In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.
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Question: Context: Transient receptor potential ankyrin 1 (TRPA1) is a membrane-associated cation channel, widely expressed in neuronal cells and involved in nociception and neurogenic inflammation. We showed recently that TRPA1 mediates cartilage degradation and joint pain in the MIA-model of osteoarthritis (OA) suggesting a hitherto unknown role for TRPA1 in OA. Therefore, we aimed to investigate whether TRPA1 is expressed and functional in human OA chondrocytes.', 'Expression of TRPA1 in primary human OA chondrocytes was assessed by qRT-PCR and Western blot. The functionality of the TRPA1 channel was assessed by Ca(2+)-influx measurements. Production of MMP-1, MMP-3, MMP-13, IL-6, and PGE2 subsequent to TRPA1 activation was measured by immunoassay.', 'We show here for the first time that TRPA1 is expressed in primary human OA chondrocytes and its expression is increased following stimulation with inflammatory factors IL-1, IL-17, LPS, and resistin. Further, the TRPA1 channel was found to be functional, as stimulation with the TRPA1 agonist AITC caused an increase in Ca(2+) influx, which was attenuated by the TRPA1 antagonist HC-030031. Genetic depletion and pharmacological inhibition of TRPA1 downregulated the production of MMP-1, MMP-3, MMP-13, IL-6, and PGE2 in osteoarthritic chondrocytes and murine cartilage, respectively.\Question: Is transient receptor potential ankyrin 1 ( TRPA1 ) functionally expressed in primary human osteoarthritic chondrocytes?

Answer: The TRPA1 cation channel was found to be functionally expressed in primary human OA chondrocytes, which is an original finding. The presence and inflammatory and catabolic effects of TRPA1 in human OA chondrocytes propose a highly intriguing role for TRPA1 as a pathogenic factor and drug target in OA.

Question: Context: Ingested proteins are known to stimulate a rise in insulin and glucagon concentrations. In our effort to explain this effect, we have begun to measure the effect of individual amino acids.', 'The objectives were to determine the effect of lysine ingestion on insulin and glucagon concentrations and whether the effect is moderated by glucose ingestion.', 'Thirteen healthy subjects were studied on 4 occasions. Water, 25 g glucose, 1 mmol lysine/kg lean body mass, or lysine plus glucose was given on separate occasions at 0800 after a 12-h fast. Serum lysine, glucose, insulin, and glucagon were measured during a 2.5-h period. The amount of lysine provided was equivalent to that present in a 672-g (24-oz) steak.', 'Lysine ingestion resulted in an approximately 3-fold increase in lysine concentration and in a small decrease in glucose concentration. When lysine was ingested with glucose, the 2.5-h glucose area response decreased by 44% (P < 0.02). Lysine alone increased the insulin area response modestly; the insulin increase when lysine was ingested with glucose was similar to that when only glucose was ingested. Lysine stimulated an increase in glucagon (P < 0.02), whereas glucose decreased glucagon.\Question: Does lysine ingestion markedly attenuate the glucose response to ingested glucose without a change in insulin response?

Answer: Lysine ingestion results in a small decrease in serum glucose and an increase in glucagon and insulin concentrations. Lysine ingested with glucose dramatically attenuated the glucose-stimulated glucose response, but there was no change in insulin response. Whether similar effects will be observed with more physiologic doses of lysine remains to be determined.

Question: Context: Matrix Metalloproteinase-26 (MMP-26) is the smallest member of matrix metalloproteinase (MMP) family that functions mainly in the extracellular milieu to cleave the extracellular matrix proteins. It is expressed in various cell types of placenta, but its function in placentation has been poorly understood. Considering the existence of a unique cysteine switch sequence in MMP-26 protein sequence, as well as the evidence in cancer cells indicating the digestion of the NH2-terminal domain of ER by MMP-26, we hypothesize that MMP-26 may have specific intracellular activity in human placental trophoblast cells.', 'This study aimed to identify the intracellular binding partners of MMP-26 and investigate how MMP-26 is involved in placentation through the interactions with its partners.', 'Yeast two-hybrid system was employed to screen potential binding partners of MMP-26 in human placenta. Immunoprecipitation and immunofluorescence assays were conducted to verify the interactions between MMP-26 and the binding partners. HEK293T and HTR8/SVneo cell lines were used as in vitro models to investigate the roles of the interaction between MMP-26 and its binding partner on cell behaviors.', 'RESULTS of yeast two-hybrid assay, immunoprecipitation, and immunofluorescence assays revealed that MMP-26 could bind to growth differentiation factor 15 (GDF15) in the intracellular milieu. The binding of MMP-26 to GDF15 was responsible for the processing and maturation of pro-GDF15, and the process was dependent on the enzymatic activity of MMP-26. In human placental trophoblast cells, MMP-26 could facilitate the pro-apoptotic effect of GDF15.\Question: Does maturation of growth differentiation factor 15 in human placental trophoblast cells depend on the interaction with Matrix Metalloproteinase-26?

Answer:
This is the first report to demonstrate the physiological function of placental MMP-26 in processing GDF15 and subsequently promoting trophoblast cell apoptosis. These findings expand our understanding of the working mechanism of the metalloproteinase in the process of placentation.