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MicroRNAs (miRNAs) serve as gene silencers involved in essential cell functions. The role of miR‐206 and E74‐like factor 3 (Elf3) has been identified in osteoarthritis (OA), while the effect of exosomal miR‐206 from bone marrow mesenchymal stem cells (BMSCs) in OA remains largely unknown. Thus, we aim to explore the role of exosomal miR‐206 from BMSCs in OA with the involvement of Elf3. BMSCs and BMSC‐derived exosomes (BMSC‐exos) were obtained and identified. OA mouse models were constructed by anterior cruciate ligament transection and then treated with BMSC‐exos or BMSC‐exos containing miR‐206 mimic/inhibitor. The expression of miR‐206, Elf3, inflammatory factors, osteocalcin (OCN) and bone morphogenetic protein 2 (BMP2) in mouse femoral tissues was assessed. The pathological changes in mouse femur tissues were observed. The mouse osteoblasts were identified and treated with untransfected or transfected BMSC‐exos, and then, the expression of miR‐206, Elf3, OCN and BMP2 was determined. The alkaline phosphatase (ALP) activity, calcium deposition level, OCN secretion, proliferation, apoptosis and cell cycle arrest in osteoblasts were measured. MiR‐206 was down‐regulated while Elf3 was up‐regulated in OA animal and cellular models. Exosomal miR‐206 ameliorated inflammation and increased expression of OCN and BMP2 in mouse femoral tissues. Moreover, exosomal miR‐206 promoted ALP activity, calcium deposition level, OCN secretion and proliferation and inhibited apoptosis in OA osteoblasts. Overexpressed Elf3 reversed miR‐206 up‐regulation‐induced effects on OA osteoblasts. BMSC‐derived exosomal miR‐206 promotes proliferation and differentiation of osteoblasts in OA by reducing Elf3. Our research may provide novel targets for OA treatment.

Plants growing in nutrient-rich environment are predicted to be less defended than conspecifics under nutrient limitation. However, less is known about the effects of nutrient levels on tolerance and induced resistance, and whether the effects differ between native and introduced populations of invasive plants. We performed a greenhouse experiment with introduced (the USA) and native (Argentina) genotypes of Alternanthera philoxeroides in order to study the effects of soil nitrogen levels on plant growth, constitutive and herbivore (Agasicles hygrophila)-induced chemical defense, and herbivory tolerance. We measured total biomass, elongation rate (as proxy of growth rate), carbon and nitrogen, and the concentration of triterpenoid saponins (defensive chemicals) in leaves and roots. Constitutive resistance (+33% higher leaf triterpenoid saponins in control treatment at low nitrogen level) and tolerance [less decreased total biomass after herbivory treatment (−24% and −15% for high and low nitrogen levels)] were favored at lower nitrogen level, while induced resistance was favored at higher nitrogen level (+24% increased leaf triterpenoid saponins after herbivory treatment at high nitrogen level). Constitutive resistance and tolerance exhibited trade-offs with growth rate, while induced resistance positively correlated with growth rate. Additionally, the introduced genotypes had −6% lower content of leaf carbon in the presence of herbivores than the native genotypes at low nitrogen level, but such difference was absent at high nitrogen level. Our results indicate that soil nitrogen levels influence the preference of different defensive strategies of plant, and interweave with herbivory to determine the performance of introduced genotypes.

Osteoarthritis (OA) is a common chronic degenerative condition in the elderly, in which inflammation plays a key role in disease pathology. Lycopene (Lye), a member of the carotenoid family, has been reported to have anti‐inflammatory effects. The purpose of this study was to investigate the effect of Lye on the inflammation of chondrocytes and the mouse OA model. Chondrocytes were treated with interleukin (IL)‐1β, and the mouse OA model was induced by the surgical destabilization of the medial meniscus (DMM). The results showed that Lye could inhibit the expression of inflammatory factors and alleviate the degradation of extracellular matrix (ECM). Additionally, Lye could activate the Nrf2/HO‐1 pathway and reverse the activations of NF‐κB and STAT3 signal pathway induced by IL‐1β, suggesting that its anti‐inflammatory effect may be mediated via these pathways. The animal experiments showed that Lye could decrease the Osteoarthritis Research Society International (OARSI) scores of the knee, indicating that it could inhibit the occurrence and development of OA in mouse. Overall, our results indicated that Lye might be used as a novel drug for OA treatment.

Re-establishment of heritable latitudinal clines in growth-related traits has been recognised as evidence for adaptive evolution in invasive plants. However, less information is known about latitudinal clines in defence and joint clinal evolution of growth and defence in invasive plants. We planted 14 native Argentinean populations and 14 introduced Chinese populations of Alternanthera philoxeroides in replicate common gardens in China. We investigated the latitudinal clines of traits related to growth and defence, and plasticity of these traits in relation to experiment site and soil nitrogen. We found that chemical defence decreased with latitude in introduced populations but increased with latitude in native populations. For growth rate, latitudinal clines were positive in introduced populations but nonexistent in native populations. There were also parallel positive latitudinal clines in total/shoot biomass and specific leaf area. Experiment site affected the occurrence or magnitude of latitudinal clines in growth rate, branch intensity and triterpenoid saponins concentration. Introduced populations were more plastic to experiment site and soil nitrogen than native populations. We provide evidence for rapid evolution of clines in growth and defence in an invasive plant. Altered herbivory gradients and trade-off between growth and defence may explain nonparallel clines between the native and introduced ranges.

Rheumatoid arthritis (RA) is a chronic and inflammatory synovitis systemic disease. Due to the unknown pathogenesis, this study was to investigate the effect of microRNA (miR)-411 on apoptosis and joint function of synoviocytes in RA mice via RIPK1-mediated NF-κB signaling pathway. The collagen-induced arthritis model mice were induced via collagen type II and Freund’s adjuvant. The mice were injected with miR-411 mimics, si-RIPK1 or miR-411 mimics + oe-RIPK1 to figure out their roles in cell apoptosis and inflammation of synovial tissues. Synoviocytes were grouped as in animal experiments. Proliferation and apoptosis of synoviocytes were detected upon treatment with overexpressed miR-411 and silenced RIPK1. The expression of miR-411, RIPK1 and NF-κB in synovial tissues and synoviocytes of RA mice was detected by RT-qPCR and Western blot analysis. Poorly expressed miR-411, and highly expressed NF-κB and RIPK1 existed in synovial tissue and synoviocytes of RA. Additionally, it was found that si-RIPK1 decreased NF-κB expression, and miR-411 mimics decreased both RIPK1 and NF-κB. MiR-411 had a targeted relationship with RIPK1. si-RIPK1 or miR-411 mimics promoted cell apoptosis and strained inflammation in synovial tissues of mice with RA. Overexpressed miR-411 or silencing RIPK1 inhibited the proliferation and promoted apoptosis of synoviocytes of RA mice. Up-regulation of miR-411 or down-regulation of RIPK1 had a certain inhibitory effect on RA. This study suggests that up-regulated miR-411 or down-regulated RIPK1 promoted apoptosis and inhibited proliferation of synoviocytes of RA mice, which may be related to the inhibition of NF-κB activation.

Steroid-induced avascular necrosis of the femoral head (SANFH) is a major complication of long-term or excessive clinical use of glucocorticoids. Allicin is a classical ingredient extracted from garlic and has many functions such as anti-apoptosis and antibacterial effects. The purpose of this study was to investigate the effect and the mechanism of allicin on apoptosis of osteoblasts induced by dexamethasone (Dex) and SANFH in rats. In vitro, we performed CCK-8, western blotting, TUNEL and other experiments, and the results of these experiments showed that allicin could inhibit the Dex-induced abnormal expression of C-caspase3, C-caspase9, Bax, cytochrome C and Bcl-2 by activating the PI3K/AKT pathway. In vivo, the results of micro-CT, hematoxylin-eosin staining and immunohistochemical analysis suggested that allicin could effectively inhibit the progress of SANFH in rats. In summary, our experiments indicate that allicin is a potential drug for the treatment of SANFH.

The relationship between herbivory and latitude may differ between native and introduced populations of invasive plants, which can generate latitudinal heterogeneity in the strength of enemy release. However, still little is known about how latitudinal heterogeneity in herbivore pressure influences latitudinal variation in defense phenotypes of invasive plants. We tested how latitudinal patterns in multi-variate defense syndromes differed between native (Argentinian) and introduced (Chinese) populations of the invasive herb Alternanthera philoxeroides. In addition, to better understand the drivers underlying latitudinal patterns, we also tested whether associations of defense syndromes with climate and herbivory differed between native and introduced ranges. We found that native plant populations clustered into three main defense syndromes associated with latitude. In contrast, we only found two defense syndromes in the introduced range. One matched the high-latitude syndrome from the native range, but was distributed at both the northern and southern range limits in the introduced range. The other was unique to the introduced range and occurred at mid-latitudes. Climatic conditions were associated with variation in syndromes in the native range, and climatic conditions and herbivory were associated with variation in syndromes in the introduced range. Together, our results demonstrate that plants may under the new environmental conditions in the introduced range show latitudinal patterns of defense syndromes that are different from those in their native range. This emphasizes that geographical dependence of population differentiation should be explicitly considered in studies on the evolution of defense in invasive plants. published

Reversible lysine methylation is essential for regulating histones and emerges to critically regulate non-histone proteins as well. Here we show that the master transcription factor OCT4 in pluripotent stem cells (PSCs) was methylated at multiple lysine residues. LSD1 that is highly expressed in PSCs can directly interact with and demethylate OCT4 at lysine 222 (K222) in the flexible linker region. Reduced LSD1 activity led to the methylation of OCT4-K222 that diminished the differentiation potential of PSCs while facilitating proteasome-independent degradation of OCT4 proteins. Furthermore, site-specifically replacing K222 with phenylalanine to mimic the constitutively methylated lysine promoted the ‘locked-in’ mode engagement of the OCT4 PORE-homodimers that tightly bind to and block the transcription of multiple PORE-motif-containing target genes regulating cell fate determination and cell junction organization, and thereby reducing the pluripotency of PSCs. Thus, LSD1-mediated demethylation of OCT4 plays a crucial role in restricting the ‘locked-in’ mode binding of OCT4 PORE-homodimers to the PORE-motif-containing genes and thereby maintaining their transcription to safeguard the pluripotency of PSCs.

This work aims to explore risk factors for ischemic stroke in young adults and analyze the Traditional Vascular Risk Factors Model based on age, hypertension, diabetes, smoking history, and drinking history. Further, the Lipid Metabolism Model was analyzed based on lipoprotein a [LP (a)], high-density lipoprotein (HDL), low-density lipoprotein (LDL), apolipoprotein AI (apo AI), apolipoprotein B (apo B), and the Early Renal Injury Model based on urinary microalbuminuria/creatinine ratio (UACR). Besides, we estimated glomerular filtration rate (eGFR), cystatin C (Cys-C), homocysteine (Hcy), β2 microglobulin (β2m), and validated their predictive efficacy and clinical value for the development of ischemic stroke in young adults. We selected and retrospectively analyzed the clinical data of 565 young inpatients admitted to Zhejiang Provincial Hospital of Chinese Medicine between 2010 and 2020, 187 of whom were young stroke patients. A single-factor analysis was used to analyze the risk factors for stroke in young people and developed a traditional vascular risk factors model, a lipid metabolism model, and an early kidney injury model based on backpropagation (BP) neural networks technology to predict early stroke occurrence. Moreover, the prediction performance by the area under the receiver operating characteristics (ROC) curve (AUC) was assessed to further understand the risk factors for stroke in young people and apply their predictive role in the clinical setting. Single-factor analysis showed that ischemic stroke in young adults was associated with hypertension, diabetes, smoking history, drinking history, LP(a), HDL, LDL, apo AI, apo B, eGFR, Cys-C, and β2m (P

Glucocorticoid-induced osteonecrosis of the femoral head (GIONFH) is a frequently occurring type of nontraumatic osteonecrosis. A failure of the timely treatment can eventually result in the collapse of the subchondral bone structure. Luteolin (Lut), a compound extracted from Rhizoma Drynariae, is reported to possess multiple pharmacological properties including anticancer, antioxidant, antiapoptosis, and antiinflammatory properties. However, whether Lut has a protective effect on the development of GIONFH remains unclear. In this study, we evaluated the effect of Lut on Dexamethasone (Dex)-induced STAT1/caspase3 pathway in vitro and evaluated GIONFH model in vivo. In vitro, Lut inhibited the upregulation of Dex-induced phospho-STAT1, cleaved caspase9, and cleaved caspase3. In addition, Lut inhibited Dex-induced expression of Bax and cytochrome c and increased the expression of B cell lymphoma-2(Bcl-2). In vivo, Lut decreased the proportion of empty lacunae in rats with GIONFH. Taken together, these findings indicate that Lut may have therapeutic potential in the treatment of GIONFH. Further, this effect might be achieved by suppressing mitochondrial apoptosis of osteoblasts via inhibition of STAT1 activity.

Biogeographical variation in herbivore communities may drive invasive plants to evolve lower defense against specialist herbivores but higher defense against generalist herbivores (shifting defense hypothesis, SDH). However, empirical tests on this topic have been strongly biased toward examining constitutive resistance and less is known about the evolution of induced resistance and tolerance. We examined constitutive and induced resistance and tolerance of the invasive plant, Alternanthera philoxeroides (alligator weed, Centrospermae: Amaranthaceae) against the specialist herbivore Agasicles hygrophila (Coleoptera, Chrysomelidae) and the generalist herbivore Spodoptera litura (Lepidoptera, Noctuidae), using genotypes from its introduced and native ranges. We found that introduced genotypes, compared to native genotypes, had higher constitutive resistance to the generalist herbivore, but similar constitutive resistance to the specialist herbivore. Furthermore, introduced genotypes, compared to native genotypes, had lower induced resistance to the generalist herbivore, but similar induced resistance to the specialist herbivore. Moreover, although introduced and native genotypes did not differ in their tolerance to the generalist, the introduced genotypes exhibited lower tolerance to the specialist than native ones. Therefore, while individual defense strategy does not indicate a shift from defense against the specialist to defense against the generalist, the results for the different defense strategies jointly support the SDH.

Steroid-induced avascular necrosis of the femoral head (SANFH) is a major limitation of long-term or excessive clinical administration of glucocorticoids. Fludarabine, which is a compound used to treat various hematological malignancies, such as chronic lymphocytic leukemia, acts by down-regulating signal transducer and activator of transcription 1 (STAT1) by inhibiting STAT1 phosphorylation in both normal and cancer cells. This study assessed the effects of fludarabine in vitro (primary murine osteoblasts) and in vivo (rat SANFH model). In vitro, pretreatment with fludarabine significantly inhibited Dexamethasone (Dex)-induced apoptosis in osteoblasts, which was examined by TUNEL staining. Treatment with Dex caused a remarkable decrease in the expression of Bcl-2; an increase in cytochrome c release; activation of BAX, caspase-9, and caspase-3; and an obvious enhancement in STAT1 phosphorylation. However, treatment resulted in the up-regulation of caspase-3 expression. Enhanced P-STAT1 activity and up-regulation of caspase-3 expression were also observed in osteoblasts. In vivo, the subchondral trabeculae in fludarabine-treated rats exhibited less bone loss and a lower ratio of empty lacunae. Taken together, our results suggest that STAT1-mediated up-regulation of caspase-3 is involved in osteoblast apoptosis induced by Dex and indicates that fludarabine may serve as a potential agent for the treatment of SANFH.

Many Anoectochilus plants are now facing extinction; hence, they are propagated mainly from tissue culture. However, growth performance and secondary metabolites have not been fully identified on tissue-cultured plantlets from multiple Anoectochilus species under shading. In the present study, five Anoectochilus species [A. roxburghii (Wall.) Lindl., Fu_1; A. koshuaensis Hayata, Fu_2; A. formosanus Hayata, Tai; un-identified species of Fu_New_1 and Fu_New_2] were generated from micropropagated plantlets and cultured under shade treatments of three levels (mean light intensities: mild, ~2000 Lx; medium, ~800 Lx; intensive, ~440 Lx) for five months. Among the five Anoectochilus species, the Tai and Fu_New_1 species had the highest survival rate and the Tai species had the best performance of stem morphology and foliar kaempferol content in the medium shade treatment, but it had fewer leaves and lower ratio of quercetin/kaempferol than the Fu_1 species. The Fu_New_2 species had the greatest biomass accumulation and highest content of total flavonoids, especially under the mild shade treatment. Therefore, among the Anoectochilus species tested in this study, A. formosanus is suggested to be used in continuous propagation, A. roxburghii is suggested to be planted in stressed environment, and the new species of Fu_New_2 is suggested to be planted for the production of flavonoids. Mild and medium levels of shading are suggested to be used when biomass production and fast growing are needed for Anoectochilus plantlets, respectively.

Purpose of the study Heterotopic ossification (HO) is a debilitating disease characterized by extraskeletal bone formation. Active TGF-β recruits mesenchymal stromal cells (MSCs), which contribute to trauma-induced HO. Inhibiting TGF-β induced MSC migration and osteogenic differentiation could be a promising treatment for HO. Matrine is an alkaloid from the genus Sophora that can suppress pancreatic and hepatic fibrosis by regulating TGF-β/Smad signaling. We conducted this study to evaluate the effects of matrine on HO and explore the mechanisms, we carried out this study. Materials and methods Achilles tendon puncture was performed in C57BL/6J male mice to establish the HO model. Following treatment with matrine for 3, 6, 9, and 15 weeks, mice were sacrificed and tendons were collected. In vivo, micro-CT, hematoxylin and eosin staining, CD73 and CD90 immunofluorescence, and osteocalcin staining were used to evaluate the development of HO. In vitro, a transwell migration assay was used to evaluate MSC migration. Immunohistochemistry, immunofluorescence and western blotting were used to evaluate the TGF-β/Smad2/3 pathway. Real-time PCR was conducted to analyze the transcription of alkaline phosphatase (Alp), runt-related transcription factor-2 (Runx2), osteocalcin (Ocn), osteopontin (Opn), and type I collagen (Col1). ALP activity and alizarin red staining were used to assess MSC osteogenic differentiation. Results In vivo, matrine significantly reduced ossification and inhibited HO progression. In vitro, matrine significantly suppressed MSC migration, ALP activity, and mineralization of MSCs. Mechanistically, matrine inhibited TGF-β induced Smad2/3 phosphorylation and transcription of Runx2, Alp, and Ocn after osteoinduction. Conclusions Matrine inhibited HO by suppressing the migration and osteogenic differentiation of TGF-β-induced-MSCsin mice.

As a chronic degenerative joint disease, osteoarthritis (OA) is clinically characterized by a high incidence, long-term pain, and limited joint activity but without effective preventative therapy. Troxerutin (Tx) is a natural flavonoid, also called vitamin P4, which is widely present in plants consumed as part of our daily diet, such as cereals, various fruits and vegetables, tea, and coffee, and possesses various biological activities, especially an anti-inflammatory effect. Here, we aimed to investigate the potential chondroprotection of Tx in experimental OA development. In in vitro studies, human chondrocytes were isolated and exposed in advanced glycation end-products (AGEs) to simulate OA development. It was found that Tx pretreatment inhibited the AGE-induced production of pro-inflammatory factors in chondrocytes, such as cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor alpha (TNF-α), and interleukin-6 (IL-6). Meanwhile, AGE-medicated extracellular matrix (ECM) degradation was decreased in Tx-pretreated chondrocytes. Furthermore, we found that Tx pretreatment suppressed the activation of the nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways in AGE-exposed chondrocytes. In vivo, Tx treatment prevented the narrowing of the joint space, the calcification of cartilage, and the loss of proteoglycans in the mouse OA model. In brief, Tx is considered as a potential therapeutic agent for OA.

Osteoarthritis (OA) is a long-term, chronic, progressive joint condition caused by a pathology characterized by the deterioration of joint cartilage and proliferation of subchondral bone. Myricitrin (Myr) is a flavonoid compound extracted from myrica rubra with potent anti-inflammatory properties, as demonstrated in various studies. However, the mechanisms by which Myr plays a protective role in OA are not completely understood. In this study, the anti-inflammatory properties and potential mechanisms of Myr on mouse chondrocytes treated with interleukin (IL) -1beta (β) were explored in vitro and the role of Myr in a mouse model of OA in vivo. The production of pro-inflammatory factors, such as IL-6, tumor necrosis factor alpha (TNF-α), prostaglandin E2 (PGE2) and nitric oxide (NO) were assessed by enzyme linked immunosorbent assay (ELISA) and the Griess reaction. Protein expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), Collagen-II, matrix metalloproteinase(MMP)-13, MMP-3, thrombospondin motifs 5(ADAMTS5), inhibitor ofnuclear factor kappa-B (IκB), p-IκB, p65, p-p65, c-jun-terminal kinase (JNK), p-JNK, extracellular regulated protein kinases (ERK), p-ERK, p38 and p-p38 were quantified using Western blot analysis. In the present study, we found that Myr inhibited IL-1β-induced production of NO and PGE2, expression of MMP-13, MMP-3 and ADAMTS5 and degradation of collagen-II in mouse chondrocytes. Mechanistically, Myr inhibited the activation of mitogen-activated protein kinase (MAPK) and nuclear factor kappa-B (NF-κB) treated with IL-1β in mouse chondrocytes. In vivo, Myr decreased OA Research Society International (OARSI) scores in a surgically-induced mouse model of OA. These data suggest that Myr could be developed as a potential therapyfor OA.

Steroid-induced avascular necrosis of the femoral head (SANFH) is mainly induced by glucocorticoids. Fludarabine (Flu) is a specific signal transducer and activator of transcription 1 (STAT1) inhibitor. In this study, we investigated the effect of Flu on SANFH and the role played by the STAT1/caspase-3 signaling pathway. Sprague-Dawley rats were divided into control, SANFH, and Flu-treated SANFH groups. Femoral head tissues were collected for hematoxylin-eosin (H&E) staining and Western blot analysis. The latter was used to measure the levels of stat1, phospho-stat1, caspase-3, cleaved caspase-3, caspase-9, cleaved caspase-9, Bax, cytochrome C, Bak, B-cell lymphoma-extra large, and B-cell lymphoma-2 protein expression. The results showed that Flu regulates protein expression in dexamethasone (Dex)-induced SANFH. H&E staining showed a decrease in the ratio of empty lacunae induced by Dex. Taken together, our study demonstrated the involvement of the STAT1/caspase-3 signaling pathway in SANFH and the potential of Flu as a therapeutic agent for patients with SANFH.

OCT4A is well established as a master transcription factor for pluripotent stem cell (PSC) self-renewal and a pioneer factor for initiating somatic cell reprogramming, yet its presence and functionality in somatic cancer cells remain controversial and obscure. By combining the CRISPR-Cas9-based gene editing with highly specific PCR assays, highly sensitive immunoassays, and mass spectrometry, we provide unequivocal evidence here that full-length authentic OCT4A transcripts and proteins were both present in somatic cancer cells, and OCT4A proteins were heterogeneously expressed in the whole cell population and when expressed, they are predominantly localized in cell nucleus. Despite their extremely low abundance (approximately three orders of magnitude lower than in PSCs), OCT4A proteins bound to the promoter/enhancer regions of the AP-1 transcription factor subunit c-FOS gene and critically regulated its transcription. Knocking out OCT4A in somatic cancer cells led to dramatic reduction of the c-FOS protein level, aberrant AP-1 signaling, dampened self-renewal capacity, deficient cell migration that were associated with cell growth retardation in vitro and in vivo, and their enhanced sensitivity to anticancer drugs. Taken together, we resolve the long-standing controversy and uncertainty in the field, and reveal a fundamental role of OCT4A protein in regulating FOS/AP-1 signaling-centered genes that mediate the adhesion, migration, and propagation of somatic cancer cells.

Invasive alien plants are likely to be released from specialist herbivores and at the same time encounter biotic resistance from resident generalist herbivores in their new ranges. The Shifting Defense hypothesis predicts that this will result in evolution of decreased defense against specialist herbivores and increased defense against generalist herbivores. To test this, we performed a comprehensive meta-analysis of 61 common garden studies that provide data on resistance and/or tolerance for both introduced and native populations of 32 invasive plant species. We demonstrate that introduced populations, relative to native populations, decreased their resistance against specialists, and increased their resistance against generalists. These differences were significant when resistance was measured in terms of damage caused by the herbivore, but not in terms of performance of the herbivore. Furthermore, we found the first evidence that the magnitude of resistance differences between introduced and native populations depended significantly on herbivore origin (i.e., whether the test herbivore was collected from the native or non-native range of the invasive plant). Finally, tolerance to generalists was found to be higher in introduced populations, while neither tolerance to specialists nor that to simulated herbivory differed between introduced and native plant populations. We conclude that enemy release from specialist herbivores and biotic resistance from generalist herbivores have contrasting effects on resistance evolution in invasive plants. Our results thus provide strong support for the Shifting Defense hypothesis. published

The morphology of Isoxys auritus Jiang, 1982 is reinterpreted in the light of abundant new specimens from the Early Cambrian Chengjiang biota, South China. I. auritus was a bivalved arthropod, its shield armed with two cardinal spines sub-equal in length. Two morphotypes (shield with and without ornamentation) which are of several original differences were interpreted as sexual dimorphs. 81 specimens examined here, which range between 4.8 mm and 47.0 mm, represent a successive developmental sequence. The earliest stages were characterized by short cardinal spines, large spherical eyes, a pair of elongated antennulae, and seven pairs of post-antennular appendages. The slim antennula is uniramous, consisting of nine articles, each armed with short spines. It differs from that of great appendage and lacks any grasping function. During the ontogeny, the body length increases, accompanied by addition of trunk somites and appearance of primary reticulated ornaments, and both cardinal spines become evident. In the fully grown adult, there are up to 11 pairs of post-antennular appendages, equipped with the stout endopod composed of 6 or 7 podomeres lacking endites, and a terminal claw; the paddle shaped exopod is fringed with long setae along its posterior margin. Secondary reticulation of the shield has developed inside each primary one; the cardinal spines more elongated; and the ratio of length to height of shield increases. However, the size of eye and antennula relative to the body length significantly decreases. Accordingly, intraspecific variation, including sexual dimorphs and developmental change, is evident in I. auritus . Recognizing such differences is important for detecting possible synonymies in the genus. Furthermore, the ontogenetic changes of I. auritus described here, particularly the postembryonic segment addition and possible allometric growth may also improve our understanding of development of Cambrian arthropods in Burgess-shale type preservation, especially those possessing such a large shield.

Harvest and salinity are two important factors of the growth of common reed (Phragmites australis). We here examined the different impact of winter harvest treatment on the Phragmites australis between high and low salinity (mean soil electrical conductivity is 7.87 ms/cm and 0.91 ms/cm) areas in Dongtan wetland of Yangtze River estuary, China. We measured phenology, Shoot density, stem diameter and height, biomass (total, aboveground and belowground biomass) and spike weight. At high salinity areas, harvest significantly inhibited the individual growth of stem height yet enhanced ramet density, and consequently led to an insignificant change in aboveground biomass. The belowground parts of reed were significantly inhibited. The root shoot ratio and the proportion of asexual reproduction decreased significantly. At low salinity areas, however, winter harvest generally has no significant influence on reed growth. Our results suggest that the winter harvest management may cause a decline of reed populations in the long term under condition of high salinity; however winter harvesting can be suggested as a proper management for sustainable utilization of reed communities at low salinity areas.

The relative contribution of long-distance dispersal and local diffusion in the spread of invasive species has been a subject of much debate. Invasion of the intertidal mudflats by Spartina alterniflora is an ideal example of stratified diffusion, involving both long-distance dispersal of seeds and local diffusion due to clonal growth. In conjunction with experimental data on range radius-versus-time curve, a traveling wave equation-based model is used to investigate the sensitivity of the spread rate of exotic S. alterniflora to parameters of long distance dispersal (c, maximum colonial establishment rate) and local colony diffusion (r, intrinsic growth rate) at two tidal marshes, the Eastern Chongming and the Jiuduansha Islands, at the Yangtze River estuary. Both Eastern Chong ming and Jiuduansha Islands are now national natural reserves in China, which were established in 2005. However, the mudflats and salt marshes in the two reserves are now heavily infested with introduced S. alterniflora, which may threaten the estuarine ecosystems and their biodiversity. S. alterniflora was first found in 1995 on Chongming. For rapid sediment accretion in mudflats in the estuary, S. alterniflora was also intentionally introduced to Jiuduansha in 1997 and Chongming in 2001, which has led to a rapid range expansion in the estuary. Our results show that range expansion of species with stratified diffusion is affected by both long-distance dispersal and local colony diffusion, and that there is a critical c*, below which the spread rate is more influenced by long-distance dispersal than by local diffusion. After applying this model to the invasion of S. alterniflora in the Yangtze River estuary, we derive that c = 1.7 × 10-3, c* = 0.126 and c = 4.8 × 10-3 km-2·yr-1, c* = 0.140 km-2·yr-1 at Chongming and Jiuduansha (Shanghai), respectively. Our results suggest that the range spread of S. alterniflora in the Yangtze River estuary is more influenced by long-distance dispersal than local colony diffusion, and that S. alterniflora generates about 1.7 × 10-3 to 4.8 × 10-3 colonies per square kilometers per year. This study provides important information about dispersal dynamics of S. alterniflora that may be useful for finding optimal control strategies. ·

We tested the hypothesis that introduced populations may have higher resource capture ability and utilization efficiency than native ones of invasive plants. We compared ecophysiological traits including maximum photosynthetic rate (Pmax), apparent quantum yield (Q), specific leaf area (SLA), photosynthetic energy use efficiency (PEUE), photosynthetic nitrogen use efficiency (PNUE), water use efficiency (WUE), mass-based and area-based leaf construction cost (CCmass and CCarea), and mass-based and area-based leaf nitrogen concentration (Nmass and Narea) between native (Argentina) and introduced (USA) populations of two varieties (North Apa and South Apo) of Alternanthera philoxeroides under common garden conditions in China. For Apo and Apa, Pmax, Q, Nmass and WUE were not significantly different between native and introduced populations; introduced populations had significantly lower SLA and lower CCmass but significantly higher Narea and CCarea than native ones. For Apa, the introduced populations showed significantly lower PEUE and lower PNUE while for Apo, PEUE and PNUE were not significantly different between native and introduced populations. The results indicated that introduced populations of A. philoxeroides do not show higher resource capture ability and resource utilization efficiency than their native ones in the common garden experiment, suggesting that these traits may not necessarily contribute to successful invasion of invasive plants.

Wear particle-induced inflammatory osteolysis is the major cause of aseptic loosening after total joint replacement. The predominant cell type within periprosthetic tissues is macrophages. We investigate the anti-inflammatory effects of the proteasome inhibitor bortezomib (Bzb) on murine macrophage-like RAW 264.7 cells stimulated with titanium (Ti) particles. RAW 264.7 cells were cultured with 1 nM Bzb and 0.1 mg/ml Ti particles for 48 h; cells without Ti and Bzb or without Bzb were used as negative and loading controls. Results showed that the expression of inflammatory cytokines (TNF-α, IL-1β, IL-6, and IL-10), chemokines [monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory protein-1 alpha (MIP-1α)], and inflammatory enzymes [inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2)] increased in RAW 264.7 cells cultured with Ti. Bzb treatment significantly reduced the expression of TNF-α, IL-1β, IL-6, MCP-1, MIP-1α, iNOS, and COX-2 and induced the expression of IL-10 in a time-dependent manner. These results suggest that Bzb inhibits Ti-induced inflammation in macrophages, and provide a promising therapeutic target for treating or preventing aseptic loosening.

Wear particle-induced vascularized granulomatous inflammation and subsequent inflammatory osteolysis is the most common cause of aseptic loosening after total joint replacement (TJR); however, the precise mechanism by which this occurs is unclear. This study investigates the effects of the proteasome inhibitor bortezomib (Bzb) on the expression of key biochemical markers of bone metabolism and vascularised granulomatous tissues, such as receptor activator of nuclear factor-κB ligand (RANKL), osteoprotegerin (OPG), vascular endothelial growth factor (VEGF) and tumor necrosis factor receptor-associated factor 6 (TRAF6). In addition, the effect of Bzb on apoptosis of CD68+ cells was examined. A total of 32 female BALB/C mice were randomly divided into four groups. After implantation of calvaria bone from syngeneic littermates, titanium (Ti) particles were injected into established air pouches for all mice (excluding negative controls) to provoke inflammatory osteolysis. Subsequently, Bzb was administered at a ratio of 0, 0.1, or 0.5 mg/kg on day 1, 4, 8, and 11 post-surgery to alleviate this response. All of the air pouches were harvested 14 days after the surgical procedure and were processed for molecular and histological analysis. The results demonstrated that Ti injection elevated the expression of RANKL, OPG, VEGF, and TRAF6 at both the gene and protein levels, increased counts of infiltrated cells and thickness of air pouch membranes, and elevated the apoptosis index (AI) of CD68+ cells. Bzb treatment significantly improved Ti particle-induced implanted bone osteolysis, attenuated vascularised granulomatous tissues and elevated AI of CD68+ cells. Therefore, the proteasome pathway may represent an effective therapeutic target for the prevention and treatment of aseptic loosening.

Macrophage migration inhibitory factor (MIF) is a significant regulator of inflammatory diseases, and local inflammation plays an important role in the aseptic loosening of failed total hip arthroplasty (THA). A high-level MIF expression was found in the interfacial membrane around implants. However, the cause of increased MIF expression and the action of MIF in the process of aseptic-loosening implant is still unknown. This study is to investigate MIF expression and its upregulating effect on matrix metalloproteinases (MMPs) expression in the particles-stimulated air pouches in mice that appear to closely resemble the interfacial membranes. A total of 48 murine air pouches were divided into four groups, and were injected with PBS, titanium particles suspensions, titanium particles suspensions with neutralizing antibody of MIF, and titanium particles suspensions with normal IgG, respectively. Histological and cytokine responses were evaluated. The inflammatory reaction of air pouch membranes induced by titanium particles was significantly suppressed by neutralizing antibody. The levels of MIF protein and mRNA were significantly increased in the titanium particles-stimulated air pouch membranes compared with the control groups. So were the levels of MMP13 protein and mRNA. However, the levels of MMP13 protein and mRNA were significantly reduced by neutralizing antibody. Our study demonstrates that titanium particles can cause the air pouch membranes to increase the expression of MIF, which upregulates the production of MMP13 and induces inflammatory reaction in vivo. The results indicate that MIF may play an important role in the process of aseptic-loosening implants after THA.

The evolution of increased competitive ability (EICA) hypothesis proposes that invasive species evolve decreased defense and increased competitive ability following natural enemy release. Previous studies have found evidence both for and against EICA. The resource-enemy release hypothesis (R-ERH) suggests that fast-growing species may experience stronger enemy release than slow-growing species. On the basis of R-ERH, the prediction of EICA will be held true for slow-growing genotypes, i.e., the slow-growing genotypes from the introduced range will be less resistant to herbivory and grow faster than those from the home range; while the EICA will not be held for fast-growing genotypes, i.e., there will be no significant differences in growth and defense traits between the introduced and native fast-growing genotypes. We tested these predictions preliminarily using five populations of the invasive plant Alternanthera philoxeroides. This species has two varieties in its home range, which showed a distinct growth-defense strategy: the northern A. p. var. acutifolia (Apa) had higher growth rate but lower resistance, while the southern A. p. var. obtusifolia (Apo) had lower growth rate but higher resistance level. Our results suggest that the EICA hypothesis is consistent with the slow-growing Apo, but not with the fast-growing Apa. We suggest that evolutionary changes in growth or resistance following enemy release are influenced by variation in growth rate within an invasive alien plant. These findings have important implications for the EICA hypothesis, and may partially explain why previous studies have found evidence both for and against EICA.

Knowledge about the life-history traits of native conspecifics of exotic invasive plants can be of fundamental importance in exploring their origin of invasiveness and disentangling distinct invasion mechanisms. We conducted a common garden experiment to examine genetically based differentiation in growth and biomass allocation among three native Alternanthera philoxeroides varieties (Alternanthera philoxeroides var. obtusifolia, Alternanthera philoxeroides var. acutifolia and Alternanthera philoxeroides var. lancifolia) from Argentina. Results showed that the high-latitude var. obtusifolia had lower values of relative growth rate and plant size. In contrast, the low-latitude var. acutifolia showed distinctly higher growth vigor. The mid-latitude var. lancifolia generally showed intermediate growth vigor. Regarding allocation, var. obtusifolia allocated a distinctly higher proportion of biomass to storage roots and leaves, whereas var. acutifolia and var. lancifolia allocated more biomass to stems. This pattern of variation might be the outcome of evolutionary differentiation in response to their geographic distributions and local habitats. The acutifolia and lancifolia varieties may have higher potential invasiveness than var. obtusifolia.

Protein phosphatase 2A (PP2A) is a ubiquitous serine/threonine phosphatase involved in meiosis, mitosis, sperm capacitation, and apoptosis. Abberant activity of PP2A has been associated with a number of diseases. The homolog PPP2CA and PPP2CB can each function as the phosphatase catalytic subunit generally referred to as PP2AC. We generated a Ppp2ca conditional knockout (CKO) in C57BL/6J mice. Exon 2 of Ppp2ca was knocked out in a spatial or temporal-specific manner in primordial germ cells at E12.5. This Ppp2ca-null mutation caused infertility in male C57BL/6J mice. These CKO mice provide a powerful tool to study the mechanisms of Ppp2ca in development and disease.

Both phenotypic plasticity and locally adapted ecotypes may contribute to the success of invasive species in a wide range of habitats. Here, we conducted common garden experiments and molecular marker analysis to test the two alternative hypotheses in invasive alligator weed (Alternanthera philoxeroides), which colonizes both aquatic and terrestrial habitats. Ninety individuals from three pairs of aquatic versus terrestrial populations across southern China were analyzed, using inter simple sequence repeat (ISSR) marker, to examine population differentiation in neutral loci. Two common gardens simulating aquatic and terrestrial habitats were set up to examine population differentiation in quantitative traits. We found no evidence of population differentiation in both neutral loci and quantitative traits. Most individuals shared the same ISSR genotype. Meanwhile, plants from different habitats showed similar reaction norms across the two common gardens. In particular, plants allocated much more biomass to the belowground roots in the terrestrial environment, where alligator weed may lose part or all of the aboveground shoots because of periodical or accidental disturbances, than those in the aquatic environment. The combined evidence from molecular marker analysis and common garden experiments support the plasticity hypothesis rather than the ecotype hypothesis in explaining the adaptation of alligator weed in a wide range of habitats.

Relatively few studies have compared invasibility and species invasiveness among microhabitats within communities, synchronously. We surveyed the abundance and performance of non-native Alternanthera philoxeroides (Mart.) Griseb. (alligator weed), its co-occurring native congener, Alternanthera sessilis (L.) DC. (sessile joyweed), and other species in a wetland community along a riparian zone in southeast China to test the hypotheses that: i) degree of invasion differs between different types of microhabitats within the community; and ii) microhabitat types that differ in invasibility also differ in soil resource availability or in sediment characteristics likely to affect resource availability; iii) phenotypic plasticity of A. philoxeroides may play a key role in its adaptation to diverse habitats as can be concluded from its extremely low genetic diversity in China. The study riparian zone comprises different types of microhabitats including wet abandoned field, swamp, marsh dunes and gravel dunes. Consistent with these hypotheses, cover of A. philoxeroides was high in abandoned fields (73 ± 2.9%) and swamps (94 ± 1.3%), which had high soil nutrients and water availability. On the contrary, cover of native A. sessilis was relatively high in marsh dunes and grave dunes, which had coarse gravel surfaces, low soil nutrients and low water availability. A. philoxeroides showed greater morphological plasticity in response to habitat variation. In abiotically harsh habitats, stems had limited growth, and were prostrate with weak adventitious roots at nodes, forming thin, scattered patches. In the two richer habitats, the highly branched plants spread over the water or soil surface, supporting dense stronger leaf-bearing stems which grew vertically. The growth pattern of A. sessilis among microhabitats did not exhibit significant variations. These results suggest that morphological plasticity and microhabitat types with high soil resources may facilitate invasions of A. philoxeroides.

Phenotypic plasticity and genetic differentiation are two possible mechanisms that plants use to cope with varying environments. Although alligator weed (Alternanthera philoxeroides) possesses very low genetic diversity, this alien weed has successfully invaded diverse habitats with considerably varying water availability (from swamps to dry lands) in China. In contrast, its native congener (Alternanthera sessilis) has a much narrower ecological breadth, and is usually found in moist habitats. To understand the mechanisms underlying the contrasting pattern, we performed a greenhouse experiment to compare the reaction norms of alligator weed with those of its native congener, in which water availability was manipulated. Our results revealed that the two congeners had similar direction of phenotypic plasticity. However, A. philoxeroides showed greater plasticity in amount than did A. sessilis in many traits examined during the switch from wet to drought treatment. Nearly all of the phenotypic variance in A. philoxeroides could be ascribed to plasticity, while A. sessilis had a much higher fraction of phenotypic variance that could be explained by genotypic variation. These interspecific differences in plastic responses to variable water availability partially explained the difference in spatial distribution of the two congeners.

Changes in plant biomass allocation in response to varying resource availabilities may result from ontogenetic drift caused by allometric growth (i.e., apparent plasticity), a true adjustment of ontogenetic trajectories (true plasticity) or both (complex plasticity). Given that the root allocation of annual species usually decreases during the growth, the developmentally explicit model predicts that annual herbs will exhibit true plasticity in root allocation under above-ground resource limitation and apparent plasticity for moderate stress of below-ground resource. For perennial species, the root allocation of which increases during growth, the reverse patterns would be expected. In this study, we tested the developmentally explicit model with a perennial weed, Alternanthera philoxeroides (Mart.) Griseb. We report its adaptive changes and ontogenetic drift of root allocation in response to different resource levels (i.e., light, water and nutrient availability) by comparing root allocation on both an age and a size basis. The root allocation of A. philoxeroides increased with the size (i.e., ontogenetic drift) during the growth, and exhibited significant changes in response to different resource availabilities. Furthermore, the root allocation in response to water or nutrient availability exhibited typical complex plasticity, while the light stress only slowed down the growth, with the ontogenetic trajectory unchanged (apparent plasticity). The contrasting responses to above-ground and below-ground stresses were consistent with the prediction of the developmentally explicit model.

Two natural macromolecules, chitosan and ovalbumin, were used to produce nanogels by a new, green, and convenient method. Chitosan and ovalbumin solutions were mixed; the pH of the resulting solution was adjusted; and the solution was successively stirred and heated. After that, ovalbumin gelled forming nanospheres. The chitosan chains are supposed to be partly trapped in the nanogel core upon heating because of the electrostatic attractions between chitosan and ovalbumin, while the rest of the chitosan chains should form the shell of the nanogels. The nanogels did not change the size distribution after long-time storage and did not dissociate in the pH range of 2-10.5. The dispersibility, size, and hydrophobicity/hydrophilicity of the nanogels are pH-dependent. The nanogels are good candidates for cosmetic and pharmaceutical applications.

structural parameters remains unavailable both for the silk I and the silk II forms. In this study, a density functional theory (DFT) approach was used to assess available structural parameters on the basis of the comparison of calculated 13 C chemical shifts or shielding tensors with experimental data. The results indicate that: (i) the silk I form, first proposed in this work, is a 3 1-helixlike conformation with torsion angle ranges of 〈E〉 )- 59 ( 2°, 〈a〉 ) 119 ( 2°, and 〈ˆ〉 ) 178 ( 2° for the alanine residue and 〈E〉 )- 78 ( 2°, 〈a〉 ) 149 ( 2°, and 〈ˆ〉 ) 178 ( 2° for the glycine residue in the silk fibroin; and (ii) the silk II structures independently determined by Marsh, Fossey, and Asakura are considered to be more rational than those determined by other authors. The resulting torsion angle ranges for the silk II form are 〈E〉 )- 143 ( 6°, 〈a〉 ) 142 ( 5°, and 〈ˆ〉 ) 178 ( 2° both for Ala and Gly residues.

Osteocyte apoptosis is the main manifestation of steroid-induced avascular necrosis of the femoral head (SANFH). STAT1 and caspase 3 participate in the process of apoptosis and STAT1 upregulates the expression of caspase 3. We examined the relationship between the STAT1-caspase 3 pathway and apoptosis in SANFH. All specimens were divided into four groups: the negative control group, Ficat I-II group, Ficat III group, and Ficat IV-V group, and examined histologically, with a TUNEL assay, immunohistochemically, with a caspase 3 activity assay, with ELISAs of STAT1 and phospo-STAT1 (p-STAT1), with a western blotting analysis of p-STAT1 and with real-time RT-PCR. The proportion of empty lacunae increased significantly with the development of SANFH. The proportion of TUNEL-positive cells and immunohistochemical analysis of caspase 3 also increased significantly, although the Ficat I-II group did not differ significantly from the negative control group. Immunohistochemical analysis of STAT1 and p-STAT1, caspase 3 activity all showed significant differences among the groups. An ELISA and a western blotting analysis of p-STAT1 showed significant differences among the groups. An ELISA of STAT1, real-time RT-PCR analysis of caspase 3 and STAT1 all showed significant differences among the groups except between the Ficat I-II and negative control groups. The correlation analysis showed strong positive relationships between the proportion of empty lacunae and the proportion of TUNEL-positive cells between caspase 3 activity and the proportion of TUNEL-positive cells and between the levels of p-STAT1 protein and caspase 3 mRNA. The apoptotic process in SANFH develops with the upregulated expression of caspase 3 via the expression and activation of STAT1. The STATI-caspase 3 pathway plays a critical role in the development of SANFH.

Release from specialist insect herbivores may allow invasive plants to evolve traits associated with decreased resistance and increased competitive ability. Given that there may be genetic trade-off between resistance and tolerance, invasive plants could also become more tolerant to herbivores. Although it is widely acknowledged that light availability affects tolerance to herbivores, little information is available for whether the effect of light availability on tolerance differ between the introduced and native populations. We conducted a common garden experiment in the introduced range of Alternanthera philoxeroides using ten invasive US and ten native Argentinean populations at two levels of light availability and in the presence or absence of a specialist stem-boring insect Agasicles hygrophila. Plant biomass (total and storage root biomass), two allocation traits (root/shoot ratio and branch intensity, branches biomass/main stem biomass) and two functional traits (specific stem length and specific leaf area), which are potentially associated with herbivore resistance and light capture, were measured. Overall, we found that A. philoxeroides from introduced ranges had comparable biomass and tolerance to specialist herbivores, lower branch intensity, lower specific stem length and specific leaf area. Moreover, introduced populations displayed higher shade tolerance of storage root biomass and lower plastic response to shading in specific stem length. Finally, light availability had no significant effect on evolution of tolerance to specialist herbivores of A. philoxeroides. Our results suggest that post-introduction evolution might have occurred in A. philoxeroides. While light availability did not influence the evolution of tolerance to specialist herbivores, increased shade tolerance and release from specialist insects might have contributed to the successful invasion of A. philoxeroides.