, Antisense/metabolism , Plaque, Atherosclerotic , Receptors, LDL/deficiency , Receptors, LDL/genetics
7.
Addict Biol ; 23(2): 631-642, 2018 03.
Article in English | MEDLINE | ID: mdl-28612502

ABSTRACT

MicroRNAs (miRNAs) within the ventral and dorsal striatum have been shown to regulate addiction-relevant behaviours. However, it is unclear how cocaine experience alone can alter the expression of addiction-relevant miRNAs within striatal subregions. Further, it is not known whether differential expression of miRNAs in the striatum contributes to individual differences in addiction vulnerability. We first examined the effect of cocaine self-administration on the expression of miR-101b, miR-137, miR-212 and miR-132 in nucleus accumbens core and nucleus accumbens shell (NAcSh), as well as dorsomedial striatum and dorsolateral striatum (DLS). We then examined the expression of these same miRNAs in striatal subregions of animals identified as being 'addiction-prone', either immediately following self-administration training or following extinction and relapse testing. Cocaine self-administration was associated with changes in miRNA expression in a regionally discrete manner within the striatum, with the most marked changes occurring in the nucleus accumbens core. When we examined the miRNA profile of addiction-prone rats following self-administration, we observed increased levels of miR-212 in the dorsomedial striatum. After extinction and relapse testing, addiction-prone rats showed significant increases in the expression of miR-101b, miR-137, miR-212 and miR-132 in NAcSh, and miR-137 in the DLS. This study identifies temporally specific changes in miRNA expression consistent with the engagement of distinct striatal subregions across the course of the addiction cycle. Increased dysregulation of miRNA expression in NAcSh and DLS at late stages of the addiction cycle may underlie habitual drug seeking, and may therefore aid in the identification of targets designed to treat addiction.


Subject(s)
Cocaine/administration & dosage , Dopamine Uptake Inhibitors/administration & dosage , MicroRNAs/metabolism , Nucleus Accumbens/metabolism , Animals , Cocaine/pharmacology , Cocaine-Related Disorders/metabolism , Corpus Striatum/drug effects , Corpus Striatum/metabolism , Dopamine Uptake Inhibitors/pharmacology , Drug-Seeking Behavior , Male , MicroRNAs/drug effects , Neuronal Plasticity/drug effects , Nucleus Accumbens/drug effects , Rats , Rats, Sprague-Dawley , Self Administration , Time Factors , Ventral Striatum/drug effects , Ventral Striatum/metabolism
8.
J Lipid Res ; 58(1): 236-246, 2017 01.
Article in English | MEDLINE | ID: mdl-27811230

ABSTRACT

G protein-coupled receptor (GPR)120/FFA receptor (FFAR)4 (GPR120/FFAR4) activation by n-3 PUFAs attenuates inflammation, but its impact on atherosclerosis is unknown. We determined whether in vivo activation of leukocyte GPR120/FFAR4 by n-3 versus n-6 PUFAs is atheroprotective. Leukocyte GPR120/FFAR4 WT or KO mice in the LDL receptor KO background were generated by bone marrow transplantation. Mice were fed one of the four atherogenic diets containing 0.2% cholesterol and 10% calories as palm oil (PO) + 10% calories as: 1) PO, 2) fish oil (FO; 20:5 n-3 and 22:6 n-3 enriched), 3) echium oil (EO; 18:4 n-3 enriched), or 4) borage oil (BO; 18:3 n-6 enriched) for 16 weeks. Compared with PO, mice fed BO, EO, and FO had significantly reduced plasma cholesterol, TG, VLDL cholesterol, hepatic neutral lipid, and atherosclerosis that were equivalent for WT and KO mice. In BO-, EO-, and FO-fed mice, but not PO-fed mice, lack of leukocyte GPR120/FFAR4 resulted in neutrophilia, pro-inflammatory Ly6Chi monocytosis, increased aortic root monocyte recruitment, and increased hepatic inflammatory gene expression. In conclusion, leukocyte GPR120 expression has minimal effects on dietary PUFA-induced plasma lipid/lipoprotein reduction and atheroprotection, and there is no distinction between n-3 versus n-6 PUFAs in activating anti-inflammatory effects of leukocyte GPR120/FFAR4 in vivo.


Subject(s)
Atherosclerosis/genetics , Leukocytes/metabolism , Receptors, G-Protein-Coupled/genetics , Receptors, LDL/genetics , Animals , Aorta/metabolism , Aorta/pathology , Atherosclerosis/metabolism , Atherosclerosis/pathology , Cholesterol/metabolism , Diet, Atherogenic , Fatty Acids, Omega-3/genetics , Fatty Acids, Omega-3/metabolism , Fatty Acids, Omega-6/genetics , Fatty Acids, Omega-6/metabolism , Gene Expression Regulation/drug effects , Humans , Inflammation/genetics , Inflammation/metabolism , Inflammation/pathology , Leukocytes/pathology , Mice , Mice, Knockout , Receptors, G-Protein-Coupled/metabolism , Transcriptional Activation/genetics
9.
Biochim Biophys Acta Mol Cell Biol Lipids ; 1862(10 Pt B): 1233-1241, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28827091

ABSTRACT

Mutations in the gene encoding comparative gene identification 58 (CGI-58), also known as α ß hydrolase domain-containing 5 (ABHD5), cause neutral lipid storage disorder with ichthyosis (NLSDI). This inborn error in metabolism is characterized by ectopic accumulation of triacylglycerols (TAG) within cytoplasmic lipid droplets in multiple cell types. Studies over the past decade have clearly demonstrated that CGI-58 is a potent regulator of TAG hydrolysis in the disease-relevant cell types. However, despite the reproducible genetic link between CGI-58 mutations and TAG storage, the molecular mechanisms by which CGI-58 regulates TAG hydrolysis are still incompletely understood. It is clear that CGI-58 can regulate TAG hydrolysis by activating the major TAG hydrolase adipose triglyceride lipase (ATGL), yet CGI-58 can also regulate lipid metabolism via mechanisms that do not involve ATGL. This review highlights recent progress made in defining the physiologic and biochemical function of CGI-58, and its broader role in energy homeostasis. This article is part of a Special Issue entitled: Recent Advances in Lipid Droplet Biology edited by Rosalind Coleman and Matthijs Hesselink.


Subject(s)
1-Acylglycerol-3-Phosphate O-Acyltransferase/metabolism , Energy Metabolism , Lipid Droplets/metabolism , Lipid Metabolism , Triglycerides/metabolism , 1-Acylglycerol-3-Phosphate O-Acyltransferase/genetics , Animals , Humans , Hydrolysis , Ichthyosiform Erythroderma, Congenital/genetics , Ichthyosiform Erythroderma, Congenital/metabolism , Ichthyosiform Erythroderma, Congenital/pathology , Lipase/genetics , Lipase/metabolism , Lipid Droplets/pathology , Lipid Metabolism, Inborn Errors/genetics , Lipid Metabolism, Inborn Errors/metabolism , Lipid Metabolism, Inborn Errors/pathology , Muscular Diseases/genetics , Muscular Diseases/metabolism , Muscular Diseases/pathology , Triglycerides/genetics
10.
Br J Clin Pharmacol ; 83(10): 2274-2282, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28488266

ABSTRACT

AIMS: Methadone is a widely used opioid agonist treatment associated with QT prolongation and torsades de pointes. We investigated the QT interval in patients treated with methadone or buprenorphine using continuous 12-lead Holter recordings. METHODS: We prospectively made 24-h Holter recordings in patients prescribed methadone or buprenorphine, compared to controls. After their normal dose a continuous 12-lead Holter recorder was attached for 24 h. Digital electrocardiograms were extracted hourly from the Holter recordings. The QT interval was measured automatically (H-scribe software, Mortara Pty Ltd) and checked manually. The QT interval was plotted against heart rate (HR) on the QT nomogram to determine abnormality. Demographics, dosing, medical history and laboratory investigations were recorded. RESULTS: There were 58 patients (19 methadone, 20 buprenorphine and 19 control); median age 35 years (20-56 years); 33 males. Baseline characteristics were similar. Median dose of methadone was 110 mg day-1 (70-170 mg day-1 ) and buprenorphine was 16 mg day-1 (12-32 mg day-1 ). Seven participants had abnormal QT intervals. There was a significant difference in the proportion of prescribed methadone with abnormal QT intervals, 7/19 (37%; 95% confidence interval: 17-61%), compared to controls 0/19 (0%; 95% confidence interval: 0-21%; P = 0.008), but no difference between buprenorphine and controls (0/20). QT vs. HR plots showed patients prescribed methadone had higher QT-HR pairs over 24 h compared to controls. There was no difference in dose for patients prescribed methadone with abnormal QT intervals and those without. CONCLUSIONS: Methadone is associated with prolonged QT intervals, but there was no association with dose. Buprenorphine did not prolong the QT interval. Twenty four-hour Holter recordings using the QT nomogram is a feasible method to assess the QT interval in patients prescribed methadone.


Subject(s)
Analgesics, Opioid/adverse effects , Long QT Syndrome/diagnosis , Opiate Substitution Treatment/adverse effects , Opioid-Related Disorders/drug therapy , Torsades de Pointes/diagnosis , Adult , Buprenorphine/administration & dosage , Buprenorphine/adverse effects , Dose-Response Relationship, Drug , Electrocardiography/methods , Female , Humans , Long QT Syndrome/chemically induced , Male , Methadone/administration & dosage , Methadone/adverse effects , Middle Aged , Prospective Studies , Torsades de Pointes/chemically induced , Young Adult
11.
Biochim Biophys Acta ; 1841(8): 1097-101, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24423940

ABSTRACT

Genome sequencing efforts have identified many uncharacterized lipase/esterase enzymes that have potential to be drug targets for metabolic diseases such as obesity, diabetes, and atherosclerosis. However, sequence information and associated structural predictions provide only a loose framework for linking enzyme function to disease risk. We are now confronted with the challenge of functionally annotating a large number of uncharacterized lipases, with the goal of generating new therapies for metabolic diseases. This daunting challenge involves gathering not only sequence-driven predictions, but also more importantly structural, biochemical (substrates and products), and physiological data. At the center of such drug discovery efforts are accurately identifying physiologically relevant substrates and products of individual lipases, and determining whether newly identified substrates/products can modulate disease in appropriate preclinical animal model systems. This review describes the importance of coupling in vivo metabolite profiling to in vitro enzymology as a powerful means to assign lipase function in disease specific contexts using animal models. In particular, we highlight recent examples using this multidisciplinary approach to functionally annotate genes within the α/ß hydrolase fold domain (ABHD) family of enzymes. These new discoveries within the ABHD enzyme family serve as powerful examples of linking novel lipase function to human disease. This article is part of a Special Issue entitled Tools to study lipid functions.


Subject(s)
Hydrolases/metabolism , Lipase/metabolism , Hydrolases/chemistry , Protein Structure, Tertiary
12.
Wound Repair Regen ; 23(6): 842-54, 2015.
Article in English | MEDLINE | ID: mdl-26342168

ABSTRACT

Chronic nonhealing skin wounds often contain bacterial biofilms that prevent normal wound healing and closure and present challenges to the use of conventional wound dressings. We investigated inhibition of Pseudomonas aeruginosa biofilm formation, a common pathogen of chronic skin wounds, on a commercially available biological wound dressing. Building on prior reports, we examined whether the amino acid tryptophan would inhibit P. aeruginosa biofilm formation on the three-dimensional surface of the biological dressing. Bacterial biomass and biofilm polysaccharides were quantified using crystal violet staining or an enzyme linked lectin, respectively. Bacterial cells and biofilm matrix adherent to the wound dressing were visualized through scanning electron microscopy. D-/L-tryptophan inhibited P. aeruginosa biofilm formation on the wound dressing in a dose dependent manner and was not directly cytotoxic to immortalized human keratinocytes although there was some reduction in cellular metabolism or enzymatic activity. More importantly, D-/L-tryptophan did not impair wound healing in a splinted skin wound murine model. Furthermore, wound closure was improved when D-/L-tryptophan treated wound dressing with P. aeruginosa biofilms were compared with untreated dressings. These findings indicate that tryptophan may prove useful for integration into wound dressings to inhibit biofilm formation and promote wound healing.


Subject(s)
Anti-Infective Agents, Local/pharmacology , Pseudomonas Infections/pathology , Pseudomonas aeruginosa/drug effects , Soft Tissue Injuries/pathology , Tryptophan/pharmacology , Wound Healing , Wound Infection/pathology , Animals , Bandages , Biofilms/drug effects , Disease Models, Animal , Mice , Mice, Inbred BALB C , Microscopy, Electron, Scanning , Pseudomonas Infections/microbiology , Soft Tissue Injuries/microbiology , Wound Infection/microbiology
13.
Arterioscler Thromb Vasc Biol ; 34(9): 1888-99, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24833800

ABSTRACT

OBJECTIVE: Transplantation studies suggest that bone marrow cell ATP-binding cassette transporter A1 protects against atherosclerosis development. However, the in vivo effect of macrophage ATP-binding cassette transporter A1 expression on atherogenesis is not fully understood because bone marrow contains other leukocytes and hematopoietic stem and progenitor cells. Myeloid-specific ATP-binding cassette transporter A1 knockout mice in the low-density lipoprotein (LDL) receptor knockout C57BL/6 background were developed to address this question. APPROACH AND RESULTS: Chow-fed myeloid-specific ATP-binding cassette transporter A1 knockout/LDL receptor knockout (double knockout [DKO]) versus LDL receptor knockout (single knockout [SKO]) mice had similar plasma lipid concentrations, but atherogenic diet (AD)-fed DKO mice had reduced plasma very-LDL (VLDL)/LDL concentrations resulting from decreased hepatic VLDL triglyceride secretion. Resident peritoneal macrophages from AD-fed DKO versus SKO mice had significantly higher cholesterol content but similar proinflammatory gene expression. Atherosclerosis extent was similar between genotypes after 10 to 16 weeks of AD but increased modestly in DKO mice by 24 weeks of AD. Lesional macrophage content was similar, likely because of the higher monocyte flux through aortic root lesions in DKO versus SKO mice. After transplantation of DKO or SKO bone marrow into SKO mice and 16 weeks of AD feeding, atherosclerosis extent was similar and plasma apolipoprotein B lipoproteins were reduced in mice receiving DKO bone marrow. When differences in plasma VLDL/LDL concentrations were minimized by maintaining mice on chow for 24 weeks, DKO mice had modest, but significantly more, atherosclerosis compared with SKO mice. CONCLUSIONS: Myeloid cell ATP-binding cassette transporter A1 increases hepatic VLDL triglyceride secretion and plasma VLDL/LDL concentrations in AD-fed LDL receptor knockout mice, offsetting its atheroprotective role in decreasing macrophage cholesterol content, resulting in a minimal increase in atherosclerosis.


Subject(s)
ATP Binding Cassette Transporter 1/physiology , Atherosclerosis/metabolism , Cholesterol/metabolism , Diet, Atherogenic/adverse effects , Macrophages, Peritoneal/metabolism , Myeloid Cells/metabolism , Animals , Aorta/metabolism , Aorta/pathology , Atherosclerosis/genetics , Atherosclerosis/prevention & control , Bone Marrow Transplantation , Cholesterol, LDL/blood , Cholesterol, VLDL/blood , Female , Genotype , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Receptors, LDL/deficiency , Receptors, LDL/genetics , Triglycerides/blood
14.
J Lipid Res ; 55(12): 2562-75, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25316883

ABSTRACT

Cellular TG stores are efficiently hydrolyzed by adipose TG lipase (ATGL). Its coactivator comparative gene identification-58 (CGI-58) strongly increases ATGL-mediated TG catabolism in cell culture experiments. To investigate the consequences of CGI-58 deficiency in murine macrophages, we generated mice with a targeted deletion of CGI-58 in myeloid cells (macCGI-58(-/-) mice). CGI-58(-/-) macrophages accumulate intracellular TG-rich lipid droplets and have decreased phagocytic capacity, comparable to ATGL(-/-) macrophages. In contrast to ATGL(-/-) macrophages, however, CGI-58(-/-) macrophages have intact mitochondria and show no indications of mitochondrial apoptosis and endoplasmic reticulum stress, suggesting that TG accumulation per se lacks a significant role in processes leading to mitochondrial dysfunction. Another notable difference is the fact that CGI-58(-/-) macrophages adopt an M1-like phenotype in vitro. Finally, we investigated atherosclerosis susceptibility in macCGI-58/ApoE-double KO (DKO) animals. In response to high-fat/high-cholesterol diet feeding, DKO animals showed comparable plaque formation as observed in ApoE(-/-) mice. In agreement, antisense oligonucleotide-mediated knockdown of CGI-58 in LDL receptor(-/-) mice did not alter atherosclerosis burden in the aortic root. These results suggest that macrophage function and atherosclerosis susceptibility differ fundamentally in these two animal models with disturbed TG catabolism, showing a more severe phenotype by ATGL deficiency.


Subject(s)
1-Acylglycerol-3-Phosphate O-Acyltransferase/metabolism , Atherosclerosis/metabolism , Gene Deletion , Lipase/metabolism , Macrophages, Peritoneal/immunology , Phagocytosis , 1-Acylglycerol-3-Phosphate O-Acyltransferase/antagonists & inhibitors , 1-Acylglycerol-3-Phosphate O-Acyltransferase/genetics , Animals , Apoptosis , Atherosclerosis/etiology , Atherosclerosis/immunology , Atherosclerosis/pathology , Cells, Cultured , Crosses, Genetic , Diet, High-Fat/adverse effects , Female , Gene Knockdown Techniques , Lipase/genetics , Lipid Droplets/immunology , Lipid Droplets/metabolism , Lipid Droplets/ultrastructure , Macrophages, Peritoneal/metabolism , Macrophages, Peritoneal/ultrastructure , Male , Mice, Inbred C57BL , Mice, Knockout , Mice, Transgenic , Microscopy, Electron, Transmission , Mitochondria/immunology , Mitochondria/metabolism , Mitochondria/ultrastructure , Oligonucleotides, Antisense/administration & dosage , Triglycerides/metabolism
15.
Pilot Feasibility Stud ; 10(1): 74, 2024 May 09.
Article in English | MEDLINE | ID: mdl-38725088

ABSTRACT

BACKGROUND: Transcranial magnetic stimulation (TMS) (including the theta burst stimulation (TBS) form of TMS used in this study) is a non-invasive means to stimulate nerve cells in superficial areas of the brain. In recent years, there has been a growth in the application of TMS to investigate the modulation of neural networks involved in substance use disorders. This study examines the feasibility of novel TMS protocols for the treatment of methamphetamine (MA) use disorder in an ambulatory drug and alcohol treatment setting. METHODS: Thirty participants meeting the criteria for moderate to severe MA use disorder will be recruited in community drug and alcohol treatment settings and randomised to receive active TMS or sham (control) intervention. The treatment is intermittent TBS (iTBS) applied to the left dorsolateral prefrontal cortex (DLPFC), then continuous TBS (cTBS) to the left orbitofrontal cortex (OFC). Twelve sessions are administered over 4 weeks with opt-in weekly standardized cognitive behaviour therapy (CBT) counselling and a neuroimaging sub-study offered to participants. Primary outcomes are feasibility measures including recruitment, retention and acceptability of the intervention. Secondary outcomes include monitoring of safety and preliminary efficacy data including changes in substance use, cravings (cue reactivity) and cognition (response inhibition). DISCUSSION: This study examines shorter TBS protocols of TMS for MA use disorder in real-world drug and alcohol outpatient settings where withdrawal and abstinence from MA, or other substances, are not eligibility requirements. TMS is a relatively affordable treatment and staff of ambulatory health settings can be trained to administer TMS. It is a potentially scalable and translatable treatment for existing drug and alcohol clinical settings. TMS has the potential to provide a much-needed adjuvant treatment to existing psychosocial interventions for MA use disorder. A limitation of this protocol is that the feasibility of follow-up is only examined at the end of treatment (4 weeks). TRIAL REGISTRATION: Australia New Zealand Clinical Trial Registry ACTRN12622000762752. Registered on May 27, 2022, and retrospectively registered (first participant enrolled) on May 23, 2022, with protocol version 7 on February 24, 2023.

16.
Nat Commun ; 15(1): 4923, 2024 Jun 11.
Article in English | MEDLINE | ID: mdl-38862484

ABSTRACT

Missions into Deep Space are planned this decade. Yet the health consequences of exposure to microgravity and galactic cosmic radiation (GCR) over years-long missions on indispensable visceral organs such as the kidney are largely unexplored. We performed biomolecular (epigenomic, transcriptomic, proteomic, epiproteomic, metabolomic, metagenomic), clinical chemistry (electrolytes, endocrinology, biochemistry) and morphometry (histology, 3D imaging, miRNA-ISH, tissue weights) analyses using samples and datasets available from 11 spaceflight-exposed mouse and 5 human, 1 simulated microgravity rat and 4 simulated GCR-exposed mouse missions. We found that spaceflight induces: 1) renal transporter dephosphorylation which may indicate astronauts' increased risk of nephrolithiasis is in part a primary renal phenomenon rather than solely a secondary consequence of bone loss; 2) remodelling of the nephron that results in expansion of distal convoluted tubule size but loss of overall tubule density; 3) renal damage and dysfunction when exposed to a Mars roundtrip dose-equivalent of simulated GCR.


Subject(s)
Cosmic Radiation , Space Flight , Animals , Humans , Mice , Cosmic Radiation/adverse effects , Rats , Male , Kidney/pathology , Kidney/radiation effects , Kidney/metabolism , Kidney Diseases/pathology , Kidney Diseases/etiology , Weightlessness/adverse effects , Astronauts , Mice, Inbred C57BL , Proteomics , Female , Mars , Weightlessness Simulation/adverse effects
17.
J Lipid Res ; 54(10): 2708-17, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23894207

ABSTRACT

Obesity-associated low-grade chronic inflammation plays an important role in the development of insulin resistance. The membrane lipid transporter ATP-binding cassette transporter A1 (ABCA1) promotes formation of nascent HDL particles. ABCA1 also dampens macrophage inflammation by reducing cellular membrane cholesterol and lipid raft content. We tested the hypothesis that myeloid-specific ABCA1 deletion may exacerbate insulin resistance by increasing the obesity-associated chronic low-grade inflammation. Myeloid cell-specific ABCA1 knockout (MSKO) and wild-type (WT) mice developed obesity, insulin resistance, mild hypercholesterolemia, and hepatic steatosis to a similar extent with a 45% high-fat (HF) diet feeding or after crossing into the ob/ob background. Resident peritoneal macrophages and stromal vascular cells from obese MSKO mice accumulated significantly more cholesterol. Relative to chow, HF diet markedly induced macrophage infiltration and inflammatory cytokine expression to a similar extent in adipose tissue of WT and MSKO mice. Among pro-inflammatory cytokines examined, only IL-6 was highly upregulated in MSKO-ob/ob versus ob/ob mouse peritoneal macrophages, indicating a nonsignificant effect of myeloid ABCA1 deficiency on obesity-associated chronic inflammation. In conclusion, myeloid-specific ABCA1 deficiency does not exacerbate obesity-associated low-grade chronic inflammation and has minimal impact on the pathogenesis of insulin resistance in both HF diet-induced and genetically obese mouse models.


Subject(s)
ATP Binding Cassette Transporter 1/genetics , Diet, High-Fat/adverse effects , Insulin Resistance , Macrophages/metabolism , Obesity/metabolism , ATP Binding Cassette Transporter 1/deficiency , Adipose Tissue, White/immunology , Adipose Tissue, White/metabolism , Animals , Cells, Cultured , Chemokines/metabolism , Cholesterol/blood , Epididymis/immunology , Epididymis/metabolism , Inflammation Mediators/metabolism , Lipid Metabolism , Liver/metabolism , Male , Mice , Mice, Inbred C57BL , Mice, Obese , Mice, Transgenic , Obesity/etiology , Obesity/immunology
18.
Arterioscler Thromb Vasc Biol ; 32(9): 2122-30, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22814747

ABSTRACT

OBJECTIVE: Fish oil, containing omega-3 fatty acids, attenuates atherosclerosis. We hypothesized that omega-3 fatty acid-enriched oils are atheroprotective through alteration of monocyte subsets and their trafficking into atherosclerotic lesions. METHODS AND RESULTS: Low-density lipoprotein receptor knockout and apolipoprotein E(-/-) mice were fed diets containing 10% (calories) palm oil and 0.2% cholesterol, supplemented with an additional 10% palm oil, echium oil (containing 18:4 n-3), or fish oil. Compared with palm oil-fed low-density lipoprotein receptor knockout mice, echium oil and fish oil significantly reduced plasma cholesterol, splenic Ly6C(hi) monocytosis by ≈50%, atherosclerosis by 40% to 70%, monocyte trafficking into the aortic root by ≈50%, and atherosclerotic lesion macrophage content by 30% to 44%. In contrast, atherosclerosis and monocyte trafficking into the artery wall was not altered by omega-3 fatty acids in apolipoprotein E(-/-) mice; however, Ly6C(hi) splenic monocytes positively correlated with aortic root intimal area across all diet groups. In apolipoprotein E(-/-) mice, fish oil reduced the percentage of blood Ly6C(hi) monocytes, despite an average 2-fold higher plasma cholesterol relative to palm oil. CONCLUSIONS: The presence of splenic Ly6C(hi) monocytes parallels the appearance of atherosclerotic disease in both low-density lipoprotein receptor knockout and apolipoprotein E(-/-) mice. Furthermore, omega-3 fatty acids favorably alter monocyte subsets independently from effects on plasma cholesterol and reduce monocyte recruitment into atherosclerotic lesions.


Subject(s)
Aorta/drug effects , Aortic Diseases/prevention & control , Atherosclerosis/prevention & control , Chemotaxis/drug effects , Dietary Supplements , Fatty Acids, Omega-3/pharmacology , Monocytes/drug effects , Plant Oils/pharmacology , Spleen/drug effects , Animals , Antigens, Ly/blood , Aorta/immunology , Aorta/metabolism , Aorta/pathology , Aortic Diseases/blood , Aortic Diseases/genetics , Aortic Diseases/immunology , Aortic Diseases/pathology , Apolipoproteins E/deficiency , Apolipoproteins E/genetics , Atherosclerosis/blood , Atherosclerosis/genetics , Atherosclerosis/immunology , Atherosclerosis/pathology , Biomarkers/blood , Cholesterol, Dietary/blood , Disease Models, Animal , Echium , Female , Inflammation Mediators/blood , Macrophages/drug effects , Macrophages/immunology , Mice , Mice, Inbred C57BL , Mice, Knockout , Monocytes/immunology , Monocytes/metabolism , Monocytes/pathology , Neutrophils/drug effects , Neutrophils/immunology , Palm Oil , Receptors, LDL/deficiency , Receptors, LDL/genetics , Spleen/immunology , Spleen/metabolism , Time Factors
19.
Cureus ; 15(1): c98, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36713820

ABSTRACT

[This corrects the article DOI: 10.7759/cureus.22513.].

20.
Front Psychiatry ; 14: 1207955, 2023.
Article in English | MEDLINE | ID: mdl-37654991

ABSTRACT

Introduction: Most pregnant women with substance use problems smoke, and few will quit during their pregnancy. Tobacco treatment is often overlooked, with the focus usually placed on other substance use. Additionally, few targeted effective treatments for this group exist. To address this, the feasibility of an intensive tobacco treatment incorporating contingency management (CM) that featured non-face-to-face delivery was examined. Methods: A single-arm pre-post design feasibility trial was conducted in three antenatal services that support women who use substances in metropolitan Australia. Participants were over the age of 15, had <33-week gestation, and smoked tobacco daily. They received financial incentives for daily carbon monoxide-verified smoking abstinence or reduction through an internet-based CM programme, nicotine replacement therapy (NRT) posted to women and partners or household members who smoked and telephone-delivered behavioral counseling from study enrolment to birth. Results: Of the 101 referrals, 46 women (46%) consented. The mean (SD) age was 31(±6) years, and the gestation period was 22(±6) weeks. Nineteen (41%) of those enrolled were retained for 12-week postpartum. Of 46 women, 32 (70%) utilized CM; 32 (70%) used NRT for ≥2 weeks; 23 (50%) attended ≥1 counseling session; and 15 (22%) received NRT for partners/household members. Fifteen (33%) were verified abstinent from tobacco at delivery after a median (IQR) period of abstinence of 65(36-128) days. All non-smokers at birth utilized NRT and financial incentives, and 9/15 (60%) utilized counseling. Four (9%) were abstinent at 12-week postpartum. Median cigarettes smoked/day reduced from baseline to delivery (10(6-20) to 1(0-6) p =< 0.001). Women who quit smoking had more education (72% vs. 33% p =< 0.02), completed more CO samples (median (IQR) 101(59-157) vs. 2(0-20) p =< 0.001), and received more incentives (median (IQR) $909($225-$1980) vs. $34($3-$64) p =< 0.001). Intervention acceptability was rated favorably by participants (9 items rated 0-10 with scores >5 considered favorable). Discussion: This study demonstrated the feasibility and acceptability of a consumer-informed, non-face-to-face intensive tobacco treatment, highlighting the potential of remotely delivered technology-based CM to reduce the health impact of tobacco smoking in high-priority populations. The intervention demonstrates scale-up potential. Future studies should extend treatment into the postpartum period, utilizing new technologies to enhance CM delivery and improve counseling provision and partner support. Clinical trial registration: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=374196, ACTRN1261800056224.

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