Fig. 1

illustrates the downregulation of the piRNA hsa_piR_019949 in osteoarthritis. A The heatmap depicts the variation in expression levels of piRNAs between cartilage affected by osteoarthritis (OA) and healthy, normal cartilage. B The volcano map illustrates the differential expression patterns of piRNAs in cartilage affected by osteoarthritis (OA) compared to normal cartilage. C The expression of hsa_piR_019949 in C28/I2 cells, stimulated with IL-1β at concentrations of 10 ng/ml, 20 ng/ml, and 30 ng/ml, was detected using RT-qPCR. D The expression of hsa_piR_019949 was analyzed using RT-qPCR in both OA (osteoarthritis) and normal tissues. Statistically significant differences are indicated by *P < 0.05, **P < 0.01. n = 3/group; piRNAs = piwi-interacting RNAs; OA = osteoarthritis; NC = negative control; RT-qPCR = real-time quantitative PCR