Restoration of the Phenotype of Dedifferentiated Rabbit Chondrocytes by Sesquiterpene Farnesol

Osteoarthritis (OA) is a joint disorder characterized by the progressive degeneration of articular cartilage. The phenotype and metabolism behavior of chondrocytes plays crucial roles in maintaining articular cartilage function. Chondrocytes dedifferentiate and lose their cartilage phenotype after successive subcultures or inflammation and synthesize collagen I and X (COL I and COL X). Farnesol, a sesquiterpene compound, has an anti-inflammatory effect and promotes collagen synthesis. However, its potent restoration effects on differentiated chondrocytes have seldom been evaluated. The presented study investigated farnesol’s effect on phenotype restoration by examining collagen and glycosaminoglycan (GAG) synthesis from dedifferentiated chondrocytes. The results indicated that chondrocytes gradually dedifferentiated through cellular morphology change, reduced expressions of COL II and SOX9, increased the expression of COL X and diminished GAG synthesis during four passages of subcultures. Pure farnesol and hyaluronan-encapsulated farnesol nanoparticles promote COL II synthesis. GAG synthesis significantly increased 2.5-fold after a farnesol treatment of dedifferentiated chondrocytes, indicating the restoration of chondrocyte functions. In addition, farnesol drastically increased the synthesis of COL II (2.5-fold) and GAG (15-fold) on interleukin-1β-induced dedifferentiated chondrocytes. A significant reduction of COL I, COL X and proinflammatory cytokine prostaglandin E2 was observed. In summary, farnesol may serve as a therapeutic agent in OA treatment.

Subaerial beach morphology change from multiple storms during the 2020 hurricane season

Frequent or consecutive storms impacting coastal areas can result in unexpected or variable impacts. This study evaluates spatiotemporal variability and cumulative impacts on the subaerial beach from four major tropical storms of varying intensity and proximity impacting the study area of Palm Beach County, Florida, during the 2020 Atlantic Basin Hurricane season. Impacts from Hurricanes Isaias, Laura, Sally, and Teddy were measured using Real-Time Kinematic Global Positioning System (RTK GPS) at 14 transects throughout the northern and southern portion of the county. Alongshore morphologic variability resulted from each storm, with some expected patterns of erosion and accretion with a few unexpected impacts. The first three storms caused swash or collision regime impacts on the Sallenger scale. Hurricane Teddy was the fourth storm to impact the study area, causing overwash at numerous locations. Whereas the first two storms of the season caused mostly erosion of the subaerial beach, the southeasterly approach of Hurricane Sally reversed the cumulative volume loss trend in the northern portion of the study area with accretion. Hurricane Teddy was the most distant storm but occurred at the highest tide and produced the largest waves and highest winds. The most variable patterns in erosion and accretion resulted from Hurricane Teddy, which also dominated the overall (or cumulative) volume and contour change. Further study is recommended for a multi-storm season that includes the subaqueous portion of the beach profile to elucidate trends of cross-shore and alongshore drivers of storm-induced morphology change.

Centennial to Multi-Decadal Morphology Change and Sediment Budget Alteration with Consideration of the Impacts of the 2011 Tohoku Earthquake Tsunami along the Nobiru Coast, Japan

The Nobiru Coast is situated on the southwest of the Ishinomaki Bay. The 2011 Great East Japan Tsunami severely devastated the Nobiru Coast and the adjacent Naruse River mouth. In this study, an investigation was conducted based on the available historic maps and images combined with in situ surveys that revealed the century-to-decade morphology change and sediment budget alteration in the Nobiru Coast. During the past two centuries, the longshore transport on the northeast coast and sediment supply from the Naruse River were the principal sediment supply onto the Nobiru Coast and the estimated annual net sediment input into the coast was 87,000 m3/y. Until several decades ago, the construction of the Ishinomaki Port and the erosion preventing constructions (breakwaters, headlands) along the Ohmagari Coast on the northeast areas caused a dramatic reduction of longshore transport to the Nobiru Coast. Hence, the net sediment input fell to 46,000 m3/y. After the tsunami, the sediment input was further reduced to 29,000 m3/y and this loss was closely related to the intruded sediment into the Naruse River. The outcomes of this study are highly valuable for the government authorities to manage the long-term coastal and riverine morphological changes after the 2011 tsunami.