Jasmonic acid mediates Ca2+ dependent signal transduction and plant immunity.

Pathogen attacks can cause significant damage to plants, posing a threaten to global food production. Plants have developed exquisite methods to rapidly store a key defensive hormone jasmonate (JA), which stimulates their entire evolutionary adaptive response to pathogen attack. However, understanding how plants initiate JA biosynthesis in response to pathogen attacks has remained elusive. In this review, we discuss the newly discovered JAV1-JAZ8-WRKY51 (JJW) complex, which plays a crucial role in regulating JA production to deter insect attacks. The JJW complex inhibits JA production in plants, maintaining a low baseline level of JA that promotes optimal plant development. However, when plants are attacked by insects, a rapid influx of calcium stimulates the JAV1 calcium-dependent protein phosphate, leading to the breakdown of the JJW complex and the activation of JA production. This surge in JA levels, initiates plant defense mechanisms against the invading insects. These findings shed light on the intricate defense system that plants have evolved to combat diseases.

Erythropoietin hyporesponsiveness in non-alcoholic fatty liver disease.

Treatment with erythropoietin (EPO) can correct anaemia in chronic kidney disease (CKD) patients; however, up to 10% exhibit resistance or hyporesponsiveness to EPO. Non-alcoholic fatty liver disease (NAFLD), prevalent liver disease in CKD patients, may limit EPO response because of thrombopoietin deficiency, iron homeostasis disorder and inflammation. Therefore, we hypothesized NAFLD is a risk factor for EPO responsiveness. To test our hypothesis, we evaluated the effect of EPO in healthy rats and rats with NAFLD induced by a high-fat, high-carbohydrate (HFHC) diet. After 12 weeks on the HFHC diet, NAFLD rats showed lower erythroid response to EPO treatment than healthy rats. We, then, determined that the primary cause of EPO hyporesponsiveness could be iron deficiency associated with inflammation, which reduces erythroid cell production. Specifically, the concentrations of hepcidin, ferritin, transferrin and white blood cells in NAFLD rats were 12.8-, 16.4-, 2.51- and 1.40-fold higher than those in healthy rats, respectively. However, erythroid cell types in the bone marrow of NAFLD rats were significantly reduced. In conclusion, our data suggest that NAFLD could be a risk factor for EPO responsiveness, which is attributed to functional iron deficiency associated with inflammation.

Thrombopoietin treats erythropoietin resistance by correcting EPO-induced progenitorcell depletion.

Recombinant human erythropoietin (rHuEPO) is a prevalent treatment for anemia in patients with chronic kidney disease. However, up to 10% of these patients exhibit EPO resistance or hyporesponsiveness, which may be caused by the depletion of erythroid progenitor cells. Thrombopoietin (TPO) has the potential to promote the growth of early progenitor cells and correct the depletion. In this study, we investigate the efficacy and the underlying mechanism of the combination therapy of TPO and EPO to EPO resistance. First, the in vivo studies suggested that intensive EPO treatment induced progenitor cell depletion in the bone marrow, where the depletion was corrected by TPO. Then, colony assays showed that EPO and TPO synergistically enhanced the burst-forming unit-erythroid (BFU-E) production but antagonistically boosted the colony-forming units of megakaryocytes (CFU-MK) production. Also, we found TPO promoted hematopoietic stem and progenitor cells (HSPCs) production, while EPO drove HSPCs toward the erythroid lineage. Additionally, EPO induced more megakaryocytic-erythroid progenitors (MEPs) toward the erythroid output. Model-based simulations indicate the efficacy of this combination therapy for treating EPO-resistant anemia in rats. In conclusion, our study demonstrated the efficacy of combination therapy in addressing EPO-resistant anemia by correcting EPO-induced erythroid progenitor depletion.

DFT-based analysis of siderophore-metal ion interaction for efficient heavy metal remediation.

Siderophores have great application potential in metal pollutant remediation because of their effective cost and friendly impact on the environment. However, the practical use of siderophores in the remediation of specific metals is rather limited because of the weak nonspecific interactions between the siderophores and different metals. Thus, screening for a siderophore with optimal interaction with a specific metal would be necessary. In this study, the interaction between metal ions and moieties that donate the oxygen ligands for the coordination of four types of siderophore (hydroxamates, catecholates, phenolates, and carboxylates) was modeled and analyzed. As revealed by DFT-based analysis, the four types of siderophore generally exhibited selection preference for different metal ions in the order Ga3+ > Al3+ > Fe3+ > Cr3+ > Ni2+ > Cu2+ > Zn2+ > Co2+ > Mn2+ > Hg2+ > Pb2+ > Cd2+, which was determined mainly by the electronegativity of the siderophore functional groups, the electronegativity of the metals, and the ionic radius of the metals, as well as the interaction between the siderophores and the metals. Moreover, the effect of linear or nonlinear (cyclic) structure on the affinity of each siderophore for different metal ions was evaluated. In most situations, metal-bound cyclic siderophores were found to be more stable than their linear counterparts. Thus, proper siderophores for the remediation of metal pollution may be rapidly screened using this model.

First Report of Exserohilum rostratum Causing Leaf Blight on Broccoli (Brassica oleracea var. italica) in China.

Broccoli (Brassica oleracea var. italica) is not only an important crop worldwide with a large amount of production and consumption annually, but also rich in biologically active compounds (Surh et al., 2021). In November 2022, an unknown leaf blight was observed in the Broccoli planting area, Wenzhou City of Zhejiang Province (28.05 °N, 120.31 °E). Symptoms initially occurred at the leaf margin with yellow to gray lesions that were irregular and wilting. Approximately 10% of the surveyed plants were affected. To determine the pathogen, leaves with blight were collected randomly from five B. oleracea plants. Tissue blocks (3×3 mm) from diseased leaf portions were disinfected with 75% ethanol, rinsed three times with sterilized water, placed aseptically onto potato dextrose agar (PDA) medium, and incubated for 5 days at 28℃ in darkness. Seven fungal isolates with the same morphology were obtained using the spore method. The observed colonies were circular, taupe, pewter in color with light gray edging and many cottony aerial mycelia. Conidia were straight, curved or slightly bent, ellipsoidal to fusiform, and septate (typically 4-8 septa per conidium), with the size of 50.0-90.0 µm × 10.0-20.0 µm (n=30). The conidia had a slightly protruding and truncate hilum. These morphological characteristics were consistent with Exserohilum rostratum (Sharma et al., 2014). To further identify the pathogen, isolate WZU-XLH1 was chosen as a representative and the internal transcribed spacer (ITS) and glyceraldehyde-3-phosphate dehydrogenase-like (GAPDH) gene were amplified and sequenced using primer pairs ITS1/ITS4 (White et al., 1990) and Gpd1/Gpd2 (Berbee et al., 1999), respectively. The ITS and gpd gene sequences of isolate WZU-XLH1 were deposited in the GenBank database with accession numbers OQ750113 and OQ714500, respectively. BLASTn analysis showed matches of 568/571 (MH859108) and 547/547 (LT882549) with Exserohilum rostratum CBS 188.68. A neighbor-joining phylogenetic tree was constructed by combining the two sequenced loci, this isolate in the E. rostratum species complex clade at 71% bootstrap support.To verify the pathogenicity of the isolate, ten healthy Broccoli (cultivar 'You Xiu') seedlings with at least five leaves were divided into two groups: one group was inoculated with the isolate, while the other group served as a control. After surface disinfection with 75% ethanol and wiping with sterile water, tiny wounds were made on two leaves (two wounds in one leaf) using an inoculation needle. Fungal culture plugs cut from the isolate were placed on the wounds, while sterile PDA plugs served as the control. The leaves were sealed in wet airtight bags to retain moisture at room temperature with natural light (Cao et al., 2022). After five days, all leaves inoculated with isolate WZU-XLH1 showed symptoms identical to those observed in the field, with no symptoms present in the control group. The pathogenicity was confirmed by repeating the test in triplicate, and fungi re-isolated from symptomatic leaves were identified as E. rostratum by the morphological and molecular methods described above. To the best of our knowledge, this is the first report of E. rostratum causing leaf blight on broccoli in China. This study contributes to our understanding of B. oleracea leaf blight and establishes a basis for future studies on E. rostratum to develop management strategies.

Growth promotion of Sargassum fusiforme by epiphytic microbes is dependent on the extent of interspecific interactions of the microbial community.

Profound growth differences such as seedling length and biomass are often observed during the cultivation of Sargassum fusiforme despite the absence of detectable variance in abiotic factors that could have affected this process. This highlights the importance of biotic factors such as epiphytic microbiota in controlling seedling growth. Yet, how, and to what extent microbial activities can affect host growth in the presence of seawater flow and continuous erosion remains debatable. Particularly, the contribution of microbial network interactions to the growth of macroalgae remains poorly understood. This study aimed to compare the physicochemical properties of S. fusiforme seedlings via 16S rRNA gene Illumina sequencing-based profiling of the epiphytic microbial communities of seedlings with different lengths. Significantly different epiphytic bacterial communities were observed among S. fusiforme seedlings of different lengths. The result showed that community from longer seedlings maintained higher bacterial diversity with the taxa Gammaproteobacteria, Burkholderiales, Alteromonadales, Vibrionaceae, Ralstonia, Colwelliaceae, and Thalassotalea being selectively enriched. More importantly, microbial interspecific interactions, which were predominantly positive, were enhanced consistently in communities of the longer seedlings, indicative of reinforced prevalent and mutually cooperative relationships among the microorganisms associated with S. fusiforme seedlings of greater length. Furthermore, longer seedlings also displayed up-regulation of microbial functional potentials involved in N fixation and mineralization, P mineralization and transportation, and ion transportation compared with shorter ones. Lastly, stochastic processes dominated the community assembly of the epiphytic microorganisms. These findings could provide new insights into the relationship between microbial communities and growth in S. fusiforme seedlings and enable us to predict the community diversity and assembly of macroalgae-associated microbial communities. This could have important implications for linking microbial community diversity and network interactions to their host productivity.

sBGC-hm: an atlas of secondary metabolite biosynthetic gene clusters from the human gut microbiome.

SUMMARY: Microbial secondary metabolites exhibit potential medicinal value. A large number of secondary metabolite biosynthetic gene clusters (BGCs) in the human gut microbiome, which exhibit essential biological activity in microbe-microbe and microbe-host interactions, have not been adequately characterized, making it difficult to prioritize these BGCs for experimental characterization. Here, we present the sBGC-hm, an atlas of secondary metabolite BGCs allows researchers to explore the potential therapeutic benefits of these natural products. One of its key features is the ability to assist in optimizing the BGC structure by utilizing the gene co-occurrence matrix obtained from Human Microbiome Project data. Results are viewable online and can be downloaded as spreadsheets. AVAILABILITY AND IMPLEMENTATION: The database is openly available at https://www.wzubio.com/sbgc. The website is powered by Apache 2 server with PHP and MariaDB.

Clearance as an Early Indicator of Efficacy for Therapeutic Monoclonal Antibodies: Circumventing Dose Selection Challenges in Oncology.

BACKGROUND AND OBJECTIVE: The designs of first-in-human (FIH) studies in oncology (e.g., 3 + 3 dose escalation design) usually do not provide a sufficient sample size to determine the dose-response relationship for efficacy. This study aimed to assess the feasibility of using monoclonal antibody (mAb) clearance as a biomarker for efficacy to facilitate the identification of potentially efficacious doses across cancer types and drug targets. METHODS: We performed electronic searches of the Drugs@FDA website, the European Medicines Agency website, and PubMed to identify reports of FIH trials of approved mAbs in oncology. The clearance, half-life, and overall response rate (ORR) data for the mAbs at different dose levels were extracted. RESULTS: Twenty-five approved mAbs were included in this study. As expected, due to the small sample sizes in FIH studies, there was no clear dose-response for ORR. However, we found a clear negative association between mAb clearance and ORR across tumors/drug targets, and a clear negative dose-clearance relationship, with clearance decreasing and saturated at high dose levels. The approved mAb doses (1-25 mg/kg) are approximately 2-fold the saturation doses (1-10 mg/kg). The associated clearance values at the approved doses vary across different cancers and drug targets (0.17-1.56 L/day), while tend to be similar within a disease/drug target. Anti-CD20 mAbs for B-cell lymphomas show a higher clearance (~ 1 L/day) than other cancers and targets (e.g., ~ 0.3 L/day for anti-PD-1). CONCLUSIONS: Clearance of mAbs can be a tumor/drug target-agnostic biomarker for potential anti-tumor activity as clearance decreases with increasing ORR. Our findings shed important insights into target clearance values that may lead to desired efficacy for different cancers and drug targets, which can be used to guide dose selection for the future development of mAbs during FIH oncology studies.

A Novel Combination Therapy of Erythropoietin and Thrombopoietin to Treat Erythropoietin-Resistance anemia.

PURPOSE: Treatment with recombinant human erythropoietin (rHuEPO) may correct anemia in patients with chronic kidney disease. However, up to 10% of these patients exhibit EPO resistance or hyporesponsiveness, which may be caused by the depletion of erythroid progenitor cells. Thrombopoietin (TPO) stimulates the self-renewal of stem cells and promotes the growth of early erythroid progenitor cells. The objective of this study was to determine whether the combination of recombinant human TPO (rHuTPO) and rHuEPO could correct the depletion of erythroid precursor cells to treat EPO-resistant anemia. METHODS: To test our hypothesis, pharmacokinetic (PK) and pharmacodynamic (PD) studies of rHuEPO and rHuTPO were performed in healthy rats. Rats received rHuEPO or rHuTPO alone or in combination. Plasma concentrations of rHuTPO and rHuEPO were measured. PD responses, including erythropoietic and thrombopoietic responses, were assessed in peripheral blood. RESULTS: On one hand, the results demonstrated the synergistic effect of the combination of rHuEPO and rHuTPO on erythropoiesis. Compared with rHuEPO monotherapy, the combination therapies further stimulated the production of red blood cells and hemoglobin. On the other hand, rHuEPO inhibited the platelet production induced by rHuTPO and mitigate the risk of blood clots. Furthermore, we successfully developed a mechanism-based PD model to simultaneously characterize the responses of the two molecules. CONCLUSIONS: Overall, our study indicated that a combination therapy of rHuTPO and rHuEPO could be used to treat EPO-resistant anemia and provided a quantitative basis for further optimizing the combination therapy for clinical use.

Variation in Glucosinolate Accumulation among Different Sprout and Seedling Stages of Broccoli (Brassica oleracea var. italica).

Glucosinolates (GLs) are plant secondary metabolites that may act against different types of cancers. Broccoli (Brassica oleracea var. italica) is rich in GLs which makes it an excellent source of these nutraceuticals. The composition and concentration of GLs vary among broccoli cultivars and throughout the developmental stages of the plant. To obtain the GL profiles of broccoli, GL compositions and contents in four early developmental stages (seeds, 3-day sprouts, 11-day and 17-day seedlings) were determined for nine cultivars of broccoli in this study. A total of 12 GLs including 9 aliphatic GLs and 3 indole GLs were identified from the nine broccoli cultivars using LC-QTOF-MS. UPLC results showed that aliphatic GLs concentrations decreased with broccoli sprouts and seedling growth for most cultivars. Interestingly, indole GLs amounts increased after germination and reached the highest level in 3-day sprouts or 11-day seedlings, and they fell back to a low level in 17-day seedlings. The GL profiles of nine cultivars documented in this study will provide useful information for high quality germplasm selection for cultivation or genetic engineering, and further understanding of the GL metabolic pathways.

Effect of autoinduction and food on the pharmacokinetics of furmonertinib and its active metabolite characterized by a population pharmacokinetic model.

Furmonertinib (AST2818) is a novel third-generation irreversible EGFR TKI and recently has been approved in China for the treatment of non-small cell lung cancer (NSCLC) with EGFR-sensitizing and T790M resistance mutations. In the current study, we developed a semi-mechanistic population pharmacokinetic model to characterize the nonstationary pharmacokinetics (PK) of the furmonertinib and its active metabolite AST5902 simultaneously. The PK data of furmonertinib and AST5902 were obtained from 38 NSCLC patients and 16 healthy volunteers receiving 20-240 mg furmonertinib in three clinical trials. A nonlinear mixed-effects modeling approach was used to describe the PK data. The absorption process of furmonertinib was described by a transit compartment model. The disposition of both furmonertinib and AST5902 was described by a two-compartment model. An indirect response model accounted for the autoinduction of furmonertinib metabolism mediated by CYP3A4. The model-based simulation suggested that furmonertinib clearance was increased in one cycle of treatment (orally once daily for 21 days) compared to baseline, ranging from 1.1 to 1.8 fold corresponding to the dose range of 20-240 mg. The concentration of furmonertinib was decreased over time whereas that of AST5902 was increased. Interestingly, the concentration of the total active compounds (furmonertinib and AST5902) appeared to be stable. The food intake, serum alkaline phosphatase and body weight were identified as statistically significant covariates. The mechanism of food effect on PK was investigated, where the food intake might increase the bioavailability of furmonertinib via increasing the splanchnic blood flow. Overall, a population PK model was successfully developed to characterize the nonstationary PK of furmonertinib and AST5902 simultaneously. The concentrations of total active compounds were less affected by the autoinduction of furmonertinib metabolism.

A Type III Polyketide Synthase (SfuPKS1) Isolated from the Edible Seaweed Sargassum fusiforme Exhibits Broad Substrate and Catalysis Specificity.

A type III polyketide synthase (SfuPKS1) from the edible seaweed Sargassum fusiforme was molecularly cloned and biochemically characterized. The recombinant SfuPKS1 catalyzed the condensation of fatty acyl-CoA with two or three malonyl-CoA using lactone-type intramolecular cyclization to produce tri- and/or tetraketides. Moreover, it can also utilize phenylpropanoyl-CoA to synthesize phloroglucinol derivatives through Claisen-type cyclization, exhibiting broad substrate and catalysis specificity. Furthermore, the catalytic efficiency (kcat/KM) for acetyl-CoA was 11.8-fold higher than that for 4-coumaroyl-CoA. A pathway for the synthesis of naringenin involving SfuPKS1 was also constructed in Escherichia coli by recombinant means, resulting in 4.9 mg of naringenin per liter.

The complete chloroplast genome of Sargassum fusiforme.

The complete chloroplast genome sequence of Sargassum fusiforme is presented here. Circular mapping revealed that the complete chloroplast DNA sequence of S. fusiforme was 124,298 bp in length and had an overall AT content of 69.57%, including 137 protein-coding genes, 2 open reading frames, 28 transfer RNA genes, and 6 ribosomal RNA genes. The phylogenetic tree based on Bayesian shows that all kinds of Phaeophyceae were clustered into two monophyletic groups.

The complete mitochondrial genome of brown algae: Sargassum fusiforme (Harvey) Setchell.

We describe the complete mitochondrial genome sequence of Sargassum fusiforme. This mitogenome is a circular molecule of 34,695 bp in length and had an overall GC content of 37.54%%. Gene annotation showed that 35 protein-coding genes, 2 open reading frames, 25 transfer RNA genes, and 3 ribosomal RNA genes. The phylogenetic tree based on Bayesian shows that S. fusiforme belongs to genus Sargassum, support current taxonomic systems.

Application of Pharmacokinetic-Pharmacodynamic Modeling in Drug Delivery: Development and Challenges.

With the advancement of technology, drug delivery systems and molecules with more complex architecture are developed. As a result, the drug absorption and disposition processes after administration of these drug delivery systems and engineered molecules become exceedingly complex. As the pharmacokinetic and pharmacodynamic (PK-PD) modeling allows for the separation of the drug-, carrier- and pharmacological system-specific parameters, it has been widely used to improve understanding of the in vivo behavior of these complex delivery systems and help their development. In this review, we summarized the basic PK-PD modeling theory in drug delivery and demonstrated how it had been applied to help the development of new delivery systems and modified large molecules. The linkage between PK and PD was highlighted. In particular, we exemplified the application of PK-PD modeling in the development of extended-release formulations, liposomal drugs, modified proteins, and antibody-drug conjugates. Furthermore, the model-based simulation using primary PD models for direct and indirect PD responses was conducted to explain the assertion of hypothetical minimal effective concentration or threshold in the exposure-response relationship of many drugs and its misconception. The limitations and challenges of the mechanism-based PK-PD model were also discussed.

Salt stress induced differential metabolic responses in the sprouting tubers of Jerusalem artichoke (Helianthus tuberosus L.).

To better understand the mechanism of inherent salt resistance in Jerusalem artichoke (Helianthus tuberosus L.), physiological and metabolic responses of tubers at the initiation stage of sprouting under different salt stress levels were evaluated in the present study. As a result, 28 metabolites were identified using proton nuclear magnetic resonance (1H-NMR) spectroscopy. Jerusalem artichoke tubers showed minor changes in metabolic response under moderate salt stress when they had not yet sprouted, where metabolism was downregulated at the start of sprouting and then upregulated significantly after plants became autotrophic. However, mild and severe salt stress levels caused different metabolic response patterns. In addition, the accumulation of fructose and sucrose was enhanced by moderate salt stress, while glucose was highly consumed. Aspartate and asparagine showed accelerated accumulation in sprouting Jerusalem artichoke tubers that became autotrophic, suggesting the enhancement of photosynthesis by moderate salt stress.

Proteomic landscape of liver tissue in old male mice that are long-term treated with polysaccharides from Sargassum fusiforme.

Sargassum fusiforme is a type of brown algae and well known as a longevity promoting vegetable in Northeastern Asia. The polysaccharides derived from Sargassum fusiforme (SFPs) have been suggested as an antioxidant component for anti-aging function. However, global molecular changes in vivo by SFPs have not been fully elucidated. Here, we present a proteomics study using liver tissues of aged male mice that were fed with SFPs. Of forty-nine protein spots, thirty-eight were up-regulated and eleven were down-regulated, showing significant changes in abundance by two-dimensional gel electrophoresis. These differentially expressed proteins were mainly involved in oxidation-reduction, amino acid metabolism, and energy metabolism. Forty-six proteins were integrated into a unified network, with catalase (Cat) at the center. Intriguingly, most of the proteins were speculated as mitochondrial-located proteins. Our findings suggested that SFPs modulated antioxidant enzymes to scavenge redundant free radicals, thus preventing oxidative damage. In conclusion, our study provides a proteomic view on how SFPs have beneficial effects on the aspects of antioxidant and energy metabolism during the aging process. This study facilitates the understanding of anti-aging molecular mechanisms in polysaccharides derived from Sargassum fusiforme.