bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of the Orphan Receptors RORα and REV‐Erb α/β in Liver Zonal Gene Regulation
Authors: Schroder Kristofer R , Clinkenbeard Erica , Spear Brett
Published: November 2023

Numerous hepatic metabolic pathways, such as glycolysis and gluconeogenesis, cannot occur in the same cell. To overcome this, opposing pathways are compartmentalized within hepatocytes located within different regions of the liver, a phenomenon called metabolic zonation or zonal regulation. The expression of hepatic genes in different zonal regions is orchestrated by multiple transcription factors. Studies by Benhamouche et al. (Dev. Cell, 10:759) revealed that activation of the β‐catenin signaling pathway, through binding of β‐catenin to TCF4, is required for expression of genes that are active solely in hepatocytes surrounding the central vein (pericentral region). In hepatocytes around the portal triad (periportal region), APC inhibits β‐catenin and prevents expression of pericentral genes. A genome wide study of chromatin occupancy of β‐catenin, TCF4, and the liver transcription factor HNF4α revealed that TCF4 is an opportunistic transcription factor that shifts between interacting with HNF4α in periportal hepatocytes and β‐catenin in pericentral hepatocytes.

Previous transgenic studies in our lab demonstrated that enhancer E3 of the activity of mouse alpha‐fetoprotein (AFP) was active in the adult liver, even though AFP expression is silenced at birth, Interestingly, E3 activity is highly restricted to a single layer of hepatocytes surrounding the central vein, thus providing a system to investigate the molecular basis of pericentral gene expression (Peyton et al, PNAS, 97:10890). Additional studies indicate that E3 activity in pericentral hepatocytes requires β‐catenin signaling, since E3 is no longer active in b‐catenin deficient hepatocytes. Additional in vitro studies indicate that a highly conserved TCF4/β‐catenin binding site at the 3′ end of E3 is required for responsiveness to b‐catenin (Clinkenbeard et al, Hepatology, 56:1892). We have also identified a site at the 5′ end of E3 that binds the related orphan nuclear receptors RORα, Rev‐Erbα, and Rev‐Erbβ. Additional data in cultured cells and mice suggest that RORα is a positive regulator of E3, whereas Rev‐Erbα/β repress E3 activity.

Based on these data, we propose that differential binding of RORa and Rev‐Erbα/β contribute to zonal E3 activity in the adult liver. We proposed that RORa binding is required for E3 activity in pericentral hepatocytes. In contrast, the binding of Rev‐Erbα/β represses E3 activity in periportal regions. To test this, we are using ChIP to evaluate RORα and Rev‐Erbα/β binding to E3 in enriched pericentral and periportal hepatocytes. We will also knock down Rev‐Erbα/β levels in the adult liver and test whether this results in increased expression of E3 transgenes (and other pericentral genes) in periportal regions. In conclusion, we present data that indicates that RORα and Rev‐Erbα/β regulate the zonal expression of AFP through binding to E3.
Zhx2: a potential regulator of sex‐biased liver gene expression
Authors: Nail Alexandra N. , Creasy Kate , Peterson Martha L. , Spear Brett T.
Published: November 2023

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide and is the third leading cause of cancer death overall. In addition, males are known to be more susceptible to HCC. Our lab primarily focuses on genetic regulation within the liver and how dysregulation of particular genes contribute to liver development and disease. We identified a novel regulator of gene expression, Zinc Fingers and Homeoboxes 2 (Zhx2), that has been shown to have potential transcriptional and post‐transcriptional mechanisms of regulation. All previously identified Zhx2 targets, including alpha‐fetoprotein (AFP), H19, and Glypican 3 (Gpc3), are dysregulated in HCC. In order to understand the contribution of Zhx2 to global gene regulation during liver development and disease, our lab developed hepatocyte‐specific and whole body Zhx2 knockout (Zhx2ΔHep and Zhx2−) mice. Using these mouse models, we identified dysregulation of a subset of cytochrome p450 enzymes (CYPs) and sex‐limited protein (C4‐Slp), genes that are well‐known to be expressed in a gender‐biased pattern within the liver. Specifically, the absence of Zhx2 in hepatocytes leads to increased expression of female‐specific CYPs and a decreased expression of C4‐Slp in male mice. Curiously, the majority of female‐specific CYPs that we have identified to be upregulated in the absence of Zhx2, are also upregulated in Stat5b knockout male mice, suggesting there may be a connection between Zhx2 and a previously characterized gender‐specific gene expression control pathway. My central hypothesis is that Zhx2 contributes to sexual‐dimorphic patterns of gene expression in the liver. Currently, we are designing experiments to test how Zhx2 regulates sex‐biased genes in the liver, and whether Zhx2 acts in coordination with previously known male‐biased transcriptional regulators such as Bcl6 and Stat5b. Understanding the role of Zhx2 in gender‐biased gene expression may lead to new insights into the basis for HCC predominance in males.
Regulation of the mRNA reading frame
Authors: Dunham Christine M. , Sunita S. , Dunkle Jack , Maehigashi Tatsuya
Published: November 2023

The ribosome is a massive, universally conserved macromolecular machine responsible for all cellular protein synthesis. The ribosome selects correct tRNAs to decode the mRNA, facilitates peptide bond formation, and then moves the tRNAs through its three functionally distinct tRNA binding sites in a dynamic and exquisitely orchestrated manner. Accurate maintenance of the universal mRNA three‐nucleotide code (or “reading frame”) is critical for correct protein expression but the molecular details of how this is controlled, or deviated from in a programmed manner, are not well understood. The absolute requirement for the precise correlation between the mRNA frame and the correct protein sequence expressed underlies an important fundamental but unanswered question in molecular biology: what regulates the mRNA reading frame? To address this question, we study two examples of defined biological mechanisms that subvert the three‐nucleotide mRNA reading frame and undergo high levels of frameshifting, i.e. movement to a noncanonical reading of the mRNA template. Here we describe two ribosomal frameshift events, a +1 (i.e. four rather than the normal three mRNA nucleotide) reading of the mRNA template by frameshift suppressor tRNAs and a ‐1 (i.e. two mRNA nucleotide) reading of the mRNA template induced by complex mRNA tertiary structures proximal to the surface of the ribosome. Our biochemical and structural results reveal that tRNA distortion and conformational changes of the small ribosomal subunit are induced by frameshift‐prone tRNAs and mRNAs. We propose nonproductive EF‐G interaction with the ribosome results in a pausing of EF‐G‐mediated translocation of the mRNA‐tRNA pair allowing for the shift in a new mRNA frame.

Support or Funding Information

NIH R01GM093278; Pew Biomedical Trusts
A Conserved Family of Proteins Facilitates Nascent Lipid Droplet Budding from the ER
Authors: Choudhary Vineet , Ojha Namrata , Golden Andy , Prinz William A.
Published: November 2023

Lipid droplets (LDs) are found in almost all cells and play central roles in energy and lipid metabolism; it is also becoming clear that LDs have additional functions, including important roles in protein degradation, ER stress, and viral replication. Unlike all other membrane‐bound organelles, LDs are surrounded by a phospholipid monolayer rather than a bilayer. How this unique structure is formed has remained an important unsolved mystery for many years. Quite a number of models of LD biogenesis have been proposed but the simplest and arguably most popular is one that has sometimes been termed the “lens” model. Neutral lipids, triacylglycerols (TAG) and steryl esters (SE) which form the core of all LDs, are synthesized in the ER and it is thought that as these lipids accumulate in the ER bilayer they form a lens (or blister) in the ER that can grow and bud. We visualized nascent LD formation in yeast using electron microscopy (EM)‐tomography and found that the lens model is correct. Lens of neutral lipid approximately 30–60 nm wide were found between the two leaflets of the ER bilayer. This is the first time the beginnings of LD biogenesis have been visualized and resolves a long‐standing question in LD biogenesis. We next asked whether proteins are necessary to facilitate nascent LD budding from the ER and focused on a conserved family of proteins, called fat storage‐inducing transmembrane (FIT) proteins. Yeast has two FITs (called Fit2a and Fit2b) and we found that in cells missing both most LDs are wrapped by the ER membrane and that this is caused by LD budding into the ER lumen rather than the cytosol. The wrapping membrane is not derived from the phagophore or related to autophagy since we found that wrapping still occurred in mutants lacking the FIT proteins and various proteins required for autophagy. The role of FIT proteins in LD budding is conserved; knock down of FIT2 in 3T3 fibroblasts and in C.elegans caused LDs to become wrapped in the ER. Interestingly deletion of the single FIT protein in C. elegans is lethal, suggesting that LD budding is an essential process in this organism. Our findings indicate that nascent LDs form lenses in the ER and that FIT proteins are necessary to promote proper budding of LDs from the ER. The mechanism of how FIT proteins control the directionality of LD budding remains to be investigated.

Support or Funding Information

This work was supported by the Intramural Research Program of the National Institute of Diabetes and Digestive and Kidney Diseases. Vineet Choudhary is supported by fellowship from Swiss National Science Foundation (Grant Nr; PA00P3_145358, P300P3_158454).
ATGL Is Not Required for Oleate Protection from Lipotoxicity in NIH3T3 Cells
Authors: Roelike Lauren , Plasek Leah , Mashek Douglas G. , Listenberger Laura L.
Published: November 2023

The long chain, saturated fatty acid palmitate is toxic to cultured cells. However, co‐supplementation with monounsaturated oleate promotes storage of excess palmitate in lipid droplets and prevents cell death. We tested whether events downstream of lipid storage in lipid droplets contribute to oleate protection from lipotoxicity. Specifically, we asked whether protection from lipotoxicity requires adipose triglyceride lipase (ATGL) or sirtuin 1 (SIRT1) activity. We found that oleate continues to prevent palmitate induction of caspase 3/7 activity in NIH3T3 cells in the presence of ATGListatin, an inhibitor of ATGL. Moreover, oleate and palmitate co‐supplementation does not increase the activity of SIRT1, a transcriptional co‐activator downstream of ATGL, nor does it lead to ATGL‐dependent changes in expression of ACOT1, ACSL1, or CPT1α mRNA. Thus, our results fail to support a role for ATGL in oleate protection from lipotoxicity in NIH3T3 cells. Additional pathways through which oleate protects a cell from lipotoxicity should be explored.

Support or Funding Information

This research was funded by the Arnold and Mabel Beckman Foundation and St. Olaf College CURI.
The Characterization of a Putative Perilipin 5 Splice Variant
Authors: Hardy Cara C , DuBreuil Daniel M , Hubbell Theresa , Tansey John T
Published: November 2023

Lipid droplets, or LDs, are very important and dynamic organelles in cells. LDs are stores of fat for use in metabolism, membrane construction, and signaling. Dysfunction of lipid droplet formation or breakdown can lead to many health risks, such as atherosclerosis and diabetes. Lipid droplet regulation occurs primarily via a dynamic and complex coat of proteins on the surface of the droplet including the perilipins. Perilipin‐5 is a member of the perilipin family of lipid droplet coat proteins and is found primarily in tissues that break down fats for energy, such as heart, liver, and skeletal muscle. We hypothesize that the perilipin 5 gene is differentially spliced into messages that code for different forms of the protein, all of which play roles in lipid metabolism. This work seeks to characterize a novel 35 kDa protein found in mouse which we have termed perilipin‐5B. Western blotting with an anti‐amino terminal perilipin 5 specific antibody showed that perilipin‐5B is expressed in the same tissues as perilipin 5. RT‐PCR showed that multiple messages exist that include intron 8 of the perilipin‐5 gene. Other splice variants of this gene may exist which may give rise to other proteins. Together, these data indicate that perilipin‐5B is a splice variant of perilipin‐5 found in oxidative tissues.
Inhibition of Macrophage CD36 Expression by Tamoxifen—A PPARgamma Dependent Mechanism
Authors: Yu Miao , Jiang Meixiu , Chen Yuanli , Duan Yajun , Han Jihong
Published: November 2023

CD36, a transmembrane glycoprotein, belongs to type B scavenger receptor family. It facilitates macrophage/foam cell formation and development of atherosclerosis. CD36 expression is transcriptionally regulated by peroxisome proliferator‐activated receptor gamma (PPARgamma), a ligand activated nuclear factor. Tamoxifen is a medicine used for treatment of patients with breast cancer for a few decades. Both clinical and basic studies have also demonstrated the cardioprotective effects of tamoxifen. In this study, we determined if tamoxifen can inhibit foam cell formation by inhibiting CD36 expression and the involved mechanisms. We initially observed that tamoxifen inhibited CD36 protein expression in both THP‐1 monocytes and THP‐1/PMA macrophages, and human blood monocyte derived macrophages. Associated with decreased CD36, tamoxifen dramatically reduced accumulated lipid droplets in the cytoplasm of cells and foam cell formation. FACS assay further showed that tamoxifen reduced cell surface CD36 levels. In vivo, administration of tamoxifen reduced CD36 protein expression in peritoneal macrophages and brown/white adipose tissues. Mechanistically, we initially determined that tamoxifen inhibited CD36 expression at the transcriptional level since it reduced CD36 mRNA levels and promoter activity. We further determined that tamoxifen inhibited CD36 expression by inactivating PPARgamma. It blocked PPARgamma‐induced THP‐1/PMA macrophage CD36 expression. In addition, tamoxifen activated ERK1/2 to phosphorylate PPARgamma. The EMSA assay demonstrated that tamoxifen inhibited the binding PPARgamma with the PPAR‐responsive element (PPRE) in CD36 promoter. Finally, we determined that tamoxifen was not able to inhibit CD36 expression in the macrophages lacking PPARgamma expression. Taken together, our study suggests that tamoxifen inhibited CD36 expression through inactivation of PPARgamma pathway and the inhibition of macrophage CD36 expression can be attributed to the anti‐atherogenic properties of tamoxifen.
Mitochondria‐Generated Acetyl‐CoA Regulates Gene Expression in Hepatic Lipid Synthesis
Authors: Patel Mulchand S , Mahmood Saleh , Birkaya Barbara , Rideout Todd C
Published: November 2023

During the absorptive state the liver stores excess glucose as glycogen and synthesizes fatty acids for triglyceride synthesis for export as very low density lipoproteins. For de novo synthesis of fatty acids from glucose, the mitochondrial pyruvate dehydrogenase complex (PDC) plays a gatekeeper's role for generation of the carbon‐flux as acetyl‐CoA. We have shown previously that there was no incorporation of radioactive glucose‐carbon into newly synthesized fatty acids in livers from liver‐specific PDC‐deficient male mice (L‐PDHKO) due to the null mutation of the Pdha1 gene. In the present study, although the postnatal growth of L‐PDHKO mice was largely unaltered, they developed hyperinsulinemia with lower blood glucose levels in the fed state. Serum and liver lipid triglyceride and cholesterol levels remained unaltered in L‐PDHKO mice. To determine the effect of liver‐specific PDC deficiency on lipid and glucose metabolism, we investigated expression of several key genes as well as their upstream regulators in lipid and glucose metabolism. Interestingly, there was significant downregulation of expression of several key genes (such as ATP‐citrate lyase, acetyl‐CoA carboxylase) in the de novo fatty acid synthesis pathway and their upstream regulators (such as LXR, SREBP1, ChREBP). Downregulation of several genes in the metabolism of glucose (glucose‐6‐phosphate dehydrogenase, pyruvate kinase, phosphoenolpyruvate carboxykinase) and fatty acid oxidation (fatty acid transporter, carnitine‐palmitoyl‐CoA transferase‐1) were also observed in livers of L‐PDHKO mice. Interestingly, there was upregulation of lipogenic genes in epididymal adipose tissue from L‐PDHKO mice. Although, the total hepatic acetyl‐CoA content remained unaltered in these mice, modified acetylation profiles of several proteins in the nucleo‐cytoplasmic compartment (including increased level of acetylated histone3lysine9, H3K9) in livers of L‐PDHKO mice suggest an important role of mitochondria‐generated acetyl‐CoA from glucose‐derived pyruvate by PDC in gene expression in hepatic lipid metabolism. This finding has important implications for regulation of hepatic lipid biosynthesis in obesity, type 2 diabetes and non‐alcoholic fatty liver disease.

Support or Funding Information

(Supported in part by NIH Grant DK20478 and Department Fund, The Research Foundation of The State University of New York.)
A Novel Mouse Model with Targeted and Inducible Deletion of Intestinal CTP:Phosphocholine Cytidylyltransferase α
Authors: Kennelly John Paul , van der Veen Jelske , Nelson Randy , da Silva Robin , Kelly Karen , Leonard Kelly‐Ann , Wan Sereana , Jacobs René
Published: November 2023

Phosphatidylcholine (PC) is the primary phospholipid in mammalian cell membranes, bile, lipid droplets and plasma lipoproteins, and also serves as a precursor for signalling molecules. PC is produced from choline by the CDP‐choline (Kennedy) pathway in all nucleated cells, and the enzyme CTP: phosphocholine Cytidylyltransferase (CT) regulates flux through the pathway. CTα is the predominant isoform in most major tissues, including the liver and intestine. CTα is an important regulator of very‐low density lipoprotein (VLDL) and high‐density lipoprotein (HDL) metabolism the liver. CT also functions to maintain the structural integrity of membranes and to incorporate fatty acids into lipid droplets to avoid cell toxicity, roles which may be particularly important in the intestine which sees large quantities of dietary lipid. However, our understanding of the role of CT and PC in intestinal lipid and lipoprotein metabolism is incomplete.

To determine the functional importance of CTα in regulating intestinal lipid and lipoprotein metabolism in vivo, we have generated mice in which we can induce partial (CTα −/+) or complete (CTα −/−) deletion of CTα using a tamoxifen‐inducible Cre‐Lox system. Preliminary data suggest that CTα+/− mice have altered levels of PC in the intestine and impaired chylomicron secretion as compared to controls with normal intestinal CTα activity. Surprisingly, plasma triglyceride was also increased in CTα+/− mice. Future studies will investigate the compensatory mechanisms in the intestine in response to impaired PC supply.

Support or Funding Information

NSERC and CIHR
Valproate increases ceramide levels and induces the unfolded protein response
Authors: Jadhav Shyamalagauri , Russo Sarah , Cowart Ashley , Greenberg Miriam
Published: November 2023

Bipolar disorder (BD), which is characterized by depression and mania, affects about 1% of the world population. Current treatments are effective in only 40–60% of cases and cause severe side effects. Valproic acid (VPA), a branched short‐chain fatty acid, is one of the most widely used drugs for the treatment BD. Although many hypotheses have been postulated to explain the molecular mechanism of action of this drug in BD, the therapeutic mechanism is not understood. This knowledge gap has hampered the development of new drugs to treat this disorder. To identify candidate pathways affected by VPA, we performed a genome wide expression analysis in yeast cells grown in the presence and absence of VPA.

In response to VPA, we observed upregulation of FEN1 and SUR4, encoding fatty acid elongases that catalyze the synthesis of very long chain fatty acids (C24 to C26) required for the synthesis of ceramide. Interestingly, fen1Δ and sur4Δ exhibit VPA sensitivity. VPA also increases levels of ceramides, especially those that contain C24 and C26 fatty acids. Ceramide acts as a signaling molecule that downregulates the expression of amino acid transporters and induces stress by reducing the intracellular levels of amino acids. Consistent with an increase in ceramide, VPA decreases the expression of amino acid transporters. In addition, VPA increases the expression of ER chaperone proteins (markers of UPR) as well as activates the unfolded protein response element (UPRE), suggesting that VPA induces the UPR pathway. In the presence of the ceramide synthase inhibitor fumonisin, the UPR pathway is not induced by VPA, suggesting that VPA induction of the UPR is mediated by ceramide. Studies show that BD patients exhibit a decreased UPR activation, decreased expression of ER chaperone proteins and a (‐116C‐‐>G) polymorphism in XBP1, a key transcription factor that upregulates the UPR. This study identifies the UPR pathway as a potential new target that could be important in the therapeutic action of VPA.
Ca2+‐dependent Pyk2 Activation Destabilizes Endothelial Adherens Junctions by Disrupting Interaction between VE‐PTP and VE‐Cadherin
Authors: Soni Dheeraj , DebRoy Auditi , Wang DongMei , Vogel Stephen M , Tiruppathi Chinnaswamy
Published: November 2023

Expression of vascular endothelial cadherin (VE‐cad) and its interacting protein partner vascular endothelial protein tyrosine phosphatase (VE‐PTP) at endothelial Adherens Junctions (AJs) is vital for endothelial barrier integrity. Previously, we showed that stromal interacting molecule 1 (STIM1)‐activated Ca2+ entry disassembles endothelial AJs to increase vascular permeability. However, the signaling pathways activated secondary to STIM1‐activated Ca2+ entry (i.e., store‐operated Ca2+ entry [SOCE]) in endothelial cells, which mediate the disassembly of endothelial AJs, are not fully understood. Here we provide genetic evidence that SOCE signaling disrupts the association between VE‐cad and VE‐PTP at endothelial AJs by activation of the Ca2+‐dependent tyrosine kinase Pyk2. We generated endothelial cell‐restricted STIM1 knockout (Stim1ΔEC) mice by crossing loxP‐flanked STIM1 (Stim1fl/fl) mice with Cdh5‐Cre transgenic mice. Lung endothelial cells (LECs) from Stim1ΔEC mice showed abrogation of SOCE in response to protease‐activated receptor‐1 (PAR‐1) activation with either thrombin or PAR‐1 agonist peptide (TFLLRNPNDK‐NH2). Further, we observed that PAR‐1‐induced Pyk2 activation (measured by Pyk2 phosphorylation at Tyr‐402) and VE‐PTP inactivation (measured by VE‐PTP phosphorylation) were prevented in LECs of Stim1ΔEC mice. Consistent with these results, PAR‐1 induced VE‐cad phosphorylation was markedly suppressed in LECs from Stim1ΔEC mice. As expected, PAR‐1 activation failed to disassemble endothelial AJs in LECs of Stim1ΔEC mice. Moreover, pharmacological inhibition or silencing of Pyk2 in human lung vascular endothelial cells prevented endothelial AJ disassembly and inactivation of VE‐PTP in response to thrombin. These findings suggest that SOCE signaling regulates endothelial AJs through Pyk2‐mediated inactivation of VE‐PTP.

Support or Funding Information

NIH/HLBI 1R01HL128359‐01
Cloning and expression of cryptochrome proteins from Sunflower and Arabidopsis
Authors: Dyer James , Ahmed Sahar
Published: November 2023

Two cryptochrome proteins, CRY1 and CRY2, occur in plants and animals. CRY1 regulates the circadian clock in a light‐dependent fashion in insects and plants. Also in plants, blue light photoreception can be used to cue developmental signals. Despite much research on the topic, the specific way that the pterin and flavin chromophores function in these proteins is still poorly understood. The goal of this research was to clone and express the Helianthus annuus (Sunflower) and Arabidopsis CRY1 proteins in an E. coli expression system. For the sunflower protein, consensus sequence primers flanking the complete coding region based on known sequences of other dicot plant cryptochromes were used in a 5′ and 3′ Rapid Amplification of cDNA Ends protocol, and the complete CRY1 sequence cloned into a pDEST vector. The sunflower CRY1 was expressed with N‐terminal GST and His tags. The Arabidopsis CRY1 coding sequence was commercially synthesized and cloned into a pDEST vector and expressed with N‐terminal GST and His tags. The expressed fusion proteins were purified using Glutathione agarose or Ni‐NTA affinity chromatography. Purified proteins will be used for structural and functional analysis.
Physicochemical properties and plasma lipid profile of walnut (Tetracapidium conophorum) oil‐based diet in rats
Authors: Fadaka Adewale Oluwaseun , Ajayi Olubunmi
Published: November 2023

Context

Walnuts are widely distributed all over the world, and they are common in Nigeria. On a global basis, walnuts rank second behind almonds in tree nut production. In 2010, global production of walnuts was 1,500,000 t. Walnuts are receiving increasing interest as a healthy foodstuff because their regular consumption has been reported to decrease the risk of coronary heart disease. Therefore, walnuts can be utilized as ingredients of many foodstuffs such as bakery products to enhance the nutrition value and sensory properties of the final product. The physicochemical properties of walnut oil (Tetracapidium conophorum) and the plasma lipid profile were investigated in Wistar rats.

Objective

This study determines the physicochemical properties, fatty acid composition and the effect of Tetracapidiun conophorum oil on the lipid profile of wister rats.

Materials and methods

The rats were assigned into three groups A, B, and C. Group A was the control fed with commercial oil based diet; Group B and C were fed with 5% and 10% walnut oil based diet, respectively. After six weeks of feeding trial, the lipid profile was evaluated.

Result

The physicochemical properties include the Refractive index (1.35), Acid value (1.01), free fatty acid (0.25), Saponification number (191.45) and Relative density with (0.64). The main fatty acids of walnut oil were oleic, linolenic, stearic and palmitic acids. Oleic acid content of the walnut was found to be 67.82 while that of linolenic is 17.06. The result shows that there is no significant difference between the test groups of triglycerides and LDL/HDL ratio but shows a reduction relative to control (P<0.05). Significant decrease was observed in the level of TC, HDL‐C and LDL‐C but there is no change in the test group of HDL‐C. The reduction observed in TC was concentration dependent.

Discussion and Conclusion

As a result, the present study showed that walnut oil could be a potential source of valuable oil which might be used for edible and other industrial applications and may also be useful for the evaluation of dietary information.
Digging into rice diterpenoid biosynthesis
Authors: Peters Reuben
Published: November 2023

Rice (Oryza sativa) is an important crop plant whose susceptibility to disease can critically impact food security. Among the means by which rice resists microbial pathogens is the production of diterpenoid phytoalexins, although the importance of such natural products biosynthesis is not fully understood. My group has taken a systematic approach towards elucidating both the underlying metabolic network and the physiological relevance of the resulting diterpenoids. Our work on diterpenoid metabolism has been based on the extensive sequence information available for rice (i.e., functional genomics), and includes the discovery of relevant biosynthetic gene clusters, as well as development of a synthetic biology approach in which we reconstitute rice metabolic pathways in E. coli, relying on the use of synthetic genes for functional incorporation of cytochrome P450 mono‐oxygenases. Based on our comprehensive map for the early steps mediated by diterpene synthase in rice metabolism, we also are now taking a reverse genetic approach towards elucidating the biological function of the resulting diterpenoid natural products, including the application of genome editing technology. Our most recent results will be discussed.

Support or Funding Information

NIH (GM109773)

USDA‐NIFA‐AFRI (2014‐67013‐21720)
Inositol Hexakisphosphate Induced Tertiary Conformational Transition In Horse Carbonmonoxyhemoglobin
Authors: OMOTOSHO Omolola Elizabeth , Chinedu Shalom N , Okonjo Kehinde
Published: November 2023

The red blood cell of the domestic horse contains two haemoglobin types. The two haemoglobins were separated on a column of carboxymethylcellulose. The equilibrium constant, Kequ, for the reaction of 5,5′‐dithiobis(2‐nitrobenzoate) — DTNB — with the CysF9[93]β sulfhydryl group of each haemoglobin was determined at 25°C as a function of pH. The reactivity of CysF9[93]β is affected by allosteric effectors such as the proton (H+) and inositol hexakisphosphate (inositol‐P6). Between pH 5.6 and 9.0 Kequ decreased by about two to four orders of magnitude, demonstrating that H+ is a heterotropic allosteric effector of haemoglobin with respect to its reaction with DTNB. Inositol‐P6 also decreased Kequ by about two to four orders of magnitude across the experimental pH range. CysF9[93]β exists in two tertiary conformations, r and t, in dynamic equilibrium. Krt, the equilibrium constant for the rt conformational transition, was determined for each of the two horse haemoglobins from an analysis of the pH dependence of Kequ. The calculations from the pH dependence of Kequ showed that the pKa values of the ionisable groups coupled to the DTNB reaction vary between 5.0 and 8.9. The equilibrium constants, Krt, for the r ↔ t tertiary structure transition, were 0.143 ± 0.05 and 0.446 ± 0.22 for the major and minor stripped horse haemoglobins respectively. In the presence of inositol‐P6, Krt for the major and minor were 2.219 ± 0.79 and 2.214 ± 0.83 respectively. The results show that inositol‐P6 increases the relative population of the t tertiary conformation. So, it increases the affinity of CysF9[93]β by changing the relative distribution of two protein conformations.

Support or Funding Information

Covenant University, Ota. Nigeria.
Supply‐ and Demand‐Side Factors Influencing Utilization of Infant and Young Child Feeding Counselling Services in Viet Nam
Authors: Nguyen Phuong , Kim Sunny , Nguyen Tuan , Tran Lan , Hajeebhoy Nemat , Frongillo Edward , Ruel Marie , Rawat Rahul , Menon Purnima
Published: November 2023

Adequate utilization of services is critical to maximize the impact of counselling on infant and young child feeding (IYCF), but little is known about factors affecting utilization. Our study examined supply‐ and demand‐side determinants of the utilization of IYCF counselling services in Viet Nam.

We used survey data from mothers with children <2y (n=1,008) and health staff (n=60) from the evaluation of the Alive & Thrive initiative, which embedded IYCF counseling in Viet Nam's health system. In addition, staff competence and performance during IYCF counseling, including technical and interpersonal communication skills, were observed and rated by trained enumerators.

The percentages of never users, one‐time users, repeat users, and achievers of the recommended minimum number of visits at health facilities were 45.1%, 13.0%, 28.4% and 13.5%, respectively. Multinomial logistic regression showed that of three demand‐generation strategies (invitation cards, billboards, and TV spots), invitation cards were the strongest determinant of one‐time use (OR 5.2, 95% CI: 3.1–8.9), repeated use (OR 10.7, 95% CI: 6.7–17.1), and achievement of minimum visits (OR 12.4, 95% CI: 7.1–21.7). Higher maternal education, being a farmer, and belonging to an ethnic minority were associated with higher utilization, both for one‐time and repeated use. Having a wasted child was associated with greater odds of achieving the minimum recommended number of visits, whereas child stunting and illness were not. Living far from health center was associated with fewer repeated visits. Among supply‐side factors, good counselling skills (OR: 2–2.5) was the most important determinant of any service use, whereas longer employment duration and greater work pressure of health center staff were associated with lower utilization. Population attributable risk estimations showed that an additional 22% of the population would have achieved the minimum number of visits if exposed to three demand‐generation strategies, and would further increase to 28% if the health staff had good counseling skills and low work pressure.

Our study provides evidence that demand‐generation strategies are essential to increase utilization of facility‐based IYCF counselling services in Viet Nam, and may be relevant for increasing and sustaining use of nutrition services in similar contexts.

Support or Funding Information

Funding support from Bill & Melinda Gates Foundation, through Alive & Thrive, managed by FHI360. Additional funding through the CGIAR Research Program on Agriculture for Nutrition and Health, hosted by IFPRI.
The Determinants of Stunting in Children under Five in Madagascar
Authors: Rakotomanana Hasina , Gates Gail , Hildebrand Deana , Stoecker Barbara J.
Published: November 2023

Maternal and child undernutrition plays an important role in the cyclical process of poverty through its negative economic and health consequences on individuals, on the community and ultimately on the nation. Madagascar is among the countries where the prevalence of stunting is dramatically high in children under 5 years old. Despite the fact that nutrition interventions are more successful when they are targeted to specific areas and/or to specific populations, there is limited knowledge about the determinants of child undernutrition in Madagascar. The purpose of this study was to investigate determinants of child stunting in the country. Using the latest Demographic and Health Survey (2009), bivariate and multivariate logistic regressions were performed to determine the variables associated with stunting. A cut‐off at 24 months was used to separate the population into two groups. Data concerning individual, maternal and household characteristics from a total of 4881 children under five years were analyzed. In 2009, 39% of the 1914 children aged 0–23 months and 53% of the 2967 children aged 24–59 months were stunted contributing to the 43.23% total prevalence in the country. The highest prevalence of stunting was observed in the region of Matsiatra Ambony (64.12%) and the lowest in Sofia (18.46%). The model showed that infants of 0–23 months who were severely anemic (OR=3.453), and males (OR=0.717 for girls) were more likely to be stunted. Increasing age among 0–23 month‐olds was significantly associated with stunting (OR=1.068) and length‐for‐age Z scores were also different by regions. Similar results with anemia level (OR=4.054), age (1.018) and region of residence were found in the older group. Additionally, children perceived as small at birth (OR=1.579) and whose parents’ worked on family‐owned land (OR=1.414) were significantly more likely to be stunted. The quality of the home was associated with better height‐for‐age Z scores in children 24–59 months (OR=0.375 compared to rudimentary construction). The results confirmed that determinants of stunting were different for the two age groups. Thus, interventions aiming to address stunting should be different for children aged 0–23 months and 24–59 months.

Support or Funding Information

Supported by Fulbright Program for Foreign Students
Establishing a Biomarker of Cortical Specialisation in infants in The Gambia and UK
Authors: Lloyd‐Fox Sarah , Lee Chuen Wai , Pirazzoli Laura , Blasi Anna , Halliday Drew , Papademetriou Maria , Begus Katarina , Cooper Robert , Darboe Momodou , Prentice Andrew , Moore Sophie E , Austin Topun , Johnson Mark H , Elwell Clare E
Published: November 2023

Brain and nervous system development in human infants during the first 1000 days ‐ which includes pregnancy and the first two years of life ‐ is critical, and risk of compromised development during this time can have a deep impact on physical growth and cognitive function into adulthood. Recent research has shown that under nutrition in infancy is linked to lifelong effects on adult health, however we still have a comparatively poor understanding of how nutrition effects brain development during early life. The development of non‐invasive brain imaging techniques, such as functional near infrared Spectroscopy (fNIRS), has allowed a recent shift in the use of neuroimaging towards the study of the developing brain in situations where this development may be at risk or compromised in some way. Furthermore, objective measures of brain function may provide information that to date has been unavailable with existing behavioural paradigms.

Recent fNIRS research in typically developing infants has shown robust and consistent activation to social vs non‐social visual and auditory stimuli in the inferior frontal, anterior temporal and posterior superior temporal – temporo parietal junction (pST‐TPJ) regions of the cortex. Having established this signature response in infants from 4 to 6 months of age, here we apply this paradigm to the investigation of social responses in infants from the first days of life to the first year in two different settings: urban European and rural Gambian. This is a cross sectional study of infants in the Gambia and UK at 0–2, 4–8 and 12–16 months of age (0–2 months ‐ N = 14 UK & N = 19 Gambia; 4 – 8 mths ‐ N = 64 UK & N = 24 Gambia; 12 – 16 months – N = 15 UK & N = 22 Gambia). Results reveal robust and consistent socially selective responses from 4 – 16 mths of life to both the visual and auditory stimuli. In contrast at 0–2 mths of age a stronger response is evidenced to the non‐social auditory stimuli in the Gambian infants. In ongoing analyses we are investigating whether these brain responses also differ in the 0–2 month olds in the UK.

These findings provide a key biomarker of cortical specialization over the first year of life. We believe this method could be applied to the study of compromised development in global health research where infants are exposed to a broad range of adversity early in life including poverty, malnourishment and recurrent infections.

Support or Funding Information

Bill and Melinda Gates Foundation, Medical Research Council UK
Maternal Nutritional Status and Dietary Diversity in Ghana
Authors: Gyenes Natalie , Agbemafle Isaac , Zotor Francis , Duggan Christopher , Willett Walter , Fawzi Wafaie , Ellahi Basma
Published: November 2023

Background

Eating from a limited number of food groups which are mainly micronutrient poor starchy staples contributes to the burden of malnutrition and increases the risk for obesity and its related non‐communicable diseases. This study assessed dietary patterns and diversity among women in rural and semi‐rural areas in Ghana due to the paucity of data for those areas outside the cities.

Methods

A cross‐sectional survey was undertaken among 1185 households in Eastern, Volta and Brong Ahafo regions of Ghana. Households with children under age 5 years were sampled. Women were surveyed at the household level using a pretested semi‐structured questionnaire. Dietary intake patterns and dietary diversity of the women were assessed using a 24‐hour recall. Pearson's chi‐square was used to determine associations between region and dietary patterns and diversity.

Results

Among the 1185 women recruited, 21.3%, 24.5% and 54.3% were from Brong Ahafo, Eastern and Volta regions, respectively. The mean ± SD age of the women was 38.4 ± 15.1 years. Drinks frequently consumed by the women were tealeaf and cocoa drink and this varied across the regions. The women consumed high amounts of assorted fats and oils but nutritional supplement use was reported by only 7.3% of the women. About More than 70% of the women in Volta region and 96% of the women in Brong Ahafo regions had ever used iodated salt but 60% of the women from Eastern region had never used iodated salt. The women (71.5%) consumed foods from roots and tubers, 82.4% consumed fish and sea foods and 85.7% consumed cereals and these consumption patterns varied from region to region. Whereas 98.1% of the caregivers consumed some sort of vegetables, only 13.4% consumed fruits of any kind. Milk and milk products and eggs were the least frequently consumed food groups. Majority (61.4%) of the women ate from at least 5–8 food groups (medium dietary diversity) whilst 37.9% ate from at least 1–4 food groups (low dietary diversity). There were significant differences in dietary diversity across the three regions (p<0.0001). BMI was within normal range for 54.2% of the women but 23.5% and 14.7% of the women were overweight and obese respectively. There was no association between BMI and dietary diversity (p=0.18).

Conclusion

Poor dietary diversity and intake of energy dense diets saturated with fats and oils is high in rural Ghanaian women. Future studies should evaluate the relationship between these dietary patterns and health and nutritional outcomes.

Support or Funding Information

This Research was supported in part by a grant from the Department of Global Health and Population, Harvard T.H.Chan School of Public Health, as well as the Department of Nutrition, Harvard T.H.Chan School of Public Health.
fNIRS in Africa & Asia: an Objective Measure of Cognitive Development for Global Health Settings
Authors: Lloyd‐Fox Sarah , Moore Sophie , Darboe Momodou , Prentice Andrew , Papademetriou Maria , Blasi Anna , Kumar Swapna , Westerlund Alissa , Perdue Katherine L , Johnson Mark H , Nelson Charles A , Elwell Clare E
Published: November 2023

The goal of our work is to establish assessments to evaluate the impact of early risk on cognitive development in infancy and childhood in global health settings. Prior work using functional near‐infrared spectroscopy (fNIRS) has shown differential brain responses in infants to social vs. nonsocial stimuli in urban European (Lloyd‐Fox et al., 2009; 2013) cohorts. This experimental paradigm has been proposed as an objective measure of social cognition that can be used in many different cohorts with minimal adaptation.

Cortical mapping of the brain during infancy is rarely undertaken in low‐income countries due to the lack of transportable neuroimaging methods. Functional near infrared spectroscopy (fNIRS) ‐ which uses the absorption of near infrared light to non‐invasively measure changes in oxygen in the blood ‐ is an elegant method for assessing cognitive function in such settings. Participants, ranging in age from 4 – 8 months (UK: N = 64; The Gambia: N = 24; Bangladesh: N = 23), were tested with a multi‐channel NIRS system that recorded brain activity over the frontal and temporal cortices. The experimental stimuli presented were videos of people moving their eyes or hands (i.e. a “Peek‐a‐boo” game), accompanied by vocal sounds (i.e. yawn, laughter), non‐vocal sounds (i.e. water running, bell), or silence. Social videos were alternated with control blocks of pictures of local modes of transportation presented with no sounds.

Here we present a comparison of data collected in urban European, rural African and urban Asian cohorts. Participants in The Gambia lived in a rural community of subsistence farmers and participants in Bangladesh lived in an urban slum. Both cohorts were exposed to a broad range of adversity early in life including poverty, under‐nourishment, recurrent infections, and lack of maternal education.

Our results indicate specialised social > non‐social activation in the superior and middle temporal cortex across all three cohorts and across 4 – 36 months of life. These results confirm the suitability of fNIRS in this age group in a resource poor setting. Changes in cortical haemoglobin may afford early biomarkers that are more sensitive to nutritional insults and early adversity affecting cognition than current standardised behavioural measures.

Support or Funding Information

Bill and Melinda Gates Foundation, Medical Research Council UK,
Anthropometry and Dengue Fever in Coastal Ecuador
Authors: Tedesco Julia M. , Mehta Saurabh , Beltrán‐Ayala Efraín , Cárdenas Washington B. , Endy Timothy P. , Ryan Sadie J. , Stewart Ibarra Anna M. , Finkelstein Julia L.
Published: November 2023

Objective

This study was conducted to examine the burden of malnutrition – both undernutrition or overnutrition – and its associations with dengue fever, as part of a prospective study of dengue transmission conducted in Machala, Ecuador.

Methods

Individuals presenting with suspected dengue fever at four sentinel clinics and the central hospital of the Ministry of Health were recruited into the study. Index cases with acute dengue infection triggered an investigation of dengue cases in the index household and four neighboring households. Dengue fever was diagnosed via RT‐qPCR (n=72); cases were sex‐ and age‐matched to controls (n=72), individuals who tested negative for dengue fever (i.e., negative for RT‐qPCR, NS1, IgG, and IgM). Anthropometric measurements, including height, weight, mid‐upper arm circumference, and waist circumference were collected using standardized procedures. World Health Organization z‐scores were calculated, and conventional cut‐offs were used to categorize variables.

Results

Median body mass index (BMI) was 23.6 kg/m2 (IQR: 20.6–29.3) in cases and 23.8 kg/m2 (IQR: 19.7–28.5) in controls. The prevalence of underweight was low in cases and controls (BMI<18.5 kg/m2; cases: 0.7%, controls: 2.1%; p>0.05); however, approximately 20% of individuals were overweight or obese (BMI≥ 25 kg/m2; cases: 18.1%, controls: 19.4%; p>0.05). Mid‐upper arm circumference (median (IQR); cases: 28.0 (25.0–30.7) vs. controls: 27.6 (24.3–31.0) cm; p>0.05) and waist circumference (median (IQR); cases: 82.8 (69.5–92.8) vs. controls: 84.5 (71.1–94.8) cm; p>0.05) were similar in dengue cases and controls. The prevalence of high waist circumference was not statistically different in cases compared to controls (men: >94 cm, women: >80 cm; cases: 16.7% vs. controls: 18.8%; p>0.05 | men: >102 cm, women: >88 cm; cases: 5.6% vs. 11.1% p=0.07).

Conclusion

The prevalence of overweight, obesity, and increased weight circumference was relatively high in this setting, in both dengue cases and controls. The implications of overnutrition for the immune response and clinical outcomes for infectious diseases in this population needs to be assessed prospectively in future studies.

Support or Funding Information

Division of Nutritional Sciences, Cornell University; Global Emerging Infections Surveillance and Response