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1.
Int J Cancer ; 2024 Jun 24.
Article in English | MEDLINE | ID: mdl-38922879

ABSTRACT

Previous studies demonstrated limited efficacy of immune checkpoint inhibitors in unresectable acral melanoma (AM); it remains unclear how this translates to the adjuvant setting. This study investigates clinical outcomes of acral compared to cutaneous melanoma (CM) patients treated with adjuvant anti-PD-1 after complete resection. All stages III-IV AM and CM patients receiving adjuvant anti-PD-1 after complete resection between 2018 and 2022 were included from the prospective nationwide Dutch Melanoma Treatment Registry. We analyzed recurrence-free survival (RFS), distant metastasis-free survival (DMFS), and overall survival (OS). A multivariable Cox regression analysis of RFS was performed to adjust for potential confounders. We included 1958 (86 AM and 1872 CM) patients. At baseline, AM patients more frequently had KIT mutations, higher disease stages, and Eastern Cooperative Oncology Group Performance Status, and fewer BRAF and NRAS mutations. Median RFS was 14.8 months (95% confidence interval [CI]: 11.5-29.3) in AM and 37.4 months (95% CI: 34.6 to not reached) in CM (p = .002). After correcting for potential confounders, AM remained associated with a higher risk of recurrence (HRadj 1.53; 95% CI: 1.07-2.17; p = .019). Two-year DMFS tended to be worse for AM than for CM: 64.5% versus 79.7% (p = .050). Two-year OS was significantly lower in AM (71.5% vs. 84.3%; p = .027). The results of this study suggest a poorer outcome of adjuvant-treated AM compared to CM. Studies assessing the added value of adjuvant treatment in AM are needed. Future research should investigate alternative treatment strategies to improve outcomes of high-risk AM.

2.
EClinicalMedicine ; 69: 102485, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38370537

ABSTRACT

Background: The prognosis of advanced melanoma patients has significantly improved over the years. We aimed to evaluate the survival per year of diagnosis. Methods: All systemically treated patients diagnosed with advanced melanoma from 2013 to 2021 were included from the Dutch Melanoma Treatment Registry. Baseline characteristics and overall survival (OS) were compared between the different years of diagnosis. A multivariable Cox proportional hazards model was used to estimate the association between year of diagnosis and OS. Findings: For this cohort study, we included 6260 systemically treated advanced melanoma patients. At baseline, there was an increase over the years in age, the percentage of patients with an ECOG PS ≥ 2, with brain metastases, and a synchronous diagnosis of primary and unresectable melanoma. Median OS increased from 11.2 months (95% CI 10.0-12.4) for patients diagnosed in 2013 to 32.0 months (95% CI 26.6-36.7) for patients diagnosed in 2019. Median OS was remarkably lower for patients diagnosed in 2020 (26.6 months; 95% CI 23.9-35.1) and 2021 (24.0 months; 95% CI 20.4-NR). Patients diagnosed in 2020 and 2021 had a higher hazard of death compared to patients diagnosed in 2019, although this was not significant. The multivariable Cox regression showed a lower hazard of death for the years of diagnosis after 2013. In contrast, patients diagnosed in 2020 and 2021 had a higher hazard of death compared to patients diagnosed in 2019. Interpretation: After a continuous survival improvement for advanced melanoma patients between 2013 and 2019, outcomes of patients diagnosed in 2020 and 2021 seem poorer. This trend of decreased survival remained after correcting for known prognostic factors and previous neoadjuvant or adjuvant treatment, suggesting that it is explained by unmeasured factors, which-considering the timing-could be COVID-19-related. Funding: For the Dutch Melanoma Treatment Registry (DMTR), the Dutch Institute for Clinical Auditing foundation received a start-up grant from governmental organization The Netherlands Organization for Health Research and Development (ZonMW, project number 836002002). The DMTR is structurally funded by Bristol-Myers Squibb, Merck Sharpe & Dohme, Novartis, and Roche Pharma. Roche Pharma stopped funding in 2019, and Pierre Fabre started funding the DMTR in 2019. For this work, no funding was granted.

3.
Int J Cancer ; 154(10): 1760-1771, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38296842

ABSTRACT

Predicting who will benefit from treatment with immune checkpoint inhibition (ICI) in patients with advanced melanoma is challenging. We developed a multivariable prediction model for response to ICI, using routinely available clinical data including primary melanoma characteristics. We used a population-based cohort of 3525 patients with advanced cutaneous melanoma treated with anti-PD-1-based therapy. Our prediction model for predicting response within 6 months after ICI initiation was internally validated with bootstrap resampling. Performance evaluation included calibration, discrimination and internal-external cross-validation. Included patients received anti-PD-1 monotherapy (n = 2366) or ipilimumab plus nivolumab (n = 1159) in any treatment line. The model included serum lactate dehydrogenase, World Health Organization performance score, type and line of ICI, disease stage and time to first distant recurrence-all at start of ICI-, and location and type of primary melanoma, the presence of satellites and/or in-transit metastases at primary diagnosis and sex. The over-optimism adjusted area under the receiver operating characteristic was 0.66 (95% CI: 0.64-0.66). The range of predicted response probabilities was 7%-81%. Based on these probabilities, patients were categorized into quartiles. Compared to the lowest response quartile, patients in the highest quartile had a significantly longer median progression-free survival (20.0 vs 2.8 months; P < .001) and median overall survival (62.0 vs 8.0 months; P < .001). Our prediction model, based on routinely available clinical variables and primary melanoma characteristics, predicts response to ICI in patients with advanced melanoma and discriminates well between treated patients with a very good and very poor prognosis.


Subject(s)
Melanoma , Skin Neoplasms , Humans , Melanoma/pathology , Immune Checkpoint Inhibitors/therapeutic use , Skin Neoplasms/pathology , Ipilimumab/therapeutic use , Nivolumab/therapeutic use , Retrospective Studies
4.
Int J Cancer ; 152(12): 2493-2502, 2023 06 15.
Article in English | MEDLINE | ID: mdl-36843274

ABSTRACT

Since the introduction of BRAF(/MEK) inhibition and immune checkpoint inhibition (ICI), the prognosis of advanced melanoma has greatly improved. Melanoma is known for its remarkably long time to first distant recurrence (TFDR), which can be decades in some patients and is partly attributed to immune-surveillance. We investigated the relationship between TFDR and patient outcomes after systemic treatment for advanced melanoma. We selected patients undergoing first-line systemic therapy for advanced melanoma from the nationwide Dutch Melanoma Treatment Registry. The association between TFDR and progression-free survival (PFS) and overall survival (OS) was assessed by Cox proportional hazard regression models. The TFDR was modeled categorically, linearly, and flexibly using restricted cubic splines. Patients received anti-PD-1-based treatment (n = 1844) or BRAF(/MEK) inhibition (n = 1618). For ICI-treated patients with a TFDR <2 years, median OS was 25.0 months, compared to 37.3 months for a TFDR >5 years (P = .014). Patients treated with BRAF(/MEK) inhibition with a longer TFDR also had a significantly longer median OS (8.6 months for TFDR <2 years compared to 11.1 months for >5 years, P = .004). The hazard of dying rapidly decreased with increasing TFDR until approximately 5 years (HR 0.87), after which the hazard of dying further decreased with increasing TFDR, but less strongly (HR 0.82 for a TFDR of 10 years and HR 0.79 for a TFDR of 15 years). Results were similar when stratifying for type of treatment. Advanced melanoma patients with longer TFDR have a prolonged PFS and OS, irrespective of being treated with first-line ICI or targeted therapy.


Subject(s)
Melanoma , Proto-Oncogene Proteins B-raf , Humans , Proto-Oncogene Proteins B-raf/genetics , Prognosis , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Mitogen-Activated Protein Kinase Kinases , Retrospective Studies
5.
N Engl J Med ; 387(23): 2113-2125, 2022 12 08.
Article in English | MEDLINE | ID: mdl-36477031

ABSTRACT

BACKGROUND: Immune checkpoint inhibitors and targeted therapies have dramatically improved outcomes in patients with advanced melanoma, but approximately half these patients will not have a durable benefit. Phase 1-2 trials of adoptive cell therapy with tumor-infiltrating lymphocytes (TILs) have shown promising responses, but data from phase 3 trials are lacking to determine the role of TILs in treating advanced melanoma. METHODS: In this phase 3, multicenter, open-label trial, we randomly assigned patients with unresectable stage IIIC or IV melanoma in a 1:1 ratio to receive TIL or anti-cytotoxic T-lymphocyte antigen 4 therapy (ipilimumab at 3 mg per kilogram of body weight). Infusion of at least 5×109 TILs was preceded by nonmyeloablative, lymphodepleting chemotherapy (cyclophosphamide plus fludarabine) and followed by high-dose interleukin-2. The primary end point was progression-free survival. RESULTS: A total of 168 patients (86% with disease refractory to anti-programmed death 1 treatment) were assigned to receive TILs (84 patients) or ipilimumab (84 patients). In the intention-to-treat population, median progression-free survival was 7.2 months (95% confidence interval [CI], 4.2 to 13.1) in the TIL group and 3.1 months (95% CI, 3.0 to 4.3) in the ipilimumab group (hazard ratio for progression or death, 0.50; 95% CI, 0.35 to 0.72; P<0.001); 49% (95% CI, 38 to 60) and 21% (95% CI, 13 to 32) of the patients, respectively, had an objective response. Median overall survival was 25.8 months (95% CI, 18.2 to not reached) in the TIL group and 18.9 months (95% CI, 13.8 to 32.6) in the ipilimumab group. Treatment-related adverse events of grade 3 or higher occurred in all patients who received TILs and in 57% of those who received ipilimumab; in the TIL group, these events were mainly chemotherapy-related myelosuppression. CONCLUSIONS: In patients with advanced melanoma, progression-free survival was significantly longer among those who received TIL therapy than among those who received ipilimumab. (Funded by the Dutch Cancer Society and others; ClinicalTrials.gov number, NCT02278887.).


Subject(s)
Immunotherapy, Adoptive , Lymphocytes, Tumor-Infiltrating , Melanoma , Humans , Cell- and Tissue-Based Therapy , Ipilimumab/adverse effects , Melanoma/drug therapy
6.
Eur J Cancer ; 167: 70-80, 2022 05.
Article in English | MEDLINE | ID: mdl-35395553

ABSTRACT

BACKGROUND: Recent reports suggest the limited efficacy of immune checkpoints inhibitors in advanced acral melanoma (AM). This study aims to investigate the clinical outcomes of immune checkpoint inhibitors in patients with stage III and IV AM and compare them to cutaneous melanoma (CM). METHODS: We included patients with advanced AM and CM treated with first-line anti-programmed cell death (PD)-1 monotherapy or ipilimumab-nivolumab registered in the prospective nationwide Dutch Melanoma Treatment Registry. Objective response rates, progression-free survival (PFS) and overall survival (OS) were calculated. A Cox proportional hazard model was used to assess the prognostic factors with PFS and OS. RESULTS: In total, 2058 patients (88 AM and 1970 CM) with advanced melanoma were included. First-line objective response rates were 34% for AM versus 54% for CM in the advanced anti-PD-1 cohort and 33% for AM versus 53% for CM in the advanced ipilimumab-nivolumab cohort. The Median PFS was significantly shorter for anti-PD-1 treated AM patients (3.1 months; 95%CI: 2.8-5.6) than patients with CM (10.1 months; 95%CI: 8.5-12.2) (P < 0.001). In patients with advanced melanoma, AM was significantly associated with a higher risk of progression (HRadj 1.63; 95%CI: 1.26-2.11; P < 0.001) and death (HRadj 1.54; 95%CI: 1.15-2.06; P = 0.004) than CM. CONCLUSIONS: This study shows lower effectiveness of anti-PD -1 monotherapy and ipilimumab-nivolumab in AM, with lower response rates, PFS and OS than CM. This group of patients should be prioritised in the development of alternative treatment strategies.


Subject(s)
Immune Checkpoint Inhibitors , Skin Neoplasms , Cohort Studies , Humans , Immune Checkpoint Inhibitors/therapeutic use , Ipilimumab/therapeutic use , Melanoma/mortality , Nivolumab/adverse effects , Prospective Studies , Skin Neoplasms/drug therapy , Skin Neoplasms/immunology , Melanoma, Cutaneous Malignant
7.
Int J Cancer ; 150(5): 816-824, 2022 03 01.
Article in English | MEDLINE | ID: mdl-34605003

ABSTRACT

The COVID-19 pandemic had a severe impact on medical care. Our study aims to investigate the impact of COVID-19 on advanced melanoma care in the Netherlands. We selected patients diagnosed with irresectable stage IIIc and IV melanoma during the first and second COVID-19 wave and compared them with patients diagnosed within the same time frame in 2018 and 2019. Patients were divided into three geographical regions. We investigated baseline characteristics, time from diagnosis until start of systemic therapy and postponement of anti-PD-1 courses. During both waves, fewer patients were diagnosed compared to the control groups. During the first wave, time between diagnosis and start of treatment was significantly longer in the southern region compared to other regions (33 vs 9 and 15 days, P-value <.05). Anti-PD-1 courses were postponed in 20.0% vs 3.0% of patients in the first wave compared to the control period. Significantly more patients had courses postponed in the south during the first wave compared to other regions (34.8% vs 11.5% vs 22.3%, P-value <.001). Significantly more patients diagnosed during the second wave had brain metastases and worse performance status compared to the control period. In conclusion, advanced melanoma care in the Netherlands was severely affected by the COVID-19 pandemic. In the south, the start of systemic treatment for advanced melanoma was more often delayed, and treatment courses were more frequently postponed. During the second wave, patients were diagnosed with poorer patient and tumor characteristics. Longer follow-up is needed to establish the impact on patient outcomes.


Subject(s)
COVID-19/complications , Melanoma/complications , Skin Neoplasms/complications , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Netherlands , SARS-CoV-2
8.
Cancers (Basel) ; 13(20)2021 Oct 11.
Article in English | MEDLINE | ID: mdl-34680228

ABSTRACT

BACKGROUND: To assure a high quality of care for patients treated in Dutch melanoma centers, hospital variation in treatment patterns and outcomes is evaluated in the Dutch Melanoma Treatment Registry. The aim of this study was to assess center variation in treatments and 2-year survival probabilities of patients diagnosed between 2013 and 2017 in the Netherlands. METHODS: We selected patients diagnosed between 2013 and 2017 with unresectable IIIC or stage IV melanoma, registered in the Dutch Melanoma Treatment Registry. Centers' performance on 2-year survival was evaluated using Empirical Bayes estimates calculated in a random effects model. Treatment patterns of the centers with the lowest and highest estimates for 2-year survival were compared. RESULTS: For patients diagnosed between 2014 and 2015, significant center variation in 2-year survival probabilities was observed even after correcting for case-mix and treatment with new systemic therapies. The different use of new systemic therapies partially explained the observed variation. From 2016 onwards, no significant difference in 2-year survival was observed between centers. CONCLUSION: Our data suggest that between 2014 and 2015, after correcting for patient case-mix, significant variation in 2-year survival probabilities between Dutch melanoma centers existed. The use of new systemic therapies could partially explain this variation. In 2013 and between 2016 and 2017, no significant variation between centers existed.

9.
Am J Trop Med Hyg ; 90(5): 835-9, 2014 May.
Article in English | MEDLINE | ID: mdl-24615130

ABSTRACT

The incidence of asymptomatic travel-related parasitic infection is uncertain. Previous studies did not distinguish new incident infections, from past infections. Regardless of symptoms, we performed multiplex real-time polymerase chain reaction on pre- and post-travel stool samples of Dutch long-term travelers to the (sub)tropics. Serological screening for Schistosoma spp. was only performed in travelers to sub-Saharan Africa. In total, 679 travelers were included in the study. The follow-up rate was 82% (556 of 679). Participants' median travel duration was 12 weeks. There was one incident infection with Strongyloides stercoralis; there were none with Entamoeba histolytica, 4 with Cryptosporidium spp. (1%), and 22 with Giardia lamblia (4%). Nine of 146 travelers (6%) seroconverted for Schistosoma spp. Routine screening of stool samples for parasitic infection is not indicated for asymptomatic people, who travel to the (sub)tropics for up to 3 months. Screening for Schistosoma spp. should be offered to travelers with fresh-water contact in endemic regions.


Subject(s)
Intestinal Diseases, Parasitic/diagnosis , Pathology, Molecular/methods , Travel , Adult , Africa South of the Sahara/epidemiology , Animals , Cohort Studies , Cross-Sectional Studies , Cryptosporidium/isolation & purification , Entamoeba histolytica/isolation & purification , Feces/parasitology , Female , Follow-Up Studies , Giardia lamblia/isolation & purification , Humans , Incidence , Male , Netherlands , Real-Time Polymerase Chain Reaction , Schistosoma/genetics , Schistosoma/isolation & purification , Strongyloides stercoralis/isolation & purification , Young Adult
10.
Atherosclerosis ; 210(2): 381-7, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20060117

ABSTRACT

OBJECTIVE: The use of the HIV-protease inhibitor ritonavir (RTV) is associated with induction of hypertriglyceridemia, which is a cardiovascular risk factor. Therefore, we investigated the effect of RTV on atherosclerosis development in APOE*3-Leiden transgenic mice, a model for human-like lipoprotein metabolism and atherosclerosis. METHODS AND RESULTS: APOE*3-Leiden mice were fed a Western-type diet without or with RTV (35 mg/kg/day) for 19 weeks. RTV increased plasma TG levels throughout the study (approximately 2-fold; P<0.05). Despite these increased TG levels, RTV decreased the atherosclerotic lesion area in the aortic root (-57%; P<0.05), concomitant with reduced macrophage area (-72%; P<0.01) and decreased lesion severity. This could not be explained by reduced inflammatory markers in plasma (i.e. serum amyloid A, E-selectin and fibrinogen), nor by decreased lipid accumulation in macrophages or increased cholesterol efflux from macrophages, as assessed using peritoneal macrophages in vitro. Rather, whereas RTV did not affect plasma total cholesterol levels, RTV decreased (V)LDL-cholesterol and increased cholesterol in apoE-rich large HDL. CONCLUSION: Despite inducing hypertriglyceridemia, RTV decreases atherosclerotic lesion area and severity, associated with decreased (V)LDL-cholesterol and increased atheroprotective apoE-rich large HDL.


Subject(s)
Apolipoprotein E3/genetics , Apolipoproteins E/genetics , Atherosclerosis/drug therapy , Ritonavir/pharmacology , Animals , Cholesterol/chemistry , Female , HIV Protease Inhibitors/pharmacology , Hypertriglyceridemia/drug therapy , Lipids/chemistry , Macrophages/metabolism , Macrophages, Peritoneal/metabolism , Mice , Mice, Transgenic , Risk Factors
11.
Biochem Biophys Res Commun ; 355(1): 204-10, 2007 Mar 30.
Article in English | MEDLINE | ID: mdl-17292863

ABSTRACT

CD36, also named fatty acid translocase, has been identified as a putative membrane transporter for long-chain fatty acids (LCFA). In the heart, contraction-induced 5' AMP-activated protein kinase (AMPK) signaling regulates cellular LCFA uptake through translocation of CD36 and possibly of other LCFA transporters from intracellular storage compartments to the sarcolemma. In this study, isolated cardiomyocytes from CD36(+/+)- and CD36(-/-) mice were used to investigate to what extent basal and AMPK-mediated LCFA uptake are CD36-dependent. Basal LCFA uptake was not altered in CD36(-/-) cardiomyocytes, most likely resulting from a (1.8-fold) compensatory upregulation of fatty acid-transport protein-1. The stimulatory effect of contraction-mimetic stimuli, oligomycin (2.5-fold) and dipyridamole (1.6-fold), on LCFA uptake into CD36(+/+) cardiomyocytes was almost completely lost in CD36(-/-) cardiomyocytes, despite that AMPK signaling was fully intact. CD36 is almost entirely responsible for AMPK-mediated stimulation of LCFA uptake in cardiomyocytes, indicating a pivotal role for CD36 in mediating changes in cardiac LCFA fluxes.


Subject(s)
Adenylate Kinase/metabolism , CD36 Antigens/genetics , CD36 Antigens/physiology , Fatty Acids, Nonesterified/metabolism , Myocardium/metabolism , Palmitic Acid/metabolism , Sarcolemma/metabolism , Animals , Biological Transport , Deoxyglucose/metabolism , Heart/drug effects , Heart/physiology , Kinetics , Mice , Mice, Inbred C57BL , Mice, Knockout , Myocardial Contraction/drug effects , Myocardium/enzymology , Oligomycins/pharmacology
12.
Am J Physiol Endocrinol Metab ; 291(6): E1360-4, 2006 Dec.
Article in English | MEDLINE | ID: mdl-16849628

ABSTRACT

Insulin is an important inhibitor of both hepatic glucose output and hepatic VLDL-triglyceride (VLDL-TG) production. We investigated whether both processes are equally sensitive to insulin-mediated inhibition. To test this, we used euglycemic clamp studies with four increasing plasma concentrations of insulin in wild-type C57Bl/6 mice. By extrapolation, we estimated that half-maximal inhibition of hepatic glucose output and hepatic VLDL-TG production by insulin were obtained at plasma insulin levels of approximately 3.6 and approximately 6.8 ng/ml, respectively. In the same experiments, we measured that half-maximal decrease of plasma free fatty acid levels and half-maximal stimulation of peripheral glucose uptake were reached at plasma insulin levels of approximately 3.0 and approximately 6.0 ng/ml, respectively. We conclude that, compared with insulin sensitivity of hepatic glucose output, peripheral glucose uptake and hepatic VLDL-TG production are less sensitive to insulin.


Subject(s)
Glucose/biosynthesis , Hypoglycemic Agents/pharmacology , Insulin/pharmacology , Lipoproteins, VLDL/biosynthesis , Liver/metabolism , Triglycerides/biosynthesis , Animals , Blood Glucose/metabolism , Dose-Response Relationship, Drug , Fatty Acids, Nonesterified/blood , Glucose Clamp Technique , Insulin/blood , Kinetics , Liver/drug effects , Male , Mice , Mice, Inbred C57BL
13.
Endocrinology ; 147(10): 4553-8, 2006 Oct.
Article in English | MEDLINE | ID: mdl-16709607

ABSTRACT

Several studies have demonstrated an association in humans between plasma levels or production capacity of the antiinflammatory cytokine IL-10 and insulin sensitivity. The aim of our study was to investigate the protective role of endogenous IL-10 availability in the development of diet-induced insulin resistance. We compared parameters of glucose and lipid metabolism between IL-10(-/-) mice and wild-type (wt) mice fed a high-fat diet for 6 wk. This diet has previously been shown to induce steatosis and insulin resistance. After 6 wk on the high-fat diet, no differences in body weight, basal metabolism (measured by indirect calorimetry), or plasma levels of glucose, triglycerides, or cholesterol were observed between IL-10(-/-) and wt mice. Nonetheless, in IL-10(-/-) mice, plasma free fatty acid levels were 75% increased compared with wt mice after overnight fasting (P < 0.05). In addition, hepatic triglyceride content was 54% increased in IL-10(-/-) mice (P < 0.05). During a hyperinsulinemic euglycemic clamp, no differences were observed in whole-body or hepatic insulin sensitivity between both groups. We conclude that basal IL-10 production protects against hepatic steatosis but does not improve hepatic or whole-body insulin sensitivity, during high-fat feeding.


Subject(s)
Dietary Fats/pharmacology , Insulin Resistance/physiology , Interleukin-10/physiology , Liver Diseases/pathology , Adipose Tissue/growth & development , Adipose Tissue/physiology , Animals , Blood Glucose/metabolism , Chromatography, Thin Layer , Diet , Energy Metabolism/genetics , Energy Metabolism/physiology , Fibrinogen/metabolism , Genotype , Glucose/metabolism , Glucose Clamp Technique , Interleukin-10/genetics , Lipid Metabolism/genetics , Lipids/blood , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Phenotype , Serum Amyloid A Protein/metabolism
14.
Arterioscler Thromb Vasc Biol ; 26(1): 124-9, 2006 Jan.
Article in English | MEDLINE | ID: mdl-16269669

ABSTRACT

OBJECTIVE: The use of the HIV protease inhibitor ritonavir (RTV) is frequently associated with hypertriglyceridemia and lipodystrophy. The aim of our study was to determine the mechanism underlying the observed hypertriglyceridemia. METHODS AND RESULTS: Feeding female APOE*3-Leiden transgenic mice a Western-type diet supplemented with RTV (35 mg/kg per day) for 2 weeks resulted in a 2-fold increase in fasting plasma triglyceride (TG) levels, which was specific for very low-density lipoprotein (VLDL). RTV did not change the hepatic VLDL-TG production. Instead, RTV did increase the postprandial TG response to an oral fat load (area under the curve, 25.5+/-12.1 versus 13.8+/-6.8 mmol/L per hour in controls; P<0.05). Likewise, RTV hampered the plasma clearance of intravenously injected glycerol tri[3H]oleate-labeled VLDL-like emulsion particles (half time, 19.3+/-10.5 versus 5.0+/-1.3 minutes in controls; P<0.05) associated with a decrease of 44% in plasma lipoprotein lipase activity. Accordingly, RTV decreased the uptake of TG-derived fatty acids (FAs) into adipose tissue, as well as the uptake of albumin-bound FA. CONCLUSIONS: We conclude that RTV causes hypertriglyceridemia via decreased lipoprotein lipase-mediated clearance of VLDL-TG. In addition, RTV specifically impairs the uptake of FA in adipose tissue, which may contribute to the lipodystrophy that is frequently observed in HIV-infected subjects on antiretroviral therapy.


Subject(s)
Fatty Acids/metabolism , HIV Protease Inhibitors/pharmacology , Hypertriglyceridemia/chemically induced , Lipolysis/drug effects , Lipoprotein Lipase/metabolism , Ritonavir/pharmacology , Adipose Tissue/drug effects , Adipose Tissue/metabolism , Animals , Anticoagulants/pharmacology , Apolipoprotein E3 , Apolipoproteins E/genetics , Cholesterol, VLDL/biosynthesis , Cholesterol, VLDL/blood , Emulsions , Enzyme Activation/drug effects , Female , HIV Infections/drug therapy , Heparin/pharmacology , Hypertriglyceridemia/metabolism , Mice , Mice, Transgenic , Postprandial Period , Triglycerides/biosynthesis , Triglycerides/blood , Triolein/pharmacokinetics , Tritium
15.
Proc Natl Acad Sci U S A ; 102(32): 11468-73, 2005 Aug 09.
Article in English | MEDLINE | ID: mdl-16051702

ABSTRACT

Sequestration of malaria-parasite-infected erythrocytes in the microvasculature of organs is thought to be a significant cause of pathology. Cerebral malaria (CM) is a major complication of Plasmodium falciparum infections, and PfEMP1-mediated sequestration of infected red blood cells has been considered to be the major feature leading to CM-related pathology. We report a system for the real-time in vivo imaging of sequestration using transgenic luciferase-expressing parasites of the rodent malaria parasite Plasmodium berghei. These studies revealed that: (i) as expected, lung tissue is a major site, but, unexpectedly, adipose tissue contributes significantly to sequestration, and (ii) the class II scavenger-receptor CD36 to which PfEMP1 can bind is also the major receptor for P. berghei sequestration, indicating a role for alternative parasite ligands, because orthologues of PfEMP1 are absent from rodent malaria parasites, and, importantly, (iii) cerebral complications still develop in the absence of CD36-mediated sequestration, dissociating parasite sequestration from CM-associated pathology. Real-time in vivo imaging of parasitic processes may be used to evaluate the molecular basis of pathology and develop strategies to prevent pathology.


Subject(s)
CD36 Antigens/metabolism , Erythrocytes/parasitology , Malaria, Cerebral/pathology , Malaria, Cerebral/physiopathology , Plasmodium berghei/genetics , Adipose Tissue/parasitology , Adipose Tissue/pathology , Animals , Brain/parasitology , Brain/pathology , Gene Transfer Techniques , Green Fluorescent Proteins , Luciferases/metabolism , Lung/parasitology , Lung/pathology , Mice , Microscopy, Fluorescence/methods , Plasmodium berghei/metabolism , Protozoan Proteins/metabolism , Time Factors
16.
J Lipid Res ; 46(10): 2175-81, 2005 Oct.
Article in English | MEDLINE | ID: mdl-16024917

ABSTRACT

CD36 is involved in high-affinity peripheral FFA uptake. CD36-deficient (cd36(-)(/)(-)) mice exhibit increased plasma FFA and triglyceride (TG) levels. The aim of the present study was to elucidate the cause of the increased plasma TG levels in cd36(-)(/)(-) mice. cd36(-)(/)(-) mice showed no differences in hepatic VLDL-TG production or intestinal [(3)H]TG uptake compared with wild-type littermates. cd36(-)(/)(-) mice showed a 2-fold enhanced postprandial TG response upon an intragastric fat load (P < 0.05), with a concomitant 2.5-fold increased FFA response (P < 0.05), suggesting that the increased FFA in cd36(-/-) mice may impair LPL-mediated TG hydrolysis. Postheparin LPL levels were not affected. However, the in vitro LPL-mediated TG hydrolysis rate as induced by postheparin plasma of cd36(-)(/)(-) mice in the absence of excess FFA-free BSA was reduced 2-fold compared with wild-type plasma (P < 0.05). This inhibition was relieved upon the addition of excess FFA-free BSA. Likewise, increasing plasma FFA in wild-type mice to the levels observed in cd36(-)(/)(-) mice by infusion prolonged the plasma half-life of glycerol tri[(3)H]oleate-labeled VLDL-like emulsion particles by 2.5-fold (P < 0.05). We conclude that the increased plasma TG levels observed in cd36(-)(/)(-) mice are caused by decreased LPL-mediated hydrolysis of TG-rich lipoproteins resulting from FFA-induced product inhibition of LPL.


Subject(s)
CD36 Antigens/genetics , Lipoprotein Lipase/physiology , Triglycerides/metabolism , Animals , Eating , Fatty Acids, Nonesterified/blood , Female , Intestinal Absorption/physiology , Lipoprotein Lipase/blood , Lipoproteins, VLDL/biosynthesis , Liver/metabolism , Male , Mice , Mice, Inbred C57BL , Triglycerides/biosynthesis , Triglycerides/blood
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