Trpm4 and Trpm5 in the murine olfactory system

The olfactory system allows the evaluation of critical environmental situations and the adaptation to different environmental conditions through a variety of behavioral responses. Several members of the Trp- (transient receptor potential) family were reported to play a crucial role in the function of the main and accessory olfactory system. This study concentrates on the expression and possible function of the Ca2+-activated monovalent cation channels Trpm4 and Trpm5 in the olfactory system. Both channels play a major role in taste chemo-transduction, but their precise role in the olfactory system is not yet clear or even unknown. Here, I used a novel generation of τGFP reporter mouse lines, Trpm5-IC/eR26-τGFP and Trpm4-IC/τGFP, in combination with Trpm4 and Trpm5 antibodies to map channel expression in different olfactory tissues. Furthermore, I employed molecular techniques such as RT-PCR and quantitative real-time PCR to identify Trpm5 splice variants and to assess Trpm4 and Trpm5 expression levels during development of the olfactory system. Additionally, I addressed gender-specific differences in Trpm4 expression in male and female mice and the sex-hormone regulated expression of Trpm4 following surgical gonadectomy in combination with hormone treatments. I discovered that besides the previously described Trpc2, Trpm4 is also expressed in vomeronasal sensory neurons (VSNs). Contrasting the expression of Trpc2, Trpm4 is sexually dimorphic and is estrous cycle dependent. In detail, Trpm4 expression in VSNs is high during receptive periods (proestrus, estrus), and low during non-ovulatory/-receptive phases (metestrus, diestrus/ pregnancy). Trpm4 expression is regulated by gonadal hormones, as surgical gonadectomy performed on male and female mice leads to a loss of Trpm4 signal in VSNs. However, Trpm4 expression can be restored by systemic treatment with 17β-estradiol and is maintained by endogenous aromatase activity in gonadal-intact mice. This study furthermore shows that the classical Trpm5 channel, known from taste receptor cells, is exclusively expressed in microvillar cells of the main olfactory epithelium (MOE) but not in adult olfactory sensory neurons (OSNs) which contain a novel short and likely non-functional splice variant. However, the classical Trpm5 is transiently expressed in a subpopulation of early-mature OSNs in the embryonic MOE. Summarizing, the spatial segregation of Trpm4 and Trpm5 in the olfactory system reveals that these channels play different roles and are not functionally interchangeable. This study suggests a differential role for Trpm4 in VSN signal processing during sexually receptive and non-receptive phases and a functional role of Trpm5 in OSNs during embryonic development. Concluding, this work provides a critical platform for understanding the role of Trp channels in the olfactory system.Das olfaktorische System ermöglicht die Erfassung kritischer Umweltsituationen und die Anpassung an unterschiedliche Umgebungsbedingungen durch eine Vielzahl von Verhaltensreaktionen. Mehrere Mitglieder der Trp- (Transient-Rezeptor-Potential) Familie spielen eine entscheidende Rolle in der Funktion des Haupt- und akzessorischen olfaktorischen Systems. Die vorliegende Arbeit befasst sich mit der Expression und der möglichen Funktion der Ca2+ aktivierten monovalenten Kationenkanäle Trpm4 und Trpm5 im olfaktorischen System. Beide Kanäle spielen eine wichtige Rolle bei der Geschmacks-Chemotransduktion, jedoch ist ihre genaue Rolle im olfaktorischen System noch nicht klar oder gar unbekannt. Im Rahmen dieser Arbeit habe ich eine neue Generation von GFP-Reporter-Mauslinien, Trpm5-IC/eR26-τGFP und Trpm4-IC/τGFP, in Kombination mit Trpm4- und Trpm5-Antikörpern verwendet, um die Kanalexpression in verschiedenen olfaktorischen Geweben zu untersuchen. Darüber hinaus habe ich molekularbiologische Techniken wie die RT-PCR und die quantitative Echtzeit-PCR eingesetzt, um Trpm5-Spleißvarianten zu identifizieren und um die Expressionsniveaus von Trpm4 und Trpm5 während der Entwicklung des olfaktorischen Systems zu ermitteln. Zusätzlich untersuchte ich geschlechtsspezifische Unterschiede in der Expression von Trpm4 in männlichen und weiblichen Mäusen und die Regulation der Trpm4-Expression über Geschlechtshormone durch chirurgische Gonadektomie in Kombination mit Hormonbehandlungen. Ich habe festgestellt, dass Trpm4, neben dem zuvor beschriebenen Trpc2, auch in vomeronasalen sensorischen Neuronen (VSNs) exprimiert ist. Im Gegensatz zur Expression von Trpc2 ist die Expression von Trpm4 sexuell dimorph und ist abhängig vom Östruszyklus. Im Detail ist die Expression von Trpm4 in VSNs während der rezeptiven Perioden (Proöstrus, Östrus) erhöht und während der nicht-ovulatorischen/ -rezeptiven Phasen (Metöstrus, Diöstrus/ Schwangerschaft) erniedrigt. Die Trpm4-Expression wird durch Gonadenhormone reguliert und eine chirurgische Gonadektomie bei männlichen und weiblichen Mäusen resultiert in dem Verlust des Trpm4-Signals in VSNs. Allerdings kann die Trpm4-Expression durch eine systemische Behandlung mit 17β-Estradiol wiederhergestellt werden und wird durch die endogene Aromatase-Aktivität bei gonadal-intakten Mäusen aufrechterhalten. Die vorliegende Arbeit zeigt zudem, dass der klassische Trpm5-Kanal, bekannt aus den Geschmacksrezeptorzellen, ausschließlich in Mikrovillarzellen des olfaktorischen Hauptepithels (MOE) exprimiert wird, aber nicht in adulten olfaktorischen sensorischen Neuronen (OSNs), die eine neuartige kurze und wahrscheinlich nicht-funktionale Spleißvariante enthalten. Der klassische Trpm5 Kanal wird jedoch transient in einer Subpopulation von frühreifen OSNs im embryonalen MOE exprimiert. Zusammenfassend zeigt die räumliche Trennung der Expression von Trpm4 und Trpm5 im olfaktorischen System, dass diese Kanäle unterschiedliche Rollen übernehmen und funktionell nicht miteinander austauschbar sind. Die vorliegende Arbeit weist auf eine differenzierte Rolle von Trpm4 in der VSN-Signalverarbeitung während sexuell rezeptiver und nicht-rezeptiver Phasen und eine funktionelle Rolle von Trpm5 in OSNs während der embryonalen Entwicklung hin. Abschließend stellt diese Arbeit eine wertvolle Plattform zum Verständnis der Rolle der Trp-Kanäle im olfaktorischen System dar

P/Q Type Calcium Channel Cav2.1 Defines a Unique Subset of Glomeruli in the Mouse Olfactory Bulb

Voltage-gated calcium (Cav) channels are a prerequisite for signal transmission at the first olfactory sensory neuron (OSN) synapse within the glomeruli of the main olfactory bulb (MOB). We showed previously that the N-type Cav channel subunit Cav2.2 is present in the vast majority of glomeruli and plays a central role in presynaptic transmitter release. Here, we identify a distinct subset of glomeruli in the MOB of adult mice that is characterized by expression of the P/Q-type channel subunit Cav2.1. Immunolocalization shows that Cav2.1+ glomeruli reside predominantly in the medial and dorsal MOB, and in the vicinity of the necklace glomerular region close to the accessory olfactory bulb. Few glomeruli are detected on the ventral and lateral MOB. Cav2.1 labeling in glomeruli colocalizes with the presynaptic marker vGlut2 in the axon terminals of OSNs. Electron microscopy shows that Cav2.1+ presynaptic boutons establish characteristic asymmetrical synapses with the dendrites of second-order neurons in the glomerular neuropil. Cav2.1+ glomeruli receive axonal input from OSNs that express molecules of canonical OSNs: olfactory marker protein, the ion channel Cnga2, and the phosphodiesterase Pde4a. In the main olfactory epithelium, Cav2.1 labels a distinct subpopulation of OSNs whose distribution mirrors the topography of the MOB glomeruli, that shows the same molecular signature, and is already present at birth. Together, these experiments identify a unique Cav2.1+ multiglomerular domain in the MOB that may form a previously unrecognized olfactory subsystem distinct from other groups of necklace glomeruli that rely on cGMP signaling mechanisms

P/Q Type Calcium Channel Cav2.1 Defines a Unique Subset of Glomeruli in the Mouse Olfactory Bulb

Voltage-gated calcium (Cav) channels are a prerequisite for signal transmission at the first olfactory sensory neuron (OSN) synapse within the glomeruli of the main olfactory bulb (MOB). We showed previously that the N-type Cav channel subunit Cav2.2 is present in the vast majority of glomeruli and plays a central role in presynaptic transmitter release. Here, we identify a distinct subset of glomeruli in the MOB of adult mice that is characterized by expression of the P/Q-type channel subunit Cav2.1. Immunolocalization shows that Cav2.1+ glomeruli reside predominantly in the medial and dorsal MOB, and in the vicinity of the necklace glomerular region close to the accessory olfactory bulb. Few glomeruli are detected on the ventral and lateral MOB. Cav2.1 labeling in glomeruli colocalizes with the presynaptic marker vGlut2 in the axon terminals of OSNs. Electron microscopy shows that Cav2.1+ presynaptic boutons establish characteristic asymmetrical synapses with the dendrites of second-order neurons in the glomerular neuropil. Cav2.1+ glomeruli receive axonal input from OSNs that express molecules of canonical OSNs: olfactory marker protein, the ion channel Cnga2, and the phosphodiesterase Pde4a. In the main olfactory epithelium, Cav2.1 labels a distinct subpopulation of OSNs whose distribution mirrors the topography of the MOB glomeruli, that shows the same molecular signature, and is already present at birth. Together, these experiments identify a unique Cav2.1+ multiglomerular domain in the MOB that may form a previously unrecognized olfactory subsystem distinct from other groups of necklace glomeruli that rely on cGMP signaling mechanisms

Movimientos sociales en America Latina : perspectivas, tendencias y casos

Este libro aporta tres cuestiones importantes: primero, explora la riqueza y variedad de los movimientos sociales en América Latina; segundo, ilustra la amplia gama de enfoques y perspectivas que existe entre los estudiosos actuales de la protesta latinoamericana; tercero, muestra que el continente tiene su especificidad propia en el estudio de los movimientos sociales, en diálogo con la academia norteamericana y la europea. Sin lugar a dudas, la presente antología resultará de especial interés a todos los pensadores y pensadoras con una visión crítica de la política, la historia y los movimientos sociales latinoamericanos. Sidney Tarro

Second asymptomatic carotid surgery trial (ACST-2) : a randomised comparison of carotid artery stenting versus carotid endarterectomy

Background: Among asymptomatic patients with severe carotid artery stenosis but no recent stroke or transient cerebral ischaemia, either carotid artery stenting (CAS) or carotid endarterectomy (CEA) can restore patency and reduce long-term stroke risks. However, from recent national registry data, each option causes about 1% procedural risk of disabling stroke or death. Comparison of their long-term protective effects requires large-scale randomised evidence. Methods: ACST-2 is an international multicentre randomised trial of CAS versus CEA among asymptomatic patients with severe stenosis thought to require intervention, interpreted with all other relevant trials. Patients were eligible if they had severe unilateral or bilateral carotid artery stenosis and both doctor and patient agreed that a carotid procedure should be undertaken, but they were substantially uncertain which one to choose. Patients were randomly allocated to CAS or CEA and followed up at 1 month and then annually, for a mean 5 years. Procedural events were those within 30 days of the intervention. Intention-to-treat analyses are provided. Analyses including procedural hazards use tabular methods. Analyses and meta-analyses of non-procedural strokes use Kaplan-Meier and log-rank methods. The trial is registered with the ISRCTN registry, ISRCTN21144362. Findings: Between Jan 15, 2008, and Dec 31, 2020, 3625 patients in 130 centres were randomly allocated, 1811 to CAS and 1814 to CEA, with good compliance, good medical therapy and a mean 5 years of follow-up. Overall, 1% had disabling stroke or death procedurally (15 allocated to CAS and 18 to CEA) and 2% had non-disabling procedural stroke (48 allocated to CAS and 29 to CEA). Kaplan-Meier estimates of 5-year non-procedural stroke were 2·5% in each group for fatal or disabling stroke, and 5·3% with CAS versus 4·5% with CEA for any stroke (rate ratio [RR] 1·16, 95% CI 0·86-1·57; p=0·33). Combining RRs for any non-procedural stroke in all CAS versus CEA trials, the RR was similar in symptomatic and asymptomatic patients (overall RR 1·11, 95% CI 0·91-1·32; p=0·21). Interpretation: Serious complications are similarly uncommon after competent CAS and CEA, and the long-term effects of these two carotid artery procedures on fatal or disabling stroke are comparable

Management of coronary disease in patients with advanced kidney disease

BACKGROUND Clinical trials that have assessed the effect of revascularization in patients with stable coronary disease have routinely excluded those with advanced chronic kidney disease. METHODS We randomly assigned 777 patients with advanced kidney disease and moderate or severe ischemia on stress testing to be treated with an initial invasive strategy consisting of coronary angiography and revascularization (if appropriate) added to medical therapy or an initial conservative strategy consisting of medical therapy alone and angiography reserved for those in whom medical therapy had failed. The primary outcome was a composite of death or nonfatal myocardial infarction. A key secondary outcome was a composite of death, nonfatal myocardial infarction, or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest. RESULTS At a median follow-up of 2.2 years, a primary outcome event had occurred in 123 patients in the invasive-strategy group and in 129 patients in the conservative-strategy group (estimated 3-year event rate, 36.4% vs. 36.7%; adjusted hazard ratio, 1.01; 95% confidence interval [CI], 0.79 to 1.29; P=0.95). Results for the key secondary outcome were similar (38.5% vs. 39.7%; hazard ratio, 1.01; 95% CI, 0.79 to 1.29). The invasive strategy was associated with a higher incidence of stroke than the conservative strategy (hazard ratio, 3.76; 95% CI, 1.52 to 9.32; P=0.004) and with a higher incidence of death or initiation of dialysis (hazard ratio, 1.48; 95% CI, 1.04 to 2.11; P=0.03). CONCLUSIONS Among patients with stable coronary disease, advanced chronic kidney disease, and moderate or severe ischemia, we did not find evidence that an initial invasive strategy, as compared with an initial conservative strategy, reduced the risk of death or nonfatal myocardial infarction

Health status after invasive or conservative care in coronary and advanced kidney disease

BACKGROUND In the ISCHEMIA-CKD trial, the primary analysis showed no significant difference in the risk of death or myocardial infarction with initial angiography and revascularization plus guideline-based medical therapy (invasive strategy) as compared with guideline-based medical therapy alone (conservative strategy) in participants with stable ischemic heart disease, moderate or severe ischemia, and advanced chronic kidney disease (an estimated glomerular filtration rate of <30 ml per minute per 1.73 m2 or receipt of dialysis). A secondary objective of the trial was to assess angina-related health status. METHODS We assessed health status with the Seattle Angina Questionnaire (SAQ) before randomization and at 1.5, 3, and 6 months and every 6 months thereafter. The primary outcome of this analysis was the SAQ Summary score (ranging from 0 to 100, with higher scores indicating less frequent angina and better function and quality of life). Mixed-effects cumulative probability models within a Bayesian framework were used to estimate the treatment effect with the invasive strategy. RESULTS Health status was assessed in 705 of 777 participants. Nearly half the participants (49%) had had no angina during the month before randomization. At 3 months, the estimated mean difference between the invasive-strategy group and the conservative-strategy group in the SAQ Summary score was 2.1 points (95% credible interval, 120.4 to 4.6), a result that favored the invasive strategy. The mean difference in score at 3 months was largest among participants with daily or weekly angina at baseline (10.1 points; 95% credible interval, 0.0 to 19.9), smaller among those with monthly angina at baseline (2.2 points; 95% credible interval, 122.0 to 6.2), and nearly absent among those without angina at baseline (0.6 points; 95% credible interval, 121.9 to 3.3). By 6 months, the between-group difference in the overall trial population was attenuated (0.5 points; 95% credible interval, 122.2 to 3.4). CONCLUSIONS Participants with stable ischemic heart disease, moderate or severe ischemia, and advanced chronic kidney disease did not have substantial or sustained benefits with regard to angina-related health status with an initially invasive strategy as compared with a conservative strategy

Helium identification with LHCb

International audienceThe identification of helium nuclei at LHCb is achieved using a method based on measurements of ionisation losses in the silicon sensors and timing measurements in the Outer Tracker drift tubes. The background from photon conversions is reduced using the RICH detectors and an isolation requirement. The method is developed using $pp$ collision data at $\sqrt{s}=13\,{\rm TeV}$ recorded by the LHCb experiment in the years 2016 to 2018, corresponding to an integrated luminosity of $5.5\,{\rm fb}^{-1}$. A total of around $10^5$ helium and antihelium candidates are identified with negligible background contamination. The helium identification efficiency is estimated to be approximately $50\%$ with a corresponding background rejection rate of up to $\mathcal O(10^{12})$. These results demonstrate the feasibility of a rich programme of measurements of QCD and astrophysics interest involving light nuclei

Observation of Cabibbo-suppressed two-body hadronic decays and precision mass measurement of the Ωc0\Omega_{c}^{0} baryon

International audienceThe first observation of the singly Cabibbo-suppressed $\Omega_{c}^{0}\to\Omega^{-}K^{+}$ and $\Omega_{c}^{0}\to\Xi^{-}\pi^{+}$ decays is reported, using proton-proton collision data at a centre-of-mass energy of $13\,{\rm TeV}$, corresponding to an integrated luminosity of $5.4\,{\rm fb}^{-1}$, collected with the LHCb detector between 2016 and 2018. The branching fraction ratios are measured to be $\frac{\mathcal{B}(\Omega_{c}^{0}\to\Omega^{-}K^{+})}{\mathcal{B}(\Omega_{c}^{0}\to\Omega^{-}\pi^{+})}=0.0608\pm0.0051({\rm stat})\pm 0.0040({\rm syst})$, $\frac{\mathcal{B}(\Omega_{c}^{0}\to\Xi^{-}\pi^{+})}{\mathcal{B}(\Omega_{c}^{0}\to\Omega^{-}\pi^{+})}=0.1581\pm0.0087({\rm stat})\pm0.0043({\rm syst})\pm0.0016({\rm ext})$. In addition, using the $\Omega_{c}^{0}\to\Omega^{-}\pi^{+}$ decay channel, the $\Omega_{c}^{0}$ baryon mass is measured to be $M(\Omega_{c}^{0})=2695.28\pm0.07({\rm stat})\pm0.27({\rm syst})\pm0.30({\rm ext})\,{\rm MeV}/c^{2}$, improving the precision of the previous world average by a factor of four

Measurement of CP violation in B0→ψ(→ℓ+ℓ−)KS0(→π+π−)decaysB^0\to \psi(\to\ell^+\ell^-)K^0_\mathrm{S}(\to \pi^+\pi^-)decays

A measurement of time-dependent $C\!P$ violation in the decays of $B^0$ and $\overline{B}^0$ mesons to the final states ${J\!/\!\psi(\to\mu^+\mu^-)K^0_\mathrm{S}}$, $\psi(2S)(\to\mu^+\mu^-)K^0_\mathrm{S}$ and $J\!/\!\psi(\to e^+e^-)K^0_\mathrm{S}$ with $K^0_\mathrm{S}\pi^+\pi^-$ is presented. The data correspond to an integrated luminosity of $6\,\mathrm{fb}^{-1}$ collected at a centre-of-mass energy of $\sqrt{s}=13\,\mathrm{TeV}$ with the LHCb detector. The $C\!P$-violation parameters are measured to be \begin{align*} S_{\psi K^0_\mathrm{S}} &= 0.717 \pm 0.013\,(\text{stat}) \pm 0.008\,(\text{syst}), \\ C_{\psi K^0_\mathrm{S}} &= 0.008 \pm 0.012\,(\text{stat}) \pm 0.003\,(\text{syst}). \end{align*} This measurement of $S_{\psi K^0_\mathrm{S}}$ represents the most precise single measurement of the CKM angle $\beta$ to date and is more precise than the current world average. In addition, measurements of the $C\!P$-violation parameters of the individual channels are reported and a combination with the LHCb Run 1 measurements is performed.A measurement of time-dependent CP violation in the decays of $B^0$ and $\overline{B}^0$ mesons to the final states $J/\psi(\to\mu^+\mu^-)K^0_S$, $\psi(2S)(\to\mu^+\mu^-)K^0_S$ and $J/\psi(\to e^+e^-)K^0_S$ with $K^0_S\to\pi^+\pi^-$ is presented. The data correspond to an integrated luminosity of 6 fb${}^{-1}$ collected at a centre-of-mass energy of $\sqrt{s}=13$ TeV with the LHCb detector. The CP-violation parameters are measured to be \begin{align*} S_{\psi K^0_S} &= 0.717 \pm 0.013 (\text{stat}) \pm 0.008 (\text{syst}), \\ C_{\psi K^0_S} &= 0.008 \pm 0.012 (\text{stat}) \pm 0.003 (\text{syst}). \end{align*} This measurement of $S_{\psi K^0_S}$ represents the most precise single measurement of the CKM angle $\beta$ to date and is more precise than the current world average. In addition, measurements of the CP-violation parameters of the individual channels are reported and a combination with the LHCb Run 1 measurements is performed