Resourcization of Argillaceous Limestone with Mn3O4 Modification for Efficient Adsorption of Lead, Copper, and Nickel.

Argillaceous limestone (AL) is comprised of carbonate minerals and clay minerals and is widely distributed throughout the Earth's crust. However, owing to its low surface area and poorly active sites, AL has been largely neglected. Herein, manganic manganous oxide (Mn3O4) was used to modify AL by an in-situ deposition strategy through manganese chloride and alkali stepwise treatment to improve the surface area of AL and enable its utilization as an efficient adsorbent for heavy metals removal. The surface area and cation exchange capacity (CEC) were enhanced from 3.49 to 24.5 m2/g and 5.87 to 31.5 cmoL(+)/kg with modification, respectively. The maximum adsorption capacities of lead (Pb2+), copper (Cu2+), and nickel (Ni2+) ions on Mn3O4-modified argillaceous limestone (Mn3O4-AL) in mono-metal systems were 148.73, 41.30, and 60.87 mg/g, respectively. In addition, the adsorption selectivity in multi-metal systems was Pb2+ > Cu2+ > Ni2+ in order. The adsorption process conforms to the pseudo-second-order model. In the multi-metal system, the adsorption reaches equilibrium at about 360 min. The adsorption mechanisms may involve ion exchange, precipitation, electrostatic interaction, and complexation by hydroxyl groups. These results demonstrate that Mn3O4 modification realized argillaceous limestone resourcization as an ideal adsorbent. Mn3O4-modified argillaceous limestone was promising for heavy metal-polluted water and soil treatment.

Regulatory effects of different anionic surfactants on the transformation of heavy metal fractions and reduction of heavy metal resistance genes in chicken manure compost.

Surfactants are widely used as a passivating agent in heavy metal passivation process, but their effect on transformation of heavy metal fraction and reduction of heavy metal resistance genes (MRGs) in composting process is still unknown. The aim of this study was to compare the effects of two anionic surfactants (rhamnolipid and sodium dodecyl sulfate) on heavy metal passivation and resistance gene reduction in chicken manure composting. The results showed that the addition of surfactant can effectively enhance degradation of organic matter (OM). Both surfactants could effectively reduce the bioavailability of heavy metals (HMs) and the relative abundance of resistance genes, especially rhamnolipids. The potential functional bacteria affecting heavy metal passivation were identified by the changes of microbial community. Redundancy analysis (RDA) showed that protease (PRT) activity was the key factor affecting the fractions of the second group of HMs including ZnF1, CuF1, CuF2, PbF1 and PbF3. These findings indicate that addition of anionic surfactants can reduce the bioavailability of HMs and the abundance of resistance genes in compost products, which is of guiding significance for the reduction of health risks in the harmless utilization of livestock and poultry manure.

Low-Arsenic Accumulating Cabbage Possesses Higher Root Activities against Oxidative Stress of Arsenic.

Cabbage grown in contaminated soils can accumulate high levels of arsenic (As) in the edible parts, posing serious health risks. The efficiency of As uptake varies drastically among cabbage cultivars, but the underlying mechanisms are not clear. We screened out low (HY, Hangyun 49) and high As accumulating cultivars (GD, Guangdongyizhihua) to comparatively study whether the As accumulation is associated with variations in root physiological properties. Root biomass and length, reactive oxygen species (ROS), protein content, root activity, and ultrastructure of root cells of cabbage under different levels of As stress (0 (control), 1, 5, or 15 mg L-1) were measured As results, at low concentration (1 mg L-1), compared to GD, HY reduced As uptake and ROS content, and increased shoot biomass. At a high concentration (15 mg L-1), the thickened root cell wall and higher protein content in HY reduced arsenic damage to root cell structure and increased shoot biomass compared to GD. In conclusion, our results highlight that higher protein content, higher root activity, and thickened root cell walls result in lower As accumulation properties of HY compared to GD.

Isolation of Primary Leydig Cells from Murine Testis.

In males, Leydig cells are the primary source of testosterone, which is necessary for testis development, masculinization, and spermatogenesis. Leydig cells are a valuable cellular model for basic research; thus, it is important to develop an improved method for isolation and purification of Leydig cells from testes. The available methods for Leydig cell isolation have some drawbacks, including the need for sophisticated instruments, high cost, tediousness, and time consumption. Here, we describe an improved protocol for isolation of primary Leydig cells from testicular tissue by digestion with collagenase IV.

Sertoli cell-derived exosome-mediated transfer of miR-145-5p inhibits Leydig cell steroidogenesis by targeting steroidogenic factor 1.

In the mammalian testis, two distinct populations of Sertoli cells (SCs), the immature SCs (ISCs) and adult SCs (ASCs), play significant roles in regulating the development and function of Leydig cells. However, the effect of different SC types on the function of Leydig cells is poorly understood. Here, our study showed that miR-145-5p expression was significantly different in SCs at different stages, with the highest expression observed in ISCs. Exosomes mediate the transfer of miR-145-5p from ISCs to Leydig cells. Overexpression of miR-145-5p in Leydig cells significantly downregulated steroidogenic gene expression and inhibited testosterone synthesis. Additionally, miR-145-5p functioned by directly targeted steroidogenic factor-1 (Sf-1) and downregulated the expression of SF-1, which further downregulated the expression of steroidogenic genes, induced accumulation of lipid droplets, and eventually suppressed testosterone production. These findings demonstrate that SC-derived miR-145-5p plays a significant role in regulating the functions of Leydig cells and may therefore serve as a diagnostic biomarker for male hypogonadism developmental abnormalities during puberty.

Sertoli cell-derived exosomal MicroRNA-486-5p regulates differentiation of spermatogonial stem cell through PTEN in mice.

Self-renewal and differentiation of spermatogonial stem cell (SSC) are critical for male fertility and reproduction, both of which are highly regulated by testicular microenvironment. Exosomal miRNAs have emerged as new components in intercellular communication. However, their roles in the differentiation of SSC remain unclear. Here, we observed miR-486-5p enriched in Sertoli cell and Sertoli cell-derived exosomes. The exosomes mediate the transfer of miR-486-5p from Sertoli cells to SSCs. Exosomes release miR-486-5p, thus up-regulate expression of Stra8 (stimulated by retinoic acid 8) and promote differentiation of SSC. And PTEN was identified as a target of miR-486-5p. Overexpression of miR-486-5p in SSCs down-regulates PTEN expression, which up-regulates the expression of STRA8 and SYCP3, promotes SSCs differentiation. In addition, blocking the exosome-mediated transfer of miR-486-5p inhibits differentiation of SSC. Our findings demonstrate that miR-486-5p acts as a communication molecule between Sertoli cells and SSCs in modulating differentiation of SSCs. This provides a new insight on molecular mechanisms that regulates SSC differentiation and a basis for the diagnosis, treatment, and prevention of male infertility.

Conversion of Fibroblast into Functional Leydig-like Cell Using Defined Small Molecules.

Recent studies have demonstrated that fibroblasts can be directly converted into functional Leydig cells by transcription factors. However, the transgenic approach used in these studies raises safety concerns for its future application. Here, we report that fibroblasts can be directly reprogrammed into Leydig-like cells by exposure to a combination of forskolin, 20α-hydroxycholesterol, luteinizing hormone, and SB431542. These chemical compound-induced Leydig-like cells (CiLCs) express steroidogenic genes and have a global gene expression profile similar to that of progenitor Leydig cells, although not identical. In addition, these cells can survive in testis and produce testosterone in a circadian rhythm. This induction strategy is applicable to reprogramming human periodontal ligament fibroblasts toward Leydig-like cells. These findings demonstrated fibroblasts can be directly converted into Leydig-like cells by pure chemical compounds. This strategy overcomes the limitations of conventional transgenic-based reprogramming and provides a simple, effective approach for Leydig cell-based therapy while simultaneously preserving the hypothalamic-pituitary-gonadal axis.

A Testis-Derived Hydrogel as an Efficient Feeder-Free Culture Platform to Promote Mouse Spermatogonial Stem Cell Proliferation and Differentiation.

Fertility preservation and assisted reproductive medicine require effective culture systems for the successful proliferation and differentiation of spermatogonial stem cells (SSCs). Many SSC culture systems require the addition of feeder cells at each subculture, which is tedious and inefficient. Here, we prepared decellularized testicular matrix (DTM) from testicular tissue, which preserved essential structural proteins of testis. The DTM was then solubilized and induced to form a porous hydrogel scaffold with randomly oriented fibrillar structures that exhibited good cytocompatibility. The viability of SSCs inoculated onto DTM hydrogel scaffolds was significantly higher than those inoculated on Matrigel or laminin, and intracellular gene expression and DNA imprinting patterns were similar to that of native SSCs. Additionally, DTM promoted SSC differentiation into round spermatids. More importantly, the DTM hydrogel supported SSC proliferation and differentiation without requiring additional somatic cells. The DTM hydrogel scaffold culture system provided an alternative and simple method for culturing SSCs that eliminates potential variability and contamination caused by feeder cells. It might be a valuable tool for reproductive medicine.