Effect of cyclosporine on apoptosis in bronchial epithelial cells.

OBJECTIVES: Among airway complications, posttransplantation infections are related to impaired mucociliary clearance, which may represent a toxicity of cyclosporine (CsA), a potent, widely used immunosuppressive drug after organ transplantations. Since several recent studies have demonstrated CsA treatment to directly induce apoptosis in several cell types, we investigated its effects on airway cells using the human bronchial epithelial cell line BEAS-2B. METHODS: Proliferation was measured by using a Cell Counting Assay Kit by exposing cells to CsA (0, 10, 30, 50, or 100 µg/mL). Apoptotic cells were identified using fluorescence microscopy after 4', 6-diamidino-2-phenylidole (DAPI) staining. Western blot analysis was performed to evaluate the contents of poly(adenosine diphosphate-ribose) polymerase (PARP), p27, Bcl-2, and caspase-3. RESULTS: Cell viability decreased dependent on the CsA concentration: 100.00 ± 0.01% with 0 µg CsA as control; 98.65 ± 0.02% with 10 µg (P < .05 vs control); 95.41 ± 0.05% with 30 µg (P < .05 vs control); 38.84 ± 0.04% (P < .001 vs control) with 50 µg; and 15.28 ± 0.05% with 100 µg (P < .001 vs control). Apoptotic cells detected with DAPI showed chromatin condensation and nuclear fragmentation. CsA induced p27 and p53, as well as degradation of 116-kd PARP into an 89-kd fragment. CONCLUSION: CsA induced apoptosis in human bronchial epithelial cells.

Effects of cyclosporine on oxidative stress in human bronchial epithelial cells.

OBJECTIVES: Some of the airway complications relate to the use of cyclosporine (CsA), a potent agent widely used after organ transplantations. Several recent studies have demonstrated CsA treatment to induce reactive oxygen species (ROS). The present study was undertaken to investigate effects of CsA on production of ROS and antoxidant defense of airway cells using the human bronchial epithelial cell line BEAS-2B. METHODS: We measured biological antioxidant potential (BAP), as well as ROS and malondialdehyde levels in BEAS-2B cells after CsA treatment, using Free Radical Analytical System 4 kits (Diacron, Grosseto, Italy). ROS production was expressed as Carr Units as established by the manufacturer and BAP as µmol/2 × 10(5) cells; malondialdehyde, by the thiobarbituric acid assay. RESULTS: ROS production was increased in the BEAS-2B cells after CsA treatment: 73.5 at 0 (controls); 82.5 at 10; 84.0 at 30; 86.0 at 50; and 93.0 Carr Unit/2 × 10(5) cells at 100 µg/mL of CsA. The levels of BAP were 1821 at 0 (controls), 1698 at 10; 1653 at 30; 1366 at 50 µg/mL; and 1391 at 100 µg/mL. The levels of malondialdehyde were increased: 3.8 at 0 (controls); 3.4 at 10; 4.4 at 30; 4.2 at 50: and 5.0 nmol/10(6) cells at 100 µg/mL. CONCLUSIONS: Increased production of ROS and decreased BAP by CsA in BEAS-2B cells may increase malondialdehyde levels by radical-induced damage.

Effects of cyclosporine on the antioxidant status and oxidative stress in the glioma cells.

OBJECTIVES: After organ transplantation, some patients suffer neurological complications. Among the immunosuppressants, cyclosporine can cause neurological side effects. However, the mechanisms of encephalopathy by cyclosporine are not fully understood. We measured the antioxidant status, the hydrogen peroxide level, and the malondialdehyde level in glioma cells after cyclosporine treatment. METHODS: The production of hydrogen peroxide was determined using a modified xylenol orange method. The amount of malondialdehyde was measured using the thiobarbituric acid assay. Total antioxidant status was measured using Free Radical Analytical System 4 with kits. RESULTS: Cyclosporine resulted in the production of hydrogen peroxide by the glioma cells. The increased production of hydrogen peroxide depended on the drug concentration. The antioxidant status was decreased in the glioma cells after cyclosporine treatment. The malondialdehyde level was not changed in glioma cells after cyclosporine treatment. CONCLUSIONS: Increased production of reactive oxygen species and decreased antioxidant status by cyclosporine in glioma cells may contribute to neurological side effects in transplantation patients.

The production of reactive oxygen species in tacrolimus-treated glial cells.

OBJECTIVE: After organ transplantation, some patients suffer from mild neurological symptoms, such as tremor, to severe complications, including seizures and encephalopathy. These neurological side effects can be caused by immunosuppressants such as tacrolimus. However, the mechanism of encephalopathy by tacrolimus is not fully understood. METHODS: We measured the production of reactive oxygen species (ROS) in glioma cells after tacrolimus treatment. Tacrolimus added to glioma cells was incubated for 60 minutes at 37 degrees C. The production of ROS was evaluated by measuring the fluorescent product from the oxidation of an oxidant-sensitive 2',7'-dichlorofluorescin using VICTOR3TM multilabel counter. RESULTS: Tacrolimus resulted in the production of the ROS in glioma cells. The production of the ROS was increased in time-dependent fashion. CONCLUSIONS: These findings indicated that the tacrolimus may contribute the neurological side effects by ROS production.

Cytokine array after cyclosporine treatment in rats.

OBJECTIVES: Long-term treatment with cyclosporine (CsA) results in chronic nephrotoxicity, which is known to be mediated by several cytokines including transforming growth factor-betal. Cytokines are known to play an important role in innate immunity, apoptosis, angiogenesis, cell growth, and differentiation. They are known to be involved in most disease processes, including cancer, cardiac disease, and nephrotoxicity. To evaluate changes of cytokines in a rat model of CsA-induced chronic nephrotoxicity, we performed a cytokine array. METHODS: Experiments were performed on two groups of rats; normal control group and CsA-treated group. Cytokine array in rat serum was performed using Cytokine Antibody Array I kit from RayBiotech. RESULTS: Serum creatinine, urine creatinine, and creatinine clearance increased in the CsA-treated group. Among the several cytokines, the expressions of the lipopolysaccharide-induced CXC chemokine (LIX), monocyte chemoattractant protein 1 (MCP-1), nerve growth factor (beta-NGF), and tissue inhibitor of metalloproteinase-1 (TIMP-1) in the CsA-treated group were increased above that of cytokines in the control group. The density of the LIX in controls was 0.62, and in the CsA-treated group was 1.24. The density of the MCP-1 in controls was 0.68, and in CsA-treated, 1.43. The density of the beta-NGF in controls was 0.62, and that in CsA-treated, 1.24. The density of the TIMP-1 in controls 1.13, and in CsA-treated, 1.40. CONCLUSIONS: Our data suggested that among several cytokines elevated levels of the LIX, MCP-1, beta-NGF, and TIMP-1 are the contributing factors to CsA-induced nephropathy.

Effects of tacrolimus on antioxidant status and oxidative stress in glioma cells.

OBJECTIVES: After organ transplantation, some patients suffer from mild neurologic symptoms, ranging from tremor to severe complications, including seizures and encephalopathy. Among the immunosuppressants, tacrolimus can cause neurologic side effects. However, the mechanisms of encephalopathy by tacrolimus are not fully understood. We measured the antioxidant status, hydrogen peroxide level, and malondialdehyde level in glioma cells after tacrolimus treatment. METHODS: The production of hydrogen peroxide was determined by the modified xylenol orange method. The amount of malondialdehyde was measured by the thiobarbituric acid assay, which is based on malondialdehyde reaction with thiobarbituric acid to give a red species absorbing at 535 nm. Total antioxidant status (TAS) was measured using TAS kits (NX2332). RESULTS: Tacrolimus resulted in dose- and time-dependent increases in the production of hydrogen peroxide by glioma cells. The antioxidant status decreased in the glioma cells after tacrolimus treatment. Malondialdehyde level was unchanged in the glioma cells after tacrolimus treatment. CONCLUSIONS: Increased production of reactive oxygen species and decreased antioxidant status by tacrolimus in glioma cells may contribute to neurologic side effects.

Effects of cyclosporine on the production of the reactive oxygen species in the glial cells.

OBJECTIVES: After organ transplantation, some patients suffer mild neurological symptoms such as tremor to severe complications including seizures and encephalopathy. Among the immunosuppressants, cyclosporine (CsA) can induce neurological side effects. However, the mechanisms of encephalopathy by CsA are not fully understood. We measured the production of reactive oxygen species (ROS) in the glioma cells after CsA treatment. METHODS: CsA (2.5 mmol/L) added to glioma cells was incubated for 60 minutes at 37 degrees C. ROS production was evaluated by measuring the fluorescent product from the oxidation of an oxidant-sensitive 2',7'-dichlorofluorescin using VICTOR3 multilabel counter. RESULTS: CsA resulted in ROS production by glioma cells. The ROS production increased with the time of exposure to CsA. CONCLUSIONS: These findings indicated that CsA may contribute to neurological side effects via ROS production.

Whey protein concentrates and isolates: processing and functional properties.

Substantial progress has been made in understanding the basic chemical and structural properties of the principal whey proteins, that is, beta-lactoglobulin (beta-Lg), alpha-lactalbumin (alpha-La), bovine serum albumin (BSA), and immunoglobulin (Ig). This knowledge has been acquired in terms of: (1) procedures for isolation, purification, and characterization of the individual whey proteins in buffer solutions; and (2) whey fractionation technologies for manufacturing whey protein concentrates (WPC) with improved chemical and functional properties in food systems. This article is a critical review of selected publications related to (1) whey fractionation technology for manufacturing WPC and WPI; (2) fundamental properties of whey proteins; and (3) factors that affect protein functionality, that is, composition, protein structure, and processing.

A synthetic study on cyclic phosphate derivatives of seconucleosides as potential antiviral agents (I). Synthesis of 3',5'-cyclic phosphates of 2'-substituted secouridines and secoribavirins.

The synthetic study of 3',5-cyclic phosphates of 2'-substituted 2',3'-secouridines and 2',3'-secoribavirins toward development of new antiviral agents is described. These cyclic phosphates were synthesized from their respective 4-nitrophenyl 3',5'-cyclic phosphate triesters. These triesters were prepared from the corresponding 2'-azido and 2'-bromo 2',3'-seconucleosides.