a-minimally-invasive-method-for-generating-syngeneic-orthotopic-mouse

A Minimally Invasive Method for Generating a Syngeneic Orthotopic Mouse Model of Lung Cancer

Non-small cell lung cancer (NSCLC) continues to be the number one cause of cancer-related death for both women and men worldwide. More information needs ...

University of Iowa

Geminii, Inc.

Hydrocephalus is a common neurological disorder that leads to expansion of the cerebral ventricles and is associated with a high rate of morbidity and mortality. Most neonatal cases are of unknown etiology and are likely to have complex inheritance involving multiple genes and environmental factors. Identifying molecular mechanisms for neonatal hydrocephalus and developing noninvasive treatment modalities are high priorities. Here we use a hydrocephalic mouse model of the human ciliopathy Bardet-Biedl Syndrome (BBS) and identify a role for neural progenitors in the pathogenesis of neonatal hydrocephalus. We found that hydrocephalus in this mouse model is caused by aberrant platelet-derived growth factor receptor α (PDGFR-α) signaling, resulting in increased apoptosis and impaired proliferation of chondroitin sulfate proteoglycan 4 (also known as neuron-glial antigen 2 or NG2)(+)PDGFR-α(+) neural progenitors. Targeting this pathway with lithium treatment rescued NG2(+)PDGFR-α(+) progenitor cell proliferation in BBS mutant mice, reducing their ventricular volume. Our findings demonstrate that neural progenitors are crucial in the pathogenesis of neonatal hydrocephalus, and we identify new therapeutic targets for this common neurological disorder.

Abnormal development of NG2+PDGFR-α+ neural progenitor cells leads to neonatal hydrocephalus in a ciliopathy mouse model.

Bardet-Biedl Syndrome (BBS) is a pleiotropic and genetically heterozygous disorder caused independently by numerous genes (BBS1-BBS17). Seven highly conserved BBS proteins (BBS1, 2, 4, 5, 7, 8, and 9) form a complex known as the BBSome, which functions in ciliary membrane biogenesis. BBS7 is both a unique subunit of the BBSome and displays direct physical interaction with a second BBS complex, the BBS chaperonin complex. To examine the in vivo function of BBS7, we generated Bbs7 knockout mice. Bbs7(-/-) mice show similar phenotypes to other BBS gene mutant mice including retinal degeneration, obesity, ventriculomegaly, and male infertility characterized by abnormal spermatozoa flagellar axonemes. Using tissues from Bbs7(-/-) mice, we show that BBS7 is required for BBSome formation, and that BBS7 and BBS2 depend on each other for protein stability. Although the BBSome serves as a coat complex for ciliary membrane proteins, BBS7 is not required for the localization of ciliary membrane proteins polycystin-1, polycystin-2, or bitter taste receptors, but absence of BBS7 leads to abnormal accumulation of the dopamine D1 receptor (D1R) to the ciliary membrane, indicating that BBS7 is involved in specific membrane protein localization to cilia.

BBS7 is required for BBSome formation and its absence in mice results in Bardet-Biedl syndrome phenotypes and selective abnormalities in membrane protein trafficking.

Syndrome de Bardet-Biedl (BBS) est un trouble pl&eacute;iotrope et g&eacute;n&eacute;tiquement h&eacute;t&eacute;rozygote caus&eacute; ind&eacute;pendamment par nombreux g&egrave;nes (BBS1-BBS17). Sept hautement conserv&eacute;e de prot&eacute;ines BBS (BBS1, 2, 4, 5, 7, 8 et 9) forment un complexe connu comme la BBSome, qui fonctionne dans la biogen&egrave;se membrane ciliaire. BBS7 est une sous-unit&eacute; les deux unique de la BBSome et affiche une interaction physique directe avec un BBS deuxi&egrave;me complexe, le BBS chaperonin complexe. Pour examiner la fonction in vivo de BBS7, nous avons g&eacute;n&eacute;r&eacute; des souris knock-out Bbs7. Bbs7(-/-) souris montrent des ph&eacute;notypes semblables d&#39;autres g&egrave;nes BBS souris mutantes dont la d&eacute;g&eacute;n&eacute;rescence r&eacute;tinienne, l&#39;ob&eacute;sit&eacute;, ventriculom&eacute;galie et infertilit&eacute; masculine, caract&eacute;ris&eacute;e par des axon&egrave;mes flagellaires de spermatozo&iuml;des anormaux. &Agrave; l&#39;aide de tissus de souris Bbs7(-/-), nous montrons que BBS7 est n&eacute;cessaire pour la formation de BBSome, et que BBS7 et BBS2 d&eacute;pendent les uns des autres pour la stabilit&eacute; des prot&eacute;ines. Bien que le BBSome sert un manteau complexe pour les prot&eacute;ines de la membrane ciliaire, BBS7 n&#39;est pas requis pour la localisation des prot&eacute;ines de membrane ciliaire polycystine-1, polycystine-2 ou les r&eacute;cepteurs de go&ucirc;t amer, mais absence de BBS7 conduit &agrave; une accumulation anormale du r&eacute;cepteur de la dopamine D1 (D1R) &agrave; la membrane ciliaire, indiquant que BBS7 est impliqu&eacute;e dans la localisation des prot&eacute;ines membranaires sp&eacute;cifiques aux cils.

BBS7 est requis pour la formation de BBSome et son absence dans les r&eacute;sultats de la souris dans les ph&eacute;notypes de syndrome de Bardet-Biedl et des anomalies dans le trafic de prot&eacute;ine de membrane s&eacute;lectives.

Sindrome di Bardet-Biedl (BBS) &egrave; un disturbo pleiotropico ed eterozigote geneticamente causato indipendentemente da numerosi geni (BBS1-BBS17). Sette altamente conservate le proteine BBS (BBS1, 2, 4, 5, 7, 8 e 9) formano un complesso conosciuto come il BBSome, che funziona nella biogenesi della membrana ciliare. BBS7 &egrave; sia un&#39;unica subunit&agrave; della BBSome e visualizza diretta interazione fisica con un secondo complesso, di BBS BBS chaperonin complesso. Per esaminare la funzione in vivo di BBS7, abbiamo generato Bbs7 topi knockout. Bbs7(-/-) topi mostrano fenotipi simili ad altri gene BBS topi mutanti tra cui degenerazione retinica, obesit&agrave;, ventricolomegalia e infertilit&agrave; maschile caratterizzata da axonemes flagellari spermatozoi anormali. Utilizzando tessuti da topi Bbs7(-/-), mostriamo che BBS7 &egrave; necessaria per la formazione di BBSome, e che BBS7 e BBS2 dipendono reciprocamente per la stabilit&agrave; proteica. Anche se il BBSome serve come un cappotto complesse per le proteine di membrana ciliare, BBS7 non &egrave; necessaria per la localizzazione delle proteine di membrana ciliare polycystin-1, polycystin-2 o i recettori del gusto amaro, ma assenza di BBS7 porta a un accumulo anormale del recettore della dopamina D1 (D1R) alla membrana ciliare, che indica che BBS7 &egrave; coinvolto nella localizzazione della proteina di membrana specifica per ciglia.

BBS7 &egrave; necessaria per la formazione di BBSome e la sua assenza in topi risultati in fenotipi sindrome di Bardet-Biedl e selettive anomalie nel traffico di proteine di membrana.

Nephronophthisis-related ciliopathies (NPHP-RC) are a group of disorders that present with end-stage renal failure in childhood/adolescence, kidney cysts, retinal degeneration, and cerebellar hypoplasia. One disorder that shares clinical features with NPHP-RC is Bardet-Biedl Syndrome (BBS). Serologically defined colon cancer antigen 8 (SDCCAG8; also known as NPHP10 and BBS16) is an NPHP gene that is also associated with BBS. To better understand the patho-mechanisms of NPHP and BBS caused by loss of SDCCAG8 function, we characterized an SDCCAG8 mouse model (Sdccag8Tn(sb-Tyr)2161B.CA1C2Ove) generated by Sleeping Beauty Transposon (SBT)-mediated insertion mutagenesis. Consistent with the previously reported, independent SDCCAG8 mouse models, our mutant mice display pre-axial polydactyly in their hind limbs. In addition, we report patterning defects in the secondary palate, brain abnormalities, as well as neonatal lethality associated with developmental defects in the lung in our mouse model. The neonatal lethality phenotype is genetic background dependent and rescued by introducing 129S6/SvEvTac background. Genetic modifier(s) responsible for this effect were mapped to a region between SNPs rs3714172 and rs3141832 on chromosome 11. While determining the precise genetic lesion in our mouse model, we found that SBT insertion resulted in a deletion of multiple exons from both Sdccag8 and its neighboring gene Akt3. We ascribe the patterning defects in the limb and the secondary palate as well as lung abnormalities to loss of SDCCAG8, while the developmental defects in the brain are likely due to the loss of AKT3. This mouse model may be useful to study features not observed in other SDCCAG8 models but cautions are needed in interpreting data.

Genotypic and phenotypic characterization of the Sdccag8Tn(sb-Tyr)2161B.CA1C2Ove mouse model.

Aberrant redox signaling underlies the pathophysiology of many chronic metabolic diseases, including type 2 diabetes (T2D). Methodologies aimed at rebalancing systemic redox homeostasis have had limited success. A noninvasive, sustained approach would enable the long-term control of redox signaling for the treatment of T2D. We report that static magnetic and electric fields (sBE) noninvasively modulate the systemic GSH-to-GSSG redox couple to promote a healthier systemic redox environment that is reducing. Strikingly, when applied to mouse models of T2D, sBE rapidly ameliorates insulin resistance and glucose intolerance in as few as 3 days with no observed adverse effects. Scavenging paramagnetic byproducts of oxygen metabolism with SOD2 in hepatic mitochondria fully abolishes these insulin sensitizing effects, demonstrating that mitochondrial superoxide mediates induction of these therapeutic changes. Our findings introduce a remarkable redox-modulating phenomenon that exploits endogenous electromagneto-receptive mechanisms for the noninvasive treatment of T2D, and potentially other redox-related diseases.

Exposure to Static Magnetic and Electric Fields Treats Type 2 Diabetes.

The art of virtual mentoring in the twenty-first century for STEM majors and beyond.

Scientific success is mainly supported by mentoring, which often occurs through face-to-face interactions. Changes to the research environment incurred by the Coronavirus 2019 (COVID-19) pandemic have necessitated mentorship adaptations. Here, we describe how mentors can broaden their mentorship to support trainee growth and provide reassurance about trainee development amid uncertain circumstances.

Mentoring during Uncertain Times.

Counterpoint: An alternative hypothesis for why exposure to static magnetic and electric fields treats type 2 diabetes.

Reply to Petersen et al.: An alternative hypothesis for why exposure to static magnetic and electric fields treats type 2 diabetes.

Primary cilia are microtubule-based organelles present on most cells that regulate many physiological processes, ranging from maintaining energy homeostasis to renal function. However, the role of these structures in the regulation of behavior remains unknown. To study the role of cilia in behavior, we employ mouse models of the human ciliopathy, Bardet-Biedl Syndrome (BBS). Here, we demonstrate that BBS mice have significant impairments in context fear conditioning, a form of associative learning. Moreover, we show that postnatal deletion of BBS gene function, as well as congenital deletion, specifically in the forebrain, impairs context fear conditioning. Analyses indicated that these behavioral impairments are not the result of impaired hippocampal long-term potentiation. However, our results indicate that these behavioral impairments are the result of impaired hippocampal neurogenesis. Two-week treatment with lithium chloride partially restores the proliferation of hippocampal neurons which leads to a rescue of context fear conditioning. Overall, our results identify a novel role of cilia genes in hippocampal neurogenesis and long-term context fear conditioning.

A mouse model of Bardet-Biedl Syndrome has impaired fear memory, which is rescued by lithium treatment.

The rise of novel, more infectious SARS-CoV-2 variants has made clear the need to rapidly deploy large-scale testing for COVID-19 to protect public health. However, testing remains limited due to shortages of personal protective equipment (PPE), naso- and oropharyngeal swabs, and healthcare workers. Simple test methods are needed to enhance COVID-19 screening. Here, we describe a simple, and inexpensive spit-test for COVID-19 screening called Patient Self-Collection of Sample-CoV2 ().

An open source and convenient method for the wide-spread testing of COVID-19 using deep throat sputum samples.

A rod-shaped appendage called a primary cilium projects from the soma of most central neurons in the mammalian brain. The importance of cilia within the nervous system is highlighted by the fact that human syndromes linked to primary cilia dysfunction, collectively termed ciliopathies, are associated with numerous neuropathologies, including hyperphagia-induced obesity, neuropsychiatric disorders, and learning and memory deficits. Neuronal cilia are enriched with signaling molecules, including specific G-protein-coupled receptors (GPCRs) and their downstream effectors, suggesting that they act as sensory organelles that respond to neuromodulators in the extracellular space. We previously showed that GPCR ciliary localization is disrupted in neurons from mouse models of the ciliopathy Bardet-Biedl syndrome (BBS). Based on this finding, we hypothesized that mislocalization of ciliary GPCRs may impact receptor signaling and contribute to the BBS phenotypes. Here, we show that disrupting localization of the ciliary GPCR dopamine receptor 1 (D) in male and female mice, either by loss of a BBS protein or loss of the cilium itself, specifically in D-expressing neurons, results in obesity. Interestingly, the weight gain is associated with reduced locomotor activity, rather than increased food intake. Moreover, the loss of a BBS protein or cilia on D-expressing neurons leads to a reduction in D-mediated signaling. Together, these results indicate that cilia impact D activity in the nervous system and underscore the importance of neuronal cilia for proper GPCR signaling. Most mammalian neurons possess solitary appendages called primary cilia. These rod-shaped structures are enriched with signaling proteins, such as G-protein-coupled receptors (GPCRs), suggesting that they respond to neuromodulators. This study examines the consequences of disrupting ciliary localization of the GPCR dopamine receptor 1 (D) in D-expressing neurons. Remarkably, mice that have either an abnormal accumulation of D in cilia or a loss of D ciliary localization become obese. In both cases, the obesity is associated with lower locomotor activity rather than overeating. As D activation increases locomotor activity, these results are consistent with a reduction in D signaling. Indeed, we found that D-mediated signaling is reduced in brain slices from both mouse models. Thus, cilia impact D signaling in the brain.

Article	Year
Abnormal development of NG2+PDGFR-α+ neural progenitor cells leads to neonatal hydrocephalus in a ciliopathy mouse model. Nature medicine\| PubMed ID: 23160237	2012
BBS7 is required for BBSome formation and its absence in mice results in Bardet-Biedl syndrome phenotypes and selective abnormalities in membrane protein trafficking. Journal of cell science\| PubMed ID: 23572516	2013
Genotypic and phenotypic characterization of the Sdccag8Tn(sb-Tyr)2161B.CA1C2Ove mouse model. PloS one\| PubMed ID: 29444170	2018
Exposure to Static Magnetic and Electric Fields Treats Type 2 Diabetes. Cell metabolism\| PubMed ID: 33027675	2020
The art of virtual mentoring in the twenty-first century for STEM majors and beyond. Nature biotechnology\| PubMed ID: 33273732	2020
Mentoring during Uncertain Times. Trends in biochemical sciences\| PubMed ID: 33622580	2021
Counterpoint: An alternative hypothesis for why exposure to static magnetic and electric fields treats type 2 diabetes. American journal of physiology. Endocrinology and metabolism\| PubMed ID: 33843282	2021
Reply to Petersen et al.: An alternative hypothesis for why exposure to static magnetic and electric fields treats type 2 diabetes. American journal of physiology. Endocrinology and metabolism\| PubMed ID: 33843283	2021
A mouse model of Bardet-Biedl Syndrome has impaired fear memory, which is rescued by lithium treatment. PLoS genetics\| PubMed ID: 33886537	2021
An open source and convenient method for the wide-spread testing of COVID-19 using deep throat sputum samples. PeerJ\| PubMed ID: 35573180	2022
Disruption of Dopamine Receptor 1 Localization to Primary Cilia Impairs Signaling in Striatal Neurons. The Journal of neuroscience : the official journal of the Society for Neuroscience\| PubMed ID: 35882560	2022

Calvin S. Carter

Biography

JoVE Journal Publications

Other Publications