Effects of Heat Stress on Plant-Nutrient Relations: An Update on Nutrient Uptake, Transport, and Assimilation.

As a consequence of global climate change, the frequency, severity, and duration of heat stress are increasing, impacting plant growth, development, and reproduction. While several studies have focused on the physiological and molecular aspects of heat stress, there is growing concern that crop quality, particularly nutritional content and phytochemicals important for human health, is also negatively impacted. This comprehensive review aims to provide profound insights into the multifaceted effects of heat stress on plant-nutrient relationships, with a particular emphasis on tissue nutrient concentration, the pivotal nutrient-uptake proteins unique to both macro- and micronutrients, and the effects on dietary phytochemicals. Finally, we propose a new approach to investigate the response of plants to heat stress by exploring the possible role of plant peroxisomes in the context of heat stress and nutrient mobilization. Understanding these complex mechanisms is crucial for developing strategies to improve plant nutrition and resilience during heat stress.

Anti-Inflammatory and Antimicrobial Properties of Thyme Oil and Its Main Constituents.

Thyme oil (TO) is derived from the flowers of various plants belonging to the genus Thymus. It has been used as a therapeutic agent since ancient times. Thymus comprises numerous molecular species exhibiting diverse therapeutic properties that are dependent on their biologically active concentrations in the extracted oil. It is therefore not surprising that oils extracted from different thyme plants present different therapeutic properties. Furthermore, the phenophase of the same plant species has been shown to yield different anti-inflammatory properties. Given the proven efficacy of TO and the diversity of its constituents, a better understanding of the interactions of the various components is warranted. The aim of this review is to gather the latest research findings regarding TO and its components with respect to their immunomodulatory properties. An optimization of the various components has the potential to yield more effective thyme formulations with increased potency.

Plant Peroxisomal Polyamine Oxidase: A Ubiquitous Enzyme Involved in Abiotic Stress Tolerance.

Polyamines (PAs) are positively charged amines that are present in all organisms. In addition to their functions specific to growth and development, they are involved in responding to various biotic and abiotic stress tolerance functions. The appropriate concentration of PA in the cell is maintained by a delicate balance between the catabolism and anabolism of PAs, which is primarily driven by two enzymes, namely diamine oxidase and polyamine oxidase (PAO). PAOs have been found to be localized in multiple subcellular locations, including peroxisomes. This paper presents a holistic account of peroxisomal PAOs. PAOs are flavin adenine dinucleotide-dependent enzymes with varying degrees of substrate specificity. They are expressed differentially upon various abiotic stress conditions, namely heat, cold, salinity, and dehydration. It has also been observed that in a particular species, the various PAO isoforms are expressed differentially with a spatial and temporal distinction. PAOs are targeted to peroxisome via a peroxisomal targeting signal (PTS) type 1. We conducted an extensive bioinformatics analysis of PTS1s present in various peroxisomal PAOs and present a consensus peroxisome targeting signal present in PAOs. Furthermore, we also propose an evolutionary perspective of peroxisomal PAOs. PAOs localized in plant peroxisomes are of potential importance in abiotic stress tolerance since peroxisomes are one of the nodal centers of reactive oxygen species (ROS) homeostasis and an increase in ROS is a major indicator of the plant being in stress conditions; hence, in the future, PAO enzymes could be used as a key candidate for generating abiotic stress tolerant crops.

Association of Lipid Accumulation Product and Triglyceride-Glucose Index with Metabolic Syndrome in Young Adults: A Cross-sectional Study.

Background: Metabolic syndrome is a cluster of elements linked with type 2 diabetes mellitus and cardiovascular disease (CVD). The early detection of individuals at the risk of developing metabolic syndrome can prevent the development of type 2 diabetes mellitus and CVD. Objectives: This study aimed to evaluate the association of the lipid accumulation product (LAP) and triglyceride-glucose (TyG) index with metabolic syndrome among young adults. Methods: This cross-sectional study included 300 young adults within the age range of 20 - 40 years. Metabolic syndrome was defined according to modified National Cholesterol Education Program Adult Treatment Panel III guidelines. The LAP and TyG index were calculated. Multivariate logistic regression and receiver operating characteristic curve analyses were performed to assess the association of the LAP and TyG index with metabolic syndrome. Results: The LAP and TyG index were significantly associated with metabolic syndrome (P < 0.05). The LAP showed the highest area under the curve (0.882 and 0.905 in male and female subjects, respectively), followed by the TyG index (0.875 and 0.886 in male and female subjects, respectively, at P < 0.0001. The cut-off values for the LAP were 45.65 in males with a sensitivity and specificity of 80% and 46.91 in females with a sensitivity and specificity of 88%. The cut-off points for the TyG index were 8.63 in males with 80% sensitivity and 78.9% specificity and 8.54 in females with 83.3% sensitivity and 79.6% specificity. Conclusions: The LAP and TyG index are significantly associated with metabolic syndrome in young adults. As simple and inexpensive markers, they can be used to identify individuals with metabolic syndrome with high sensitivity and specificity.

Association of hemoglobin glycation index with cardiovascular risk factors in non-diabetic adults: A cross-sectional study.

BACKGROUND AND AIMS: The study aimed to explore the association of hemoglobin glycation index (HGI) with cardiovascular risk factors in non-diabetic adults. METHODS: This cross-sectional study included 200 adults of 20-60 years of age. Predicted glycated hemoglobin (HbA1c) was calculated from linear regression equation. HGI was calculated using the formula HGI = measured HbA1c- predicted HbA1c. The study subjects were classified into three groups based on their HGI tertiles. Cardiovascular risk factors were compared between the groups and Pearson correlation test was done to correlate HGI with cardiovascular risk factors. RESULTS: Serum total cholesterol, triglyceride, low density lipoprotein cholesterol (LDL-C) and very low density lipoprotein cholesterol (VLDL-C) showed significant increase with increase in HGI in non diabetic individuals. High HGI group had significantly high serum total cholesterol, triglyceride, LDL-C and VLDL-C compared to low HGI group. Serum total cholesterol, triglyceride, LDL-C and VLDL-C showed a statistically significant positive correlation with HGI. CONCLUSION: We have found a statistically significant correlation of HGI with serum lipid profile, a significant cardiovascular risk factor in non-diabetic individuals. HGI, a simple derivative of HbA1c and fasting plasma glucose may be used to identify cardiovascular risk in non-diabetic individuals. Further prospective studies are required in larger sample size to confirm the clinical implications of HGI.

Hepatitis E, Schistosomiasis and Echinococcosis-Prevalence in a Cohort of Pregnant Migrants in Germany and Their Influence on Fetal Growth Restriction.

BACKGROUND: Infections, as well as adverse birth outcomes, may be more frequent in migrant women. Schistosomiasis, echinococcosis, and hepatitis E virus (HEV) seropositivity are associated with the adverse pregnancy outcomes of fetal growth restriction and premature delivery. METHODS: A cohort study of 82 pregnant women with a history of migration and corresponding delivery of newborns in Germany was conducted. RESULTS: Overall, 9% of sera tested positive for anti-HEV IgG. None of the patients tested positive for anti-HEV IgM, schistosomiasis, or echinococcus serology. Birth weights were below the 10th percentile for gestational age in 8.5% of the neonates. No association between HEV serology and fetal growth restriction (FGR) frequency was found. CONCLUSIONS: In comparison to German baseline data, no increased risk for HEV exposure or serological signs of exposure against schistosomiasis or echinococcosis could be observed in pregnant migrants. An influence of the anti-HEV serology status on fetal growth restriction could not be found.

Fetal growth restriction in a cohort of migrants in Germany.

BACKGROUND: Migrant women may have an increased risk of adverse birth outcomes. This study analyses the occurrence of low birth weight, preterm birth and intrauterine growth restriction / fetal growth restriction (IUGR/FGR) in pregnant migrants. METHOD: Cross-sectional study of 82 mother-child pairs of pregnant migrants attending medical care in Germany. RESULTS: The Median age was 27 years, 49% of patients were of oriental-asian ethnicity and median year of migration was 2015. At least one previous pregnancy was reported in 76% of patients, in 40% the delivery mode was caesarian section. Median gestational age was 39.7 weeks. Preterm birth occurred in 6.1% of pregnancies. Median gestational age for preterm birth was 32.3 weeks. Low birth weight (< 2500 g) occurred in 6.1%. Birth weights below the 10th percentile of birth weight for gestational age were observed in 8.5% of the total cohort. CONCLUSIONS: Compared to German data no increased occurrence of low birth weight, preterm birth or IUGR/FGR was found. We note that the rate of caesarian section births was higher than in the general population for reasons yet to be identified. The authors propose stratification according to migration status for the national documentation of birth outcomes in Germany.

Synergistic therapeutic benefit by combining the antibody drug conjugate, depatux-m with temozolomide in pre-clinical models of glioblastoma with overexpression of EGFR.

PURPOSE: Depatux-m is an antibody drug conjugate (ADC) that targets and inhibits growth of cancer cells overexpressing the epidermal growth factor receptor (EGFR) or the 2-7 deletion mutant (EGFRvIII) in tumor models in vitro and in vivo. Treatment of patients suffering from relapsed/refractory glioblastoma (GBM) with a combination of depatux-m and temozolomide (TMZ) tended to increase overall survival. As a first step to understand the nature of the interaction between the two drugs, we investigated whether the interaction was synergistic, additive or antagonistic. METHODS: The efficacy of ADCs, antibodies, TMZ and radiation was tested in xenograft models of GBM, U-87MG and U-87MG EGFRvIII. Both models express EGFR. U-87MG EGFRvIII was transduced to express EGFRvIII. Changes in tumor volume, biomarkers of cell death and apoptosis after treatment were used to measure efficacy of the various treatments. Synergism of depatux-m and TMZ was verified in three-dimensional cultures of U-87MG and U-87MG EGFRvIII by the method of Chou and Talalay. RESULTS: Combined with TMZ and radiotherapy (RT), depatux-m inhibited xenograft growth of U-87MG and U-87MG EGFRvIII more than either treatment with depatux-m or TMZ + RT. Durability of the response to depatux-m + TMZ + RT or depatux-m + TMZ was more pronounced in U-87MG EGFRvIII than in U-87MG. Efficacy of depatux-m + TMZ was synergistic in U-87MG EGFRvIII and additive in U-87MG. CONCLUSION: Adding depatux-m enhances the efficacy of standard of care therapy in preclinical models of GBM. Durability of response to depatux-m + TMZ in vivo and synergy of the drug-drug interaction correlates with the amount of antigen expressed by the tumor cells.

Development of High-Throughput Assays for Evaluation of Hematopoietic Progenitor Kinase 1 Inhibitors.

Hematopoietic progenitor kinase 1 (HPK1), also referred to as mitogen-activated protein kinase kinase kinase kinase 1 (MAP4K1), is a serine/threonine kinase that negatively regulates T-cell signaling by phosphorylating Ser376 of Src homology 2 (SH2) domain-containing leukocyte protein of 76 kDa (SLP-76), a critical mediator of T-cell receptor activation. HPK1 loss of function mouse models demonstrated enhanced immune cell activation and beneficial antitumor activity. To enable discovery and functional characterization of high-affinity small-molecule HPK1 inhibitors, we have established high-throughput biochemical, cell-based, and novel pharmacodynamic (PD) assays. Kinase activity-based time-resolved fluorescence energy transfer (TR-FRET) assays were established as the primary biochemical approach to screen for potent inhibitors and assess selectivity against members of MAP4K and other closely related kinases. A proximal target engagement (TE) assay quantifying pSLP-76 levels as a readout and a distal assay measuring IL-2 secretion as a functional response were established using human peripheral blood mononuclear cells (PBMCs) from two healthy donors. Significant correlations between biochemical and cellular assays as well as excellent correlation between the two donors for the cellular assays were observed. pSLP-76 levels were further used as a PD marker in the preclinical murine model. This effort required the development of a novel ultrasensitive single-molecule array (SiMoA) assay to monitor pSLP-76 changes in mouse spleen.

Functional Assessment In Vivo of the Mouse Homolog of the Human Ala-9-Ser NHE6 Variant.

Christianson syndrome (CS) is an X-linked neurogenetic disorder resulting from loss-of-function (LoF) mutations in SLC9A6, which encodes the endosomal Na+/H+ exchanger 6 (NHE6). NHE6 regulates proton efflux from endosomes and, thus, participates in regulating cargo processing and trafficking. LoF mutations in NHE6 cause aberrant acidification of endosomes. While CS arises in males generally due to clear LoF mutations, other potentially hypomorphic variants have emerged, yet most of these variants have not been evaluated for functional effects, particularly in vivo Here we characterize an SLC9A6 variant that has been previously reported in patients, yet now also appears in exome datasets of largely control individuals-c.25G>T, p.A9S. By heterologous expression in cell lines, we show that human NHE6A9S is expressed and localizes in a manner comparable to control NHE6. By genome editing, we generated the equivalent NHE6 mutation in mouse-p.A11S-and determined that male NHE6A11S mice have normal brain size at 6 months of age and do not show cerebellar degeneration or defective neuronal arborization. Neurons from male NHE6A11S mice also did not demonstrate an abnormality in intraendosomal pH compared with controls. These findings are in contrast to findings in NHE6-null mice previously reported and indicate that the NHE6A11S variant functions at a level equivalent to control NHE6 for many of the assays performed. These data stand in support of the population genetic data, which are also evaluated here, indicating that the A9S variant is unlikely to confer disease susceptibility with high penetrance.

GPT2 mutations in autosomal recessive developmental disability: extending the clinical phenotype and population prevalence estimates.

The glutamate pyruvate transaminase 2 (GPT2) gene produces a nuclear-encoded mitochondrial enzyme that catalyzes the reversible transfer of an amino group from glutamate to pyruvate, generating alanine and alpha-ketoglutarate. Recessive mutations in GPT2 have been recently identified in a new syndrome involving intellectual and developmental disability (IDD), postnatal microcephaly, and spastic paraplegia. We have identified additional families with recessive GPT2 mutations and expanded the phenotype to include small stature. GPT2 loss-of-function mutations were identified in four families, nine patients total, including: a homozygous mutation in one child [c.775T>C (p.C259R)]; compound heterozygous mutations in two siblings [c.812A>C (p.N271T)/c.1432_1433delGT (p.V478Rfs*73)]; a novel homozygous, putative splicing mutation [c.1035C>T (p.G345=)]; and finally, a recurrent mutation, previously identified in a distinct family [c.1210C>T (p.R404*)]. All patients were diagnosed with IDD. A majority of patients had remarkably small stature throughout development, many < 1st percentile for height and weight. Given the potential biological function of GPT2 in cellular growth, this phenotype is strongly suggestive of a newly identified clinical susceptibility. Further, homozygous GPT2 mutations manifested in at least 2 of 176 families with IDD (approximately 1.1%) in a Pakistani cohort, thereby representing a relatively common cause of recessive IDD in this population, with recurrence of the p.R404* mutation in this population. Based on variants in the ExAC database, we estimated that approximately 1 in 248 individuals are carriers of moderately or severely deleterious variants in GPT2.

LRRC15 Is a Novel Mesenchymal Protein and Stromal Target for Antibody-Drug Conjugates.

Progress in understanding tumor stromal biology has been constrained in part because cancer-associated fibroblasts (CAF) are a heterogeneous population with limited cell-type-specific protein markers. Using RNA expression profiling, we identified the membrane protein leucine-rich repeat containing 15 (LRRC15) as highly expressed in multiple solid tumor indications with limited normal tissue expression. LRRC15 was expressed on stromal fibroblasts in many solid tumors (e.g., breast, head and neck, lung, pancreatic) as well as directly on a subset of cancer cells of mesenchymal origin (e.g., sarcoma, melanoma, glioblastoma). LRRC15 expression was induced by TGFß on activated fibroblasts (αSMA+) and on mesenchymal stem cells. These collective findings suggested LRRC15 as a novel CAF and mesenchymal marker with utility as a therapeutic target for the treatment of cancers with LRRC15-positive stromal desmoplasia or cancers of mesenchymal origin. ABBV-085 is a monomethyl auristatin E (MMAE)-containing antibody-drug conjugate (ADC) directed against LRRC15, and it demonstrated robust preclinical efficacy against LRRC15 stromal-positive/cancer-negative, and LRRC15 cancer-positive models as a monotherapy, or in combination with standard-of-care therapies. ABBV-085's unique mechanism of action relied upon the cell-permeable properties of MMAE to preferentially kill cancer cells over LRRC15-positive CAF while also increasing immune infiltrate (e.g., F4/80+ macrophages) in the tumor microenvironment. In summary, these findings validate LRRC15 as a novel therapeutic target in multiple solid tumor indications and support the ongoing clinical development of the LRRC15-targeted ADC ABBV-085.Significance: These findings identify LRRC15 as a new marker of cancer-associated fibroblasts and cancers of mesenchymal origin and provide preclinical evidence for the efficacy of an antibody-drug conjugate targeting the tumor stroma. Cancer Res; 78(14); 4059-72. ©2018 AACR.

Effects of Drought on Nutrient Uptake and the Levels of Nutrient-Uptake Proteins in Roots of Drought-Sensitive and -Tolerant Grasses.

Climate change will increase drought in many regions of the world. Besides decreasing productivity, drought also decreases the concentration (%) of nitrogen (N) and phosphorous (P) in plants. We investigated if decreases in nutrient status during drought are correlated with decreases in levels of nutrient-uptake proteins in roots, which has not been quantified. Drought-sensitive (Hordeum vulgare, Zea mays) and -tolerant grasses (Andropogon gerardii) were harvested at mid and late drought, when we measured biomass, plant %N and P, root N- and P-uptake rates, and concentrations of major nutrient-uptake proteins in roots (NRT1 for NO3, AMT1 for NH4, and PHT1 for P). Drought reduced %N and P, indicating that it reduced nutrient acquisition more than growth. Decreases in P uptake with drought were correlated with decreases in both concentration and activity of P-uptake proteins, but decreases in N uptake were weakly correlated with levels of N-uptake proteins. Nutrient-uptake proteins per gram root decreased despite increases per gram total protein, because of the larger decreases in total protein per gram. Thus, drought-related decreases in nutrient concentration, especially %P, were likely caused, at least partly, by decreases in the concentration of root nutrient-uptake proteins in both drought-sensitive and -tolerant species.

Meeting Report: Tissue-based Image Analysis.

Quantitative image analysis (IA) is a rapidly evolving area of digital pathology. Although not a new concept, the quantification of histological features on photomicrographs used to be cumbersome, resource-intensive, and limited to specialists and specialized laboratories. Recent technological advances like highly efficient automated whole slide digitizer (scanner) systems, innovative IA platforms, and the emergence of pathologist-friendly image annotation and analysis systems mean that quantification of features on histological digital images will become increasingly prominent in pathologists' daily professional lives. The added value of quantitative IA in pathology includes confirmation of equivocal findings noted by a pathologist, increasing the sensitivity of feature detection, quantification of signal intensity, and improving efficiency. There is no denying that quantitative IA is part of the future of pathology; however, there are also several potential pitfalls when trying to estimate volumetric features from limited 2-dimensional sections. This continuing education session on quantitative IA offered a broad overview of the field; a hands-on toxicologic pathologist experience with IA principles, tools, and workflows; a discussion on how to apply basic stereology principles in order to minimize bias in IA; and finally, a reflection on the future of IA in the toxicologic pathology field.

A "Prozone-Like" Effect Influences the Efficacy of the Monoclonal Antibody ABT-700 against the Hepatocyte Growth Factor Receptor.

ABT-700 is a therapeutic antibody against the hepatocyte growth factor receptor (MET). At doses or regimens that lead to exposures exceeding optimum in vivo, the efficacy of ABT-700 is unexpectedly reduced. We hypothesized that this reduction in efficacy was due to a "prozone-like" effect in vivo. A prozone-like effect, which is a reduction in efficacy beyond optimum exposure, is caused due a mechanism similar to the generation of false negative flocculation tests by excessive antibody titres. In vitro, we demonstrate that at higher ABT-700 concentrations, this "prozone-like" effect is mediated by a progressive conversion from bivalent to ineffective monovalent binding of the antibody. In vivo, the efficacy of ABT-700 is dependent on an optimum range of exposure as well. Our data suggest that the "prozone-like" effect is operative and independent of target expression. ABT-700 dose, regimen, exposure, and tumor burden are interdependent variables influencing the "prozone-like" effect and mediating and in vivo efficacy. By optimization of dosage and regimen we demonstrate that the "prozone-like" effect can be alleviated and ABT-700 efficacy at varying tumor loads can be further extended in combination with cisplatin. Our results suggest that optimization of exposure taking tumor burden into account may alleviate "prozone-like" effects without compromising efficacy.

Viral epitope-specific T cell responses induced in chronic, hepatitis C virus-infected patients.

BACKGROUND: Approximate 180 million people worldwide are infected with hepatitis C virus (HCV). Historically, vaccination has been the most effective strategy for controlling infections of such major health concern. Therapeutic vaccine strategies for HCV, however, have demonstrated negligible success. AIM: Demonstrate the ability of highly-conserved viral epitopes to overcome the immune dysfunction often associated with chronic HCV infections. METHODS: T cells from five chronic, HCV-infected patients were immunophenotyped by flow cytometry. The ex vivo T cell responses to highly-conserved viral epitopes were assessed by ELISpot assay and cytokine bead array analysis. RESULTS: Both HLA-DRB-1- and HLA-A2-restricted viral epitopes induced specific, TH1-type cytokine production by T cells derived from the patients. Induction occurred despite expression of cell-surface inhibitory molecules and the presence of regulatory T cells. CONCLUSION: These findings support the potential ability of a broad, multi-epitope-based therapeutic vaccine to elicit virus-specific immune responses in chronic hepatitis C virus-infected patients.