Search

Earth harbours an extraordinary plant phenotypic diversity 1 that is at risk from ongoing global changes 2,3 . However, it remains unknown how increasing aridity and livestock grazing pressure-two major drivers of global change 4-6 -shape the trait covariation that underlies plant phenotypic diversity 1,7 . Here we assessed how covariation among 20 chemical and morphological traits responds to aridity and grazing pressure within global drylands. Our analysis involved 133,769 trait measurements spanning 1,347 observations of 301 perennial plant species surveyed across 326 plots from 6 continents. Crossing an aridity threshold of approximately 0.7 (close to the transition between semi-arid and arid zones) led to an unexpected 88% increase in trait diversity. This threshold appeared in the presence of grazers, and moved toward lower aridity levels with increasing grazing pressure. Moreover, 57% of observed trait diversity occurred only in the most arid and grazed drylands, highlighting the phenotypic uniqueness of these extreme environments. Our work indicates that drylands act as a global reservoir of plant phenotypic diversity and challenge the pervasive view that harsh environmental conditions reduce plant trait diversity 8-10 . They also highlight that many alternative strategies may enable plants to cope with increases in environmental stress induced by climate change and land-use intensification., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

The use of magnetic metal nanoparticles has been considered in cancer treatment studies. In this study, BiFe 2 O 4 @Ag nanoparticles were synthesized biologically by Scenedesmus obliquus for the first time and their anticancer mechanism in a gastric cancer cell line was characterized. The physicochemical properties of the nanoparticles were evaluated by fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic Light Scattering (DLS), and zeta potential analyses. Cell viability and nuclear damage were investigated by the MTT and Hoechst staining assays, respectively. Flow cytometry analysis was performed to determine the frequency of the necrotic and apoptotic cells as well as cell cycle analysis of the nanoparticles-treated cells. Physicochemical characterization showed that the synthesized particles were spherical, without impurities, in a size range of 38-83 nm, with DLS size and zeta potential of 295.7 nm and -27.7 mV, respectively. BiFe 2 O 4 @Ag nanoparticles were considerably more toxic for the gastric cancer cells (AGS cell line) than HEK293 normal cells with IC 50 of 67 and 117 µg/ml, respectively. Treatment of AGS cells with the nanoparticles led to a remarkable increase in the percentage of late apoptosis (38.5 folds) and cell necrosis (13.4 folds) and caused cell cycle arrest, mainly at the S phase. Also, nuclear fragmentation and apoptotic bodies were observed in the gastric cancer cells treated with the nanoparticles. This study represents BiFe 2 O 4 @Ag as a novel anticancer candidate against gastric cancer that can induce cell apoptosis through DNA damage and inhibition of cell cycle progression., (© 2024. The Author(s).)

Background:   miR-29c-3p  manages a set of genes involved in regenerative medicine, and It seems that hyperglycemia in diabetic patients influences the power of stem cells to tissue regeneration the difficulties of diabetes by affecting the expression  miR-29c-3p  in mesenchymal stem cells. The study aims to analyze the effect of various glucose concentrations on the miR -29c-3p expression  in mesenchymal stem cells. Materials and Methods:  After receiving donated mesenchymal stem cells from Tarbiat Modares University, these cells were cultivated in a DMEM culture medium, including three different concentrations of glucose 250, 140, and 100 mg/dl. RNA was extracted from these cells after 72 hours, the Real-Time PCR technique assessed the expression of miR-29c-3p, and the results were analyzed by REST software. Results:   miR-29c-3p  expression in cells at concentrations of 140 and 250 mg/dL compared to typical situations (100 mg/dl) was significantly decreased (P˂0.05), which declined at a concentration of 250 mg/dl was more. Conclusion:  Reduced  miR-29c-3p  expression in mesenchymal stem cells in chronic and mild diabetic situations demonstrated that diabetes might be one of the significant reasons for mesenchymal stem cells' reduced ability to repair tissue damage., Competing Interests: The authors declare that they have no competing interests., (Copyright © 2024 Tehran University of Medical Sciences.)