These results identify K. septempunctata as the etiological agent of this novel food-borne illness outbreak associated with consumption of raw P. olivaceus. This is the first report, to our knowledge, demonstrating the human pathogenicity of Kudoa spores.
Positive remodeling was more frequently observed in ACS than in stable CAD. Moreover, the degree of positive remodeling was greater in AMI than in UAP. These results may reflect the impact of remodeling types and its degree in the culprit lesion of CAD on clinical presentation.
We examined the effect of curcumin (CUR) ingestion before or after exercise on changes in muscle damage and inflammatory responses after exercise. We conducted two parallel experiments with different CUR ingestion timings using a double‐blind crossover. In Exp. 1, ten healthy men ingested 180 mg d−1 of CUR or placebo (PLA) 7 days before exercise. In Exp. 2, ten other healthy men ingested 180 mg d−1 of CUR or PLA 7 days after exercise. They performed 30 maximal isokinetic (120°s−1) eccentric contractions of the elbow flexors using an isokinetic dynamometer, and this was repeated with the other arm ≥4 weeks later. Maximal voluntary contraction (MVC) torque of the elbow flexors, elbow joint range of motion (ROM), muscle soreness, and serum creatine kinase (CK) activity were measured before, immediately after, and 1‐7 days after exercise. Plasma interleukin‐8 (IL‐8) was measured before, immediately after, 12 hours after, and 1‐7 days after exercise. The changes were compared over time. In Exp. 1, no significant differences were found between CUR and PLA subjects for each parameter. However, increases in IL‐8 were significantly reduced 12 hours after exercise when CUR was ingested before exercise. In Exp. 2, compared to the PLA subjects, MVC torque and ROM were higher 3‐7 days and 2‐7 days after exercise (P < 0.05), respectively, whereas muscle soreness and CK activity were lower 3‐6 days and 5‐7 days after exercise (P < 0.05), respectively, in CUR subjects. CUR ingestion before exercise could attenuate acute inflammation, and after exercise could attenuate muscle damage and facilitate faster recovery.
Helicobacter pylori is recognized as an etiologic agent of gastroduodenal diseases. Among toxic substances produced by H. pylori, LPS exhibits extremely low endotoxic activity as compared to the typical LPSs, such as that produced by Escherichia coli. We found that the LPS-low-responder stomach cancer cell line MKN28, which expresses Toll-like receptor 4 (TLR4) at extremely low levels, showed similar levels of interleukin-8 (IL-8) induction by H. pylori or E. coli LPS preparations. Weak IL-8 induction by H. pylori LPS preparations was suppressed by expression of a dominant negative mutant of TLR2 but not of TLR4. Data from luciferase reporter analysis indicated that cotransfection of TLR2-TLR1 or TLR2-TLR6 was required for the activation induced by H. pylori LPS preparations. In conclusion, the H. pylori LPS preparations significantly induce an inflammatory reaction via the receptor complex containing TLR2-TLR1 or TLR2-TLR6 but not that containing TLR4. The TLR2-TLR1 complex was preferentially recognized by the H. pylori LPS preparations over the TLR2-TLR6 complex. Whereas the magnitude of response to H. pylori LPS preparation was markedly less than that to E. coli LPS preparation in LPS-high-responder cells strongly expressing TLR4, it was comparable to that of E. coli LPS in low-responder cells expressing negligible amount of TLR4.
MD-2 has been reported to be required for the translocation of the Toll-like receptor 4 (TLR4) to the cell surface. However, the mechanism by which MD-2 promotes TLR4 translocation is unknown. We identified the presence of two forms of TLR4 with different molecular masses (approximately 110 and 130 kDa) when TLR4 was expressed together with MD-2. Expressing TLR4 alone produced only the 110-kDa form. Using a membrane-impermeable biotinylation reagent, we found that only the 130-kDa form of TLR4 was expressed on the cell surface. When a cellular extract prepared from cells expressing TLR4 and MD-2 was treated with N-glycosidase, the two forms of TLR4 converged into a single band whose size was smaller than the 110-kDa form of TLR4. Mutation of TLR4 at Asn 526 or Asn 575 resulted in the disappearance of the 130-kDa form and prevented TLR4 from being expressed on the cell surface without affecting the ability of TLR4 to associate with MD-2. These results indicate that TLR4 is able to undergo multiple glycosylations without MD-2 but that the specific glycosylation essential for cell surface expression requires the presence of MD-2.
MD-2 is physically associated with Toll-like receptor 4 (TLR4) and is required for TLR4-mediated LPS signaling. Western blotting analysis revealed the presence of three forms of human (h)MD-2 with different electrophoretic mobilities. After N-glycosidase treatment of the cellular extract prepared from cells expressing hMD-2, only a single form with the fastest mobility was detected. Mutation of either one of two potential glycosylation sites (Asn26 and Asn114) of MD-2 resulted in the disappearance of the slowest mobility form, and only the fastest form was detected in hMD-2 carrying mutations at both Asn26 and Asn114. Although these mutants were expressed on the cell surface and maintained its ability to associate with human TLR4, these mutations or tunicamycin treatment substantially impaired the ability of MD-2 to complement TLR4-mediated activation of NF-κB by LPS. LPS binding to cells expressing CD14, TLR4, and MD-2 was unaffected by these mutations. These observations demonstrate that hMD-2 undergoes N-linked glycosylation at Asn26 and Asn114, and that these glycosylations are crucial for TLR4-mediated signal transduction of LPS.
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