Pervasive soil phosphorus losses in terrestrial ecosystems in China.

Future phosphorus (P) shortages could seriously affect terrestrial productivity and food security. We investigated the changes in topsoil available P (AP) and total P (TP) in China's forests, grasslands, paddy fields, and upland croplands during the 1980s-2010s based on substantial repeated soil P measurements (63,220 samples in the 1980s, 2000s, and 2010s) and machine learning techniques. Between the 1980s and 2010s, total soil AP stock increased with a small but significant rate of 0.13 kg P ha-1 year-1 , but total soil TP stock declined substantially (4.5 kg P ha-1 year-1 ) in the four ecosystems. We quantified the P budgets of soil-plant systems by harmonizing P fluxes from various sources for this period. Matching trends of soil contents over the decades with P budgets and fluxes, we found that the P-surplus in cultivated soils (especially in upland croplands) might be overestimated due to the great soil TP pool compared to fertilization and the substantial soil P losses through plant uptake and water erosion that offset the P additions. Our findings of P-deficit in China raise the alarm on the sustainability of future biomass production (especially in forests), highlight the urgency of P recycling in croplands, and emphasize the critical role of country-level basic data in guiding sound policies to tackle the global P crises.

pH-Responsive Injectable Multifunctional Pluronic F127/Gelatin-Based Hydrogels with Hydrogen Production for Treating Diabetic Wounds.

Diabetic chronic wounds remain a major clinical challenge with long-term inflammatory responses and extreme oxidative damage. Hence, a pH-responsive injectable multifunctional hydrogel [Gel/CUR-FCHO/Mg (GCM) micromotors] via a Schiff base reaction between gelatin and benzaldehyde-grafted Pluronic F127 drug-loaded micelles (FCHO) was fabricated for the first time. Dynamic Schiff base linkage endowed the GCM hydrogel with the ability to be self-healing, injectable, and pH-responsive for on-demand drug delivery at the wound site. Curcumin (CUR), a hydrophobic drug with antioxidative, anti-inflammatory, and antibacterial activities, was encapsulated into the hydrogel matrix by micellization (CUR-FCHO micelles). Simultaneously, magnesium-based micromotors (Mg micromotors) were physically entrapped into the system for providing active hydrogen (H2) to scavenge reactive oxygen species and alleviate inflammatory responses. As a result, the GCM micromotor hydrogel displayed an inherent antibacterial property, extraordinary antioxidative performance, and remarkable biocompatibility. In the diabetic mouse with a full-thickness cutaneous defect wound, the GCM hydrogel could remodel the inflammatory microenvironment and stimulate vascularization and collagen deposition, thereby facilitating wound closure and enhancing tissue regeneration, which offered a promising therapeutic option for diabetic chronic wound management.

[Effect and mechanism of Dahuang Zhechong Pills in improving liver aging in rats by regulating ROS-mediated PI3K/Akt/FoxO4 signaling pathway].

Recent studies have shown that the occurrence and development of common liver diseases, including non-alcoholic fatty liver disease, cirrhosis, and liver cancer, are related to liver aging(LA). Therefore, to explore the effect and mechanism of Dahuang Zhechong Pills(DHZCP), a traditional classic prescription in improving LA with multiple targets, the present study randomly divided 24 rats into a normal group, a model group, a DHZCP group, and a vitamin E(VE) group, with six rats in each group. The LA model was induced by continuous intraperitoneal injection of D-galactose(D-gal) in rats. For the LA model rats, the general situation was evaluated by aging phenotype and body weight(BW). LA was assessed by the pathological characteristics of hepatocyte senescence, hepatic function indexes, the staining characteristics of phosphorylated histone family 2A variant(γ-H2AX), and the expression levels of cell cycle arrest proteins(P21, P53, P16) and senescence-associated secretory phenotype(SASP) in the liver. The activation of the reactive oxygen species(ROS)-mediated phosphatidylinositol-3 kinase(PI3K)/protein kinase B(Akt)/forkhead box protein O4(FoxO4) signaling pathway was estimated by hepatic ROS expression feature and the protein expression levels of the key signaling molecules in the PI3K/Akt/FoxO4 signaling pathway. The results showed that after the treatment with DHZCP or VE for 12 weeks, for the DHZCP and VE groups, the characterized aging phenotype, BW, pathological characteristics of hepatocyte senescence, hepatic function indexes, relative expression of ROS in the liver, protein expression levels of key signaling molecules including p-PI3K, p-Akt, and FoxO4 in the liver, staining characteristics of γ-H2AX, and the protein expression levels of P16, P21, P53, interleukin-6(IL-6), and tumor necrosis factor-α(TNF-α) in the liver were improved, and the effects of DHZCP and VE were similar. Based on the D-gal-induced LA model in rats, this study demonstrates that DHZCP can ameliorate LA with multiple targets in vivo, and its effects and mechanism are related to regulating the activation of the ROS-mediated PI3K/Akt/FoxO4 signaling pathway in the liver. These findings are expected to provide new pharmacological evidence for the treatment of DHZCP in aging-related liver diseases.

[Effects and mechanisms of total flavones of Abelmoschus manihot in attenuating diabetic tubulopathy by targeting endoplasmic reticulum stress-induced cell apoptosis].

Renal tubular injury in patients with diabetic kidney disease(DKD) may be accompanied by glomerular and microvascular diseases. It plays a critical role in the progression of renal damage in DKD, and is now known as diabetic tubulopathy(DT). To explore the multi-targeted therapeutic effects and pharmacological mechanisms in vivo of total flavones of Abelmoschus manihot(TFA), an extract from traditional Chinese medicine for treating kidney disease, in attenuating DT, the authors randomly divided all rats into four groups: a normal control group(normal group), a DT model group(model group), a DT model+TFA-treated group(TFA group) and a DT model+rosiglitazone(ROS)-treated group(ROS group). The DT rat model was established based on the DKD rat model by means of integrated measures. After successful modeling, the rats in the four groups were continuously given double-distilled water, TFA suspension, and ROS suspension, respectively by gavage every day. After 6 weeks of treatment, all rats were sacrificed, and the samples of their urine, blood, and kidneys were collected. The effects of TFA and ROS on various indicators related to urine and blood biochemistry, renal tubular injury, renal tubular epithelial cell apoptosis and endoplasmic reticulum stress(ERS), as well as the activation of the protein kinase R-like endoplasmic reticulum kinase(PERK)-eukaryotic translation initiation factor 2α(eIF2α)-activating transcription factor 4(ATF4)-C/EBP homologous protein(CHOP) signaling pathway in the kidney of the DT model rats were investigated. The results indicated that hypertrophy of renal tubular epithelial cells, renal tubular hyperplasia and occlusion, as well as interstitial extracellular matrix and collagen deposition occurred in the DT model rats. Moreover, significant changes were found in the expression degree and the protein expression level of renal tubular injury markers. In addition, there was an abnormal increase in tubular urine proteins. After TFA or ROS treatment, urine protein, the characteristics of renal tubular injury, renal tubular epithelial cell apoptosis and ERS, as well as the activation of the PERK-eIF2α-ATF4-CHOP signaling pathway in the kidney of the DT model rats were improved to varying degrees. Therein, TFA was superior to ROS in affecting the pathological changes in renal tubule/interstitium. In short, with the DT model rats, this study demonstrated that TFA could attenuate DT by multiple targets through inhibiting renal tubular ERS-induced cell apoptosis in vivo, and its effect and mechanism were related to suppressing the activation of the PERK-eIF2α-ATF4-CHOP signaling pathway in the kidney. These findings provided preliminary pharmacological evidence for the application of TFA in the clinical treatment of DT.

Lysine-specific demethylase 1 in primary sensory neurons participates in chronic compression of dorsal root ganglion-induced neuropathic pain.

Low back and radicular pain syndromes, usually caused by local inflammation and irritation to the nerve root and dorsal root ganglion (DRG), are common throughout medical practice, but sufficient pain relief is scarce. In this study, we employed a chronic compression of DRG (CCD)-induced radicular pain model in rats to explore whether lysine-specific demethylase 1 (LSD1), a histone demethylase and transcriptional co-repressor, is involved in the pathological process of radicular pain. We found that LSD1 was expressed in various-sized DRG neurons by immunohistochemistry. CCD induced the upregulation of LSD1 in compressed L4-L5 DRGs. Moreover, either LSD1 small interfering RNAs or LSD1 inhibitor attenuated CCD-induced pain hypersensitivities. LSD1 was also upregulated in the injured lumbar 4 (L4) DRG in a spinal nerve ligation (SNL)-induced neuropathic pain mouse model. Nevertheless, LSD1 was not altered in L3-L5 DRGs in complete Freund's adjuvant-induced inflammatory pain mouse model, paclitaxel- or streptozotocin-induced neuropathic pain models. Furthermore, knockdown of LSD1 in the injured L4 DRG reversed SNL-induced pain hypersensitivities in mice. Therefore, we speculate that nerve injury induced the upregulation of LSD1 in the injured DRGs, which contributes to neuropathic pain hypersensitivities; thus, LSD1 may serve as a potential target for the treatment of radicular pain and neuropathic pain.

Identification of AP2/ERF transcription factors in Tetrastigma hemsleyanum revealed the specific roles of ERF46 under cold stress.

Tetrastigma hemsleyanum (T. hemsleyanum) is a traditional medicinal plant that is widely used in China. Cultivated T. hemsleyanum usually encounters cold stress, limiting its growth and quality at key developmental stages. APETALA2 (AP2)/ethylene-responsive factor (ERF) transcription factors (TFs) comprise one of the largest gene superfamilies in plants and are widely involved in biotic and abiotic stresses. To reveal the roles of AP2/ERF TFs during T. hemsleyanum development, 70 AP2/ERF TFs were identified in T. hemsleyanum. Among them, 18 and 2 TFs were classified into the AP2 and RAV families, respectively. The other 50 TFs belonged to the ERF family and were further divided into the ERF and (dehydration reaction element binding factor) DREB subfamilies. The ERF subfamily contained 46 TFs, while the DREB subfamily contained 4 TFs. Phylogenetic analysis indicated that AP2/ERF TFs could be classified into five groups, in which 10 conserved motifs were confirmed. Several motifs were group- or subgroup-specific, implying that they were significant for the functions of the AP2/ERF TFs of these clades. In addition, 70 AP2/ERF TFs from the five groups were used for an expression pattern analysis under three low-temperature levels, namely, -4, 0, and 4°C. The majority of these AP2/ERF TFs exhibited a positive response to cold stress conditions. Specifically, ThERF5, ThERF31, ThERF46, and ThERF55 demonstrated a more sensitive response to cold stress. Moreover, AP2/ERF TFs exhibited specific expression patterns under cold stress. Transient overexpression and RNA interference indicated that ThERF46 has a specific tolerance to cold stress. These new insights provide the basis for further studies on the roles of AP2/ERF TFs in cold stress tolerance in T. hemsleyanum.

Effects of dietary sweeteners supplementation on growth performance, serum biochemicals, and jejunal physiological functions of broiler chickens.

The objective of this study was to investigate the effects of dietary 3 kinds of sweeteners supplementation on growth performance, serum biochemicals, and jejunal physiological functions of broiler chickens for 21 D. A total of one hundred ninety-two 1-day-old male Ross 308 broiler chicks were randomly divided into 4 treatments with 6 replicates for each treatment. The treatments were basal diet (CON), a basal diet supplemented with 250 mg/kg stevioside (STE), a basal diet supplemented with 100 mg/kg sucralose (SUC), and a basal diet supplemented with 600 mg/kg saccharin sodium (SAC). All birds were housed in 3-level battery cages. The results showed that dietary STE supplementation increased (P < 0.05) growth performance, serum total protein, serum albumin, and jejunal antioxidant capacity of broiler chickens. Both SUC and SAC supplementation decreased (P < 0.05) serum total protein and albumin. Dietary SAC supplementation impaired the intestinal integrity, permeability, and mucus layer of the jejunum in broiler chickens. In addition, SAC supplementation elevated (P < 0.05) the transcription expression level of jejunal bitter taste receptors and induced excessive jejunal apoptosis. Our data suggest that STE could be potentially applied as a growth-promoting and antioxidant feed additive in broiler chickens. Whereas, dietary supplementation with high level SAC has side-effects on the jejunal physiological functions of broiler chickens.

Pillar[5]arene-Based Switched Supramolecular Photosensitizer for Self-Amplified and pH-Activated Photodynamic Therapy.

Photodynamic therapy (PDT) has emerged as a promising and spatiotemporally controllable cancer treatment modality. However, serious skin photosensitization during the PDT process limits the clinical application of PDT. Thus, the construction of "smart" and multifunctional photosensitizers has attracted substantial interest. Herein, we develop a mitochondria-targeting and pH-switched hybrid supramolecular photosensitizer by the host-guest interaction. The PDT efficacy of supramolecular photosensitizers can be quenched by the Förster resonance energy transfer (FRET) effect during long circulation and activated by the dissociation of supramolecular photosensitizers in an acidic tumor microenvironment, benefitting from the dynamic feature of the host-guest interaction and pH responsiveness of the water-soluble pillar[5]arene on gold nanoparticles. The rational integration of mitochondria-targeting and reductive glutathione (GSH) elimination in the hybrid switchable supramolecular photosensitizer prolongs the lifetime of reactive oxygen species generated in the PDT near mitochondria and further amplifies the PDT efficacy. Thus, the facile and versatile construction of switchable supramolecular photosensitizer offers not only the targeted and precise phototherapy but also high therapeutic efficacy, which would provide a new path for the clinic application of PDT.

[HUVECs extraction and UHPLC LTQ Orbitrap analysis for screening vascular endothelium protective components in Kudiezi injection].

An effective method has been employed as a tool for screening active components in Kudiezi injection by using cell chromatography and sensitive UHPLC-HR-MSn method. The potential bioactive components in Kudiezi injection could be selectively bound to the HUVECs target cells first. After cell target desensitization and inactivation, the chemical constituents with cell target affinity were identified by LC-MS, so as to screen the possible active components in Kudiezi injection. Based on the accurate mass measurements and the retention time, in total, 9 compounds were tentatively identified and characterized, including 4 sesquiterpene lactones, 3 phenolic acids and 2 flavonoids. HUVECs biospecific extraction coupled with UHPLC-LTQ-Orbitrap analysis could provide a rapid and efficient method for the identification of potential bioactive components in Kudiezi injection, and provide the reference for further research on its effective materials basis.

UHPLC-LTQ-Orbitrap-based metabolomics coupled with metabolomics pathway analysis method for exploring the protection mechanism of Kudiezi injection in a rat anti-ischemic cerebral reperfusion damage model.

Kudiezi injection has been used extensively in the treatment of cerebrovascular and cardiovascular diseases. However, its therapeutic effects and underlying mechanism of action are not fully understood. The aim of the present study was to clarify the protective mechanisms of Kudiezi injection on cerebral ischemic injury, using metabolomics methods. Middle cerebral artery occlusion (MCAO) was introduced in rats to build the cerebral ischemic damage. UHPLC-LTQ-Orbitrap-based analytical method was established for analysis of the metabolites. The raw mass data of all samples were normalized with Sieve 2.2 software and then introduced to orthogonal partial least squares discriminant analysis (OPLS-DA) model. Finally, 23 metabolites in plasma (15 were tentatively identified) were chosen as potential biomarkers, according to accurate mass measurements (< 5 ppm), MS/MS fragmentation patterns, and diagnostic product ions. Furthermore, on the basis of metabolic pathway analysis via metabolomics pathway analysis (MetPA), we first discovered that the protection mechanism in anti-ischemic cerebral reperfusion damage of Kudiezi injection was possibly related to the biosynthesis of phenylalanine, tyrosine, and tryptophan. The present study provided a useful approach for exploring the mechanism of ischemic stroke and evaluating the efficacy of Kudiezi injection or other traditional medicines.

Identification of Metabolites of 6'-Hydroxy-3,4,5,2',4'-pentamethoxychalcone in Rats by a Combination of Ultra-High-Performance Liquid Chromatography with Linear Ion Trap-Orbitrap Mass Spectrometry Based on Multiple Data Processing Techniques.

In this study, an efficient strategy was established using ultra-high-performance liquid chromatography coupled with linear ion trap-Orbitrap mass spectrometry (UHPLC-LTQ-Orbitrap MS) to profile the in vivo metabolic fate of 6'-hydroxy-3,4,5,2',4'-pentamethoxychalcone (PTC) in rat urine and feces. The UHPLC-LTQ-Orbitrap method combines the high trapping capacity and MS(n) scanning function of the linear ion trap along with accurate mass measurements within 5 ppm and a resolving power of up to 30,000 over a wider dynamic range compared to many other mass spectrometers. In order to reduce the potential interferences of endogenous substances, the post-acquisition processing method including high-resolution extracted ion chromatogram (HREIC) and multiple mass defect filters (MMDF) were developed for metabolite detection. As a result, a total of 60 and 35 metabolites were detected in the urine and feces, respectively. The corresponding in vivo reactions such as methylation, hydroxylation, hydrogenation, decarbonylation, demethylation, dehydration, methylation, demethoxylation, sulfate conjugation, glucuronide conjugation, and their composite reactions were all detected in this study. The result on PTC metabolites significantly expanded the understanding of its pharmacological effects, and could be targets for future studies on the important chemical constituents from herbal medicines.

[Rapid characterization of chemical constituents and rats metabolites of Kudiezi injection by UHPLC-LTQ-Orbitrap].

A rapid and sensitive UHPLC-HR-MSn method was used for the identification of Kudiezi injection and its main metabolites in rat plasma. After the tail intravenous injection of Kudiezi, ACQUITY UHPLC BEH C18 (2.1 mm×100 mm, 1.7 µm) was used, with 0.1% formic acid-acetonitrile solution as the mobile phase for gradient elution. Kudiezi injection and plasma were detected by ESI-LTQ-Orbitrap equipped with an ESI ion source in a negative mode. Based on the accurate mass measurements, the retention time and the mass fragmentation patterns, a total of 53 compounds were tentatively identified and characterized. Furthermore, metabolites in rat plasma after the intravenous administration of Kudiezi injection were also analyzed. A total of 38 compounds were identified, including 27 prototypes and 11 metabolites through metabolic pathways of methylation, glucuronide conjugation, sulfate conjugation and hydrolysis. As a result, UHPLC-LTQ-Orbitrap technique was applied to comprehensively expound Kudiezi injection's chemical components and constituents migrating to rat plasma, and provide scientific basis for further studies on Kudiezi injection's in vivo metabolic process and effective material base.

[Influence of different drying methods on steroidal saponins and homoisoflavonoids in Ophiopogon japonicus].

To study the influence of three different drying methods (including 50 ℃-drying, 80 ℃-drying and －70 ℃-freeze-drying methods) on steroidal saponins and homoisoflavonoids in Ophiopogon japonicus,a HPLC-DAD-ELSD-MSn method was investigated to screen and identify the differential components. Through comparing the HPLC chromatograms with that of fresh O. japonicus, 50 ℃-drying medicine was similar with fresh medicine whereas the other two drying methods had great influence on the components of O. japonicus. In this study, 36 differential components were screened, among which 24 constituents(13 homoisoflavonoids and 11 steroidal saponins) were identified via HPLC-LTQ-Orbitrap MS.As a result, it was revealed that different drying methods had significant influences on the components of steroidal saponins and homoisoflavonoids. Among them, 50 ℃-drying method was the most suitable drying approach when the stability of components, cost and practicability were considered.

[Rapid characterization of constituents absorbed into blood after oral administration of steroidal saponins from Radix Ophiopogonis using UHPLC-LTQ-Orbitrap MS coupled with higher energy collision induced dissociation].

The method of UHPLC-LTQ-Orbitrap mass spectrometry coupled with higher energy collision dissociation (HCD) was established to rapidly analyze the constituents absorbed into blood after oral administration of steroidal saponins from Radix Ophiopogonis. A total of 31 constituents, including 13 furostanol steroidal saponins and 18 spirostanol steroidal saponins, were characterized based on the accurate mass measurements, fragmentation patterns, chromatographic retention times, and diagnostic product ions. Among them, 8 compounds were unambiguously identified by comparison with their corresponding standards. The results provide comprehensive insights and guidance for elucidation of material basis of Radix Ophiopogonis activity.