scholarly journals Effects of the Human Immunodeficiency Virus-Protease Inhibitor, Ritonavir, on Basal and Catecholamine-Stimulated Lipolysis

2005 ◽  
Vol 90 (6) ◽  
pp. 3251-3261 ◽  
Author(s):  
Diane C. Adler-Wailes ◽  
Hanguan Liu ◽  
Faiyaz Ahmad ◽  
Ningping Feng ◽  
Constantine Londos ◽  
...  
Keyword(s):  
Protein Expression ◽  
Protease Inhibitor ◽  
Hormone Sensitive Lipase ◽  
Hiv Protease ◽  
Intracellular Camp ◽  
Cellular Mechanisms ◽  
Protein Levels ◽  
Immunodeficiency Virus ◽  
Hormone Sensitive ◽  
Phenylisopropyl Adenosine

Several of the aspartic acid protease inhibitors used to treat HIV infection increase basal lipolysis in adipocytes, but the cellular mechanisms leading to this augmentation are not well understood. We therefore studied the effects of chronic exposure to the HIV protease inhibitor, ritonavir, on the lipolytic cascade in 3T3-L1 adipocytes. Treatment of 3T3-L1 adipocytes with ritonavir for 14 d (during and after differentiation) enhanced basal, isoproterenol (Iso)-stimulated, and cAMP analog-stimulated lipolysis. Enhancement of lipolysis was observed after Iso at concentrations between 0.1 and 10 μm. Despite a significant decrease in cyclic nucleotide phosphodiesterase (PDE)3B activity and protein levels, there were no changes in Iso-stimulated intracellular cAMP, protein kinase A (PKA) expression, or PKA activity. Ritonavir-augmented lipolysis was also observed under conditions that reversed the effect on PDE3B activity via preincubation with 1 μm (-)-N6-(2-phenylisopropyl)adenosine. In ritonavir-treated cells, protein expression of the lipid droplet-protective protein, perilipin, was significantly decreased, whereas there was no change in hormone-sensitive lipase. Activation of ERK1/2 by Iso did not play a role in the augmentation. We conclude that ritonavir decreases PDE3B and perilipin protein expression and affects both basal and catecholamine-stimulated lipolysis in 3T3-L1 adipocytes primarily through actions at sites downstream of PKA.

scholarly journals Evaluation of reverse transcriptase and protease inhibitors in two-drug combinations against human immunodeficiency virus replication.

1996 ◽  
Vol 40 (6) ◽  
pp. 1346-1351 ◽  
Author(s):  
C A Deminie ◽  
C M Bechtold ◽  
D Stock ◽  
M Alam ◽  
F Djang ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Combination Therapy ◽  
Protease Inhibitor ◽  
Reverse Transcriptase ◽  
Protease Inhibitors ◽  
Nucleoside Analogs ◽  
Drug Combinations ◽  
Hiv Protease ◽  
Human Immunodeficiency Virus Replication ◽  
Immunodeficiency Virus

Current treatments for human immunodeficiency virus (HIV) include both reverse transcriptase and protease inhibitors. Results from in vitro and clinical studies suggest that combination therapy can be more effective than single drugs in reducing viral burden. To evaluate compounds for combination therapy, stavudine (d4T), didanosine (ddI), or BMS-186,318, an HIV protease inhibitor, were combined with other clinically relevant compounds and tested in a T-cell line (CEM-SS) that was infected with HIV-RF or in peripheral blood mononuclear cells infected with a clinical HIV isolate. The combined drug effects were analyzed by the methods described by Chou and Talalay (Adv. Enzyme Regul. 22:27-55, 1984) as well as by Prichard et al. (Antimicrob. Agents Chemother. 37:540-545, 1993). The results showed that combining two nucleoside analogs (d4T-ddI, d4T-zidovudine [AZT], and d4T-zalcitabine [ddC]), two HIV protease inhibitors (BMS-186,318-saquinavir, BMS-186,318-SC-52151, and BMS-186,318-MK-639) or a reverse transcriptase and a protease inhibitor (BMS-186,318-d4T, BMS-186,318-ddI, BMS-186,318-AZT, d4T-saquinavir, d4T-MK-639, and ddI-MK-639) yielded additive to synergistic antiviral effects. In general, analysis of data by either method gave consistent results. In addition, combined antiviral treatments involving nucleoside analogs gave slightly different outcomes in the two cell types, presumably because of a difference in phosphorylation patterns. Importantly, no strong antagonism was observed with the drug combinations studied. These data should provide useful information for the design of clinical trials of combined chemotherapy.

scholarly journals ABT-378, a Highly Potent Inhibitor of the Human Immunodeficiency Virus Protease

1998 ◽  
Vol 42 (12) ◽  
pp. 3218-3224 ◽  
Author(s):  
Hing L. Sham ◽  
Dale J. Kempf ◽  
Akhteruzammen Molla ◽  
Kennan C. Marsh ◽  
Gondi N. Kumar ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Protease Inhibitor ◽  
Response To Therapy ◽  
Hiv Protease ◽  
Healthy Human ◽  
Human Volunteers ◽  
Immunodeficiency Virus ◽  
Potent Protease Inhibitor

ABSTRACT The valine at position 82 (Val 82) in the active site of the human immunodeficiency virus (HIV) protease mutates in response to therapy with the protease inhibitor ritonavir. By using the X-ray crystal structure of the complex of HIV protease and ritonavir, the potent protease inhibitor ABT-378, which has a diminished interaction with Val 82, was designed. ABT-378 potently inhibited wild-type and mutant HIV protease (Ki = 1.3 to 3.6 pM), blocked the replication of laboratory and clinical strains of HIV type 1 (50% effective concentration [EC50], 0.006 to 0.017 μM), and maintained high potency against mutant HIV selected by ritonavir in vivo (EC50, ≤0.06 μM). The metabolism of ABT-378 was strongly inhibited by ritonavir in vitro. Consequently, following concomitant oral administration of ABT-378 and ritonavir, the concentrations of ABT-378 in rat, dog, and monkey plasma exceeded the in vitro antiviral EC50 in the presence of human serum by >50-fold after 8 h. In healthy human volunteers, coadministration of a single 400-mg dose of ABT-378 with 50 mg of ritonavir enhanced the area under the concentration curve of ABT-378 in plasma by 77-fold over that observed after dosing with ABT-378 alone, and mean concentrations of ABT-378 exceeded the EC50 for >24 h. These results demonstrate the potential utility of ABT-378 as a therapeutic intervention against AIDS.

scholarly journals Comparative studies of the role of hormone-sensitive lipase and adipose triglyceride lipase in human fat cell lipolysis

2007 ◽  
Vol 292 (6) ◽  
pp. E1847-E1855 ◽  
Author(s):  
Mikael Rydén ◽  
Johan Jocken ◽  
Vanessa van Harmelen ◽  
Andrea Dicker ◽  
Johan Hoffstedt ◽  
...  
Keyword(s):  
Protein Expression ◽  
Polycystic Ovary ◽  
Human Mesenchymal Stem Cells ◽  
Hormone Sensitive Lipase ◽  
Adipose Triglyceride Lipase ◽  
Human Adipocytes ◽  
Fat Cell ◽  
Triglyceride Lipase ◽  
Knock Down ◽  
Hormone Sensitive

Hormone-sensitive lipase (HSL) and adipose triglyceride lipase (ATGL) regulate adipocyte lipolysis in rodents. The purpose of this study was to compare the roles of these lipases for lipolysis in human adipocytes. Subcutaneous adipose tissue was investigated. HSL and ATGL protein expression were related to lipolysis in isolated mature fat cells. ATGL or HSL were knocked down by RNA interference (RNAi) or selectively inhibited, and effects on lipolysis were studied in differentiated preadipocytes or adipocytes derived from human mesenchymal stem cells (hMSC). Subjects were all women. There were 12 lean controls, 8 lean with polycystic ovary syndrome (PCOS), and 27 otherwise healthy obese subjects. We found that norepinephrine-induced lipolysis was positively correlated with HSL protein levels ( P < 0.0001) but not with ATGL protein. Women with PCOS or obesity had significantly decreased norepinephrine-induced lipolysis and HSL protein expression but no change in ATGL protein expression. HSL knock down by RNAi reduced basal and catecholamine-induced lipolysis. Knock down of ATGL decreased basal lipolysis but did not change catecholamine-stimulated lipolysis. Treatment of hMSC with a selective HSL inhibitor during and/or after differentiation in adipocytes reduced basal lipolysis by 50%, but stimulated lipolysis was inhibited completely. In contrast to findings in rodents, ATGL is of less importance than HSL in regulating catecholamine-induced lipolysis and cannot replace HSL when this enzyme is continuously inhibited. However, both lipases regulate basal lipolysis in human adipocytes. ATGL expression, unlike HSL, is not influenced by obesity or PCOS.

scholarly journals Molecular Basis for Increased Susceptibility of Isolates with Atazanavir Resistance-Conferring Substitution I50L to Other Protease Inhibitors

2005 ◽  
Vol 49 (9) ◽  
pp. 3825-3832 ◽  
Author(s):  
Joseph Yanchunas ◽  
David R. Langley ◽  
Li Tao ◽  
Ronald E. Rose ◽  
Jacques Friborg ◽  
...  
Keyword(s):  
Protease Inhibitor ◽  
Protease Inhibitors ◽  
Hiv Protease ◽  
Cross Resistance ◽  
Titration Calorimetry ◽  
Binding Affinities ◽  
The Novel ◽  
Immunodeficiency Virus ◽  
Effective Drugs ◽  
Hiv 1

ABSTRACT Protease inhibitors (PIs) are highly effective drugs against the human immunodeficiency virus (HIV), yet long-term therapeutic use is limited by emergence of HIV type 1 (HIV-1) protease substitutions that confer cross-resistance to multiple protease inhibitor drugs. Atazanavir is a highly potent HIV protease inhibitor with a distinct resistance profile that includes effectiveness against most HIV-1 isolates resistant to one or two PIs. The signature resistance substitution for atazanavir is I50L, and it is frequently (53%) accompanied by a compensatory A71V substitution that helps restore viability and increases atazanavir resistance levels. We measured the binding affinities of wild-type (WT) and I50L/A71V HIV-1 proteases to atazanavir and other currently approved PIs (ritonavir, lopinavir, saquinavir, nelfinavir, indinavir, and amprenavir) by isothermal titration calorimetry. Remarkably, we find that all of the PIs have 2- to 10-fold increased affinities for I50L/A71V protease, except for atazanavir. The results are also manifested by thermal stability measures of affinity for WT and I50L/A71V proteases. Additional biophysical and enzyme kinetics experiments show I50L/A71V protease is a stable enzyme with catalytic activity that is slightly reduced (34%) relative to the WT. Computational modeling reveals that the unique resistance phenotype of I50L/A71V protease likely originates from bulky tert-butyl groups at P2 and P2′ (specific to atazanavir) that sterically clash with methyl groups on residue L50. The results of this study provide a molecular understanding of the novel hypersusceptibility of atazanavir-resistant I50L/A71V-containing clinical isolates to other currently approved PIs.

Cytoplasm lipids can be modulated through hormone-sensitive lipase and are related to mitochondrial function in porcine IVM oocytes

2020 ◽  
Vol 32 (7) ◽  
pp. 667
Author(s):  
Qingrui Zhuan ◽  
Haojia Ma ◽  
Jing Chen ◽  
Yuxi Luo ◽  
Yan Luo ◽  
...  
Keyword(s):  
Oocyte Maturation ◽  
Mitochondrial Function ◽  
Polar Body ◽  
Treated Group ◽  
Hormone Sensitive Lipase ◽  
Control Group ◽  
Intracellular Camp ◽  
Mrna Levels ◽  
Negative Effects ◽  
Hormone Sensitive

Intracellular lipids provide energy for oocyte maturation and development. Triglycerides are the main components of cytoplasm lipid droplets, and hydrolysis of triglycerides requires several lipase-mediated steps. The aim of this study was to determine the effects of the β-adrenoceptor agonist isoproterenol (ISO) and the hormone-sensitive lipase (HSL) inhibitor CAY10499 on the IVM of porcine oocytes. ISO (5mg L−1) and CAY10499 (20mg L−1) had positive and negative effects respectively on invitro oocyte maturation and subsequent embryo development. The rates of polar body extrusion, cleavage and blastocyst formation were significantly higher in the ISO-treated group than the control and CAY10499-treated groups. ISO treatment also upregulated intracellular cAMP levels in comparison with the control group, while CAY10499 significantly increased the triglyceride content of matured oocytes when compared with other groups, consistent with the observed decrease in LIPE (HSL) mRNA levels. Furthermore, the inhibitory effects of CAY10499 included decreases in mitochondrial membrane potential and mitochondrial temperature. These results indicate that ISO has a positive effect on the IVM of porcine oocytes, and that intracellular lipid metabolism can be modulated by CAY10499 through inhibition of HSL and is closely related to mitochondrial function.

scholarly journals In vitro anti-human immunodeficiency virus (HIV) activity of XM323, a novel HIV protease inhibitor.

1993 ◽  
Vol 37 (12) ◽  
pp. 2606-2611 ◽  
Author(s):  
M J Otto ◽  
C D Reid ◽  
S Garber ◽  
P Y Lam ◽  
H Scarnati ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Protease Inhibitor ◽  
Hiv Protease ◽  
Hiv Protease Inhibitor ◽  
Immunodeficiency Virus

An analysis of the delay-dependent HIV-1 protease inhibitor model

2018 ◽  
Vol 11 (03) ◽  
pp. 1850031
Author(s):  
M. Divya ◽  
M. Pitchaimani
Keyword(s):  
Human Immunodeficiency Virus ◽  
Sensitivity Analysis ◽  
Stability Analysis ◽  
Protease Inhibitor ◽  
Numerical Simulations ◽  
Humoral Immunity ◽  
Hiv Protease ◽  
Immunodeficiency Virus ◽  
Delay Dependent ◽  
Hiv 1

In this paper, we have studied about the sensitivity analysis of the human immunodeficiency virus (HIV) protease inhibitor (PI) model and estimated the length of the delay. We have fabricated an HIV PI model accompanied with humoral immunity. Stability analysis of the constructed model about its steady states has been deliberated. We have evaluated some numerical simulations for PI model with humoral immunity by using the existing patient data.

Fasting upregulates adipose triglyceride lipase and hormone-sensitive lipase levels and phosphorylation in mouse kidney

2015 ◽  
Vol 93 (3) ◽  
pp. 262-267 ◽  
Author(s):  
Phillip M. Marvyn ◽  
Ryan M. Bradley ◽  
Emily B. Button ◽  
Emily B. Mardian ◽  
Robin E. Duncan
Keyword(s):  
Fatty Acids ◽  
Hormone Sensitive Lipase ◽  
Binding Motif ◽  
Adipose Triglyceride Lipase ◽  
Triglyceride Lipase ◽  
Protein Levels ◽  
Fasted State ◽  
Esterified Fatty Acids ◽  
Glomerular Filtrate ◽  
Hormone Sensitive

Circulating non-esterified fatty acids (NEFA) rise during fasting and are taken up by the kidneys, either directly from the plasma or during re-uptake of albumin from glomerular filtrate, and are stored as triacylglycerol (TAG). Subsequent utilization of stored fatty acids requires their hydrolytic release from cellular lipid droplets, but relatively little is known about renal lipolysis. We found that total [3H]triolein hydrolase activity of kidney lysates was significantly increased by 15% in the fasted state. Adipose triglyceride lipase (Atgl) and hormone-sensitive lipase (Hsl) mRNA expression was time-dependently increased by fasting, along with other fatty acid metabolism genes (Pparα, Cd36, and Aox). ATGL and HSL protein levels were also significantly induced (by 239 ± 7% and 322 ± 8%, respectively). Concomitant with changes in total protein levels, there was an increase in ATGL phosphorylation at the AMPK-regulated serine 406 site in the 14-3-3 binding motif, and an increase in HSL phosphorylation at serines 565 and 660 that are regulated by AMPK and PKA, respectively. Using immunofluorescence, we further demonstrate nearly ubiquitous expression of ATGL in the renal cortex with a concentration on the apical/lumenal surface of some cortical tubules. Our findings suggest a role for ATGL and HSL in kidney lipolysis.

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