Targeting Topics 17q1

Photoentrainment and Pupillary Light Reflex Are Mediated By Distinct Populations of Iprgcs.

Chen SK, Badea TC, Hattar S.

Nature 476(7358):92-95, 2011. PMID: 21765429

Intinsically photosensitive retinal ganglion cells (ipRGCs) express the photopigment Melanopsin and regulate a wide array of light dependent physiological processes. Genetic ablation of ipRGCs eliminates circadian photoentrainment and severely disrupts the pupillary light reflex (PLR). Scientists showed that ipRGCs consist of distinct subpopulation that differentially express the Brn3b transcription factor, and can be functionally distinguished. Brn3b-negative M1 ipRGCs innervate the suprachiasmatic nucleus (SCN) of the hypothalamus, whereas Brn3b-positive ipRGCs innervate all other known brain targets. Selective ablation of Brn3b-postive ipRGCs severly disrupts the PLR, but does not impair circadian photoentrainment. The scientists concluded that molecularly distinct subpopulations of M1 ipRGCs, which are morphologically and electrophysiologically similar, innervate different brain regions to execute light-induced functions. A dilution of 1:1000 of Anti-Melanopsin (Cat. #AB-N38) was used for immunohistochemical analysis of retina sections.

Gate Control of Mechanical Itch By a Subpopulation of Spinal Cord Interneurons.

Bourane S, Duan B, Koch SC, Dalet A, Britz O, Garcia-Campmany L, Kim E, Cheng L, Ghosh A, Ma Q, Goulding M.

Science 350(6260):550-554, 2015. PMID: 26516282

Light mechanical stimulation of the hairy skin can induce a form of itch known as mechanical itch. This itch sensation is normally suppressed by inputs from mechanoreceptors, however, in many forms of chronic itch, including alloknesis, this gating mechanism is lost. Scientists demonstrated that a population of spinal inhibitory interneurons (INs), that are defined by the expression of neuropeptide Y::Cre (NPY::Cre), act to gate mechanical itch. Mice in which dorsal NPY::Cre-derived neurons are selectively ablated or silenced develop mechanical itch without an increase in sensitivity to chemical itch or pain. This chronic itch state is histamine-independent and is transmitted independently of the GRP-GRPR signaling pathway. The scientists thereby revealed a dedicated spinal cord inhibitory pathway that gates the transmission of mechanical itch. Mice were given an intrathecal injection of 400 ng of Bombesin-SAP (Cat. #IT-40) in 10 ml of sterile saline to ablate GRPR-expressing neurons.

Different Immune Cells Mediate Mechanical Pain Hypersensitivity in Male and Female Mice.

Sorge RE, Mapplebeck JC, Rosen S, Beggs S, Taves S, Alexander JK, Martin LJ, Austin JS, Sotocinal SG, Chen D, Yang M, Shi XQ, Huang H, Pillon NJ, Bilan PJ, Tu Y, Klip A, Ji RR, Zhang J, Salter MW, Mogil JS.

Nat Neurosci 18(8):1081-1083, 2015. PMID: 26120961

A large and rapidly increasing body of evidence indicates that microglia-to-neuron signaling is essential for chronic pain hypersensitivity. Using multiple approaches, the authors found that microglia are not required for mechanical pain hypersensitivity in female mice; female mice achieved similar levels of pain hypersensitivity using adaptive immune cells, likely T lymphocytes. This sexual dimorphism suggests that male mice cannot be used as proxies for females in pain research. Mac-1-SAP mouse/human toxin (Cat. #IT-06, 15 μg in 8.8 μl) and Saporin control (Cat. #PR-01, 8.8 μg in 8.8 μl) were administered via i.t. injection. The topic of immune system involvement in chronic pain pathophysiology is one of the most active in the pain field; that this sex difference has not been observed until now is very surprising indeed. An important implication of the current findings is that distinct strategies targeting neuroimmune signaling might be required for the treatment of chronic pain in men versus women.

C-Terminal Phosphorylation Regulates the Kinetics of a Subset of Melanopsin-Mediated Behaviors in Mice.

Somasundaram P, Wyrick GR, Fernandez DC, Ghahari A, Pinhal CM, Simmonds Richardson M, Rupp AC, Cui L, Wu Z, Brown RL, Badea TC, Hattar S, Robinson PR.

Proc Natl Acad Sci U S A 114(10):2741-2746, 2017. PMID: 28223508

The authors show that the melanopsin photoresponse shutoff due to C-terminal phosphorylation determines the kinetics of the intrinsic light response in ipRGCs, the PLR, and reentrainment, but not masking and phase angle of entrainment. Immunofluorescence was performed using rabbit Anti-Melanopsin (1:1,000, Cat. #AB-N38) as the primary antibody with a 2-d incubation period, followed by goat anti-rabbit IgG 488 as the secondary antibody. (read more)

Rehabilitation Drives Enhancement of Neuronal Structure in Functionally Relevant Neuronal Subsets.

Wang L, Conner JM, Nagahara AH, Tuszynski MH.

Proc Natl Acad Sci U S A 113(10):2750-2755, 2016. PMID: 26903653

Rehabilitation is often prescribed after brain injury, but the basis for how training can influence brain plasticity and recovery is unclear. In this study, the authors show that intense rehabilitation training after focal brain injury drives significant structural changes in brain cells located adjacent to the injury. Importantly, a key brain modulatory system, the basal forebrain cholinergic system, is required for enabling rehabilitation to impact brain structure. Rats underwent cholinergic ablations by injecting 192-IgG-Saporin (Cat. #IT-01) into the nucleus basalis (0.2-0.25 mcl of 0.375 mg/ml solution in artificial CSF). Damage to the cholinergic system, which can occur naturally during aging, completely blocks brain plasticity mediated by rehabilitation and significantly attenuates functional recovery. These results provide new insights into how rehabilitation may promote recovery and suggest that brain cholinergic systems may be a possible therapeutic target for influencing recovery.

Antibody Therapy Targeting Cd47 and Cd271 Effectively Suppresses Melanoma Metastasis in Patient-Derived Xenografts.

Ngo M, Han A, Lakatos A, Sahoo D, Hachey SJ, Weiskopf K, Beck AH, Weissman IL, Boiko AD.

Cell Rep 16(6):1701-1716, 2016. PMID: 27477289

The high rate of metastasis and recurrence among melanoma patients indicates the presence of cells within melanoma that have the ability to both initiate metastatic programs and bypass immune recognition. The authors identified CD47 as a regulator of melanoma tumor metastasis and immune evasion. The study involved antibody-mediated blockade of CD47 coupled with targeting of CD271+ melanoma cells by way of ME20.4-SAP (Cat. #IT-15). Mice bearing human melanoma tumor (M213 or M727) were randomized into four treatment groups with one of those groups receiving treatment with ME20.4-SAP. 1 ug in 50 ul volumes were injected directly into the center mass of the tumor once every 2 days. A therapeutic effect was observed where tumor metastasis in patient-derived xenografts was strongly inhibited when treated with the combination of antibody-mediated blockade of CD47 and targeted with ME20.4-SAP.

Targeting Cd73 in the Tumor Microenvironment With Medi9447.

Hay CM, Sult E, Huang Q, Mulgrew K, Fuhrmann SR, McGlinchey KA, Hammond SA, Rothstein R, Rios-Doria J, Poon E, Holoweckyj N, Durham NM, Leow CC, Diedrich G, Damschroder M, Herbst R, Hollingsworth RE, Sachsenmeier KF.

Oncoimmunology 5(8):e1208875, 2016. PMID: 27622077

MEDI9447 is a human monoclonal antibody that is specific for the ectoenzyme CD73 and currently undergoing Phase I clinical trials. Here the authors show that MEDI9447 is a potent inhibitor of CD73 ectonucleotidase activity, with wide ranging immune regulatory consequences. MEDI9447 results in relief from adenosine monophosphate (AMP)-mediated lymphocyte suppression in vitro and inhibition of mouse syngeneic tumor growth in vivo. In contrast with other cancer immunotherapy agents such as checkpoint inhibitors or T-cell agonists, MEDI9447 drives changes in both myeloid and lymphoid infiltrating leukocyte populations within the tumor microenvironment of mouse models. In vitro experiments validating the internalization of antibodies into cell lines MDA-MB-231 and 4T1 were measured using the Fab-ZAP human antibody internalization kit (Cat. #KIT-51-Z). Combination data showing additive activity between MEDI9447 and anti-PD-1 antibodies using human cells in vitro and mouse tumor models further demonstrate the potential value of relieving adenosine-mediated immunosuppression. Based on these data, a Phase I study to test the safety, tolerability, and clinical activity of MEDI9447 in cancer patients was initiated (NCT02503774).

Impact of Altered Cholinergic Tones on the Neurovascular Coupling Response to Whisker Stimulation.

Lecrux C, Sandoe CH, Neupane S, Kropf P, Toussay X, Tong XK, Lacalle-Aurioles M, Shmuel A, Hamel E.

J Neurosci 37(6):1518-1531, 2016. PMID: 28069927

The authors assessed the effects of varying ACh tone on whisker-evoked NVC responses in rat barrel cortex. ACh depletion was achieved via unilateral icv injection (4 mcg/2 mcl) with 192 IgG-SAP (Cat# IT-01) or saline. They conclude that ACh is not only a facilitator, but also a prerequisite for the full expression of sensory-evoked NVC responses. (read more)

A Non-Inheritable Maternal Cas9-Based Multiple-Gene Editing System in Mice.

Sakurai T, Kamiyoshi A, Kawate H, Mori C, Watanabe S, Tanaka M, Uetake R, Sato M, Shindo T.

Sci Rep 6:20011, 2016. PMID: 26817415

In this work, the authors generated transgenic mice with systemic Cas9 overexpression (Cas9 mice) in order to simplify the procedure of generating genetically modified animals using the CRISPR/Cas9 system – only guide RNAs (gRNAs) would need to be administered to induce mutations at target loci. To test Cas9 mice for genome editing in vitro, the authors transiently transfected primary fibroblasts from Cas9 mice with Ggta1 gRNA (Ggta1 is responsible for synthesizing the cell-surface α-Gal epitope). They treated the fibroblasts with rIB4-SAP (Cat. #IT-10) and found that it killed Ggta1 +/+ and KO/+ cells, while biallelic Ggta1 KO cells survived as they did not synthesize the α-Gal epitope. This indicated that primary cells from the Cas9 transgenic mice have CRISPR/Cas9 genome editing capability with the administration of gRNA alone. The success of their experiments indicate that this method could potentially be used to generate other genetically modified animals.

Acute Hypoxia Activates Hypothalamic Paraventricular Nucleus-Projecting Catecholaminergic Neurons in the C1 Region.

Silva TM, Takakura AC, Moreira TS.

Exp Neurol 285(Pt A):1-11, 2016. PMID: 27569537

Catecholaminergic C1 cells reside in the rostral and intermediate portions of the ventrolateral medulla (RVLM) and can be activated by hypoxia. These neurons regulate the hypothalamic pituitary axis via direct projections to the hypothalamic paraventricular nucleus (PVH) and regulate the autonomic nervous system via projections to sympathetic and parasympathetic preganglionic neurons. The present results suggest that catecholaminergic C1-PVH projection is hypoxia-sensitive and the pathway between these two important brain areas can be one more piece in the complex puzzle of neural control of autonomic regulation during hypoxia. Male Wistar rats were injected with the targeted toxin Anti-DβH-SAP (Cat. #IT-03), 21 ng/100 nl, or saline, unilaterally into the PVH using the following coordinates: 1.2 mm caudal to bregma, 0.4 mm lateral to the midline and 7.8 mm below the dura mater. The author’s work adds a piece in the complex puzzle of the physiological role of the C1 cells by showing that this catecholaminergic group of cells must be activated only in emergency situations such as acute hypoxia, producing autonomic, metabolic, and neuroendocrine responses designed to help the organism survive major acute physical stresses.

Targeted Ablation of Cardiac Sympathetic Neurons: A Promising Approach to Prevent Sudden Cardiac Death.

Xia W, Liu Y.

Int J Cardiol 202:425-426, 2016. PMID: 26433164

Sudden cardiac death (SCD) refers to an unexpected death due to cardiovascular causes, occurring generally within 1 hr of symptom onset, in a person without any prior condition that would appear fatal. Currently, the implantable cardioverter-defibrillator (ICD) has been shown to be the most effective therapy for preventing SCD. However, the occurrence of lead complications is significant and more importantly, the ICD implantation remains costly and the quality of life for recipients is significantly affected with appropriate and inappropriate shocks. Sympathetic activation plays an important role in the pathophysiology of arrhythmias leading to SCD, and neuraxial modulation is emerging as an important avenue of therapeutic intervention. The authors demonstrate that targeted ablation of cardiac sympathetic neurons by bilateral stellate ganglia injection of CTB-SAP (Cat. #IT-14) is a novel method for sympathetic blockade. CTB-SAP will be retrogradely transported to the plasma membranse of sympathetic preganglionic neurons (SPNs) and bind to the GM1 gangliosides and subsequently ablate these neurons. Targeted ablation of cardiac sympathetic neurons by injection of CTB-SAP avoids the limitations of medical therapy and thoracic sympathectomy, such as incomplete compliance, Horner’s syndrome, and compensatory hyperhidrosis. Furthermore, they found that targeted ablation of cardiac sympathetic neurons reduces resting, reflex and exercise-induced sustained ventricular tachycardia, associated with a reduced number of neurons in the stellate ganglia and spinal cord, as well as a reduced left ventricular norepinephrine content and sympathetic innervation density. Therefore, targeted ablation of cardiac sympathetic neurons may be a promising approach to prevent SCD via regulating the cardiac autonomic nervous system.

Cholinergic Basal Forebrain Lesion Decreases Neurotrophin Signaling Without Affecting Tau Hyperphosphorylation in Genetically Susceptible Mice.

Turnbull MT, Coulson EJ.

J Alzheimers Dis 55(3):1141-1154, 2017. PMID: 27767994

Alzheimer’s disease(AD) is a progressive, irreversible neurodegenerative disease that destroys memory and cognitive function. Aggregates of hyperphosphorylated tau protein are a prominent feature in the brain of patients with AD, and area major contributor to neuronal toxicity and disease progression. However, the factors that initiate the toxic cascade that results in tau hyperphosphorylation in AD are unknown. The authors investigated whether degeneration of basal forebrain cholinergic neurons (BFCNs) and/or resultant decrease in neurotrophin signaling cause aberrant tau hyperphosphorylation. Two-month-old male and female pR5 mice were infused with murine p75-SAP (Cat. #IT-16) at a concentration of 0.4 mg/ml or 0.4 mg/ml of control Rabbit IgG-SAP (Cat. #IT-35) using a 30G needle attached to a 5 ml Hamilton syringe and pump. The needle was lowered into the medial septum according to coordinates in a mouse brain atlas, and the toxin was infused at a rate of 0.4 ul/min (1.5 u total volume). The results reveal that the loss of BFCNs in pre-symptomatic pR5 tau transgenic mice results in a decrease in hippocampal brain-derived neurotrophic factor levels and reduced TrkB receptor activation. However, there was no exacerbation of the levels of phosphorylated tau or its aggregation in the hippocampus of susceptible mice. Furthermore the animals’ performance in a hippocampal-dependent learning and memory task was unaltered, and no changes in hippocampal synaptic markers were observed. This suggests that tau pathology is likely to be regulated independently of BFCN degeneration and the corresponding decrease in hippocampal neurotrophin levels, although these features may still contribute to disease etiology.

Characterization of the First Fully Human Anti-Tem1 Scfv in Models of Solid Tumor Imaging and Immunotoxin-Based Therapy.

Yuan X, Yang M, Chen X, Zhang X, Sukhadia S, Musolino N, Bao H, Chen T, Xu C, Wang Q, Santoro S, Ricklin D, Hu J, Lin R, Yang W, Li Z, Qin W, Zhao A.

Cancer Immunol Immunother Epub, 2016. PMID: 27933426

Tumor endothelial marker 1 (TEM1) has been identified as a novel surface marker upregulated on the blood vessels and stroma in many solid tumors. The authors previous isolated a single-chain variable fragment (scFv) 78 against TEM1 from a yeast display scFv library and evaluated potential applications of scFv78 as a tool for tumor molecular imaging, immunotoxin-based therapy and nanotherapy. MS1 and MS1-hTEM1 cells were treated with site-specifically biotinylated scFv78 conjugated with the Streptavidin-ZAP (Cat. #IT-27) at a molar ratio of 4:1 (scFv78:ZAP) starting from 40 nM serially diluted down to 0.04 nM. The scFv78-saporin immunoconjugate exerted dose-dependent cytotoxicity with high specificity to TEM1-positive cell in vitro. The data indicate that scFv78, the first fully human anti-TEM1 recombinant antibody, recognizes both human and mouse TEM1 and has features advantageous for the development of imaging probes or antibody-toxin conjugates for a large spectrum of human TEM1-positive solid tumors.

Differential Roles for Cortical Versus Sub-Cortical Noradrenaline and Modulation of Impulsivity in the Rat.

Benn A, Robinson ES.

Psychopharmacology (Berl) 234(2):255-266, 2017. PMID: 27744551

Atomoxetine is a noradrenaline re-uptake inhibitor licensed for the treatment of adult and childhood attention deficit hyperactivity disorder. Although atomoxetine has established efficacy, the mechanisms which mediate its effects are not well understood. In this study, the authors investigated the role of cortical versus sub-cortical noradrenaline by using focal dopamine beta hydroxylase-saporin-induced lesions, to the prefrontal cortex (PFC) or nucleus accumbens shell (NAcSh). Male Lister hooded rats received bilateral lesions by using stereotaxic injections of the immunotoxin Anti-DβH-SAP (Cat. #IT-03), 0.02 μg in 0.5 μL per injection into the PFC and 0.004 μg in 0.2 μL per injection for NAcSh lesions. The data suggest that noradrenaline in the nucleus accumbens shell plays an important role in the effects of atomoxetine. Under these conditions, prefrontal cortex noradrenaline did not appear to contribute to atomoxetine’s effects suggesting a lack of cortical-mediated “top-down” modulation. Noradrenaline in the prefrontal cortex appears to contribute to the modulation of impulsive responding in amphetamine-treated animals, with a loss of noradrenaline associated with potentiation of its effects. These data demonstrate a potential dissociation between cortical and sub-cortical noradrenergic mechanisms and impulse control in terms of the actions of atomoxetine and amphetamine.

Neuroprotective Effects of Testosterone Metabolites and Dependency on Receptor Action on the Morphology of Somatic Motoneurons Following the Death of Neighboring Motoneurons.

Cai Y, Chew C, Muñoz F, Sengelaub DR.

Dev Neurobiol Epub, 2016. PMID: 27569375

In this study the authors examined whether the protective effects of testosterone could be mediated via its androgenic or estrogenic metabolites and if these neuroprotective effects were mediated through steroid hormone receptors. Analysis was done using receptor antagonists to attempt to prevent the neuroprotective effects of hormones after partial motoneuron depletion. These motoneurons were selectively killed by intramuscular injection of CTB-SAP (2 ul, 0.1%) (Cat. #IT-14). Compared with intact normal animals, partial motoneuron depletion resulted in decreased dendritic length in remaining quadriceps motoneurons. Dendritic atrophy was attenuated with both dihydrotestosterone and estradiol treatment to a degree similar to that seen with testosterone and attenuation of atrophy was prevented by receptor blockade. Together, the results suggest that neuroprotective effects on motoneurons can be mediated by either androgenic or estrogenic hormones and require action via steroid hormone receptors, further supporting a role for hormones as neurotherapeutic agents in the injured nervous system.

Transcriptomic Analysis of Mouse Cochlear Supporting Cell Maturation Reveals Large-Scale Changes in Notch Responsiveness Prior to the Onset of Hearing.

Maass JC, Gu R, Cai T, Wan YW, Cantellano SC, Asprer JS, Zhang H, Jen HI, Edlund RK, Liu Z, Groves AK.

PLoS One 11(12):e0167286, 2016. PMID: 27918591

The ability of neonatal mouse cochlear supporting cells to divide and differentiate into hair cells is very limited and declines in the first two weeks after birth. This decline is associated with the morphological and functional maturation of the organ of Corti prior to the onset of hearing, however little is known of the molecular changes that underlie these events. The authors attempt to identify these changes using RNA-seq to generate transcriptional profiles of purified cochlear supporting cells and found significant changes in gene expression related to regulation of proliferation, differentiation of inner ear components and the maturation of the organ of Corti. The authors also examined the regenerative potential of supporting cells in production of hair cells in response to a blockade of the Notch signaling pathway at the time of birth, but a complete lack of response just a few days later. Analysis included IHC on frozen sections of paraformaldehyde-fixed temporal bones of LfngEGFP mice. Anti-NGFr (mup75) (Cat. #AB-N01AP) was used at a 1:200 dilution. The results offer first molecular insights into the failure of hair cell regeneration in the mammalian cochlea.

Lack of Phenotypical and Morphological Evidences of Endothelial to Hematopoietic Transition in the Murine Embryonic Head During Hematopoietic Stem Cell Emergence.

Iizuka K, Yokomizo T, Watanabe N, Tanaka Y, Osato M, Takaku T, Komatsu N.

PLoS One 11(5):e0156427, 2016. PMID: 27227884

Hemogenic endothelial cells have been observed in several embryonic tissues, such as the dorsal aorta, the placenta and the yolk sac. Recent work also suggest that the mouse embryonic head also produces hematopoietic stem cells (HSCs)/progenitors. However, a histological basis for HSC generation in the head hasn’t been determined because the hematopoietic cluster and hemogenic endothelium have not been well characterized. The authors in this study used whole-mount immunostaining and 3D confocal reconstruction techniques to analyze both c-Kit hematopoietic cluster and Runx1 hemogenic endothelium in the whole-head vasculature. Alexa488 labeled anti-NGFr (Cat. #FL-N01AP) was used in flow cytometry. The number of c-Kit hematopoietic cells was 20-fold less in the head arteries than in the dorsal aorta. In addition, nascent hematopoietic cells, observed by a budding structure and a Runx1 hemogenic endothelium, were not observed in the head. These results suggest that head HSCs may not be or are rarely generated from the endothelium in the same manner as aortic HSCs.

The P75 Neurotrophin Receptor Augments Survival Signaling in the Striatum of Pre-Symptomatic Q175(wt/hd) Mice.

Wehner AB, Milen AM, Albin RL, Pierchala BA.

Neuroscience 324:297-306, 2016. PMID: 26947127

Huntington’s disease (HD) is a dominantly inherited neurodegenerative disorder. It’s characterized by a combination of motor, cognitive, and psychiatric features. Striatal spiny neurons are dependent on brain-derived neurotropic factor for proper function and survival. Studies suggest both the receptors for BDNF, TrkB and the p75 neurotrophin receptor (p75), are improperly regulated in the striata of HD patients and mouse models. The authors investigated the role of p75 in the Q175 knock-in mouse model of HD be examining levels of activation of downstream signaling molecules to determine if p75 represents a promising therapeutic target. Anti-NGFr (mup75) (Cat. #AB-N01AP) was used at a 1:2000 dilution in immunoblotting. The data suggest that p75 signaling plays an early role in augmenting pro-survival signaling in the striatum and that disruption of p75 signaling at a pre-symptomatic age may exacerbate pathologic changes in these knock-in mouse models.

Immunohistochemical Detection of Corticotropin-Releasing Hormone (Crh) in the Brain and Pituitary of the Hagfish, Eptatretus Burgeri.

Amano M, Amiya N, Yokoyama T, Onikubo K, Yamamoto N, Takahashi A.

Gen Comp Endocrinol 236:174-180, 2016. PMID: 27444128

The distribution of corticotropin-releasing hormone (CRH) in the brain and pituitary of the hagfish Eptatretus burgeri, representing the earliest branch of vertebrates, was examined by immunohistochemistry to better understand the neuroendocrine system of hagfish. A rabbit polyclonal antibody raised against human/mouse/rat CRH (Cat. #AB-02) was used. A standard curve was obtained from 0.78 ng/ml to 50 ng/ml. The cross-reactivity of anti-CRH antibody against CRH family peptides was found to be less than 0.01%, indicating the specificity of the antibody. The specificity of the antibody raised against human/mouse/rat CRH was demonstrated by a TR-FIA and absorption test. CRH-ir cell bodies were detected in two brain regions; the preopticohypothalamic area (PO, POp, and Hyinf) and the medulla oblongata. CRH-ir fibers were mainly distributed in the hypothalamus and the medulla oblongata, in which CRH-ir cell bodies were detected.

Participation of D-Serine in the Development and Reproduction of the Silkworm Bombyx Mori.

Tanigawa M, Suzuki C, Niwano K, Kanekatsu R, Tanaka H, Horiike K, Hamase K, Nagata Y.

J Insect Physiol 87:20-29, 2016. PMID: 26828952

The silkworm Bombyx mori is known to contain high levels of free D-serine, an optical isomer of L-serine. In this work, the authors investigated the localization of D-serine in various organs of the silkworms in various stages of life in an effort to elucidate its role. They used an immunohistochemical approach to localize D-serine to the silkworm hemolymph, midgut, testes, ovaries, and fat bodies. They also used rabbit antibody against glutaraldehyde-conjugated D-alanine (Cat. #AB-T049) to examine the distribution of D-alanine throughout the silkworms. The authors treated silkworms with an inhibitor of serine racemase to reduce the conversion of L- to D-serine and on the basis of their results suggested the possible involvement of D-serine in ATP synthesis for metamorphosis and reproduction.

Differentiation Defect in Neural Crest-Derived Smooth Muscle Cells in Patients With Aortopathy Associated With Bicuspid Aortic Valves.

Jiao J, Xiong W, Wang L, Yang J, Qiu P, Hirai H, Shao L, Milewicz D, Chen YE, Yang B.

EBioMedicine 10:282-290, 2016. PMID: 27394642

Individuals with bicuspid aortic valves (BAV) are at a higher risk of developing thoracic aortic aneurysms (TAA) than patients with trileaflet aortic valves (TAV). Aneurysms associated with BAV most commonly involve the ascending aorta. Smooth muscle cells (SMCs) in the ascending and descending aorta arise from neural crest (NC) and paraxial mesoderm (PM), respectively. Scientists hypothesized defective differentiation of the neural crest stem cells (NCSCs)-derived SMCs but not paraxial mesoderm cells (PMCs)- derived SMCs contributes to the aortopathy associated with BAV. Induced pluripotent stem cells (iPSCs) from BAV/TAA patients were differentiated into NCSC-derived SMCs and showed decreased expression of a marker of SMC differentiation (MYH11) and impaired contraction. The scientists demonstrated that decreased differentiation and contraction of patient’s NCSC-derived SMCs may contribute to the aortopathy associated with BAV. Anti-NGFr (ME20.4, p75, Cat. #AB-N07) was used for the immunofluorescence staining and flow cytometry of NCSCs.