Phenolic composition, antioxidant, cytotoxic activities and cardioprotective effect of hydroalcoholic extract from aerial-parts of Hypericum attenuatum Fisch. ex Choisy.

This study investigated phenolic metabolites, antioxidant, cytotoxic and cardioprotective effects of the hydroalcoholic extract from the aerial parts of Hypericum attenuatum Fisch. ex Choisy. The total phenolic and flavonoid contents of the extract were 132.40 ± 2.06 mg GAE/g and 101.46 ± 1.47 mg QE/g respectively. The extract exhibited antioxidant activities with an EC50 value against DPPH radical of 0.099 ± 0.03 mg/mL and a FRAP value of 1.22 ± 0.086 mmol/L Fe2+. The extract could protect H9c2 cardiomyoblasts from the injury of H2O2, while it restored the H9c2 cell viability to 82.69 ± 2.33% at 100 µg/mL. The extract possessed cytotoxicity on MGC803, C666-1 and SW620 cells with IC50 values of 69.77 ± 2.43 µg/mL, 74.97 ± 1.08 µg/mL and 58.91 ± 1.81 µg/mL, respectively. Moreover, it could promote apoptosis of the tested cancer cells. This research provided useful information for the utilization of H. attenuatum as herbal medicine.

Root-knot nematode infections and soil characteristics significantly affected microbial community composition and assembly of tobacco soil microbiota: a large-scale comparison in tobacco-growing areas.

Introduction: Tobacco root-knot nematode (RKN) is a highly destructive soil-borne disease worldwide. However, there is a lack of research on the relationship between RKN and tobacco root microbial community composition under large-scale geographical conditions in China. Methods: In this study, we collected 65 samples from 28 main tobacco-growing areas across 10 provinces in China and conducted 16S rDNA sequencing to investigate the dynamic microbial changes in tobacco soil infected by RKN compared to healthy tobacco soil. Based on the analysis of rhizosphere soil bacterial communities, changes after RKN infection, and soil environmental factors. Results: We found the 28 tobacco-growing areas could be divided into two distinct groups with different microbial compositions and varying responses to RKN infection. In group1 of the provinces of Anhui, Henan, Shanxi, and Heilongjiang, Vicinamibacteria dominated the bacterial community, while Acidobacteriae was present in low abundance. In contrast, group2 of the other six provinces (Yunnan, Guizhou, Chongqing, Guangxi, Hubei, and Shandong) exhibited an opposite pattern. After infected by RKN, the genera Chitinophaga increased significant in group 1, while the genera Rhodococcus in group 2 exhibited a substantial increase. Alpha-diversity analysis revealed that RKN-infected tobacco exhibited a richer and more diverse rhizosphere soil bacterial community compared to healthy tobacco in most growing areas. A total of 12 kinds of soil environmental factors were measured in healthy and RKN-infected tobacco soil, and based on the co-occurrence and correlation analysis between environmental factors and microbial species, the pH level, calcium (Ca), magnesium (Mg), phosphorus (P), iron (Fe), and sodium (Na) were identified as key environmental factors influencing the population composition of rhizosphere microorganisms during RKN infection. We observed that RKN infection further increased the pH in weakly alkaline group 1 soil, while weakly acidic group 2 soil experienced a further decrease in pH. Furthermore, we identified three genera as potential biocontrol or plant growth-promoting bacteria for tobacco. Discussion: These findings provide valuable reference data for managing RKN disease in different tobacco-growing areas and contribute to the exploration of new and effective biological control methods.

Hollow polyester/kapok/hollow polyester fiber-based needle punched nonwoven composite materials for rapid and efficient oil sorption.

Nowadays oil pollution poses a serious threat to the environment and people's daily life. As reusable and environmentally friendly materials, fiber-based oil sorption materials can effectively alleviate this phenomenon. However, maintaining a high sorption rate along with improved mechanical properties remains a challenge for oil sorption materials. Herein, we report a novel hollow PET/kapok/hollow PET nonwoven with high porosity and oil retention, outstanding cyclic oil sorption rate and improved mechanical performance using kapok as the oil preserver and hollow PET as the conductor and structure enhancer. Benefiting from the three-layer composite structure fabricated by carding and needle punching reinforcement, the resulting oil sorption materials, with kapok proportion more than or equal to 60%, exhibited high oil sorption rate and oil sorption speed. The materials of 20HP/60K/20HP component content present a high initial oil sorption rate of 28.22 g g-1, a maximum oil sorption rate of 31.17 g g-1 and a sorption rate constant of the Quasi second-order kinetic equation of 0.067 in plant oil. On the other hand, when the proportion of kapok fiber in the material was below 60%, due to the introduction of hollow PET, the mechanical properties were significantly boosted, and its oil retention and reusability were distinguished, with a reuse rate stabilizing at a relatively high level (>93%) in plant oil after undergoing three oil sorption cycles. The successful fabrication of hollow PET/kapok/hollow PET nonwovens could provide a new approach for the design and development of oil sorption materials.

The cAMP-PKA signalling pathway regulates hyphal growth, conidiation, trap morphogenesis, stress tolerance, and autophagy in Arthrobotrys oligospora.

The cyclic adenosine monophosphate-protein kinase A (cAMP-PKA) signalling pathway is evolutionarily conserved in eukaryotes and plays a crucial role in defending against external environmental challenges, which can modulate the cellular response to external stimuli. Arthrobotrys oligospora is a typical nematode-trapping fungus that specializes in adhesive networks to kill nematodes. To elucidate the biological roles of the cAMP-PKA signalling pathway, we characterized the orthologous adenylate cyclase AoAcy, a regulatory subunit (AoPkaR), and two catalytic subunits (AoPkaC1 and AoPkaC2) of PKA in A. oligospora by gene disruption, transcriptome, and metabolome analyses. Deletion of Aoacy significantly reduced the levels of cAMP and arthrobotrisins. Results revealed that Aoacy, AopkaR, and AopkaC1 were involved in hyphal growth, trap morphogenesis, sporulation, stress resistance, and autophagy. In addition, Aoacy and AopkaC1 were involved in the regulation of mitochondrial morphology, thereby affecting energy metabolism, whereas AopkaC2 affected sporulation, nuclei, and autophagy. Multi-omics results showed that the cAMP-PKA signalling pathway regulated multiple metabolic and cellular processes. Collectively, these data highlight the indispensable role of cAMP-PKA signalling pathway in the growth, development, and pathogenicity of A. oligospora, and provide insights into the regulatory mechanisms of signalling pathways in sporulation, trap formation, and lifestyle transition.

Modulating Activity Evaluation of Gut Microbiota with Versatile Toluquinol.

Gut microbiota have important implications for health by affecting the metabolism of diet and drugs. However, the specific microbial mediators and their mechanisms in modulating specific key intermediate metabolites from fungal origins still remain largely unclear. Toluquinol, as a key versatile precursor metabolite, is commonly distributed in many fungi, including Penicillium species and their strains for food production. The common 17 gut microbes were cultivated and fed with and without toluquinol. Metabolic analysis revealed that four strains, including the predominant Enterococcus species, could metabolize toluquinol and produce different metabolites. Chemical investigation on large-scale cultures led to isolation of four targeted metabolites and their structures were characterized with NMR, MS, and X-ray diffraction analysis, as four toluquinol derivatives (1-4) through O1/O4-acetyl and C5/C6-methylsulfonyl substitutions, respectively. The four metabolites were first synthesized in living organisms. Further experiments suggested that the rare methylsulfonyl groups in 3-4 were donated from solvent DMSO through Fenton's reaction. Metabolite 1 displayed the strongest inhibitory effect on cancer cells A549, A2780, and G401 with IC50 values at 0.224, 0.204, and 0.597 µM, respectively, while metabolite 3 displayed no effect. Our results suggest that the dominant Enterococcus species could modulate potential precursors of fungal origin and change their biological activity.

NLRP3 inflammasome inhibitor cucurbitacin B suppresses gout arthritis in mice.

Gouty arthritis is a common inflammatory disease characterized by monosodium urate (MSU) crystal-induced nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) family pyrin domain containing 3 (NLRP3) inflammasome activation with upregulated caspase 1 protease and IL-1ß in macrophages. Cucurbitacin B (CuB) is a tetracyclic triterpene that possesses a potential anti-inflammatory activity. However, the immunomodulatory and anti-inflammatory effects of CuB on gout have not been well characterized. Therefore, the purpose of the present study was to determine whether CuB exhibits anti-inflammatory effects on gout and to analyze the underlying molecular mechanism. We examined the effects of CuB on various stimuli-activated bone marrow-derived macrophages (BMDMs) and in a mouse model with MSU-induced acute gouty arthritis. Our results demonstrated that CuB effectively suppressed multiple stimuli-activated IL-1ß secretion by interrupting NLRP3 inflammasome complex formation, inhibiting NLRP3 inflammasome activation and suppressing key enzymes of glycolysis in macrophages. Consistent with this, CuB pretreatment also ameliorated MSU-induced arthritis in vivo models of gout arthritis, manifested by reduced foot swelling and inflammatory cell infiltration. Taken together, our data provide the evidence that CuB is an NLRP3 inflammasome inhibitor with therapeutic potential for treating NLRP3 inflammasome-mediated diseases, especially gouty arthritis.

TOR functions as a molecular switch connecting an iron cue with host innate defense against bacterial infection.

As both host and pathogen require iron for survival, iron is an important regulator of host-pathogen interactions. However, the molecular mechanism by which how the availability of iron modulates host innate immunity against bacterial infections remains largely unknown. Using the metazoan Caenorhabditis elegans as a model, we demonstrate that infection with a pathogenic bacterium Salmonella enterica serovar Typhimurium induces autophagy by inactivating the target of rapamycin (TOR). Although the transcripts of ftn-1 and ftn-2 encoding two H-ferritin subunits are upregulated upon S. Typhimurium infection, the ferritin protein is kept at a low level due to its degradation mediated by autophagy. Autophagy, but not ferritin, is required for defense against S. Typhimurium infection under normal circumstances. Increased abundance of iron suppresses autophagy by activating TOR, leading to an increase in the ferritin protein level. Iron sequestration, but not autophagy, becomes pivotal to protect the host from S. Typhimurium infection in the presence of exogenous iron. Our results show that TOR acts as a regulator linking iron availability with host defense against bacterial infection.

The Autophagy-Related Gene Aolatg4 Regulates Hyphal Growth, Sporulation, Autophagosome Formation, and Pathogenicity in Arthrobotrys oligospora.

Autophagy plays an important role in cell growth and development. The autophagy-related gene atg4 encodes a cysteine protease, which can cleave the carboxyl terminus of Atg8, thus plays a role in autophagosome formation in yeast and filamentous fungi. Arthrobotrys oligospora is well known for producing special trapping-devices (traps) and capturing nematodes. In this study, two ΔAolatg4 mutants were generated using targeted gene replacement and were used to investigate the biological functions of autophagy in A. oligospora. Autophagic process was observed using the AoAtg8-GFP fusion protein. The mutants showed a defective in hyphal growth and sporulation and were sensitive to chemical stressors, including menadione and Congo red. The spore yield of the ΔAolatg4 mutants was decreased by 88.5% compared to the wild type (WT), and the transcript levels of six sporulation-related genes, such as abaA, fluG, brlA, and wetA, were significantly downregulated during the conidiation stage. Deletion of Aolatg4 also affected the cell nuclei and mycelial septal development in A. oligospora. Importantly, autophagosome formation and the autophagic process were impaired in the ΔAolatg4 mutant. Moreover, the ΔAolatg4 mutant lost its ability to form mature traps. Our results provide novel insights into the roles of autophagy in A. oligospora.

Tumor necrosis factor superfamily 14 is critical for the development of renal fibrosis.

OBJECTIVE: Tumor necrosis factor superfamily protein 14 (TNFSF14) was recently identified as a risk factor in some fibrosis diseases. However, the role of TNFSF14 in renal fibrosis pathogenesis remains unknown. RESULTS: It was found that TNFSF14 levels were significantly increased both in UUO-induced renal fibrotic mice and in patients with fibrotic nephropathy, compared with those in controls. Accordingly, Tnfsf14 deficiency led to a marked reduction in renal fibrosis lesions and inflammatory cytokines expression in the UUO mice. Furthermore, the levels of Sphk1, a critical molecule that causes fibrotic nephropathy, were remarkably reduced in Tnfsf14 KO mice with UUO surgery. In vitro recombinant TNFSF14 administration markedly up-regulated the expression of Sphk1 of primary mouse renal tubular epithelial cells (mTECs). CONCLUSION: TNFSF14 is a novel pro-fibrotic factor of renal fibrosis, for which TNFSF14 up-regulates Sphk1 expression, which may be the underlying mechanism of TNFSF14-mediated renal fibrosis. METHODS: We investigated the effect of TNFSF14 on renal fibrosis and the relationship between TNFSF14 and pro-fibrotic factor sphingosine kinase 1 (Sphk1) by using the unilateral urethral obstruction (UUO)-induced mice renal fibrosis as a model and the specimen of patients with fibrosis nephropathy, by Masson trichrome staining, immunohistochemistry, qRT-PCR, and western blot analysis.

LIGHT aggravates sepsis-associated acute kidney injury via TLR4-MyD88-NF-κB pathway.

Sepsis-associated acute kidney injury (SA-AKI) is a common clinical critical care syndrome. It has received increasing attention due to its high morbidity and mortality; however, its pathophysiological mechanisms remain elusive. LIGHT, the 14th member of the tumour necrosis factor (TNF) superfamily and a bidirectional immunoregulatory molecule that regulates inflammation, plays a pivotal role in disease pathogenesis. In this study, mice with an intraperitoneal injection of LPS and HK-2 cells challenged with LPS were employed as a model of SA-AKI in vivo and in vitro, respectively. LIGHT deficiency notably attenuated kidney injury in pathological damage and renal function and markedly mitigated the inflammatory reaction by decreasing inflammatory mediator production and inflammatory cell infiltration in vivo. The TLR4-Myd88-NF-κB signalling pathway in the kidney of LIGHT knockout mice was dramatically down-regulated compared to the controls. Recombinant human LIGHT aggravated LPS-treated HK-2 cell injury by up-regulating the expression of the TLR4-Myd88-NF-κB signalling pathway and inflammation levels. TAK 242 (a selective TLR4 inhibitor) reduced this trend to some extent. In addition, blocking LIGHT with soluble receptor fusion proteins HVEM-Fc or LTßR-Fc in mice attenuated renal dysfunction and pathological damage in SA-AKI. Our findings indicate that LIGHT aggravates inflammation and promotes kidney damage in LPS-induced SA-AKI via the TLR4-Myd88-NF-κB signalling pathway, which provide potential strategies for the treatment of SA-AKI.

YAP in epithelium senses gut barrier loss to deploy defenses against pathogens.

Pathogens commonly disrupt the intestinal epithelial barrier; however, how the epithelial immune system senses the loss of intestinal barrier as a danger signal to activate self-defense is unclear. Through an unbiased approach in the model nematode Caenorhabditis elegans, we found that the EGL-44/TEAD transcription factor and its transcriptional activator YAP-1/YAP (Yes-associated protein) were activated when the intestinal barrier was disrupted by infections with the pathogenic bacterium Pseudomonas aeruginosa PA14. Gene Ontology enrichment analysis of the genes containing the TEAD-binding sites revealed that "innate immune response" and "defense response to Gram-negative bacterium" were two top significantly overrepresented terms. Genetic inactivation of yap-1 and egl-44 significantly reduced the survival rate and promoted bacterial accumulation in worms after bacterial infections. Furthermore, we found that disturbance of the E-cadherin-based adherens junction triggered the nuclear translocation and activation of YAP-1/YAP in the gut of worms. Although YAP is a major downstream effector of the Hippo signaling, our study revealed that the activation of YAP-1/YAP was independent of the Hippo pathway during disruption of intestinal barrier. After screening 10 serine/threonine phosphatases, we identified that PP2A phosphatase was involved in the activation of YAP-1/YAP after intestinal barrier loss induced by bacterial infections. Additionally, our study demonstrated that the function of YAP was evolutionarily conserved in mice. Our study highlights how the intestinal epithelium recognizes the loss of the epithelial barrier as a danger signal to deploy defenses against pathogens, uncovering an immune surveillance program in the intestinal epithelium.

Fibrinogen-like protein 2 deficiency aggravates renal fibrosis by facilitating macrophage polarization.

Renal fibrosis has no effective target for its prevention or reversal. Fibinogen-like protein 2 (Fgl2) is a novel prothrombinase exhibiting coagulation activity and immunomodulatory effects. Although Fgl2 is known to play a vital role in the development of liver and interstitial fibrosis, its function in renal fibrosis remains unclear. In this study, Fgl2 expression was found to be markedly increased in kidney tissues from mice with unilateral ureteral obstruction (UUO)-induced renal fibrosis and patients with chronic kidney disease. However, Fgl2 deficiency aggravated UUO-induced renal fibrosis, as evidenced by the significantly increasing collagen I, fibronectin, and α-SMA expression, extracellular matrix deposition, and profibrotic factor (TGF-ß1) secretion. Administration of rmFgl2 (recombinant mouse Fgl2) significantly alleviated UUO-induced renal fibrosis in mice, suggesting that the increased fibrosis can be reversed by supplementing rmFgl2. Although there was no difference in the percentages of total macrophages between Fgl2+/+ and Fgl2-/- mice, Fgl2 deficiency remarkably facilitated M2 macrophage polarization and accelerated M1 macrophage polarization to a low degree, during UUO-induced renal fibrosis development in mice. Similar results were observed when Fgl2+/+ and Fgl2-/- mice bone marrow-derived macrophages were treated for M1 or M2 polarization. Moreover, Fgl2 deficiency significantly increased the phosphorylation of STAT6, a critical mediator of M2 polarization, in both UUO-induced fibrotic kidney tissues and bone marrow-derived M2 macrophages. In conclusion, the aggravation of renal fibrosis by Fgl2 deficiency is facilitated by the p-STAT6-dependent upregulation of macrophage polarization, especially of M2.

Effect of probucol on autophagy and apoptosis in the penile tissue of streptozotocin-induced diabetic rats.

Autophagy and apoptosis have been regarded as important processes in the development of diabetic erectile dysfunction (DMED). Probucol is considered to have anti-apoptotic effects, but its relationship with autophagy has not been reported. The aim of this study was to investigate the effects and mechanisms of probucol on erectile function. Thirty Sprague-Dawley (SD) male rats (12 weeks old) were fasted for 12 h. Twenty SD rats were injected with a single intraperitoneal injection of 60 mg kg-1 streptozotocin (STZ). Ten rats were given vehicle only and used as a sham group. After 72 h, 20 STZ-treated rats with random blood glucose concentrations consistently greater than 16.7 mmol l-1 were used as successfully established diabetic rats. The diabetic rats were divided randomly into two groups and treated with a daily gavage of probucol at a dose of 0 or 500 mg kg-1 for 12 weeks. After treatment, the intracavernous pressure (ICP) was used to measure erectile function upon electrical stimulation of the cavernous nerve. After euthanasia, penile tissue was examined using immunohistochemistry and Western blot to assess the protein levels of B-cell lymphoma-2 (Bcl-2), BCL2-associated X (Bax), microtubule-associated protein light chain 3-II (LC3-II), mammalian target of rapamycin (mTOR), and sequestosome 1 (P62). Caspase-3 activity was measured to determine apoptosis using a caspase-3 assay kit. After 12 weeks of treatment, the erectile function of the probucol group was significantly better than that of the DM group (P < 0.05). Bax and LC3-II protein expression and caspase-3 activity were significantly lower in the probucol group than those in the DM group (all P < 0.05), while Bcl-2, mTOR, and P62 protein expression levels were significantly higher than those in the DM group (all P < 0.05). We demonstrated that probucol inhibited apoptosis and autophagy in STZ-induced diabetic rats.

C5a/C5aR1 Pathway Is Critical for the Pathogenesis of Psoriasis.

Psoriasis is one of the most common chronic inflammatory skin diseases, affecting ~2% of the population. The lack of characterization of the pathogenesis of psoriasis has hindered efficient clinical treatment of the disease. In our study, we observed that expression of complement component 5a receptor 1(C5aR1) was significantly increased in skin lesions of both imiquimod (IMQ) and IL23-induced psoriatic mice and patients with psoriasis. C5aR1 deficiency or treatment with C5a receptor 1 antagonist (C5aR1a) in mice significantly attenuated psoriasis-like skin lesions and expression of inflammatory cytokines and chemokines. Moreover, C5aR1 deficiency significantly decreased IMQ-induced infiltration of plasmacytoid dendritic cells (pDCs), monocytes and neutrophils in psoriatic skin lesions and functions of pDCs, evidenced by the remarkable reduction in the IMQ-induced production of interferon-α (IFN-α) and tumor necrosis factor α (TNF-α), and FMS-like tyrosine kinase 3 ligand (FLT3L)-dependent pDCs differentiation. Accordingly, in vitro treatment with recombinant C5a accelerated pDCs migration and the differentiation of bone marrow cells into pDCs. Furthermore, biopsies of psoriatic patients showed a dramatic increase of C5aR1+ pDCs infiltration in psoriatic skin lesions, compared to healthy subjects. Our results provide direct evidence that C5a/C5aR1 signaling plays a critical role in the pathogenesis of psoriasis. Inhibition of C5a/C5aR1 pathway is expected to be beneficial in the treatment of patients with psoriasis.

Unexpected Biosynthesis of Fluorescein-Like Arthrocolins against Resistant Strains in an Engineered Escherichia coli.

Here we provide an unprecedented biofactory where fluorescent dye-like complex xanthenes could be produced in an engineered Escherichia coli. Feeding the strain with toluquinol or hydroquinones resulted in production of novel "unnatural" natural products including four arthrocolins embedded with indolyltriphenyl quaternary carbons. Arthrocolins A-C potently inhibited various human cancer cell lines including paclitaxel-resistant cell line A549/Taxol and methicillin-resistant Staphylococcus aureus and immensely restored the sensitivity of intractable fluconazole-resistant human pathogen Candida albicans to fluconazole.

High expression of herpes virus entry mediator is associated with poor prognosis in clear cell renal cell carcinoma.

Herpes virus entry mediator (HVEM), also called tumor necrosis factor receptor superfamily 14 (TNFRSF14), is highly expressed in various tumor tissues and plays critical roles in tumor biology. However, the role of HVEM in clear cell renal cell carcinoma (ccRCC) is unknown. This study evaluated the clinical importance of HVEM in patients with ccRCC. HVEM expression was assessed in fresh and 140 archived paraffin-embedded ccRCC tissue samples by quantitative RT-PCR, western blot, and immunohistochemical staining. HVEM expression was higher in ccRCC than in paired peritumor tissue. Kaplan-Meier analysis showed that high level of HVEM expression was associated with poor overall survival (OS) and disease-free survival (DFS) in patients with ccRCC (both P < 0.001). Multivariate analysis indicated that HVEM overexpression was independently prognostic of survival in ccRCC patients. Two novel nomogram systems were constructed by integrating HVEM expression and other clinical parameters to predict OS (c-index 0.75) and DFS (c-index 0.74) in these patients, with both having better predictive accuracy than traditional TNM (c-index 0.65 for OS and 0.639 for DFS) and Fuhrman (c-index 0.612 for OS and 0.641 for DFS) systems. In addition, HVEM silencing led to an observable reduction in tumor cells growth in vitro and in vivo. Taken together, these findings indicate that high HVEM expression is a novel and independent adverse predictor of clinical outcomes in patients with ccRCC and that HVEM may be a potential therapeutic target.

Mitochondrial pyruvate carrier 1 functions as a tumor suppressor and predicts the prognosis of human renal cell carcinoma.

Invasion and subsequent metastasis are major characteristics of malignant human renal cell carcinoma (RCC), though the mechanisms remain elusive. Mitochondrial pyruvate carrier (MPC), a key factor that controls pyruvate transportation in mitochondria, is frequently dysregulated in tumor cells and loss of MPC predicts poor prognosis in various types of cancer. However, the clinical relevance and functional significance of MPC in RCC remain to be elucidated. In this study, we investigated the expression of MPC1 and MPC2 in specimens from RCC patients and observed downregulation of MPC1, but not MPC2, in RCC tissues compared with adjacent non-cancerous tissue. Moreover, RCC patients with higher MPC1 expression exhibited longer overall survival rate than those with lower MPC1. Functionally, MPC1 suppressed the invasion of RCC cells in vitro and reduced the growth of RCC cells in vivo, possibly through inhibition of MMP7 and MMP9. Further studies revealed that loss of MPC1 was induced by hypoxia in RCC cells, and notably, MPC1 expression, was negatively correlated with HIF1α expression in RCC cells and patient samples. Taken together, our results identify anti-tumor function of MPC1 in RCC and revealed MPC1 as a novel prognostic biomarker to predict better patient survival.

Aprotinin Encapsulated Gold Nanoclusters: A Fluorescent Bioprobe with Dynamic Nuclear Targeting and Selective Detection of Trypsin and Heavy Metal.

Fluorescence imaging has currently emerged as one of the most frequently used noninvasive imaging technologies to selectively monitor biological processes in living systems. In past decades, gold nanoclusters (Au NCs) has received increasing attraction because of their intrinsic fluorescence and their inherent biocompatibility. As a stabilizing and reducing agent, an abundant, sustainable, and widely used polypeptide derived drug molecule, aprotinin (Ap), is selected for the synthesis of Au nanoclusters (Ap-Au NCs) due to characteristic bioactivity, excellent biocompatibility, biodegradability, and non-allergenic character. Herein, Ap encapsulated Au NCs with desirable red fluorescence was facilely produced for the first time, which were subsequently used for cell imaging and detection of various analytes. Much interestingly, dynamically subcellular targeting  from the cytoplasm to the nucleus in HeLa cells was observed. Besides, it has shown that, the selective and quantitative detection of trypsin has been established by using Ap-Au NCs. Finally, Ap-Au NCs were readily used for quantitative detection of mercury and copper. The photoluminescence of the Ap-Au NCs was quenched with the addition of the aforementioned analytes. This study not only  discusses a multifunctional nanomaterial  for cell imaging, dynamically nuclear targeting and biosensing, but also opens crucial insights on the integration of funtional biomolecule with metal nanoclusters intended for extensively biomedical applications.

Mesenchymal stem cells alleviate acute kidney injury by down-regulating C5a/C5aR pathway activation.

BACKGROUND: Acute kidney injury (AKI) leads to serious renal damage, and early inhibition of inflammation is necessary for its treatment. C5a/C5aR signaling activation promotes inflammatory response in tissue injury. Anti-inflammatory activity of mesenchymal stem cells (MSCs) makes it possible to alleviate AKI by controlling the C5a/C5aR signaling activation. METHODS: Ischemia reperfusion (I/R)-induced AKI models in wild-type and C5aR KO mice were used. In addition, human bone marrow MSCs (hBM-MSCs) or C5aR antagonist were injected in this model. All animals were killed at 72 h after reperfusion. In vitro, the LPS-activated macrophage line RAW264.7 cells were co-cultured with or without hBM-MSCs in the presence of recombinant C5a or not for indicated time points. After that, C5aR expression, the inflammatory factor production, and NF-κB translocation in RAW264.7 cells were measured. RESULTS: hBM-MSC treatment and C5a/C5aR signaling blockade or C5aR-deficiency exhibited similar attenuated effects on I/R-induced AKI, macrophages infiltration, and the pro-inflammatory cytokines TNF-α and IL-1ß expression in renal tissues in mice. Moreover, hBM-MSC administration led to a significant reduction in C5a levels in serum and C5aR expression in the kidney tissues in mice after I/R. In vitro, upon co-culture with hBM-MSCs, both C5aR expression and the secretion of pro-inflammatory factors TNF-α, IL-6, and nitric oxide in LPS-activated macrophages were markedly reduced. Accordingly, recombinant complement C5a accelerated LPS-induced NF-κB translocation and pro-inflammatory factors expression in macrophages, but the addition of hBM-MSCs reversed these C5a-induced effects. CONCLUSIONS: The present study indicates that hBM-MSCs alleviate AKI via suppressing C5a/C5aR-NF-κB pathway activation.