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1.
Crit Rev Food Sci Nutr ; : 1-24, 2024 May 27.
Article in English | MEDLINE | ID: mdl-38803274

ABSTRACT

Adult humans generally experience a 0.5-1%/year loss in whole-body skeletal muscle mass and a reduction of muscle strength by 1.5-5%/year beginning at the age of 50 years. This results in sarcopenia (aging-related progressive losses of skeletal muscle mass and strength) that affects 10-16% of adults aged ≥ 60 years worldwide. Concentrations of some amino acids (AAs) such as branched-chain AAs, arginine, glutamine, glycine, and serine are reduced in the plasma of older than young adults likely due to insufficient protein intake, reduced protein digestibility, and increased AA catabolism by the portal-drained viscera. Acute, short-term, or long-term administration of some of these AAs or a mixture of proteinogenic AAs can enhance blood flow to skeletal muscle, activate the mechanistic target of rapamycin cell signaling pathway for the initiation of muscle protein synthesis, and modulate the metabolic activity of the muscle. In addition, some AA metabolites such as taurine, ß-alanine, carnosine, and creatine have similar physiological effects on improving muscle mass and function in older adults. Long-term adequate intakes of protein and the AA metabolites can aid in mitigating sarcopenia in elderly adults. Appropriate combinations of animal- and plant-sourced foods are most desirable to maintain proper dietary AA balance.

2.
Adv Exp Med Biol ; 1446: 135-154, 2024.
Article in English | MEDLINE | ID: mdl-38625527

ABSTRACT

The hair and skin of domestic cats or dogs account for 2% and 12-24% of their body weight, respectively, depending on breed and age. These connective tissues contain protein as the major constituent and provide the first line of defense against external pathogens and toxins. Maintenance of the skin and hair in smooth and elastic states requires special nutritional support, particularly an adequate provision of amino acids (AAs). Keratin (rich in cysteine, serine and glycine) is the major protein both in the epidermis of the skin and in the hair. Filaggrin [rich in some AAs (e.g., serine, glutamate, glutamine, glycine, arginine, and histidine)] is another physiologically important protein in the epidermis of the skin. Collagen and elastin (rich in glycine and proline plus 4-hydroxyproline) are the predominant proteins in the dermis and hypodermis of the skin. Taurine and 4-hydroxyproline are abundant free AAs in the skin of dogs and cats, and 4-hydroxyproline is also an abundant free AA in their hair. The epidermis of the skin synthesizes melanin (the pigment in the skin and hair) from tyrosine and produces trans-urocanate from histidine. Qualitative requirements for proteinogenic AAs are similar between cats and dogs but not identical. Both animal species require the same AAs to nourish the hair and skin but the amounts differ. Other factors (e.g., breeds, coat color, and age) may affect the requirements of cats or dogs for nutrients. The development of a healthy coat, especially a black coat, as well as healthy skin critically depends on AAs [particularly arginine, glycine, histidine, proline, 4-hydroxyproline, and serine, sulfur AAs (methionine, cysteine, and taurine), phenylalanine, and tyrosine] and creatine. Although there are a myriad of studies on AA nutrition in cats and dogs, there is still much to learn about how each AA affects the growth, development and maintenance of the hair and skin. Animal-sourced foodstuffs (e.g., feather meal and poultry by-product meal) are excellent sources of the AAs that are crucial to maintain the normal structure and health of the skin and hair in dogs and cats.


Subject(s)
Cat Diseases , Dog Diseases , Cats , Dogs , Animals , Amino Acids , Histidine , Cysteine , Hydroxyproline , Hair , Glycine , Tyrosine , Taurine , Serine , Proline , Arginine
3.
Adv Exp Med Biol ; 1446: 15-38, 2024.
Article in English | MEDLINE | ID: mdl-38625523

ABSTRACT

As for other mammals, the digestive system of dogs (facultative carnivores) and cats (obligate carnivores) includes the mouth, teeth, tongue, pharynx, esophagus, stomach, small intestine, large intestine, and accessory digestive organs (salivary glands, pancreas, liver, and gallbladder). These carnivores have a relatively shorter digestive tract but longer canine teeth, a tighter digitation of molars, and a greater stomach volume than omnivorous mammals such as humans and pigs. Both dogs and cats have no detectable or a very low activity of salivary α-amylase but dogs, unlike cats, possess a relatively high activity of pancreatic α-amylase. Thus, cats select low-starch foods but dogs can consume high-starch diets. In contrast to many mammals, the vitamin B12 (cobalamin)-binding intrinsic factor for the digestion and absorption of vitamin B12 is produced in: (a) dogs primarily by pancreatic ductal cells and to a lesser extent the gastric mucosa; and (b) cats exclusively by the pancreatic tissue. Amino acids (glutamate, glutamine, and aspartate) are the main metabolic fuels in enterocytes of the foregut. The primary function of the small intestine is to digest and absorb dietary nutrients, and its secondary function is to regulate the entry of dietary nutrients into the blood circulation, separate the external from the internal milieu, and perform immune surveillance. The major function of the large intestine is to ferment undigested food (particularly fiber and protein) and to absorb water, short-chain fatty acids (serving as major metabolic fuels for epithelial cells of the large intestine), as well as vitamins. The fermentation products, water, sloughed cells, digestive secretions, and microbes form feces and then pass into the rectum for excretion via the anal canal. The microflora influences colonic absorption and cell metabolism, as well as feces quality. The digestive tract is essential for the health, survival, growth, and development of dogs and cats.


Subject(s)
Cat Diseases , Dog Diseases , Humans , Cats , Dogs , Animals , Swine , Mouth , Vitamins , Mammals , Starch , Water
4.
Res Sq ; 2024 Mar 06.
Article in English | MEDLINE | ID: mdl-38496632

ABSTRACT

Radiotherapy (RT) and anti-PD-L1 synergize to enhance local and distant (abscopal) tumor control. However, clinical results in humans have been variable. With the goal of improving clinical outcomes, we investigated the underlying synergistic mechanism focusing on a CD8+ PD-1+ Tcf-1+ stem-like T cell subset in the tumor-draining lymph node (TdLN). Using murine melanoma models, we found that RT + anti-PD-L1 induces a novel differentiation program in the TdLN stem-like population which leads to their expansion and differentiation into effector cells within the tumor. Our data indicate that optimal synergy between RT + anti-PD-L1 is dependent on the TdLN stem-like T cell population as either blockade of TdLN egress or specific stem-like T cell depletion reduced tumor control. Together, these data demonstrate a multistep stimulation of stem-like T cells following combination therapy which is initiated in the TdLN and completed in the tumor.

5.
Front Plant Sci ; 14: 1177844, 2023.
Article in English | MEDLINE | ID: mdl-37139105

ABSTRACT

Micronutrient deficiencies caused by malnutrition and hidden hunger are a growing concern worldwide, exacerbated by climate change, COVID-19, and conflicts. A potentially sustainable way to mitigate such challenges is the production of nutrient-dense crops through agronomic biofortification techniques. Among several potential target crops, microgreens are considered suitable for mineral biofortification because of their short growth cycle, high content of nutrients, and low level of anti-nutritional factors. A study was conducted to evaluate the potential of zinc (Zn) biofortification of pea and sunflower microgreens via seed nutri-priming, examining the effect of different Zn sources (Zn sulfate, Zn-EDTA, and Zn oxide nanoparticles) and concentrations (0, 25, 50, 100, and 200 ppm) on microgreen yield components; mineral content; phytochemical constituents such as total chlorophyll, carotenoids, flavonoids, anthocyanin, and total phenolic compounds; antioxidant activity; and antinutrient factors like phytic acid. Treatments were arranged in a completely randomized factorial block design with three replications. Seed soaked in a 200 ppm ZnSO4 solution resulted in higher Zn accumulation in both peas (126.1%) and sunflower microgreens (229.8%). However, an antagonistic effect on the accumulation of other micronutrients (Fe, Mn, and Cu) was seen only in pea microgreens. Even at high concentrations, seed soaking in Zn-EDTA did not effectively accumulate Zn in both microgreens' species. ZnO increased the chlorophyll, total phenols, and antioxidant activities compared to Zn-EDTA. Seed soaking in ZnSO4 and ZnO solutions at higher concentrations resulted in a lower phytic acid/Zn molar ratio, suggesting the higher bioaccessibility of the biofortified Zn in both pea and sunflower microgreens. These results suggest that seed nutrient priming is feasible for enriching pea and sunflower microgreens with Zn. The most effective Zn source was ZnSO4, followed by ZnO. The optimal concentration of Zn fertilizer solution should be selected based on fertilizer source, target species, and desired Zn-enrichment level.

6.
Nature ; 611(7934): 139-147, 2022 11.
Article in English | MEDLINE | ID: mdl-36044993

ABSTRACT

Severe SARS-CoV-2 infection1 has been associated with highly inflammatory immune activation since the earliest days of the COVID-19 pandemic2-5. More recently, these responses have been associated with the emergence of self-reactive antibodies with pathologic potential6-10, although their origins and resolution have remained unclear11. Previously, we and others have identified extrafollicular B cell activation, a pathway associated with the formation of new autoreactive antibodies in chronic autoimmunity12,13, as a dominant feature of severe and critical COVID-19 (refs. 14-18). Here, using single-cell B cell repertoire analysis of patients with mild and severe disease, we identify the expansion of a naive-derived, low-mutation IgG1 population of antibody-secreting cells (ASCs) reflecting features of low selective pressure. These features correlate with progressive, broad, clinically relevant autoreactivity, particularly directed against nuclear antigens and carbamylated proteins, emerging 10-15 days after the onset of symptoms. Detailed analysis of the low-selection compartment shows a high frequency of clonotypes specific for both SARS-CoV-2 and autoantigens, including pathogenic autoantibodies against the glomerular basement membrane. We further identify the contraction of this pathway on recovery, re-establishment of tolerance standards and concomitant loss of acute-derived ASCs irrespective of antigen specificity. However, serological autoreactivity persists in a subset of patients with postacute sequelae, raising important questions as to the contribution of emerging autoreactivity to continuing symptomology on recovery. In summary, this study demonstrates the origins, breadth and resolution of autoreactivity in severe COVID-19, with implications for early intervention and the treatment of patients with post-COVID sequelae.


Subject(s)
Autoantibodies , B-Lymphocytes , COVID-19 , Humans , Autoantibodies/immunology , B-Lymphocytes/immunology , B-Lymphocytes/pathology , COVID-19/immunology , COVID-19/pathology , COVID-19/physiopathology , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity , Immunoglobulin G/immunology , Single-Cell Analysis , Autoantigens/immunology , Basement Membrane/immunology , Post-Acute COVID-19 Syndrome
7.
J Am Pharm Assoc (2003) ; 62(1): 49-54, 2022.
Article in English | MEDLINE | ID: mdl-34736865

ABSTRACT

BACKGROUND: Access to naloxone is a primary public health strategy to prevent opioid overdose death. Factors associated with primary medication nonadherence (PMN) to naloxone are underreported in the literature. OBJECTIVE: The objective of this study was to evaluate naloxone dispensing trends and PMN in a community pharmacy setting. METHODS: This retrospective analysis included patients of a community pharmacy chain in Maine and New Hampshire (57 and 29 pharmacy locations, respectively) for whom a claim for a naloxone prescription was billed between January 1, 2019, and July 31, 2020. RESULTS: A total of 2152 patients associated with 2606 naloxone claims were identified for analysis. A majority of the subjects were women (52.7%) and the mean age of all the subjects was 46.4 ± 16.0 years. Of the 2606 naloxone claims, 565 prescriptions were returned to stock and never dispensed to the patient for a PMN rate of 21.7%. Gender and age were not associated with naloxone PMN. Factors associated with naloxone PMN were urban location [x2(1) = 12.49, P = 0.0004], concomitant opioid analgesic [x2(1) = 4.56, P = 0.0328], and payment method [x2(4) = 251.07, P < 0.0001]. Regarding payment method, nonadherence was higher among cash (138 of 386, 35.8%) and private insurance (191 of 455, 42.0%) transactions whereas lower among Medicare (132 of 681, 19.4%) and Medicaid (89 of 899, 9.9%) transactions. Concomitant buprenorphine [x2(1) = 44.57, P < 0.0001] and the use of a naloxone standing order [x2(1) = 4.79, P = 0.0162] were associated with primary adherence to take-home naloxone. CONCLUSION: A notable portion of naloxone prescribed and filled in the community pharmacy setting was never obtained by the patient. Factors associated with PMN in this study included geographic location, use of a standing order, concomitant prescriptions for buprenorphine or opioid analgesic medications, and payment method. Underlying causes of PMN must be addressed (e.g., removing financial barriers and optimizing the use of standing orders) to increase naloxone access for persons at risk of opioid overdose.


Subject(s)
Drug Overdose , Opioid-Related Disorders , Pharmacies , Adult , Aged , Drug Overdose/drug therapy , Drug Overdose/prevention & control , Female , Humans , Male , Medicare , Medication Adherence , Middle Aged , Naloxone/therapeutic use , Narcotic Antagonists/therapeutic use , Opioid-Related Disorders/drug therapy , Retrospective Studies , United States
8.
Plant Signal Behav ; 15(6): 1758455, 2020 06 02.
Article in English | MEDLINE | ID: mdl-32351167

ABSTRACT

Iron (Fe) is a mineral nutrient and a metal cofactor essential for plants. Iron limitation can have detrimental effects on plant growth and development, while excess iron inside plant cells leads to oxidative damage. As a result, plants have evolved complex regulatory networks to respond to fluctuations in cellular iron concentrations. The mechanisms that regulate these responses however, are not fully understood. Heterologous expression of an Arabidopsis thaliana monothiol glutaredoxin S17 (GRXS17) suppresses the over-accumulation of iron in the Saccharomyces cerevisiae Grx3/Grx4 mutant and disruption of GRXS17 causes plant sensitivity to exogenous oxidants and iron deficiency stress. GRXS17 may act as an important regulator in the plant's ability to respond to iron deficiency stress and maintain redox homeostasis. Here, we extend this investigation by analyzing iron-responsive gene expression of the Fer-like iron deficiency-induced transcription factor (FIT) network (FIT, IRT1, FRO1, and FRO2) and the bHLH transcription factor POPEYE (PYE) network (PYE, ZIF1, FRO3, NAS4, and BTS) in GRXS17 KO plants and wildtype controls grown under iron sufficiency and deficiency conditions. Our findings suggest that GRXS17 is required for tolerance to iron deficiency, and plays a negative regulatory role under conditions of iron sufficiency.


Subject(s)
Arabidopsis/metabolism , Glutaredoxins/metabolism , Iron/metabolism , Arabidopsis/genetics , Arabidopsis Proteins/metabolism , Homeostasis , Plants, Genetically Modified/genetics , Plants, Genetically Modified/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism
9.
G3 (Bethesda) ; 10(5): 1511-1520, 2020 05 04.
Article in English | MEDLINE | ID: mdl-32132167

ABSTRACT

Simple sugars are the essential foundation to plant life, and thus, their production, utilization, and storage are highly regulated processes with many complex genetic controls. Despite their importance, many of the genetic and biochemical mechanisms remain unknown or uncharacterized. Sorghum, a highly productive, diverse C4 grass important for both industrial and subsistence agricultural systems, has considerable phenotypic diversity in the accumulation of nonstructural sugars in the stem. We use this crop species to examine the genetic controls of high levels of sugar accumulation, identify genetic mechanisms for the accumulation of nonstructural sugars, and link carbon allocation with iron transport. We identify a species-specific tandem duplication event controlling sugar accumulation using genome-wide association analysis, characterize multiple allelic variants causing increased sugar content, and provide further evidence of a putative neofunctionalization event conferring adaptability in Sorghum bicolor Comparative genomics indicate that this event is unique to sorghum which may further elucidate evolutionary mechanisms for adaptation and divergence within the Poaceae. Furthermore, the identification and characterization of this event was only possible with the continued advancement and improvement of the reference genome. The characterization of this region and the process in which it was discovered serve as a reminder that any reference genome is imperfect and is in need of continual improvement.


Subject(s)
Sorghum , Carbohydrates , Genome, Plant , Genome-Wide Association Study , Poaceae/genetics , Sorghum/genetics
10.
Transgend Health ; 5(3): 166-172, 2020 Sep.
Article in English | MEDLINE | ID: mdl-33644310

ABSTRACT

Objectives: With expanding coverage of gender-affirming care in the United States, many insurers default to the World Professional Association for Transgender Health (WPATH) Standards of Care 7 (SOC 7) to establish eligibility requirements for surgery coverage. Informed by bariatric and transplant surgery evaluation models, the Mount Sinai Center for Transgender Medicine and Surgery (CTMS) developed patient-centered criteria to assess readiness for surgery, focusing on concerns that could impair recovery. To make recommendations for the next version of the WPATH SOC, SOC 8, we compared Mount Sinai patient-centered surgical readiness criteria with the WPATH SOC 7 criteria. Methods: Data were extracted from a deidentified data set developed as part the quality dashboard for CTMS. The data set included all patients seeking vaginoplasty who were evaluated by a single mental health provider, from July 2016 through August 2018, and who completed the full CTMS assessment. The number of patients eligible for surgery based on the Mount Sinai CTMS criteria was compared with the number of patients eligible for surgery according to WPATH SOC 7 criteria. Results: Of 139 patients identified, 63 (45%) were ready for surgery immediately based on the Mount Sinai patient-centered model. By contrast, only 21 (15%) out of the 139 met criteria for surgery based on WPATH SOC 7. Fifty patients (40%) were ready for surgery as per Mount Sinai patient-centered readiness review but not WPATH criteria. Conclusion: An assessment designed to better prepare patients for surgery may also result in fewer barriers to care than existing criteria used by insurance companies in the United States.

11.
Front Plant Sci ; 10: 1449, 2019.
Article in English | MEDLINE | ID: mdl-31850005

ABSTRACT

Iron (Fe) is an essential nutrient for virtually all organisms, where it functions in critical electron transfer processes, like those involved in respiration. Photosynthetic organisms have special requirements for Fe due to its importance in photosynthesis. While the importance of Fe for mitochondria- and chloroplast-localized processes is clear, our understanding of the molecular mechanisms that underlie the trafficking of Fe to these compartments is not complete. Here, we describe the Arabidopsis mitochondrial iron transporters, MIT1 and MIT2, that belong to the mitochondrial carrier family (MCF) of transport proteins. MIT1 and MIT2 display considerable homology with known mitochondrial Fe transporters of other organisms. Expression of MIT1 or MIT2 rescues the phenotype of the yeast mrs3mrs4 mutant, which is defective in mitochondrial iron transport. Although the Arabidopsis mit1 and mit2 single mutants do not show any significant visible phenotypes, the double mutant mit1mit2 displays embryo lethality. Analysis of a mit1 -- /mit2 + - line revealed that MIT1 and MIT2 are essential for iron acquisition by mitochondria and proper mitochondrial function. In addition, loss of MIT function results in mislocalization of Fe, which in turn causes upregulation of the root high affinity Fe uptake pathway. Thus, MIT1 and MIT2 are required for the maintenance of both mitochondrial and whole plant Fe homeostasis, which, in turn, is important for the proper growth and development of the plant.

12.
Oncoimmunology ; 7(7): e1440930, 2018.
Article in English | MEDLINE | ID: mdl-29900046

ABSTRACT

The combination of CTLA-4 blockade ipilimumab (Ipi) with VEGF-A blocking antibody bevacizumab (Bev) has demonstrated favorable clinical outcomes in patients with advanced melanoma. Galectin-3 (Gal-3) plays a prominent role in tumor growth, metastasis, angiogenesis, and immune evasion. Here we report that Ipi plus Bev (Ipi-Bev) therapy increased Gal-3 antibody titers by 50% or more in approximately one third of treated patients. Antibody responses to Gal-3 were associated with higher complete and partial responses and better overall survival. Ipi alone also elicited antibody responses to Gal-3 at a frequency comparable to the Ipi-Bev combination. However, an association of elicited antibody responses to Gal-3 with clinical outcomes was not observed in Ipi alone treated patients. In contrast to being neutralized in Ipi-Bev treated patients, circulating VEGF-A increased by 100% or more in a subset of patients after Ipi treatment, with most having progressive disease. Among the Ipi treated patients with therapy-induced Gal-3 antibody increases, circulating VEGF-A was increased in 3 of 6 nonresponders but in none of 4 responders as a result of treatment. Gal-3 antibody responses occurred significantly less frequently (3.2%) in a cohort of patients receiving PD-1 blockade where high pre-treatment serum Gal-3 was associated with reduced OS and response rates. Our findings suggest that anti-CTLA-4 elicited humoral immune responses to Gal-3 in melanoma patients which may contribute to the antitumor effect in the presence of an anti-VEGF-A combination. Furthermore, pre-treatment circulating Gal-3 may potentially have prognostic and predictive value for immune checkpoint therapy.

13.
Leuk Lymphoma ; 59(4): 837-843, 2018 04.
Article in English | MEDLINE | ID: mdl-28782395

ABSTRACT

Fludarabine and melphalan (Flu/Mel) has emerged as a more tolerable chemotherapy-based conditioning regimen compared with busulfan and cyclophosphamide (Bu/Cy) for allogeneic stem cell transplant (allo-hematopoietic stem cell transplantation (HSCT)) patients with acute myelogenous leukemia (AML). We conducted a retrospective review of a single-institution database including patients with AML who received allo-HSCT following conditioning with Mel/Flu or Bu/Cy-based regimens. We performed descriptive statistical analysis to examine patient demographics and clinical outcomes. We identified 156 patients meeting criteria between 2005 and 2014. Overall, patients conditioned with Bu/Cy were significantly younger, but more likely to be treated in an earlier era than those receiving Flu/Mel. Regimen choice was not associated with relapse rates (RR), relapse-free survival (RFS), or overall survival (OS) on both univariate and multivariable analyses. Bu/Cy was associated with increased non-relapse mortality (NRM) on multivariable analysis. These findings demonstrate that Flu/Mel provides non-inferior disease control and could be an appropriate regimen for selected patients.


Subject(s)
Graft vs Host Disease/prevention & control , Hematopoietic Stem Cell Transplantation/adverse effects , Leukemia, Myeloid, Acute/therapy , Myeloablative Agonists/therapeutic use , Transplantation Conditioning/methods , Adult , Age Factors , Busulfan/therapeutic use , Cyclophosphamide/therapeutic use , Disease-Free Survival , Female , Follow-Up Studies , Humans , Leukemia, Myeloid, Acute/mortality , Male , Melphalan/therapeutic use , Middle Aged , Patient Selection , Retrospective Studies , Transplantation, Homologous/adverse effects , Treatment Outcome , Vidarabine/analogs & derivatives , Vidarabine/therapeutic use
14.
Cell Rep ; 20(8): 1921-1935, 2017 Aug 22.
Article in English | MEDLINE | ID: mdl-28834754

ABSTRACT

DNA double-strand break (DSB) repair by homologous recombination (HR) is initiated by CtIP/MRN-mediated DNA end resection to maintain genome integrity. SAMHD1 is a dNTP triphosphohydrolase, which restricts HIV-1 infection, and mutations are associated with Aicardi-Goutières syndrome and cancer. We show that SAMHD1 has a dNTPase-independent function in promoting DNA end resection to facilitate DSB repair by HR. SAMHD1 deficiency or Vpx-mediated degradation causes hypersensitivity to DSB-inducing agents, and SAMHD1 is recruited to DSBs. SAMHD1 complexes with CtIP via a conserved C-terminal domain and recruits CtIP to DSBs to facilitate end resection and HR. Significantly, a cancer-associated mutant with impaired CtIP interaction, but not dNTPase-inactive SAMHD1, fails to rescue the end resection impairment of SAMHD1 depletion. Our findings define a dNTPase-independent function for SAMHD1 in HR-mediated DSB repair by facilitating CtIP accrual to promote DNA end resection, providing insight into how SAMHD1 promotes genome integrity.


Subject(s)
DNA End-Joining Repair , Homologous Recombination , SAM Domain and HD Domain-Containing Protein 1/genetics , DNA Breaks, Double-Stranded , HCT116 Cells , HEK293 Cells , HeLa Cells , Humans , MCF-7 Cells , SAM Domain and HD Domain-Containing Protein 1/deficiency , SAM Domain and HD Domain-Containing Protein 1/metabolism , Transfection
15.
Front Plant Sci ; 8: 1045, 2017.
Article in English | MEDLINE | ID: mdl-28674546

ABSTRACT

Iron (Fe) is an essential mineral nutrient and a metal cofactor required for many proteins and enzymes involved in the processes of DNA synthesis, respiration, and photosynthesis. Iron limitation can have detrimental effects on plant growth and development. Such effects are mediated, at least in part, through the generation of reactive oxygen species (ROS). Thus, plants have evolved a complex regulatory network to respond to conditions of iron limitations. However, the mechanisms that couple iron deficiency and oxidative stress responses are not fully understood. Here, we report the discovery that an Arabidopsis thaliana monothiol glutaredoxin S17 (AtGRXS17) plays a critical role in the plants ability to respond to iron deficiency stress and maintain redox homeostasis. In a yeast expression assay, AtGRXS17 was able to suppress the iron accumulation in yeast ScGrx3/ScGrx4 mutant cells. Genetic analysis indicated that plants with reduced AtGRXS17 expression were hypersensitive to iron deficiency and showed increased iron concentrations in mature seeds. Disruption of AtGRXS17 caused plant sensitivity to exogenous oxidants and increased ROS production under iron deficiency. Addition of reduced glutathione rescued the growth and alleviates the sensitivity of atgrxs17 mutants to iron deficiency. These findings suggest AtGRXS17 helps integrate redox homeostasis and iron deficiency responses.

16.
Curr Opin Plant Biol ; 39: 106-113, 2017 10.
Article in English | MEDLINE | ID: mdl-28689052

ABSTRACT

Iron is essential for plant growth and development, but excess iron is cytotoxic. While iron is abundant in soil, it is often a limiting nutrient for plant growth. Consequentially, plants have evolved mechanisms to tightly regulate iron uptake, trafficking and storage. Recent work has contributed to a more comprehensive picture of iron uptake, further elucidating molecular and physiological processes that aid in solubilization of iron and modulation of the root system architecture in response to iron availability. Recent progress in understanding the regulators of the iron deficiency response and iron translocation from root to shoots, and especially to seeds are noteworthy. The molecular bases of iron sensing and signaling are gradually emerging, as well.


Subject(s)
Arabidopsis/metabolism , Iron/metabolism , Plant Roots/metabolism , Plant Shoots/metabolism , Seeds/metabolism
17.
Cancer Immunol Res ; 5(6): 446-454, 2017 06.
Article in English | MEDLINE | ID: mdl-28473314

ABSTRACT

The combination of anti-VEGF blockade (bevacizumab) with immune checkpoint anti-CTLA-4 blockade (ipilimumab) in a phase I study showed tumor endothelial activation and immune cell infiltration that were associated with favorable clinical outcomes in patients with metastatic melanoma. To identify potential immune targets responsible for these observations, posttreatment plasma from long-term responding patients were used to screen human protein arrays. We reported that ipilimumab plus bevacizumab therapy elicited humoral immune responses to galectin-1 (Gal-1), which exhibits protumor, proangiogenesis, and immunosuppressive activities in 37.2% of treated patients. Gal-1 antibodies purified from posttreatment plasma suppressed the binding of Gal-1 to CD45, a T-cell surface receptor that transduces apoptotic signals upon binding to extracellular Gal-1. Antibody responses to Gal-1 were found more frequently in the group of patients with therapeutic responses and correlated with improved overall survival. In contrast, another subgroup of treated patients had increased circulating Gal-1 protein instead, and they had reduced overall survival. Our findings suggest that humoral immunity to Gal-1 may contribute to the efficacy of anti-VEGF and anti-CTLA-4 combination therapy. Gal-1 may offer an additional therapeutic target linking anti-angiogenesis and immune checkpoint blockade. Cancer Immunol Res; 5(6); 446-54. ©2017 AACR.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/pharmacology , Bevacizumab/pharmacology , CTLA-4 Antigen/antagonists & inhibitors , Galectin 1/immunology , Ipilimumab/pharmacology , Melanoma/immunology , Vascular Endothelial Growth Factor A/antagonists & inhibitors , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Bevacizumab/therapeutic use , Humans , Immunity, Humoral/drug effects , Ipilimumab/therapeutic use , Leukocyte Common Antigens/immunology , Melanoma/drug therapy
18.
J Therm Biol ; 65: 1-7, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28343561

ABSTRACT

Medicinal leeches (Hirudo verbana) thermoregulate with respect to their sanguivorous feeding behavior. Immediate postprandial preferences are for warmer than their initial acclimation temperature (Ta, 21°C, Petersen et al. 2011), while unfed leeches have a lower preferred temperature (Tpref, 12.5°C). This may reduce energy expenditure and defer starvation if feeding opportunities are limited. Energetic benefits may have an associated cost if low temperatures reduce mobility and the ability to locate further hosts. These costs could be limited if mobility is unimpaired at low temperatures, or if acclimation can restore locomotor performance to the levels at Ta. The transition from Ta to the unfed Tpref significantly reduced speed and propulsive cycle frequency during swimming, and extension and retraction rates during crawling. Aerobic metabolic rate was also reduced from 0.20±0.03Wkg-1 at Ta to 0.10±0.03Wkg-1 at Tpref. The Q10 values of 1.7-2.9 for energetic and swimming parameters indicate a substantial temperature effect, although part of the decline in swimming performance can be attributed to temperature-related changes in water viscosity. 6 weeks at Ta resulted in no detectable acclimation in locomotor performance or aerobic metabolism. The energetic savings associated with a lower Tpref in unfed leeches effectively doubled the estimated time until depletion of energy reserves. Given that some mobility is still retained at Tpref, and that acclimation is in itself costly, the energetic benefits of selecting cooler temperatures between feedings may outweigh the costs associated with reduced locomotor performance.


Subject(s)
Body Temperature Regulation , Hirudo medicinalis/physiology , Acclimatization , Animals , Cold Temperature , Energy Metabolism , Feeding Behavior , Locomotion , Swimming
19.
Cancer Immunol Res ; 5(1): 17-28, 2017 01.
Article in English | MEDLINE | ID: mdl-28003187

ABSTRACT

Immune checkpoint therapies targeting CTLA-4 and PD-1 have proven effective in cancer treatment. However, the identification of biomarkers for predicting clinical outcomes and mechanisms to overcome resistance remain as critical needs. Angiogenesis is increasingly appreciated as an immune modulator with potential for combinatorial use with checkpoint blockade. Angiopoietin-2 (ANGPT2) is an immune target in patients and is involved in resistance to anti-VEGF treatment with the monoclonal antibody bevacizumab. We investigated the predictive and prognostic value of circulating ANGPT2 in metastatic melanoma patients receiving immune checkpoint therapy. High pretreatment serum ANGPT2 was associated with reduced overall survival in CTLA-4 and PD-1 blockade-treated patients. These treatments also increased serum ANGPT2 in many patients early after treatment initiation, whereas ipilimumab plus bevacizumab treatment decreased serum concentrations. ANGPT2 increases were associated with reduced response and/or overall survival. Ipilimumab increased, and ipilimumab plus bevacizumab decreased, tumor vascular ANGPT2 expression in a subset of patients, which was associated with increased and decreased tumor infiltration by CD68+ and CD163+ macrophages, respectively. In vitro, bevacizumab blocked VEGF-induced ANGPT2 expression in tumor-associated endothelial cells, whereas ANGPT2 increased PD-L1 expression on M2-polarized macrophages. Treatments elicited long-lasting and functional antibody responses to ANGPT2 in a subset of patients receiving clinical benefit. Our findings suggest that serum ANGPT2 may be considered as a predictive and prognostic biomarker for immune checkpoint therapy and may contribute to treatment resistance via increasing proangiogenic and immunosuppressive activities in the tumor microenvironment. Targeting ANGPT2 provides a rational combinatorial approach to improve the efficacy of immune therapy. Cancer Immunol Res; 5(1); 17-28. ©2016 AACR.


Subject(s)
Angiopoietin-2/antagonists & inhibitors , Angiopoietin-2/metabolism , Antineoplastic Agents, Immunological/pharmacology , Biomarkers, Tumor/antagonists & inhibitors , Immunomodulation/drug effects , Neoplasms/immunology , Neoplasms/metabolism , Angiopoietin-2/blood , Antineoplastic Agents, Immunological/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Biomarkers , CTLA-4 Antigen/antagonists & inhibitors , Humans , Macrophages/immunology , Macrophages/metabolism , Macrophages/pathology , Molecular Targeted Therapy , Neoplasms/drug therapy , Neoplasms/mortality , Neovascularization, Pathologic/immunology , Neovascularization, Pathologic/metabolism , Programmed Cell Death 1 Receptor/antagonists & inhibitors , Survival Analysis , Treatment Outcome , Vascular Endothelial Growth Factor A/antagonists & inhibitors
20.
Am J Surg ; 213(6): 1019-1023, 2017 Jun.
Article in English | MEDLINE | ID: mdl-27837903

ABSTRACT

BACKGROUND: Magnetic sphincter augmentation (MSA) is FDA approved for the surgical treatment of GERD. While multiple reports from academic settings exist, we report the early experience from two community-based health systems. METHODS: The first 102 post-trial cases of MSA were reviewed. Outcomes were compared to those in the initial clinical trial. RESULTS: Mean follow-up duration was 7.6 months. GERD medication use decreased from 98% preoperative to 8% postoperative (P<0.001). Median GERD health-related quality of life (HRQL) improved from 27 preoperative to 5 postoperative (P<0.001). Patient satisfaction increased from 8% preoperative to 84% postoperative (P<0.001). Results were similar to the trial data. CONCLUSIONS: MSA is a safe and effective treatment for GERD, with significant improvement in quality of life. GERD-HRQL, medication reduction, operative times, and dysphagia rates were similar to other reports, demonstrating the reproducibility of MSA. Lower dilation rates may be due to refinements in technique and postoperative dietary management.


Subject(s)
Esophageal Sphincter, Lower , Gastroesophageal Reflux/surgery , Magnets , Prostheses and Implants , Adult , Aged , Aged, 80 and over , Female , Health Status , Hospitals, Community , Humans , Male , Middle Aged , Patient Satisfaction , Quality of Life , Retrospective Studies , Treatment Outcome , Young Adult
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