Function (Oxford, England)Pub Date : 2023-09-01eCollection Date: 2023-01-01DOI: 10.1093/function/zqad044
Robin Elaine Duncan
{"title":"Deficiency of phosphatidylethanolamine synthesis: consequences for skeletal muscle.","authors":"Robin Elaine Duncan","doi":"10.1093/function/zqad044","DOIUrl":"10.1093/function/zqad044","url":null,"abstract":"hosphatidylethanolamine (PE) is a major gl ycer ophospholipid PL) in cellular and organellar membranes, and dysregulation of E synthesis has been associated with ener gy o v er-stora ge and nsulin resistance. 1 Due to the small size of its ethanolamine eadgr oup r elati v e to the v olume occupied by its long and, in articular, unsaturated fatty acyl side chains (which impart a kink” to the molecule), PE forms a conical shape. 2 This moleclar structure is key to sculpting the curv atur e of the inner layer f cellular and organellar membranes, where PE is quantitati v el y he most abundant type of PL. 3 In organelles where a high degree of membrane curv atur e s critical for the translation of structure to function, such s in the cristae that form the inner mitochondrial memranes, increases in PE content can impr ov e performance, hile losses can result in dysfunction that is so critical as o be incompatible with cellular and organismal life. 4 While his provides a direct connection between PE and the conrol of energy metabolism, recent studies demonstrate addiional roles for this gl ycer olipid in the regulation of wholeody metabolic homeostasis that are both complex and overlaping. For example, PE is primarily synthesized in the Kennedy athw ay thr ough the cytidine diphosphate (CDP)-ethanolamine athw ay, wher e CTP:phosphoethanolamine c ytid ylyltr ansfer ase Pcyt2) catalyzes the second and rate-limiting step. Because iacylgl ycer ol (DAG) is a substrate in the third and final step f the PE-K ennedy pathw ay, limitations in Pcyt2 activity are ssociated with reduced utilization, and therefore increased t","PeriodicalId":73119,"journal":{"name":"Function (Oxford, England)","volume":"4 6","pages":"zqad044"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10533200/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41158101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Function (Oxford, England)Pub Date : 2023-09-01eCollection Date: 2023-01-01DOI: 10.1093/function/zqad048
Darby S Easterday, Daniel S Lark
{"title":"Circulating Tetraspanins: From Markers to Mechanisms Driving Systemic Exercise Adaptation.","authors":"Darby S Easterday, Daniel S Lark","doi":"10.1093/function/zqad048","DOIUrl":"10.1093/function/zqad048","url":null,"abstract":"Exercise impr ov es cardiometa bolic health thr ough a range of systemic [ie , bey ond w orking skeletal muscle (SkM)] mec ha-nisms typically attributed to small molecules and peptide hormones. Recent discoveries have shown that the abundance and cargo of circulating small extracellular vesicles (sEVs) like exosomes ar e alter ed by exer cise , but linking these c hanges to SkM-deri v ed systemic exercise adaptations has been challenging. A key barrier to linking SkM sEVs to exercise adaptations is determining which of the hundreds of molecules that may be transported by SkM sEVs have functional relevance in the context of exer cise . One surprisingly untested str ate gy is to start with the most abundant sEV car go . Tetraspanins like CD81 are tr ansmembr ane protein hallmarks of sEVs. To date, CD81 has only been described as an sEV marker, not an instrument of sEV function. However, ∼ 30 yr of resear c h has established CD81 as a tr ansmembr ane adaptor protein that influences a variety of cellular functions by altering the organization of r ece ptor pr oteins within membranes. Multiple groups","PeriodicalId":73119,"journal":{"name":"Function (Oxford, England)","volume":"4 6","pages":"zqad048"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10519272/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41163799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Function (Oxford, England)Pub Date : 2023-08-29eCollection Date: 2023-01-01DOI: 10.1093/function/zqad046
Mir Md Nasim Hossain, Nien-Wen Hu, Maram Abdelhamid, Simerpreet Singh, Walter L Murfee, Peter Balogh
{"title":"Angiogenic Microvascular Wall Shear Stress Patterns Revealed Through Three-dimensional Red Blood Cell Resolved Modeling.","authors":"Mir Md Nasim Hossain, Nien-Wen Hu, Maram Abdelhamid, Simerpreet Singh, Walter L Murfee, Peter Balogh","doi":"10.1093/function/zqad046","DOIUrl":"10.1093/function/zqad046","url":null,"abstract":"<p><p>The wall shear stress (WSS) exerted by blood flowing through microvascular capillaries is an established driver of new blood vessel growth, or angiogenesis. Such adaptations are central to many physiological processes in both health and disease, yet three-dimensional (3D) WSS characteristics in real angiogenic microvascular networks are largely unknown. This marks a major knowledge gap because angiogenesis, naturally, is a 3D process. To advance current understanding, we model 3D red blood cells (RBCs) flowing through rat angiogenic microvascular networks using state-of-the-art simulation. The high-resolution fluid dynamics reveal 3D WSS patterns occurring at sub-endothelial cell (EC) scales that derive from distinct angiogenic morphologies, including microvascular loops and vessel tortuosity. We identify the existence of WSS hot and cold spots caused by angiogenic surface shapes and RBCs, and notably enhancement of low WSS regions by RBCs. Spatiotemporal characteristics further reveal how fluctuations follow timescales of RBC \"footprints.\" Altogether, this work provides a new conceptual framework for understanding how shear stress might regulate EC dynamics in vivo.</p>","PeriodicalId":73119,"journal":{"name":"Function (Oxford, England)","volume":"4 6","pages":"zqad046"},"PeriodicalIF":5.1,"publicationDate":"2023-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10519277/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41123551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Function (Oxford, England)Pub Date : 2023-08-08eCollection Date: 2023-01-01DOI: 10.1093/function/zqad041
Alexandria B Marciante, Yasin B Seven, Mia N Kelly, Raphael R Perim, Gordon S Mitchell
{"title":"Magnitude and Mechanism of Phrenic Long-term Facilitation Shift Between Daily Rest Versus Active Phase.","authors":"Alexandria B Marciante, Yasin B Seven, Mia N Kelly, Raphael R Perim, Gordon S Mitchell","doi":"10.1093/function/zqad041","DOIUrl":"10.1093/function/zqad041","url":null,"abstract":"<p><p>Plasticity is a fundamental property of the neural system controlling breathing. One key example of respiratory motor plasticity is phrenic long-term facilitation (pLTF), a persistent increase in phrenic nerve activity elicited by acute intermittent hypoxia (AIH). pLTF can arise from distinct cell signaling cascades initiated by serotonin versus adenosine receptor activation, respectively, and interact via powerful cross-talk inhibition. Here, we demonstrate that the daily rest/active phase and the duration of hypoxic episodes within an AIH protocol have profound impact on the magnitude and mechanism of pLTF due to shifts in serotonin/adenosine balance. Using the historical \"standard\" AIH protocol (3, 5-min moderate hypoxic episodes), we demonstrate that pLTF magnitude is unaffected by exposure in the midactive versus midrest phase, yet the mechanism driving pLTF shifts from serotonin-dominant (midrest) to adenosine-dominant (midactive). This mechanistic \"flip\" results from combined influences of hypoxia-evoked adenosine release and daily fluctuations in basal spinal adenosine. Since AIH evokes less adenosine with shorter (15, 1-min) hypoxic episodes, midrest pLTF is amplified due to diminished adenosine constraint on serotonin-driven plasticity; in contrast, elevated background adenosine during the midactive phase suppresses serotonin-dominant pLTF. These findings demonstrate the importance of the serotonin/adenosine balance in regulating the amplitude and mechanism of AIH-induced pLTF. Since AIH is emerging as a promising therapeutic modality to restore respiratory and nonrespiratory movements in people with spinal cord injury or ALS, knowledge of how time-of-day and hypoxic episode duration impact the serotonin/adenosine balance and the magnitude and mechanism of pLTF has profound biological, experimental, and translational implications.</p>","PeriodicalId":73119,"journal":{"name":"Function (Oxford, England)","volume":"4 6","pages":"zqad041"},"PeriodicalIF":0.0,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/76/d9/zqad041.PMC10519274.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41124716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Function (Oxford, England)Pub Date : 2023-08-07eCollection Date: 2023-01-01DOI: 10.1093/function/zqad043
Natalia M Mathieu, Eva M Fekete, Patricia C Muskus, Daniel T Brozoski, Ko-Ting Lu, Kelsey K Wackman, Javier Gomez, Shi Fang, John J Reho, Connie C Grobe, Ibrahim Vazirabad, Gary C Mouradian, Matthew R Hodges, Jeffrey L Segar, Justin L Grobe, Curt D Sigmund, Pablo Nakagawa
{"title":"Genetic Ablation of Prorenin Receptor in the Rostral Ventrolateral Medulla Influences Blood Pressure and Hydromineral Balance in Deoxycorticosterone-Salt Hypertension.","authors":"Natalia M Mathieu, Eva M Fekete, Patricia C Muskus, Daniel T Brozoski, Ko-Ting Lu, Kelsey K Wackman, Javier Gomez, Shi Fang, John J Reho, Connie C Grobe, Ibrahim Vazirabad, Gary C Mouradian, Matthew R Hodges, Jeffrey L Segar, Justin L Grobe, Curt D Sigmund, Pablo Nakagawa","doi":"10.1093/function/zqad043","DOIUrl":"10.1093/function/zqad043","url":null,"abstract":"<p><p>Non-enzymatic activation of renin via its interaction with prorenin receptor (PRR) has been proposed as a key mechanism of local renin-angiotensin system (RAS) activation. The presence of renin and angiotensinogen has been reported in the rostral ventrolateral medulla (RVLM). Overactivation of bulbospinal neurons in the RVLM is linked to hypertension (HTN). Previous studies have shown that the brain RAS plays a role in the pathogenesis of the deoxycorticosterone (DOCA)-salt HTN model. Thus, we hypothesized that PRR in the RVLM is involved in the local activation of the RAS, facilitating the development of DOCA-salt HTN. Selective PRR ablation targeting the RVLM (PRR<sup>RVLM-Null</sup> mice) resulted in an unexpected sex-dependent and biphasic phenotype in DOCA-salt HTN. That is, PRR<sup>RVLM-Null</sup> females (but not males) exhibited a significant delay in achieving maximal pressor responses during the initial stage of DOCA-salt HTN. Female PRR<sup>RVLM-Null</sup> subsequently showed exacerbated DOCA-salt-induced pressor responses during the \"maintenance\" phase with a maximal peak at 13 d on DOCA-salt. This exacerbated response was associated with an increased sympathetic drive to the resistance arterioles and the kidney, exacerbated fluid and sodium intake and output in response to DOCA-salt, and induced mobilization of fluids from the intracellular to extracellular space concomitant with elevated vasopressin. Ablation of PRR suppressed genes involved in RAS activation and catecholamine synthesis in the RVLM but also induced expression of genes involved in inflammatory responses. This study illustrates complex and sex-dependent roles of PRR in the neural control of BP and hydromineral balance through autonomic and neuroendocrine systems. Graphical abstract.</p>","PeriodicalId":73119,"journal":{"name":"Function (Oxford, England)","volume":"4 5","pages":"zqad043"},"PeriodicalIF":5.1,"publicationDate":"2023-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10440998/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10206983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Function (Oxford, England)Pub Date : 2023-07-26eCollection Date: 2023-01-01DOI: 10.1093/function/zqad039
Marharyta Semenikhina, Joshua H Lipschutz, Oleg Palygin
{"title":"Breaking New Ground: The Crucial Role of Animal Research in the Advancement of Rhabdomyolysis-Induced AKI Treatment and Prevention.","authors":"Marharyta Semenikhina, Joshua H Lipschutz, Oleg Palygin","doi":"10.1093/function/zqad039","DOIUrl":"10.1093/function/zqad039","url":null,"abstract":"","PeriodicalId":73119,"journal":{"name":"Function (Oxford, England)","volume":"4 5","pages":"zqad039"},"PeriodicalIF":0.0,"publicationDate":"2023-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10413931/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10006225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Function (Oxford, England)Pub Date : 2023-07-25eCollection Date: 2023-01-01DOI: 10.1093/function/zqad038
Shima Sadri, Xiao Zhang, Said H Audi, Allen W Cowley, Ranjan K Dash
{"title":"Computational Modeling of Substrate-Dependent Mitochondrial Respiration and Bioenergetics in the Heart and Kidney Cortex and Outer Medulla.","authors":"Shima Sadri, Xiao Zhang, Said H Audi, Allen W Cowley, Ranjan K Dash","doi":"10.1093/function/zqad038","DOIUrl":"10.1093/function/zqad038","url":null,"abstract":"<p><p>Integrated computational modeling provides a mechanistic and quantitative framework to characterize alterations in mitochondrial respiration and bioenergetics in response to different metabolic substrates <i>in-silico</i>. These alterations play critical roles in the pathogenesis of diseases affecting metabolically active organs such as heart and kidney. Therefore, the present study aimed to develop and validate thermodynamically constrained integrated computational models of mitochondrial respiration and bioenergetics in the heart and kidney cortex and outer medulla (OM). The models incorporated the kinetics of major biochemical reactions and transport processes as well as regulatory mechanisms in the mitochondria of these tissues. Intrinsic model parameters such as Michaelis-Menten constants were fixed at previously estimated values, while extrinsic model parameters such as maximal reaction and transport velocities were estimated separately for each tissue. This was achieved by fitting the model solutions to our recently published respirometry data measured in isolated rat heart and kidney cortex and OM mitochondria utilizing various NADH- and FADH<sub>2</sub>-linked metabolic substrates. The models were validated by predicting additional respirometry and bioenergetics data, which were not used for estimating the extrinsic model parameters. The models were able to predict tissue-specific and substrate-dependent mitochondrial emergent metabolic system properties such as redox states, enzyme and transporter fluxes, metabolite concentrations, membrane potential, and respiratory control index under diverse physiological and pathological conditions. The models were also able to quantitatively characterize differential regulations of NADH- and FADH<sub>2</sub>-linked metabolic pathways, which contribute differently toward regulations of oxidative phosphorylation and ATP synthesis in the heart and kidney cortex and OM mitochondria.</p>","PeriodicalId":73119,"journal":{"name":"Function (Oxford, England)","volume":"4 5","pages":"zqad038"},"PeriodicalIF":0.0,"publicationDate":"2023-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10413947/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10006232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Function (Oxford, England)Pub Date : 2023-07-04eCollection Date: 2023-01-01DOI: 10.1093/function/zqad035
Kinga B Stopa, Filip Łoziński, Agnieszka A Kusiak, Jacek Litewka, Daria Krzysztofik, Sylwester Mosiołek, Jan Morys, Paweł E Ferdek, Monika A Jakubowska
{"title":"Driver Mutations of Pancreatic Cancer Affect Ca<sup>2+</sup> Signaling and ATP Production.","authors":"Kinga B Stopa, Filip Łoziński, Agnieszka A Kusiak, Jacek Litewka, Daria Krzysztofik, Sylwester Mosiołek, Jan Morys, Paweł E Ferdek, Monika A Jakubowska","doi":"10.1093/function/zqad035","DOIUrl":"10.1093/function/zqad035","url":null,"abstract":"<p><p>Glandular pancreatic epithelia of the acinar or ductal phenotype may seem terminally differentiated, but they are characterized by remarkable cell plasticity. Stress-induced trans-differentiation of these cells has been implicated in the mechanisms of carcinogenesis. Current consensus links pancreatic ductal adenocarcinoma with onco-transformation of ductal epithelia, but under the presence of driver mutations in <i>Kras</i> and <i>Trp53</i>, also with trans-differentiation of pancreatic acini. However, we do not know when, in the course of cancer progression, physiological functions are lost by mutant acinar cells, nor can we assess their capacity for the production of pancreatic juice components. Here, we investigated whether two mutations-Kras<sup>G12D</sup> and Trp53<sup>R172H</sup>-present simultaneously in acinar cells of KPC mice (model of oncogenesis) influence cytosolic Ca<sup>2+</sup> signals. Since Ca<sup>2+</sup> signals control the cellular handling of digestive hydrolases, any changes that affect intracellular signaling events and cell bioenergetics might have an impact on the physiology of the pancreas. Our results showed that physiological doses of acetylcholine evoked less regular Ca<sup>2+</sup> oscillations in KPC acinar cells compared to the control, whereas responses to supramaximal concentrations were markedly reduced. Menadione elicited Ca<sup>2+</sup> signals of different frequencies in KPC cells compared to control cells. Finally, Ca<sup>2+</sup> extrusion rates were significantly inhibited in KPC cells, likely due to the lower basal respiration and ATP production. Cumulatively, these findings suggest that driver mutations affect the signaling capacity of pancreatic acinar cells even before the changes in the epithelial cell morphology become apparent.</p>","PeriodicalId":73119,"journal":{"name":"Function (Oxford, England)","volume":"4 5","pages":"zqad035"},"PeriodicalIF":0.0,"publicationDate":"2023-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10413928/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10006228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Function (Oxford, England)Pub Date : 2023-07-03eCollection Date: 2023-01-01DOI: 10.1093/function/zqad034
Gaurav Kumar, Shi Fang, Daria Golosova, Ko-Ting Lu, Daniel T Brozoski, Ibrahim Vazirabad, Curt D Sigmund
{"title":"Structure and Function of RhoBTB1 Required for Substrate Specificity and Cullin-3 Ubiquitination.","authors":"Gaurav Kumar, Shi Fang, Daria Golosova, Ko-Ting Lu, Daniel T Brozoski, Ibrahim Vazirabad, Curt D Sigmund","doi":"10.1093/function/zqad034","DOIUrl":"10.1093/function/zqad034","url":null,"abstract":"<p><p>We identified Rho-related BTB domain containing 1 (RhoBTB1) as a key regulator of phosphodiesterase 5 (PDE5) activity, and through PDE5, a regulator of vascular tone. We identified the binding interface for PDE5 on RhoBTB1 by truncating full-length RhoBTB1 into its component domains. Co-immunoprecipitation analyses revealed that the C-terminal half of RhoBTB1 containing its two BTB domains and the C-terminal domain (B1B2C) is the minimal region required for PDE5 recruitment and subsequent proteasomal degradation via Cullin-3 (CUL3). The C-terminal domain was essential in recruiting PDE5 as constructs lacking this region could not participate in PDE5 binding or proteasomal degradation. We also identified Pro<sup>353</sup> and Ser<sup>363</sup> as key amino acid residues in the B1B2C region involved in CUL3 binding to RhoBTB1. Mutation of either of these residues exhibited impaired CUL3 binding and PDE5 degradation, although the binding to PDE5 was preserved. Finally, we employed ascorbate peroxidase 2 (APEX2) proximity labeling using a B1B2C-APEX2 fusion protein as bait to capture unknown RhoBTB1 binding partners. Among several B1B2C-binding proteins identified and validated, we focused on SET domain containing 2 (SETD2). SETD2 and RhoBTB1 directly interacted, and the level of SETD2 increased in response to pharmacological inhibition of the proteasome or Cullin complex, CUL3 deletion, and RhoBTB1-inhibition with siRNA. This suggests that SETD2 is regulated by the RhoBTB1-CUL3 axis. Future studies will determine whether SETD2 plays a role in cardiovascular function.</p>","PeriodicalId":73119,"journal":{"name":"Function (Oxford, England)","volume":"4 5","pages":"zqad034"},"PeriodicalIF":0.0,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10413933/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10400406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Function (Oxford, England)Pub Date : 2023-06-27eCollection Date: 2023-01-01DOI: 10.1093/function/zqad033
Megan R Beggs, Kennedi Young, Allen Plain, Debbie D O'Neill, Ahsan Raza, Veit Flockerzi, Henrik Dimke, R Todd Alexander
{"title":"Maternal Epidermal Growth Factor Promotes Neonatal Claudin-2 Dependent Increases in Small Intestinal Calcium Permeability.","authors":"Megan R Beggs, Kennedi Young, Allen Plain, Debbie D O'Neill, Ahsan Raza, Veit Flockerzi, Henrik Dimke, R Todd Alexander","doi":"10.1093/function/zqad033","DOIUrl":"10.1093/function/zqad033","url":null,"abstract":"<p><p>A higher concentration of calcium in breast milk than blood favors paracellular calcium absorption enabling growth during postnatal development. We aimed to determine whether suckling animals have greater intestinal calcium permeability to maximize absorption and to identify the underlying molecular mechanism. We examined intestinal claudin expression at different ages in mice and in human intestinal epithelial (Caco-2) cells in response to hormones or human milk. We also measured intestinal calcium permeability in wildtype, <i>Cldn2</i> and <i>Cldn12</i> KO mice and Caco-2 cells in response to hormones or human milk. Bone mineralization in mice was assessed by μCT. Calcium permeability across the jejunum and ileum of mice were 2-fold greater at 2 wk than 2 mo postnatal age. At 2 wk, <i>Cldn2</i> and <i>Cldn12</i> expression were greater, but only <i>Cldn2</i> KO mice had decreased calcium permeability compared to wildtype. This translated to decreased bone volume, cross-sectional thickness, and tissue mineral density of femurs. Weaning from breast milk led to a 50% decrease in <i>Cldn2</i> expression in the jejunum and ileum. Epidermal growth factor (EGF) in breast milk specifically increased only CLDN2 expression and calcium permeability in Caco-2 cells. These data support intestinal permeability to calcium, conferred by claudin-2, being greater in suckling mice and being driven by EGF in breast milk. Loss of the CLDN2 pathway leads to suboptimal bone mineralization at 2 wk of life. Overall, EGF-mediated control of intestinal claudin-2 expression contributes to maximal intestinal calcium absorption in suckling animals.</p>","PeriodicalId":73119,"journal":{"name":"Function (Oxford, England)","volume":"4 5","pages":"zqad033"},"PeriodicalIF":0.0,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/1e/06/zqad033.PMC10413934.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10006231","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}