Beyond the green: assessing quarry restoration success through plant and beetle communities

In assessing the effectiveness of ecological restoration actions, outcomes evaluation using a multi‐taxa approach can greatly contribute to a clearer understanding of their success/failure. Since comprehensive biodiversity assessments are rarely possible, choosing taxa groups that are indicative of the ecosystem's structural and functional recovery is of major importance. Our goal was to evaluate the success of revegetation actions performed in a Mediterranean limestone quarry, using plants and epigean beetles as indicators. We compared their abundance, diversity, and community composition between revegetated sites aged 5, 13, and 19 years and a natural reference. Total plant cover significantly increased with restoration age and quickly reached reference values. However, native woody species cover dropped in the oldest site, while non‐native species became dominant. The abundance of beetles was always lower in restoration sites when compared to the reference, increasing with age, although not significantly. The richness of both plant species and beetle families was lower in restoration sites and did not show any trend towards the reference values. Finally, using nonmetric multidimensional scaling, the composition of plant and beetle communities from restoration sites showed a clear separation from the reference. Restoration efforts have successfully modified post‐quarry sites, but considerable differences remain, probably largely related to the use of the non‐native species Pinus halepensis in restoration plans. P. halepensis high cover in restoration sites greatly affects the structure of the ecosystem, and most likely its functioning too, as well as related ecosystem services, causing divergence from the reference values and compromising restoration success.     

Wild gregarious settlements of Ostrea edulis in a semi‐enclosed sea lough: a case study for unassisted restoration

Ostrea edulis was once prolific throughout Europe and considered as the continent's native oyster. However, O. edulis currently exists in small fragmented assemblages where natural unaided recovery is rarely encountered. This research identified the small semi‐enclosed sea Lough of Strangford on the northeast coast of Northern Ireland as one of the few locations within Europe where the native oyster displayed gregarious natural rejuvenation. On close examination, four influential parameters appeared to assist in concentrated settlement; raised topographical cultch formations, shell coverage, the number of fecund in situ adults, and site protection. If these components were to be combined and managed as part of reintroduction and restoration initiatives, high‐density settlements and self‐sustaining populations may be possible. The research also identified that unregulated harvesting of intertidal O. edulis assemblages has the potential to seriously hinder natural recoveries. Indeed, the findings suggest that a review of policy in regards to intertidal hand gathering is necessary. However, naturally occurring high‐density settlements recorded during this research should be inspirational to all involved in the restoration of the native oyster.     

Guild‐level responses by mammalian predators to afforestation and subsequent restoration in a formerly treeless peatland landscape

Afforestation of formerly open landscapes can transform mammalian predator communities, potentially impacting prey species like ground‐nesting birds. In Scotland's Flow Country, a globally important peatland containing many forestry plantations, earlier studies found reduced densities of breeding waders on open bogs, when forestry plantations were present within 700 m. One plausible explanation for this pattern is mammalian predation. We tested whether mammalian predator indices, based on scats (feces), differed between (1) open bog, forestry plantations, and former plantations being restored as bog (“restoration” habitats); (2) restoration habitats of different ages; and (3) open bogs with differing amounts of nearby forestry. We measured summer scat density and size over 14 years in 26 transects 0.6–4.5 km in length, collecting data during 93, 96, and 79 transect‐years in bog, forestry, and restoration habitats respectively. In forestry, scat density increased eightfold, reaching values ~6 times higher than those of bogs. On open bogs with over 10% forestry within 700 m, scat densities were 2.9 times higher than on open bogs with less forestry nearby. Results support the hypothesis that mammalian predators might be responsible for the low densities of breeding waders close to forests, on adjacent open bogs. In restoration habitats, scat densities rose 6–10 years after felling but fell to levels similar to open bogs in older restoration habitats, supporting restoration management as a means of reducing mammalian predator activity/abundance. We urge caution around decisions to establish forestry plantations in open landscapes of high biodiversity importance.     

Phosphorylation of Dab2 is involved in inhibited VEGF‐VEGFR‐2 signaling induced by downregulation of syndecan‐1 in glomerular endothelial cell

Disabled‐2 (Dab2) and PAR‐3 (partitioning defective 3) are reported to play critical roles in maintaining retinal microvascular endothelial cells biology by regulating VEGF‐VEGFR‐2 signaling. The role of Dab2 and PAR‐3 in glomerular endothelial cell (GEnC) is unclear. In this study, we found that, no matter whether with vascular endothelial growth factor (VEGF) treatment or not, decreased expression of Dab2 could lead to cell apoptosis by preventing activation of VEGF‐VEGFR‐2 signaling in GEnC, accompanied by reduced membrane VEGFR‐2 expression. And silencing of PAR‐3 gene expression caused increased apoptosis of GEnC by inhibiting activation of VEGF‐VEGFR‐2 signaling and membrane VEGFR‐2 expression. In our previous research, we found that the silencing of syndecan‐1 gene expression inhibited VEGF‐VEGFR‐2 signaling by modulating internalization of VEGFR‐2. And our further research demonstrated that downregulation of syndecan‐1 lead to no significant change in the expression of Dab2 and PAR‐3 both at messenger RNA and protein levels in GEnC, while phosphorylation of Dab2 was significantly increased in GEnC transfected with Dab2 small interfering RNA (siRNA) compared with control siRNA. Atypical protein kinase C (aPKC) could induce phosphorylation of Dab2, thus negatively regulating VEGF‐VEGFR‐2 signaling. And we found that decreased expression of syndecan‐1 lead to activation of aPKC, and aPKC inhibitor treatment could block phosphorylation of Dab2 in GEnC. Besides, aPKC inhibitor treatment could activate VEGF‐VGEFR‐2 signaling in GEnC transfected with syndecan‐1 siRNA in a dose‐dependent manner. In conclusion, we speculated that phosphorylation of Dab2 is involved in preventing activation of VEGF‐VEGFR‐2 signaling in GEnC transfected with syndecan‐1 siRNA. This provides a new target for the therapy of GEnC injury and kidney disease.     

Protosappanin‐A and oleanolic acid protect injured podocytes from apoptosis through inhibition of AKT‐mTOR signaling

Protosappanin‐A (PrA) and oleanolic acid (OA), which are important effective ingredients isolated from Caesalpinia sappan L., exhibit therapeutic potential in multiple diseases. This study focused on exploring the mechanisms of PrA and OA function in podocyte injury. An in vitro model of podocyte injury was induced by the sC5b‐9 complex and assays such as cell viability, apoptosis, immunofluorescence, quantitative real‐time polymerase chain reaction, and western blot were performed to further investigate the effects and mechanisms of PrA and OA in podocyte injury. The models of podocyte injury were verified to be successful as seen through significantly decreased levels of nephrin, podocin, and CD2AP and increased level of desmin. The sC5b‐9‐induced podocyte apoptosis was inhibited in injured podocytes treated with PrA and OA, accompanied by increased protein levels of nephrin, podocin, CD2AP, and Bcl2 and decreased levels of desmin and Bax. The p‐AKT/p‐mTOR levels were also reduced by treatment of PrA and OA while AKT/mTOR was unaltered. Further, the effects of PrA and OA on injured podocytes were similar to that of LY294002 (a PI3K‐AKT inhibitor). PrA and OA were also seen to inhibit podocyte apoptosis and p‐AKT/p‐mTOR levels induced by IGF‐1 (a PI3K‐AKT activator). Our data demonstrate that PrA and OA can protect podocytes from injury or apoptosis, which may occur through inhibition of the abnormal activation of AKT‐mTOR signaling.     

Involvement of intracellular caveolin‐1 distribution in the suppression of antigen‐induced mast cell activation by cationic liposomes

Cationic liposomes are commonly used as vectors to effectively introduce foreign genes into target cells. In another function, we recently showed that cationic liposomes bound to the mast cell surface suppress the degranulation induced by the cross‐linking of high‐affinity immunoglobulin E receptor in a time‐ and dose‐dependent manner. This suppression is mediated by the impairment of the sustained level of intracellular Ca²⁺ concentration ([Ca²⁺]_i) via the inhibition of store‐operated Ca²⁺ entry. Further, we revealed that the mechanism underlying an impaired [Ca²⁺]_i increase is the inhibition of the activation of the phosphatidylinositol 3‐kinase (PI3K)‐Akt pathway. Yet, how cationic liposomes inhibit the PI3K‐Akt pathway is still unclear. Here, we focused on caveolin‐1, a major component of caveolae, which is reported to be involved in the activation of the PI3K‐Akt pathway in various cell lines. In this study, we showed that caveolin‐1 translocated from the cytoplasm to the plasma membrane after the activation of mast cells and colocalized with the p85 subunit of PI3K, which seemed to be essential for PI3K activity. Meanwhile, cationic liposomes suppressed the translocation of caveolin‐1 to the plasma membrane and the colocalization of caveolin‐1 with PI3K p85 also at the plasma membrane. This finding provides new information for the development of therapies using cationic liposomes against allergies.     

DJ‐1 inhibits autophagy activity of prostate cancer cells by repressing JNK–Bcl2–Beclin1 signaling

The regulation of DJ‐1 on AR signaling plays an important role in the pathogenesis of prostate cancer (PCa). DJ‐1 could alter autophagy and regulate Beclin1‐involved autophagy response through JNK‐dependent pathway. JNK is known to mediate autophagy through Bcl2–Beclin1 complex. Therefore, this study aimed to investigate the significance of autophagy in DJ‐1‐modulated PCa cells. The current studies showed that DJ‐1 overexpression in LNCaP decreased LC3 transformation and autophagosome formation. However, DJ‐1 knockdown exerted the opposite effect. Moreover, DJ‐1 silencing inhibited survival and promoted death in LNCaP, which was recovered by autophagy inhibition with 3‐MA. In addition, DJ‐1 overexpression inhibited the phosphorylation of JNK and Bcl2, and the dissociation of Beclin1 and Bcl2; while the effect of silencing DJ‐1 was completely opposite. More important, JNK activated by anisimycin inhibited the proliferation and promoted death of DJ‐1‐overexpressed LNCaP while increasing LC3 transformation and LC3‐puncta formation, but these results were reversed by the decrease of Beclin1 (by spautin‐1). In contrast, when DJ‐1 was silenced, the death of LNCaP, LC3 transformation, and LC3‐puncta formation were inhibited by JNK inhibitor SP600125, which promoted cell proliferation. However, Bcl2 inhibition (by ABT737) reversed all the effects of SP600125. Our results suggested that DJ‐1 in PCa cells could promote the growth of PCa through autophagy inhibition, and JNK–Bcl2–Beclin1 signaling played an important role in it. The study provided new insights into the role of DJ‐1 in the development of PCa.     

Invasive legume management strategies differentially impact mutualist abundance and benefit to native and invasive hosts

Determining the best management practices for plant invasions is a critical, but often elusive goal. Invasive removals frequently involve complex and poorly understood biotic interactions. For example, invasive species can leave potent legacies that influence the success of native species restoration efforts, and positive plant‐microbial feedbacks may promote continued reinvasion by an exotic species following restoration. Removal methods can vary in their effects on plant–soil feedbacks, with consequences for restoration of native species. We determined the effects of invasion by a leguminous shrub (French broom; Genista monspessulana) on the density and community composition of, and benefit conferred by, its microbial mutualists in its invading range. Densities of soil‐dwelling rhizobia were much higher in areas invaded by G. monspessulana relative to uninvaded areas, and this increased density of rhizobia fed back to increase seedling growth of both the invader and native legumes. We further compared how three techniques for removing G. monspessulana affected the densities of rhizobia relative to areas where G. monspessulana was still present. Removal by hand‐pulling reduced soil rhizobial densities, and reduced growth of one native legume, while having no effect on the growth of the invader. Overall, our results show that the consequences of restoration techniques, both above‐ and belowground, could be critical for the successful removal of an invasive legume and restoration of native species.     

Soil amendment interacts with invasive grass and drought to uniquely influence aboveground versus belowground biomass in aridland restoration

Water‐holding soil amendments such as super‐absorbent polymer (SAP) may improve native species establishment in restoration but may also interact with precipitation or invasive species such as Bromus tectorum L. (cheatgrass or downy brome) to influence revegetation outcomes. We implemented an experiment at two sites in Colorado, U.S.A., in which we investigated the interactions of drought (66% reduction of ambient rainfall), B. tectorum seed addition (BRTE, 465 seeds/m²), and SAP soil amendment (25 g/m²) on initial plant establishment and 3‐year aboveground and belowground biomass and allocation. At one site, SAP resulted in higher native seeded species establishment but only with ambient precipitation. However, by the third year, we detected no SAP effects on native seeded species biomass. Treatments interacted to influence aboveground and belowground biomass and allocation differently. At one site, a SAP × precipitation interaction resulted in lower belowground biomass in plots with SAP and drought (61.7 ± 7.3 g/m²) than plots with drought alone (91.6 ± 18.1 g/m²). At the other site, a SAP × BRTE interaction resulted in higher belowground biomass in plots with SAP and BRTE (56.6 ± 11.2 g/m²) than BRTE alone (35.0 ± 3.7 g/m²). These patterns were not reflected in aboveground biomass. SAP should be used with caution in aridland restoration because initial positive effects may not translate to long‐term benefits, SAP may uniquely influence aboveground versus belowground biomass, and SAP can interact with environmental variables to impact developing plant communities in positive and negative ways.