bluuebunny/crossref_metadata_2025 huggingface dataset:
A novel rat model of orthopedic trauma for prehospital pain studies
Authors: Xiang Lusha , Avila Martha M , Klemcke Harold G , Ryan Kathy L , Hinojosa‐Laborde Carmen
Published: November 2023

Animal models of orthopedic trauma usually consist of tibia or femur fractures that require a post‐fracture fixation surgery. Such an approach compromises subsequent assessments of pain following orthopedic trauma. The goal of the current study was to establish a rat model of long bone fracture that needs no post‐trauma surgeries, thereby optimizing its utility for future studies especially with prehospital pain management. Orthopedic trauma, including soft tissue injury and fibula fracture, was performed on the right hindlimb in Sprague Dawley rats. Soft tissue injury was induced in anesthetized rats via clamping the retrofemoral tissue groups for 30 sec, followed by closed fibula fracture using a 15‐gauge needle. Thermal hyperalgesia (paw withdrawal time, PW, n = 24), mechanical allodynia (mechanical threshold, MT, n = 17), weight‐bearing ratio (right/left, WB, n = 12), and tail flick latency (n = 10) were determined before and 90 minutes after the injury. Rats were then treated with 5 mg/kg ketamine or vehicle (saline) through jugular catheters, and nociceptive measurements were repeated at 10, 40, 80, and 120 minutes after injection. Trauma had no effect on tail flick responses but decreased PW, MT, and WB (Table 1). Ketamine increased PW, WB, and tail flick latency mainly within the first 40 minutes following injection (Figure 1). As no post‐trauma surgery is required, our data suggest that this trauma model may be ideal for prehospital pain research. To our knowledge, this is the first study to show that 5 mg/kg of ketamine iv could be considered for instant analgesia in rats.

Thermal hyperalgesia (PW), mechanical allodynia (MT), weight‐bearing ratio (WB), and tail flick response before and after trauma.

PW (second)
MT (gram)
WB (right/left)
Tail flick (second)

Basal
11.3±0.5
40.5±1.5
1.0±0.1
5.6±0.2

Trauma
6.5±0.2*
31.7±2.3*
0.5±0.1*
5.6±0.1

P < 0.05 trauma vs. basal.
Anti‐Retroviral Therapy Increases Hepatic Gluconeogenic and Lipogenic Enzyme Expression but does not Alter Expression of Insulin Signaling Cascade Proteins in Chronic Binge Alcohol‐Administered SIV‐Infected Rhesus Macaques
Authors: Ford Stephen Michael , Nelson Steve , Bagby Gregory J. , Simon Liz , Molina Patricia E.
Published: November 2023

Chronic alcohol consumption, HIV infection, and anti‐retroviral therapy (ART) have independently been shown to increase risk for metabolic dysregulation. Previously we demonstrated that chronic binge alcohol (CBA) administration to simian immunodeficiency virus (SIV) infected male rhesus macaques impaired glucose‐insulin dynamics at 11 months post‐SIV infection. This was reflected in reduced acute insulin response to a glucose load, and decreased whole body glucose effectiveness, a measure of the rate of systemic glucose disappearance. The aim of this study was to determine whether CBA and/or ART altered hepatic gene expression of gluconeogenic and lipogenic enzymes and insulin signaling proteins in association with our previous findings of CBA‐mediated impairments in whole body glucose‐insulin dynamics. CBA or sucrose (SUC) was administered intragastrically through a surgically implanted indwelling catheter beginning at 3 mos prior to infection with SIVmac251 (and continued for the duration of the study) in male rhesus macaques. At 2.5 mos. post‐SIV infection, daily administration of ART was initiated in half of the SUC/SIV and CBA/SIV macaques. At necropsy (11 mos post‐SIV infection), livers were collected for analyses of mRNA and protein expression. Liver from ART‐treated SIV‐infected macaques showed increased mRNA expression of phosphoenolpyruvate carboxykinase‐1 (PEPCK‐1), glucose‐6‐phosphatase (G6Pase), and acetyl CoA carboxylase (ACC), compared to that of ART‐negative macaques, irrespective of CBA or SUC administration. Neither CBA nor ART administration altered hepatic protein expression of phosphatase and tensin homolog (PTEN) or protein tyrosine phosphatase 1B (PTP1B), phosphatase enzymes that attenuate insulin signaling. In addition, neither CBA nor ART reduced insulin signaling as determined by the ratio of phosphorylated/total protein expression for mTOR (S2448) and Akt (S473). ART‐treated animals showed higher P‐AMPK (T172)/total AMPK ratio irrespective of SUC or CBA administration, compared to ART‐negative animals. These findings suggest that ART contributes to impaired anabolic metabolism in an organ‐specific manner. Ongoing studies will demonstrate whether CBA and/or ART adversely affect(s) catabolic pathways of metabolism, including the glycolytic pathway. Taken together, our data suggest that chronic alcohol and ART may act synergistically to potentiate the progression of metabolic dysregulation in people living with HIV/AIDS.

Support or Funding Information

The work was supported by National Institutes of Health (NIH) grants: P60AA09803, T32AA07577, and F30AA024030‐01A1.
Intestinal Epithelial TCPTP Deficiency Reduces Expression of the Tight Junction Protein Tricellulin through MEK/ERK Signaling
Authors: Krishnan Moorthy , Chan Alvin Lee , Wong Brandon Matthew , Sayoc Anica , McCole Declan F.
Published: November 2023

Genome‐wide association studies identified protein tyrosine phosphatase non‐receptor type‐2 (PTPN2) as a susceptibility gene for inflammatory bowel disease (IBD), Diabetes and Celiac disease, while loss of the PTPN2 protein product T‐cell protein tyrosine phosphatase (TCPTP) compromises intestinal epithelial barrier function. The protein composition of tight junctions (TJ) determines the tightness of the barrier and alterations in select TJ proteins leads to increased paracellular permeability. Tricellulin (also called marvelD2) is a recently discovered tight junction (TJ) protein, which is preferentially localized at tricellular contacts. Tricellulin plays an important role in the maintenance of intestinal epithelial barrier function by restricting paracellular permeability to macromolecules. The aim of the present study was to identify the molecular mechanism underlying barrier defects in TCPTP‐deficient intestinal epithelial cells (IEC). For this purpose, we developed Caco2‐BBe and HT‐29 intestinal epithelial cell lines (IECs) expressing short hairpin RNA for TCPTP using a lentiviral system to stably knock down TCPTP expression (TCPTP‐KD). Western blot analysis indicated that TCPTP expression was significantly reduced (by 45 ± 4%, p<0.01, n=3) in TCPTP‐KD cells. FD4 permeability was increased in KD cells (p<0.001; n=3) compared to control cells. Western blot and immunofluorescence studies revealed that the expression of tricellulin expression was decreased (WB: 44 ± 8.8%, p<0.05; n=3) in unchallenged TCPTP‐KD cells compared to control shRNA transfected cells. This decrease was further enhanced by challenge with the pro‐inflammatory cytokine interferon‐gamma (IFN‐g) (n=2). In previous studies, we observed increased basal phosphorylation of the TCPTP substrate ERK1/2 in TCPTP‐KD cells. Moreover, an inverse relationship exists between mitogen‐activated protein kinase kinase kinase 1 (MEKK1) that lies upstream of ERK1/2, and MarvelD3, a member of the same protein family as tricellulin. To investigate whether tricellulin loss in TCPTP‐KD cells occurs through MEK/ERK signaling, TCPTP‐KD IEC were treated with the ERK1/2 inhibitor U0126 (10mM) for 14 hours. ERK inhibition rescued tricellulin expression in TCPTP‐KD cells. In conclusion, we report that tricellulin expression is down regulated, at least in part, by the MEK/ERK pathway and that decreased tricellulin levels could contribute to the increased macromolecule permeability in cells lacking TCPTP.

Support or Funding Information

NIH‐R01‐DK‐091281 and Crohn's & Colitis Foundation of America(CCFA) to Declan F. McCole
Why Does Bone Remodel, What Happens When It Doesn't, and How Can We Use This to Change Our Therapeutic Mindset?
Authors: Burr David B
Published: November 2023

Bone remodeling serves both long‐term metabolic as well as mechanical needs. Within the mechanical realm, remodeling helps to renew the bone matrix to prevent the tissue from aging to the point at which its mechanical properties are compromised, and skeletal fragility is increased. It is now well known that severely suppressing bone remodeling is as detrimental to skeletal health as is the rapid bone remodeling found in conditions such as osteoporosis or Paget's Disease. Failure to remodel bone can result in excessive microdamage burden, accumulation of advanced glycation end products (AGEs), and hypermineralization. Microdamage, left unrepaired, reduces the residual strength and stiffness of bone, and can lead to stress fractures. Hypermineralization and accumulation of AGEs cause tissue brittleness, which reduce bone toughness and increase the risk for fracture. Many current treatments for postmenopausal, glucocorticoid‐induced and age‐related osteoporosis prevent bone loss by suppressing bone remodeling, reducing the risk for some kinds of fractures (eg hip fractures), but this has negative effects on tissue material properties that may increase the risk for other types of fractures (stress fractures and atypical femoral fractures). Knowing this, investigations have begun into how to alter the physical properties of bone matrix without manipulating the activity of osteoclasts or osteoblasts. These cell independent approaches rely on moving bone water from compartments in which it is freely flowing, to those in which it is tightly bound, within the interface between the collagen and the mineral. Increasing bound water allows the collagen and mineral to slide at their interfaces, reducing stresses when bone is loaded, and delaying both the initiation of microcracks and the ultimate fracture of the bone. Agents that increase water content of bone, and move water between compartments, have been tested both ex vivo, and in living animal models. They have been shown to increase toughness in bone that is devoid of living cells. These agents have also been shown in diabetic animal models to reduce the skeletal fragility that is associated with Type II diabetes, a case in which fragility is not related to bone mass but only to the deterioration of matrix material properties consequent to AGE accumulation. These treatments offer the opportunity to reduce risk for fracture without manipulating cell activity. Given the importance of a vital and viable remodeling system to bone health, these new approaches promise an approach to reduce fracture risk without negative side effects associated with suppressing remodeling, and can be applied to cases of skeletal fragility that are not caused by aberrations of the remodeling system.
Dietary Kynurenine, the oxidized metabolite of tryptophan, suppresses osteoprogenitor expression of Hdac3 resulting in increased marrow adiposity and age‐related bone loss
Authors: McGee‐Lawrence Meghan , Pierce Jessica , Yu Kanglun , Davis Colleen , Dukes Amy , Zhong Qing , Xu Jianrui , Bollag Wendy , Elsalanty Mohammed , Kennedy Eileen , Ding Kehong , Hill William , Hamrick Mark W , Isales Carlos
Published: November 2023

Background

Aging results in loss of skeletal bone mass resulting in osteoporosis and increased marrow fat although the mechanism remains poorly understood. Our previous studies support Hdac3 as a regulator of this process, as osteoprogenitor Hdac3 expression is decreased in aged vs. young mice, and decreased expression of Hdac3 causes an osteopenic, high marrow fat phenotype with increased lipid storage in osteoprogenitors. However, causative factors for decreased Hdac3 expression with aging are unknown. Our group has shown that aromatic amino acids (tyrosine, phenylalanine, tryptophan) function as antioxidants with a protective role in bone, whereas their oxidized byproducts antagonize this effect and promote bone loss. Circulating levels of kynurenine, the oxidized product of tryptophan, are increased in aged (24mo) vs. mature (12mo) mice, and we recently observed that kynurenine‐treated mice have high marrow fat and low bone mass, mimicking the phenotype of Hdac3‐deficient and aged animals. This raises the possibility that oxidized by products, in particular kynurenine, could be a mechanistic link between aging and bone loss.

Objective

We explored intersecting roles of kynurenine and osteoprogenitor Hdac3 in marrow adiposity and osteoprogenitor lipid storage.

Methods and Results

Mature (12 months) male C57BL6 mice were fed 18% protein (normal diet), 8% protein+50μM kynurenine or 8% protein+100μM kynurenine for 8 weeks. We also injected young male CD‐1 mice with kynurenine (2 or 20 mg/day) for 10 days to study kynurenine's acute effects. Kynurenine caused bone loss through increased osteoclast activity and decreased osteoblast activity. Bone marrow adiposity was dose‐dependently increased in kynurenine‐fed mice, and osteogenic BMSC cultures from kynurenine‐treated mice showed decreased expression of Hdac3 and co‐factor NCoR1, increased expression of lipid storage genes Cidec and Plin1, and no changes in expression of Pparγ2 or Fasn. These results mimic expression patterns in osteoprogenitors from Hdac3‐insufficient and aged mice.

Conclusion

Aging‐induced increases in kynurenine may suppress Hdac3 which impairs osteoblast function and increases marrow fat with age.
Diacylglycerol and Phosphatidic: Regulation of Levels and Roles in Synaptic Vesicle Cycling
Authors: Goldschmidt Hana , Barber Casey , Huganir Richard , Raben Daniel
Published: November 2023

Recognition that lipids and lipid metabolism play critical structural and regulatory roles in the central nervous system (CNS) is increasing. The phosphoinositides (PtdIns) have received the most attention but two related lipids, diacylglycerol (DAG) and phosphatidic acid (PtdOH) are also believed to play key roles in neurotransmission. In contrast to inositol lipid metabolism, the enzymes involved in modulating the levels of these lipids, and their regulation are not well studied. Recently we reported evidence demonstrating a role for diacylglycerol kinase‐θ (DGK‐θ) in modulating evoked endocytosis in the in synaptic vesicle cycling in mammalian central nervous system neurons. This enzyme reduces DAG while elevating PtdOH by catalyzing the ATP‐dependent phosphorylation of DAG to PtdOH. Another class of enzymes involved in generating PtdOH in signaling pathways are phospholipases D (PLDs). These enzymes generate PdOH by catalyzing the hydrolysis of phosphatidylcholine (PtdCho) leading to the generation of PtdOH. This PtdOH may in turn be de‐phosphorylated to DAG. Both DGK‐θ and a PLD (PLD1) have been implicated in neurotransmitter release. We have presented some data implicating DGK‐θ in modulating endocytosis during synaptic vesicle cycling. The role of PLD1 in this cycle is less clear. We have been studying the role of both enzymes, and their regulation, in synaptic vesicle cycling and given some attention to the potential involvement of these enzymes in neurons that depend on rapid and repetitive neurotransmitter release as seen in ribbon synapses.

Support or Funding Information

NIH R01NS077923
A Fluorogenic Proteostasis Sensor to Monitor Proteome Stress in Real‐Time
Authors: Zhang Xin , Liu Yu
Published: November 2023

Cellular stress can lead to global misfolding and aggregation of the endogenous proteome, resulting in a disruption of protein homeostasis (proteostasis). Monitoring proteostasis efficacy in response to stress in real time remains one of the major technical challenges facing established sensors of this process. Herein we introduce a fluorogenic proteostasis sensor based on a metastable Halo mutant in which misfolding and aggregation visually reports proteostasis deficiency. For this purpose, a solvatochromic fluorophore was designed to act as a ligand that can form a stable conjugate with Halo. The Halo•ligand conjugate maintains a fluorescent dark state when the Halo protein is folded but fluoresces strongly when the Halo•ligand conjugate misfolds and aggregates. In both E. coli and mammalian cells, we have demonstrated the utility of the sensor in monitoring proteostasis deficiency under a variety of stress conditions including environmental perturbations and incubation with a proteasome inhibitor. We show that the fluorogenic properties of this proteostasis sensor enables facile monitoring the proteome stress and allows us to discover the proteome aggregation that is induced by a series of anti‐cancer drugs. This work highlights the utility of solvatochromic fluorophores in direct visualization of protein misfolding and aggregation in live cells, providing new methodologies for real‐time analyses of cellular proteostasis upon exposure to different types of stress conditions.

Support or Funding Information

This work has been supported by the Burroughs Wellcome Fund Career Award at the Scientific Interface, the Paul Berg Early Career Professorship, and the Lloyd and Dottie Huck Early Career Award.
Imaging developmentally‐regulated secretory granule biogenesis and exocytosis
Authors: Hagen Kelly Ten , Tran Duy T , Ji Suena
Published: November 2023

Regulated secretion is an essential process by which cells deliver molecules to the cell surface and extracellular space in response to an external signal. We have established a system to directly visualize the secretion of high molecular weight cargo such as mucins in vivo, to define the critical factors at each step in this process. Using Drosophila salivary glands expressing fluorescently‐labeled secretory cargo (Sgs3‐GFP), myosin II (Zipper‐GFP), actin binding protein (Lifeact‐Ruby) or a PIP2 reporter (PLC□PH‐EGFP), we are able to visualize the spatial and temporal dynamics of regulated secretion. Through 4D‐imaging of secreting glands, we show that actin is cleared at the site of vesicle fusion and re‐assembled directionally around secreting granules. Moreover, we demonstrate that fusion pore formation and PIP2 redistribution precede actin and myosin recruitment to fused granules. Additionally, we show a crucial role for the branched actin nucleators Arp2, Arp3 and their nucleation promoting factor WASp in cargo expulsion and integration of the granular membrane with the apical plasma membrane. By combining in vivo and ex vivo imaging of fluorescently‐labeled molecules with the power of Drosophila genetics, we have developed a tractable experimental system for studying the factors that regulate hormone‐induced secretion during development. Ongoing experiments focus on investigating the role of O‐glycosylation in secretory granule biogenesis, morphology and secretion.

Support or Funding Information

This work was supported by the Intramural Research Program of the NIDCR, National Institutes of Health (Z01‐DE‐000713 to K.G.T.H.).
Vitamin E δ‐tocotrienol inhibits NF‐κB activation by up‐regulating A20 in macrophages and suppresses colitis‐promoted colon tumorigenesis in mice
Authors: Yang Chao , Jiang Qing
Published: November 2023

Nuclear factor‐κB (NF‐κB) plays a key role in inflammatory responses and cancer development. Inhibition of NF‐κB has been shown to attenuate inflammation and cancer progression. δ‐Tocotrienol (δTE) is a natural vitamin E form rich in annatto seeds and has been shown to inhibit NF‐κB in pancreatic cells. However, potential effect of δTE on NF‐κB activation in immune cells and the underlying mechanism have not been investigated. In the present study, we found that δTE inhibited TNF‐α induced activation of NF‐κB, as indicated by diminished phosphorylation and degradation of IκBα in the cytosol, and phosphorylation of p65 in the nucleus. Furthermore, δTE potently inhibited TNF‐α‐induced phosphorylation of TAK1, a key upstream kinase that is required for the activation of NF‐κB. Interestingly, δTE significantly increased the expression of A20 and CYLD, both of which are negative regulators of NF‐κB. Knockout of A20 partially diminished δTE's anti‐NF‐κB effect, supporting the notion that induction of A20 plays a key role in δTE's anti‐NF‐κB effect. To translate mechanistic findings to a whole body environment, we further investigated the effectiveness of δTE and its metabolite, δTE‐13′‐COOH, against azoxymethane (AOM) induced and colitis‐promoted colon tumorigenesis in male BALB/c mice. We found that δTE‐rich mixed tocotrienols (δTE/ɣTE ~8/1, at 0.035% diet) inhibited colon tumorigenesis, as indicated by 36% reduction of multiplicity of large adenomatous polyps (>2mm(2), P=0.07) and decreased tumor surface area by 31% (P<0.05). δTE‐13′‐COOH (at 0.04% diet) significantly suppressed multiplicity of total polyps by 25% (P=0.06) and large polyps by 54% (P<0.01). Our study demonstrates that δTE has potent anti‐NF‐κB activity and this vitamin E form and its metabolite suppress colitis‐promoted colon tumorigenesis in mice.
Docosahexaenoic acid, an omega‐3 fatty acid, induces autophagy in human breast cancer cells: role of oxidative stress‐induced growth inhibitor 1
Authors: Tsai Chia Han , Li Chien Chun
Published: November 2023

Oxidative stress‐induced growth inhibitor 1 (OSGIN1) was identified as not only an oxidative stress response gene but also a tumor suppressor gene. Docosahexaenoic acid (DHA), a long‐chain omega‐3 polyunsaturated fatty acid that abounds in oily fish, is well documented to exhibit antitumor activity. It has been shown DHA induces both apoptosis and autophagy in cancer cells. The aim of this study was to determine whether OSGIN1 is involved in the induction of autophagy and apoptosis by DHA in human breast cancer cells and the possible mechanisms involved. MCF‐7 cells were grown to 70–80 % confluence and were then treated with or without DHA and OSGIN1 siRNA for the times indicated. Afterward, the proapoptotic protein, such as Bcl2, Bax, and cytochrome c as well as the autophagy‐related markers, including LC3B‐I, LC3B‐II, mTOR, Beclin‐1, and p62 were determined by Western Blotting. Moreover, the index of autophagy and apoptosis were assayed by using Premo™ Autophagy Tandem Sensor RFP‐GFP‐LC3B Kit and FITC Annexin V Apoptosis Detection Kit, respectively. In this study, 100 μM DHA dramatically upregulated OSGIN1 protein and mRNA expression as well as LC3B‐1/‐II and p62 level, whereas the level of mTOR and Beclin‐1 was decreased by DHA in a dose‐dependent manner. After knockdown of OSGIN1 expression by siRNA transfection, DHA‐mediated LC3B‐I and LC3B‐II expression was abrogated. OSGIN1 siRNA alleviated the suppression of mTOR and Beclin1 expression by DHA. Overexpression of OSGIN1 by transient transfection of plasmid OSGIN1 significantly increases LC3B‐II and autophagy via activation of AMPK/Raptor and inactivation mTOR/ULK ser757 signaling pathways. Furthermore, OSGIN1 overexpression mimics DHA decreases Bcl2, elevates Bax expression and cytochrome c release from mitochondria. Taken together, these results suggest that DHA induces OSGIN1 expression, and subsequently promotes autophagy through activation of AMPK/mTOR signaling pathway. Overexpression of OSGIN1 partially contributes to DHA‐mediated cytochrome c release and apoptosis in breast cancer cells.
Bacterial fermentation end‐products are related to hepatic steatosis among overweight and obese adults
Authors: Thompson Sharon V. , Berndt Jake W. , Edwards Caitlyn G. , Erdman John W. , Khan Naiman A. , O'Brien William D. , Holscher Hannah D.
Published: November 2023

Background

Nonalcoholic fatty liver disease (NAFLD) is an increasingly prevalent manifestation of metabolic dysfunction characterized by elevated hepatic fat accumulation and elevated liver enzymes. Currently it is estimated that NAFLD may affect up to half of the US population. Although previous work has linked excess adiposity with NAFLD, there is a paucity of data examining whether hepatic steatosis is also related to gut microbiota fermentation end‐products, particularly among humans. Discovering this knowledge stands to benefit future dietary approaches to preventing the development of NAFLD in the increasingly overweight and obese US population.

Methods

Accordingly, this study aimed to characterize the relationships between hepatic steatosis and markers of liver function, fat mass, and gut microbiota fermentation end‐products. We conducted correlational analyses concerning adiposity (%Fat), volatile fatty acid (VFA) concentrations, and measures of hepatic health within a sample of overweight/obese (BMI ≥ 27.5 kg/m2) adults (N=57, 64.9% females). Whole body and total, visceral, and subcutaneous abdominal adiposity (% Fat Mass) were measured using DXA. Gas chromatography mass spectroscopy was used to assess VFA concentrations, including short‐chain fatty acids (SCFAs; acetate, propionate, butyrate) and branched‐chain fatty acids (BCFAs; isovalerate, valerate, and isobutryate). Hepatic enzyme concentrations (whole blood) were assessed using an automated chemical analyzer. Hepatic steatosis (fat fraction [FF]) was measured using quantitative ultrasound in a subset of participants (n=21). Initial bivariate correlations were conducted to examine relationships between hepatic health measures, adiposity, and bacterial fermentation end products. Subsequently, a partial correlation was conducted to determine whether the relationships between bacterial fermentation end‐products and hepatic measures persisted following the adjustment of adiposity.

Results

Elevated alanine aminotransferase (ALT), aspartate aminotransferase (AST), and hepatic FF were present in 16.7%, 13.0%, and 5.1% of participants, respectively. Whole body %Fat was negatively correlated with butyrate concentrations (r=−0.29, p=0.03, n=57). Hepatic FF was positively related to isovalerate (r=0.48, p=0.03, n=21) and tended to correlate with isobutyrate (r=0.40, p=0.07, n=21). Partial correlational analyses revealed that the relationships between hepatic FF and BCFA concentrations may be mediated by BMI and whole body, visceral, and subcutaneous adiposity.

Conclusions

Results of the present study indicate that VFA concentrations differ by hepatic health and adiposity status. Further research is needed to determine if these observed relationships are mediated by dietary factors or gastrointestinal microbial abundances.
Correlations of Abdominal Fat and Colonic Sulfidogenic Bacteria in African Americans and Non‐Hispanic Whites with Newly Diagnosed Colorectal Cancer
Authors: Gomez‐Perez Sandra L , Yazici Cemal , Wolf Patricia M , Braunschweig Carol , Xicola Rosa , Llor Xavier , Ellis Nathan , Tussing‐Humphreys Lisa , Mutlu Ece A , Gaskins Rex H
Published: November 2023

Objective

To determine correlations between abdominal fat distribution (AFD) and abundance of gut microbiota bacterial gene targets in African Americans (AAs) and Non‐Hispanic Whites (NHWs) with incident CRC.

Methods

Adults (n=64; AAs=44, NHWs=20) with incident colorectal cancer with a preoperative abdominal computed tomography scan and non‐involved colonic tissue for assessment of gene targets of sulfate‐reducing bacteria [SRB] in the colonic mucosa were included. A cross‐sectional CT slice at mid‐point of L3 vertebra was analyzed for waist circumference (cm) and surface areas (cm2) of abdominal fat: total (TAT), subcutaneous (SAT), superficial subcutaneous (SSAT), deep subcutaneous (DSAT), and visceral (VAT) adipose tissues. Quantitative PCR was used to measure abundance of SRB gene targets in non‐involved colonic mucosa including: pan‐dissimulatory sulfate reductase A (DSR1F4r), Desulfovibrio (DSV), Desulfobacter (DSB), and Desulfotomaculum (DFM). Pearson correlation stratified by race was used to assess relationships between abdominal fat and gut microbiota.

Results

Mean age (SD), BMI (SD) and waist circumference (SD) for AA vs. NHW were: 63.4(8.9) vs. 60.2(6.7), 27(5.6) vs 29.2(6.1) and 97.6(11.4) vs 103.9(15.6), respectively. About 60% (27/44) of AAs and 85% (17/20) of NHWs were male. Significant correlations were observed between the abundance gene targets of sulfidogenic bacteria, DSV, DSB, and DFM with cross‐sectional (cm2) levels of SSAT and DSAT. SSAT was negatively associated with the abundance of DSB (r=−0.4985, p=0.0027, n=34) whereas DSAT was negatively associated with abundance of DSV (r=−0.3469, p=0.0262, n=41) and DFM (R=−0.3099, p=0.0486, n=41) in AAs only. No associations for bacterial gene targets and AFD were observed for NHWs.

Conclusions

These findings suggest that AFD may be related to sulfidogenic bacterial species in colonic mucosa differentially in AAs compared to NHWs.

Support or Funding Information

Funding: The project described was supported by grant numbers 5R25‐CA057699 and 1R01‐CA204808 from the National Cancer Institute and its contents are solely the responsibility of the authors and do not necessarily represent the official views of the National Cancer Institute.
Effect of delta‐tocotrienols and green tea polyphenols on high‐fat‐diet‐induced bone deterioration in male C57BL/6J mice
Authors: Shen Chwan‐Li , Tomison Michael D , Kaur Gurvinder , Ramalingam Latha , Dufour Jannette , Moustaid‐Moussa Naima , Chung Eunhee , Mo Huanbiao , Cao Jay
Published: November 2023

Our previous studies demonstrated an osteo‐protective roles for tocotrienols (TT, extracted from annatto consisting of 90% delta‐TT and 10% gamma TT) and green tea polyphenols (GTP, extracted from green tea) in obese animals. This study further examined the combined effects of TT with GTP on high‐fat‐diet (HFD) induced bone deterioration in obese male mice. Forty male C57BL/6J mice were assigned to 4 groups (n=10/group) in a 2 (no TT vs. TT) × 2 (no GTP vs. GTP) factorial design: HFD, HFD+TT (400 mg TT/kg diet), HFD+GTP [0.5% (w/v) in drinking water], and HFD+TT+GTP for 14 weeks. The results showed that either TT or GTP supplementation lowered fasting glucose concentration based on glucose tolerance test, while only GTP supplementation lowered blood glucose concentration based on insulin tolerance test, with no change in caloric intake. GTP supplementation increased serum procollagen type I intact N‐terminal (a bone formation marker) and there was an interaction between TT and GTP on lowering serum collagen type I cross‐linked C‐telopeptide (a bone resorption marker). TT supplementation increased the total area, bone area, and bone volume (BV) at the femur midshaft. GTP supplementation increased the BV, bone volume/total volume (BV/TV), and connectivity density at the 2nd lumbar vertebrae. GTP supplementation increased trabecular number and tended to increase BV/TV (p=0.08), and decreased trabecular separation at the distal femur. However, TT supplementation tended to increase BV (p=0.10), BV/TV (p=0.06), and trabecular thickness (p=0.10) at distal femur. There was a synergistic interaction between TT and GTP on BV/TV trabecular thickness (Tb.Th) at the femur midshaft, resulting in the lowest values of BV/TV and Tb.Th in HFD group. This study suggests a potentially significant prophylactic role of TT and green tea in bone health of obese animals.
Effects of a 6‐Month Lifestyle Intervention on Dietary Intake and Blood Pressure in Hemodialysis Patients
Authors: Chan Lauren E. , Perez Luis , Burrows Brett , Biruete Annabel , Barnes Jennifer L , Wilund Kenneth R
Published: November 2023

Previous studies have demonstrated a positive correlation between dietary sodium intake and blood pressure (BP) in hemodialysis (HD) patients. High BP is linked to increased cardiovascular (CV) mortality, and CV disease contributes to 41% of deaths among HD patients. To reduce these risks, HD patients are often counseled to restrict their dietary sodium intake, but few studies have examined the efficacy of this strategy.

In this study, we aimed to assess the impacts of individualized low sodium dietary counseling in conjunction with a liberalized diet approach on sodium intake and BP. Liberalized dietary guidelines include more whole food consumption, decreasing foods eaten outside the home, and increased food label reading.

32 patients (age = 53.8 ± 13.5y, 44% female) enrolled in the study and underwent baseline testing, including three 24‐hour recalls, and standardized BP measurement. Dietary recalls were analyzed using the Nutrition Data System for Research. During the 6‐month intervention, participants received weekly one‐on‐one dietary counseling to reduce sodium intake, address a liberalized diet, and set individual goals. Study coordinators performed counseling, supervised by both research and clinical dietitians. Baseline testing measures were repeated at the end of the 6‐month intervention period.

Comparing baseline (BL) measurements to those post‐intervention (6m), average kilocalorie (kcal) intake was not significantly different (BL 1489 ± 968 vs. 6m 1445 ± 484 kcal, p= 0.876). Daily protein intake did not change over 6 months (BL 55.16 ± 21.62 vs. 6m 59.63 ± 21.15 grams, p=0.605). Total sodium intake numerically decreased (BL 2780.4 ± 1112.6 vs 6m 2482.5 ± 1147.6 mg, p=0.297), as did milligrams of sodium normalized per kcal (BL 2.07 ± 0.87 vs 1.68 ± 0.54 mg/kcal, p=0.08). Systolic BP (BL 154.71 ± 26.89 vs. 6m 157.57 ± 25.07 mmHg, p=0.674) and diastolic BP (BL 77.78 ± 20.54 vs 6m 77.85 ± 16.17 mmHg, p= 0.991) showed no significant changes, but total number of BP medications prescribed to patients (BL 2.93 ± 1.26 vs 6m 1.5 ± 1.09 medications) were significantly reduced (p=0.004).

Maintenance of energy and protein intake is important for HD patients to preserve their lean mass and serum protein values, a potential challenge during sodium restrictions. Notably, this six‐month dietary intervention was not associated with decreases in kcal and protein intake, although patients remain below recommendations. Though not statistically significant, the modestly reduced sodium intake that was found may suggest developing changes in consumption due to our intervention. Minimal changes in sodium intake had no significant effects on systolic and diastolic BP values, but may have played a role in the significant decrease in number of BP medications. This indicates that a six‐month dietary intervention may be meaningful for both systolic and diastolic BP maintenance with decreased BP medication usage.
Markers of Renal Function are Unchanged in Obese Older Adults Consuming a Higher Protein, Hypocaloric Diet for 6 Months
Authors: Starr Kathryn N Porter , McDonald Shelley R , Orenduff Melissa C , Jarman Aubrey K , Sloane Richard , Pieper Carl F , Bales Connie W
Published: November 2023

Higher intakes of dietary protein (i.e., exceeding the RDA of 0.8 g/kg body weight/day) are being widely advocated for older adults with the intent of mitigating age‐related loss of muscle mass and strength. However, these recommendations are accompanied by concerns about the potential impact on renal function, especially because kidney function declines with age in many individuals. Yet, there is a lack of evidence on the topic, especially in older adults, leading to ambiguity in the clinical setting about the pros and cons of higher protein diets for high‐risk elders whose function is threatened by sarcopenia or sarcopenic obesity. We analyzed blood indicators of renal function collected in our recent trial of higher protein, hypocaloric (500 kcal deficit) diets for obese (mean BMI= 37.7±6.5 kg/m2), functionally frail (by Short Physical Performance Battery) older (mean age = 68.4±5.3 yr) adults (n=40) with age‐normal renal status (estimated glomerular filtration rate [eGFR] ≥ 45 mL/min/1.73m2) to examine the protein effect during a period of challenge to muscle mass (negative energy balance). Control participants were prescribed 0.8 g protein/kg body weight (bw) and Protein participants 1.2 g protein/kg bw distributed as 30+ grams of lean, high‐quality protein three times a day. The Protein group significantly increased dietary protein intake (3‐day diet record) to 1.12 g/kg/bw, while the Control group maintained a protein intake of 0.90 g/kg/bw; both groups had significantly (P<0.0001) decreased their bw at 6 months (Protein = −7.7±6.0%, Control = −5.7±5.4%). Blood indicators of renal function (eGFR and blood urea nitrogen [BUN]) were assessed at baseline and 6 months. At 6 months, both GFR (Control = 79.7±15.5 and Protein = 77.1±16.6 mL/min/1.73m2, P=0.17) and BUN (Control = 17.1±4.8 and Protein = 18.8±5.1 mg/dL, P=0.56) remained unchanged. While additional studies with subject larger numbers are needed, our finding that renal function was not impaired by the higher protein weight loss intervention has important implications for treatment of sarcopenic obesity and aligns with recent recommendations that older adults consume generous amounts of protein at each meal.

Support or Funding Information

This study was funding by the Beef Checkoff Program and received additional support from the National Institutes of Health (5T32 AG000029; 1P30 AG028716) and the VA Advanced Fellowship Program, GRECC.
Saturated or Monounsaturated Fatty Acids Have Different Effect on Body Weight and Feed Intake
Authors: Tamer Funda , Nergiz‐Unal Reyhan
Published: November 2023

INTRODUCTION

Various epidemiologic studies showed that high intake fat, with a rapid and extensive growth of the processed food industry in the last three decades, is considered to be the major risk factors for weight control and obesity. Currently, not only consumption of high quantities of fat but also type of fatty acids is recognized as a vital factor in the development of obesity. Therefore, the aim of this study was to investigate the variations in body weight and food intake of male C57Bl/6 mice after high fat diet either with different fatty acid contents.

METHODS

Male C57Bl/6 mice (8 weeks of age) were individually housed and fed ad libitum with a control chow diet (CD, 3.5 kcal/g diet, 10% calories from fat), high monounsaturated fatty acid consisting diet (MUFA, 5 kcal/g diet, 40% calories from fat), or high saturated fatty acid consisting diet (SFA, 5 kcal/g diet, 40% calories from fat) for 15 weeks after a two‐weeks of wash out period. Food intake was measured daily and body weight were measured at least two times in a week. Body weight change was calculated from the terminal and initial body weights. Analysis were carried out by Kruskal‐Wallis test using SPSS software version 23.

RESULTS

The mean feed intake was highest in MUFA diet group (4.2±0.21g) significantly compared to the control CD (3.9±0.14g) and SFA (3.6±0.13g) groups (p<0.05). Despite the food intake, the mean body weight change was different between dietary groups (CD: 5.5±0.49g; SFA: 9.5±0.66g; MUFA: 8.4±0.62g) (p<0.05) after 15 weeks with the highest change in high saturated fat diet (p<0.05).

CONCLUSION

In conclusion, a high monounsaturated fatty acid diet might stimulate the food intake but high saturated fatty acid diet adversely affected the body weight. Although feed consumption was higher in MUFA intake compared to the SFA intake, the body weight change was higher with SFA intake revealing a lipogenic potential of the saturated fatty acids.
Eicosapentaenoic acid (EPA) promotes differentiation of human brown precursor cells into metabolically active classical brown adipocytes via Gq/11 signaling
Authors: Fan Rong , Kim Jiyoung , Giraud David , Chung Soonkyu
Published: November 2023

Eicosapentaenoic acid (EPA) supplementation exerts a plethora of health benefits. Previously, we demonstrated that EPA promotes brown adipogenesis by mediating G‐coupled protein receptor 120 (GPR120) activation in rodent brown precursor cells. The aim of this study is to establish the role of EPA in regulating brown adipogenesis in human classical brown precursor cells. The immortalized human brown precursor cells were employed to induce differentiation in the presence of oleic acid, palmitic acid, and EPA. EPA treatment significantly increased brown‐specific gene expressions including Ucp1, Prdm16, Cidea, DiO2, UCP1 protein expressions and oxygen consumption rate. To further investigate the role of GPR120, a receptor family involved in Gq/11 subtype, human brown precursor cells were treated with either GPR120‐specific agonist cdpA or a potent Gq/11 inhibitor (YM‐254890) during differentiation. GPR120 agonism significantly promoted EPA‐mediated brown adipogenesis, while inhibition of Gq/11 signaling completely abrogated brown adipogenesis. Consistently, the genetic deletion of GRR120 by CRISPR/Cas9 abrogated EPA‐mediated brown adipogenic effects. Collectively, these results demonstrate that EPA supplementation mediates Gq/11 signaling of GPR120 leading to augmentation of brown adipogenesis in human brown precursor cells.

Support or Funding Information

NIH 1P20GM104320
Roles of Vascular Endothelial Growth Factor in Skeletal Development, Postnatal Homeostasis and Disease
Authors: Olsen Bjorn R , Berendsen Agnes D , Duan Xuchen , Hu Kai , Nagao Masashi
Published: November 2023

Vascular endothelial growth factor (VEGF), critical for cardiovascular development, is essential for skeletal development, growth and homeostasis. It couples angiogenesis with bone formation, and it stimulates differentiation of chondrocytes, osteoblasts and osteoclasts during development of synovial joints and membranous as well as endochondral bones. Loss of VEGF expression in chondrocytes during development results in increased apoptotic cell death. Loss of trabecular bone with an increase in marrow fat is the consequence of reduced VEGF expression in bone marrow‐derived osteoblastic progenitors in long bones.

In endochondral bone development, VEGF has a major role in establishing primary ossification centers within cartilage models of future bones. High expression of VEGF by hypertrophic chondrocytes establishes a VEGF gradient that induces migration of osteoclasts, endothelial cells, preosteoblasts and hematopoietic stem cells from the perichondrium into the center of ossifying cartilage. As the primary ossification center expands, hypertrophic chondrocytes continue to express high levels of VEGF and as osteoclasts, endothelial cells and preosteoblasts continue to invade the VEGF‐rich environment, metaphyseal growth plates are established.

VEGF produced by osteoblastic progenitor cells in periosteum and perichondrium of developing membranous and endochondral bones, stimulates angiogenesis and induces differentiation of progenitor cells to preosteoblasts and bone‐forming osteoblasts. The stimulatory effect on angiogenesis in turn results in endothelial‐derived osteogenic factors that may induce periosteal/perichondrial bone formation. In addition, osteoblast lineage cell‐derived VEGF may also induce osteoblast differentiation based on autocrine/intracrine mechanisms involving cytoplasmic and/or nuclear VEGF.

Intracellular VEGF functions are made possible by a gene that contains two transcriptional start sites. Transcripts from the downstream site are translated into proteins with a signal peptide, allowing direct entry into the secretory pathway. In contrast, transcripts from the upstream site are translated into proteins that are about twice the size of secreted VEGF. This “long” VEGF is processed in the cytoplasm to forms that can enter the secretory pathway, or high molecular weight forms that are entering the nuclear compartment.

VEGF expression by chondrocytes is required for synovial joint development and the timely differentiation of articular chondrocytes. However, in aging joints the growth factor shows its dark side in that increasing expression levels of VEGF in cells of synovial joints stimulate both articular cartilage degeneration and increased joint pain in osteoarthritis.

Support or Funding Information

NIH‐NIAMS
Associations between Nursing Care Levels and Nutrition Status in the Elderly in Nursing Care Facilities in Japan
Authors: Oe Yukiko , Goda Toshinao
Published: November 2023

Most of elderly who requires nursing care has chronic disease, and due to a diminished food intake and physical activity, they tend to show decreased skeletal muscle mass. As a result, there is a great increase in the risk of fall and malnutrition in the elderly. Malnutrition is known to worsen the prognosis after infection and delay healing of disease in the elderly due to decreased immune function. In this study, we have examined the associations between nutrition status and blood biochemical parameters, the degree of independence in dementia elderly's activity of daily living, the nursing care levels, and the form of food in 1,823 elderly persons aged 61–106 y (average 86.7 y) who lives in nursing care facilities. The percentages of the elderly at risk of malnutrition according to GNRI (Geriatric Nutritional Risk Index) were 67.0% for men and 66.2% for women. The GNRI scores tended to be lower according to an increase in the nursing care level. In elderly men, the GNRI scores were remarkably lower in the groups categorized as nursing care levels 4 and higher than those in nursing care level 3 or lower. In elderly women, the GNRI scores were greatly decreased in the groups categorized as nursing care levels 2 and higher. The lower the degree of independence in dementia elderly's activity of daily living was, the lower the GNRI, and the GNRI scores of the groups categorized □a and over were significantly lower than those categorized as of □b or under. The GNRI scores were associated with the provided form of food, according to the transition from regular to liquid form. The results of this study suggest that the nutrition status of elderly who requires nursing care in nursing homes was associated with the degree of independence in dementia elderly's activity of daily living, the nursing care level, and the form of food, and it may be attributable to a decrease in physical function required for activity of daily living.
Excessive Free Fatty Acid Oxidation in Non‐obese Healthy Asian Men with Insulin Resistance is Associated with Impaired Branched‐chain Amino Acid Oxidation
Authors: Tan Hong Chang , Hsu Jean W. , Sidney Yu , Khoo Chin Meng , Tai E Shyong , Jahoor Farook
Published: November 2023

Background

Branched‐chain Amino Acids (BCAA) are elevated in insulin resistant (IR) states and may be involved in the pathogenesis of IR in non‐obese individuals. It remains unclear whether this could be secondary to impairment in clearance from oxidation or increased rate of appearance (Ra) because of IR.

Objectives

Our study compared leucine and palmitate kinetics between 14 insulin sensitive (IS) and 12 IR non‐obese healthy Asian men. We hypothesized that greater free fatty acid (FFA) availability for oxidation in IR impairs BCAA oxidation leading to higher blood BCAA concentration.

Methods

Subjects underwent oral glucose tolerance testing for measurement of their whole body insulin sensitivity index (WBISI) and body composition measured using the 2H2O method. [U‐13C16] palmitate and [U‐13C6] leucine were infused at least 1‐week apart for quantification of their rates of oxidation and Ra. Kinetic data are expressed as μmol/kgFFM/h.

Results

Compared to IS subjects, IR subject had significantly lower WBISI (3.30 ± 0.26 vs. 8.03 ± 0.92), higher body mass index (24.4 ± 0.6 vs. 23.0 ± 0.3 kg/m2), body fat % (29.8 ± 2.4 vs. 23.7 ± 1.3) and total blood BCAA (438.1 ± 21.7 vs. 385.0 ± 14.5 umol/L, p = 0.048). Palmitate Ra was much higher in IR subjects (189.0 ± 13.5 vs. 151.8 ± 8.5, p = 0.027) indicating greater exposure of skeletal tissue to circulatory FFA. This was accompanied by greater palmitate oxidation (60.6 ± 4.3 vs. 46.2 ± 3.5, p = 0.016) such that plasma concentration was not significantly different between the comparator groups (124.7 ± 5.7 vs. 108.9 ± 13.1, p = 0.295). Leucine Ra (152.8 ± 5.5 vs. 144.6 ± 3.2, p = 0.067) and oxidation (19.2 ± 0.4 vs. 16.3 ± 0.7, p = 0.028) were also higher in IR but leucine oxidative capacity, defined as percentage leucine flux oxidized, was significantly lower (11.9 ± 0.4 vs. 10.6 ± 0.4, p = 0.028).

Conclusions

Elevated blood BCAA in healthy non‐obese but IR men is a consequence of both greater Ra and impaired BCAA oxidative capacity and this is associated with excessive FFA oxidation.

Support or Funding Information

Supported by SingHealth Medicine Academic Clinical Program (03/FY2014/P1/06‐A16)