Arthrogenicity of type II collagen monoclonal antibodies associated with complement activation and antigen affinity

<p>Abstract</p> <p>Background</p> <p>The collagen antibody-induced arthritis (CAIA) model, which employs a cocktail of monoclonal antibodies (mAbs) to type II collagen (CII), has been widely used for studying the pathogenesis of autoimmune arthritis. In this model, not all mAbs to CII are capable of inducing arthritis because one of the initial events is the formation of collagen-antibody immune complexes on the cartilage surface or in the synovium, and subsequent activation of the complement by the complexes induces arthritis, suggesting that a combination of mAbs showing strong ability to bind mouse CII and activate the complement may effectively induce arthritis in mice. In the present study, we examined the relationship between the induction of arthritis by the combination of IgG2a (CII-6 and C2A-12), IgG2b (CII-3, C2B-14 and C2B-16) and IgM (CM-5) subclones of monoclonal antibodies (mAb) of anti-bovine or chicken CII and the ability of mAbs to activate complement and bind mouse CII.</p> <p>Methods</p> <p>DBA/1J mice were injected with several combinations of mAbs followed by lipopolysaccharide. Furthermore, the ability of mAbs to activate the complement and bind mouse CII was examined by ELISA.</p> <p>Results</p> <p>First, DBA/1J mice were injected with the combined 4 mAbs (CII-3, CII-6, C2B-14, and CM-5) followed by lipopolysaccharide, resulting in moderate arthritis. Excluding one of the mAbs, i.e., using only CII-3, CII-6, and C2B-14, induced greater inflammation of the joints. Next, adding C2A-12 but not C2B-16 to these 3 mAbs produced more severe arthritis. A combination of five clones, consisting of all 5 mAbs, was less effective. Histologically, mice given the newly developed 4-clone cocktail had marked proliferation of synovial tissues, massive infiltration by inflammatory cells, and severe destruction of cartilage and bone. Furthermore, 4 of the 6 clones (CII-3, CII-6, C2B-14, and C2A-12) showed not only a strong cross-reaction with mouse CII but also marked activation of the complement <it>in vitro</it>.</p> <p>Conclusion</p> <p>The combination of 4 mAbs showing strong abilities to activate the complement and bind mouse CII effectively induced arthritis in DBA/1J mice. This <it>in vitro </it>system may be useful for the selection of mAbs associated with the development of arthritis.</p

Protective effect of valproic acid on MPP+ -induced neurotoxicity in dopaminergic SH-SY5Y cells through Cdk5/p35/Erk signaling cascade

Purpose: To investigate the neuroprotective effect of valproic acid (VPA) on 1-methyl-4- phenylpyridinium (MPP+)-induced dopaminergic cell loss in human neuroblastoma SH-SY5Y cells. Methods: Cell viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Reactive oxygen species (ROS) generation in MPP+-treated SH-SY5Y cells was investigated by DCFH-DA. Apoptotic cell death was confirmed by Hoechst 33342 staining. The protective effect of VPA via Cdk5 and p35 cascade was investigated by reverse transcription polymerase chain reaction (RT-PCR) and Western blot (WB) analysis. In addition, further investigation on cell survival was performed using Western blot analysis through Erk signaling pathway. Results: Cell viability was dramatically decreased in cells treated with MPP+ in a concentrationdependent manner (p &lt; 0.05). Pre-treatment with VPA ameliorated MPP+-induced death of dopaminergic cell via inhibition of ROS generation (p &lt; 0.05). VPA restored Cdk5 and p35 expression and significantly increased cell survival mediated by Erk activity (pErk/Erk). Conclusion: The results from this study confirmed that VPA attenuated MPP+-induced dopaminergic cell death by the inhibition of ROS production via Cdk5/p35 cascade and Erk signaling pathway. VPA is thus a potential therapeutic candidate for the treatment of dopaminergic cell death via Cdk5/p35 cascade

Apoptotic effect of astaxanthin from white shrimp shells on lung cancer A549 cells

Purpose: To investigate the anti-cancer potential of astaxanthin from Litopenaeus vannamei encapsulated in liposomes (ASX) to treat lung cancer A549 cells.Methods: Lung adenocarcinoma A549 cells were cultured and treated with ASX, following which cell viability and nuclear staining were performed. Generation of ROS was identified by the DCFH-DA assay while tetramethylrhodamine ethyl ester was used to determine the mitochondrial membrane potential. Flow cytometry was applied to investigate caspase-3/7 activity and cell cycle distribution.Results: ASX inhibited growth of A549 in a concentration- and time- dependent manner. The IC50 values at 24, 48 and 72 h were 53.73, 22.85, 17.46 μg/mL, respectively (p &lt; 0.05). After incubation with ASX, the morphological changes were observed in A549 cells following Hoechst 33342/PI fluorescent staining. ASX increased ROS generation and was associated with the collapse of mitochondrial membrane potential, which subsequently triggered the activation of caspase-3/7 activity leading to apoptosis (p &lt; 0.05). In addition, A549 cells accumulated in the G0/G1 phase.Conclusion: The results suggest that ASX is a valuable nutraceutical agent to target A549 lung cancer cells via ROS-dependent pathway as well as blockage of cell cycle progression. Keywords: Astaxanthin, Litopenaeus vannamei, Lung cancer, A549, Apoptosi

Downsizing a human inflammatory protein to a small molecule with equal potency and functionality

A significant challenge in chemistry is to rationally reproduce the functional potency of a protein in a small molecule, which is cheaper to manufacture, non-immunogenic, and also both stable and bioavailable. Synthetic peptides corresponding to small bioactive protein surfaces do not form stable structures in water and do not exhibit the functional potencies of proteins. Here we describe a novel approach to growing small molecules with protein-like potencies from a functionally important amino acid of a protein. A 77-residue human inflammatory protein (complement C3a) important in innate immunity is rationally transformed to equipotent small molecules, using peptide surrogates that incorporate a turn-inducing heterocycle with correctly positioned hydrogen-bond-accepting atoms. Small molecule agonists (molecular weigh

Effects of Astaxanthin from Shrimp Shell on Oxidative Stress and Behavior in Animal Model of Alzheimer’s Disease

This study aimed to investigate the effect of astaxanthin (ASX) extracted and ASX powder from shrimp (Litopenaeus vannamei) shells on Wistar rats with Alzheimer&rsquo;s disease, induced by amyloid-&beta; (1-42) peptides. In this task, the rats were divided into eight groups: (1) Control, (2) sham operate, (3) negative control (vehicle) + A&beta;1-42, (4) ASX extract+A&beta;1-42, (5) commercial ASX + A&beta;1-42, (6) ASX powder + A&beta;1-42, (7) blank powder + A&beta;1-42, and (8) vitamin E + A&beta;1-42. All treatments were orally administrated for 30 days. At 14- and 29-days post injection, animals were observed in behavioral tests. On the 31st day, animals were sacrificed; the hippocampus and cortex were collected. Those two brain areas were then homogenized and stored for biochemical and histological analysis. The results showed that the A&beta;1-42 infused group significantly reduced cognitive ability and increased memory loss, as assessed by the Morris water maze test, novel object recognition test, and novel object location test. Moreover, the A&beta;1-42 infused group exhibited a deterioration of oxidative markers, including glutathione peroxidase enzymes (GPx), lipid peroxidation (MDA), products of protein oxidation, and superoxide anion in the cortex and the hippocampus. Meanwhile, ASX powder (10 mg/kg body weight) showed a significant reduction in cognitive and memory impairments and oxidative stress which is greater than ASX extract in the same dose of compound or vitamin E (100 mg/kg body weight). Our study indicates the beneficial properties of ASX in alleviation of cognitive functions and reducing neurodegeneration in Wistar rats induced by amyloid-&beta; (1-42) peptides

Pulsed electric field-assisted extraction of Djenkol (Archidendron pauciflorum) peel: Characterization, suppression of intracellular ROS generation and inflammatory cytokines in LPS-activated RAW264.7 macrophage cells

Djenkol (Archidendron pauciflorum) peel is a source of phenolics with an antioxidative activity. Nevertheless, the high extraction efficacy of the target compounds is crucial for the isolation of such compounds. Pulsed electric field (PEF)-assisted extraction is the means that increase the efficacy of extraction via an electroporation mechanism. This research aimed to study the extraction of phenolics with antioxidative activities using the PEF and to investigate the anti-inflammation and antioxidative activities of the Djenkol peel extract (DPE) in RAW264.7 macrophage cells. The PEF at different electric field strengths (E) (4.5 and 6 kV/cm) and times (180, 360, and 540 ms) was implemented to extract the phenolic compounds. The PEF with the E level at 6 kV/cm for 540 ms provided the highest yield, the total phenolic content, and antioxidative activities, compared to other conditions (P < 0.05). The dominant compounds in the DPE were the gallic acid and catechin. When the RAW264.7 cells were treated with the DPE at different levels (0.125, 0.25, 0.5, 0.75 and 1 μg/mL), the DPE at 0.125 and 0.25 μg/mL had no cytotoxicity, compared to the control (P < 0.05). With adding lipopolysaccharide (LPS), the DPE-treated cells at 0.125 μg/mL showed the similar cell viability to that of the control (P < 0.05). Additionally, the use of the DPE, particularly at 0.125 and 0.25 μg/mL, could reduce the TNF-α and IL-6 levels and reactive oxygen species (ROS) generation in the LPS-activated cells. Thus, the DPE could be used as a functional ingredient in food