Schang, AL;Van Steenwinckel, J;Ioannidou, ZS;Lipecki, J;Rich-Griffin, C;Woolley-Allen, K;Dyer, N;Le Charpentier, T;Schäfer, P;Fleiss, B;Ott, S;Sabéran-Djoneidi, D;Mezger, V;Gressens, P;
PMID: 36513635 | DOI: 10.1038/s41419-022-05483-4
Prenatal inflammatory insults accompany prematurity and provoke diffuse white matter injury (DWMI), which is associated with increased risk of neurodevelopmental pathologies, including autism spectrum disorders. DWMI results from maturation arrest of oligodendrocyte precursor cells (OPCs), a process that is poorly understood. Here, by using a validated mouse model of OPC maturation blockade, we provide the genome-wide ID card of the effects of neuroinflammation on OPCs that reveals the architecture of global cell fate issues underlining their maturation blockade. First, we find that, in OPCs, neuroinflammation takes advantage of a primed epigenomic landscape and induces abnormal overexpression of genes of the immune/inflammatory pathways: these genes strikingly exhibit accessible chromatin conformation in uninflamed OPCs, which correlates with their developmental, stage-dependent expression, along their normal maturation trajectory, as well as their abnormal upregulation upon neuroinflammation. Consistently, we observe the positioning on DNA of key transcription factors of the immune/inflammatory pathways (IRFs, NFkB), in both unstressed and inflamed OPCs. Second, we show that, in addition to the general perturbation of the myelination program, neuroinflammation counteracts the physiological downregulation of the cell cycle pathway in maturing OPCs. Neuroinflammation therefore perturbs cell identity in maturing OPCs, in a global manner. Moreover, based on our unraveling of the activity of genes of the immune/inflammatory pathways in prenatal uninflamed OPCs, the mere suppression of these proinflammatory mediators, as currently proposed in the field, may not be considered as a valid neurotherapeutic strategy.
Carey, LM;Xu, Z;Rajic, G;Makriyannis, A;Romero, J;Hillard, C;Mackie, K;Hohmann, AG;
PMID: 36417942 | DOI: 10.1016/j.phrs.2022.106560
Painful peripheral neuropathy is a common neurological complication associated with human immunodeficiency virus (HIV) infection and anti-retroviral therapy. We characterized the impact of two CB2 cannabinoid agonists (AM1710 and LY2828360 - ligands differing in signaling bias and CNS penetration) on neuropathic nociception induced by the antiretroviral agent Zalcitabine (2',3'-dideoxycytidine; ddC). We also used a conditional knockout approach to identify cell types mediating CB2 agonist-induced antinociceptive efficacy and sparing of morphine tolerance. AM1710 and LY2828360 alleviated ddC-induced neuropathic nociception in mice of both sexes. These benefits were absent in global CB2 knockout mice, which exhibited robust morphine antinociception. Like morphine, AM1710 blunted ddC-induced increases in proinflammatory cytokine (IL-1β, TNF-α) and chemokine (CCL2) mRNA expression levels. We generated advillinCre/+;CB2f/f conditional knockout mice to ascertain the role of CB2 localized to primary sensory neurons in CB2-mediated therapeutic effects. Antinociceptive efficacy of both AM1710 and LY2828360, but not reference analgesics, were absent in advillinCre/+;CB2f/f mice, which exhibited robust ddC-induced neuropathy. In ddC-treated CB2f/f mice, LY2828360 suppressed development of morphine tolerance and reversed established morphine tolerance, albeit with greater efficacy in male compared to female mice. LY2828360 failed to block or reverse morphine tolerance in advillinCre/+;CB2f/f mice. The present studies indicate that CB2 activation may alleviate HIV-associated antiretroviral neuropathy and identify a previously unreported mechanism through which CB2 activation produces antinociceptive efficacy. Our results also provide the first evidence that a CB2 agonist can reverse established morphine tolerance and demonstrate that CB2 localized to peripheral sensory neurons mediates the opioid tolerance sparing efficacy of CB2 agonists.
Histochemistry and cell biology
Kitazawa, S;Haraguchi, R;Takaoka, Y;Kitazawa, R;
PMID: 36418613 | DOI: 10.1007/s00418-022-02165-2
Since epigenetic modifications differ from cell to cell, detecting the DNA methylation status of individual cells is requisite. Therefore, it is important to conduct "morphology-based epigenetics research", in which the sequence-specific DNA methylation status is observed while maintaining tissue architecture. Here we demonstrate a novel histochemical technique that efficiently shows the presence of a single methylated cytosine in a sequence-dependent manner by applying ICON (interstrand complexation with osmium for nucleic acids) probes. By optimizing the concentration and duration of potassium osmate treatment, ICON probes selectively hybridize to methylated cytosine on tissue sections. Since the elongation process by rolling-circle amplification through the padlock probe and synchronous amplification by the hyperbranching reaction at a constant temperature efficiently amplifies the reaction, it is possible to specifically detect the presence of a single methylated cytosine. Since the ICON probe is cross-linked to the nuclear or mitochondrial DNA of the target cell, subsequent elongation and multiplication reactions proceed like a tree growing in soil with its roots firmly planted, thus facilitating the demonstration of methylated cytosine in situ. Using this novel ICON-mediated histochemical method, detection of the methylation of DNA in the regulatory region of the RANK gene in cultured cells and of mitochondrial DNA in paraffin sections of mouse cerebellar tissue was achievable. This combined ICON and rolling-circle amplification method is the first that shows evidence of the presence of a single methylated cytosine in a sequence-specific manner in paraffin sections, and is foreseen as applicable to a wide range of epigenetic studies.
Matsumura, T;Hashimoto, H;Sekimizu, M;Saito, A;Asakura, M;Kimura, K;Iwata, Y;
| DOI: 10.1016/j.nmd.2022.07.253
The transient receptor potential cation channel subfamily V member 2 (TRPV2) is a stretch-sensitive calcium channel. Myocytes' damage induces TRPV2 expression on the sarcolemma, which causes calcium influx into the cytoplasm, and triggers degeneration. TRPV2 inhibition was effective in animal models of cardiomyopathy and muscular dystrophy (MD). Our pilot study showed that tranilast, a TRPV2 inhibitor, reduced brain natriuretic peptide (BNP) levels in two MD patients with advanced heart failure. Then, we planned a study to evaluate the safety and efficacy of tranilast for heart failure of MD patients. Subjects were MD patients whose serum BNP levels exceeded 100 pg/mL despite receiving standard therapy. Tranilast was administered orally at 100 mg thrice daily. The primary endpoint was the change in log (BNP) (⊿log [BNP]) at 6 months from baseline. The null hypothesis was determined based on a previous carvedilol study that resulted in a mean population ⊿log [BNP] of 0.18. TRPV2 expression on the mononuclear cell (MNC) surface, cardiac events, left ventricular fractional shortening (FS), human atrial natriuretic peptide (hANP), creatine kinase, and pinch strength were also assessed. Because of the poor general condition of many patients, among 18 patients included, 13 patients could be treated according to the protocol throughout the 6-month period. There were no serious adverse events related to tranilast except diarrhea, a known adverse effect. TRPV2 expression on the MNC surface was elevated at baseline and reduced after treatment. BNP, hANP, and FS remained stable. In the per-protocol set group, ⊿log [BNP] was -0.2 and significantly lower than that in the null hypothesis. In conclusion, tranilast is safe and effectively inhibits TRPV2 expression, even in MD patients with advanced heart failure. To evaluate the efficacy of tranilast in preventing heart failure, motor impairment, and respiratory failure, we are planning a study for mild MD patients.
Alcalá-Vida, R;Lotz, C;Seguin, J;Decraene, C;Brulé, B;Awada, A;Bombardier, A;Cosquer, B;Pereira de Vasconcelos, A;Brouillet, E;Cassel, J;Boutillier, A;Merienne, K;
| DOI: 10.1136/jnnp-2022-ehdn.2
Epigenetic mechanisms are altered in the striatum of HD patients and mouse models, but how they might contribute to pathogenesis, including cognitive deficits, is unclear. Epigenetic regulation is critical to learning and memory processes, through transcriptional control of gene program promoting neural plasticity. We asked whether memory-associated epigenetic and transcriptional responses were impaired in HD R6/1 mice. To this end, we trained R6/1 mice (and control mice) in an aquatic navigation task, the double H maze, which allows assessing striatum-dependent memory (e.g. egocentric spatial memory). We then generated ChIP-seq, 4C-seq and RNA-seq datasets on striatal tissue of HD and control mice during egocentric memory processing, including memory acquisition and consolidation/recall. Egocentric memory was altered since early symptomatic stage in R6/1 mice, which correlated with dramatic reduction of striatal epigenetic and transcriptional changes induced by memory process. More specifically, multi-omic analysis showed that, during memory acquisition, 3D chromatin re-organization and transcriptional induction at BDNF-related genes were diminished in R6/1 striatum. Moreover, we found that changes in H3K9 acetylation (H3K9ac), which accompanied memory process in normal striatum, were attenuated in R6/1 striatum. Functional enrichment analyses further indicated that altered H3K9ac regulation during late phase of egocentric memory process (e.g. consolidation/recall) contributed to impaired TGFβ-dependent cellular plasticity. Together, this study provides support to the hypothesis that epigenetic dysregulation in HD contributes to cognitive deficits, and shed light on new targets of striatal plasticity, particularly H3K9ac and TFGβ signaling.
Ruiz de Sabando, A;Ciosi, M;Galbete, A;Monckton, D;Ramos-Arroyo, M;
| DOI: 10.1136/jnnp-2022-ehdn.1
We aimed to determine the possible role of CAG somatic expansions on the clinical expression of intermediate allele (IA) carriers of the HTT gene, responsible for Huntington disease (HD). We performed exon one sequencing analysis of the HTT gene on peripheral blood DNA in a Spanish cohort of asymptomatic IA carriers (n=55), symptomatic IA carriers (n=86) and HD subjects (n=124). Additionally, we investigated different brain regions of an individual carrying an HTT allele with 33 CAGs, with neurocognitive symptoms. Linear regression models were used to analyse the association between CAG length and age with somatic mosaicism. Symptomatic IA carriers presented with motor (80%), cognitive (20%) and/or behavioural (22%) signs, and an average age of onset of 58.7 years±18.6. Somatic mosaicism is CAG- and age-dependent in alleles of CAG≥27 CAGs, with b=0.04 (95% CI: 0.035-0.046), and b=0.001 (95% CI: 0.001-0.002), respectively, for all IAs. There was no statistical difference between HTT somatic mosaicism in symptomatic vs asymptomatic IA carriers (p=0.066). Somatic expansions of +1 and +2 CAGs were detected in the brain of the individual with 33 CAGs, with the highest expansion ratio observed in the putamen, where up to 10% of the DNA molecules underwent somatic expansion. In conclusion, somatic CAG expansions observed in blood cannot explain, overall, the neurocognitive signs of IA carriers. However, somatic instability occurs in IAs, which changes with CAG number and age; therefore, the presence of cells in the brain that express up to +2 CAGs may be important when considering the phenotypes of those alleles close to the pathological threshold.
Journal of cancer research and clinical oncology
Bakker, A;Slack, JC;Palanisamy, N;Carskadon, S;Ghosh, S;Khalifeh, I;Bismar, TA;
PMID: 35982181 | DOI: 10.1007/s00432-022-04279-5
KLK4::KLKP1 fusion is a recently described pseudogene that is enriched in prostate cancer (PCa). This new biomarker has not been characterized in the Middle Eastern population.To establish the incidence and prognostic value of KLK4::KLKP1 fusion in a cohort of Middle Eastern men with PCa and explore the relationship of this marker to other relevant biomarkers (PTEN, ERG, SPINK1).We interrogated a cohort of 340 Middle Eastern men with localized PCa treated by radical prostatectomy between 2005 and 2015. KLK4::KLKP1 fusion status was assessed by RNA Chromogenic in situ hybridization (CISH) and correlated to pathological and clinical parameters.RNA-CISH expression of KLK4::KLKP1 was correlated with prognostic factors, ERG, PTEN, and SPINK1 expression, and biochemical recurrence (BCR) following prostatectomy.51.7% of patient samples showed positive KLK4::KLKP1 expression; more commonly in cores of PCa (38%) versus non-cancer (20.6%) (p < 0.0001) and in lower Gleason Grade Group tumors (1-3) vs (4-5). KLK4::KLKP1 expression positively correlated with ERG positivity and inversely associated with PTEN loss. No significant association was found with SPINK1 expression, seminal vesicle invasion, positive surgical margin, pathological stage, or patient age (< 50 or ≥ 50). The association between PTEN loss and BCR increased when combined with KLK4::KLKP1 negativity (HR 2.31, CI 1.03-5.20, p = 0.042).KLK4::KLKP1 expression is more common in this cohort of Middle Eastern men than has been reported in North American men. It is associated with ERG positivity and inversely correlated with PTEN loss. In isolation, KLK4::KLKP1 expression was not significantly associated with clinical outcome or pathological parameters. However, its expression is associated with certain molecular subtypes (ERG-positive, PTEN-intact) and as we demonstrate may help further stratify the risk of recurrence within these groups.
American journal of respiratory and critical care medicine
Borie, R;Cardwell, J;Konigsberg, IR;Moore, CM;Zhang, W;Sasse, SK;Gally, F;Dobrinskikh, E;Walts, A;Powers, J;Brancato, J;Rojas, M;Wolters, PJ;Brown, KK;Blackwell, TS;Nakanishi, T;Richards, JB;Gerber, AN;Fingerlin, TE;Sachs, N;Pulit, SL;Zappala, Z;Schwartz, DA;Yang, IV;
PMID: 35816432 | DOI: 10.1164/rccm.202110-2308OC
Common genetic variants have been associated with idiopathic pulmonary fibrosis (IPF).To determine functional relevance of the 10 IPF-associated common genetic variants we previously identified.We performed expression quantitative trait loci (eQTL) and methylation quantitative trait loci (mQTL) mapping, followed by co-localization of eQTL and mQTL with genetic association signals and functional validation by luciferase reporter assays. Illumina MEGA genotyping arrays, mRNA sequencing, and Illumina 850k methylation arrays were performed on lung tissue of participants with IPF (234 RNA and 345 DNA samples) and non-diseased controls (188 RNA and 202 DNA samples).Focusing on genetic variants within 10 IPF-associated genetic loci, we identified 27 eQTLs in controls and 24 eQTLs in cases (false-discovery-rate-adjusted p<0.05). Among these signals, we identified associations of lead variants rs35705950 with expression of MUC5B and rs2076295 with expression of DSP in both cases and controls. mQTL analysis identified CpGs in gene bodies of MUC5B (cg17589883) and DSP (cg08964675) associated with the lead variants in these two loci. We also demonstrated strong co-localization of eQTL/mQTL and genetic signal in MUC5B (rs35705950) and DSP (rs2076295). Functional validation of the mQTL in MUC5B using luciferase reporter assays demonstrates that the CpG resides within a putative internal repressor element.We have established a relationship of the common IPF genetic risk variants rs35705950 and rs2076295 with respective changes in MUC5B and DSP expression and methylation. These results provide additional evidence that both MUC5B and DSP are involved in the etiology of IPF.
Le, MT;Shon, HK;Nguyen, HP;Lee, CH;Kim, KS;Na, HK;Lee, TG;
PMID: 35696262 | DOI: 10.1021/acs.analchem.2c00676
The importance of multi-omic-based approaches to better understand diverse pathological mechanisms including neurodegenerative diseases has emerged. Spatial information can be of great help in understanding how biomolecules interact pathologically and in elucidating target biomarkers for developing therapeutics. While various analytical methods have been attempted for imaging-based biomolecule analysis, a multi-omic approach to imaging remains challenging due to the different characteristics of biomolecules. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is a powerful tool due to its sensitivity, chemical specificity, and high spatial resolution in visualizing chemical information in cells and tissues. In this paper, we suggest a new strategy to simultaneously obtain the spatial information of various kinds of biomolecules that includes both labeled and label-free approaches using ToF-SIMS. The enzyme-assisted labeling strategy for the targets of interest enables the sensitive and specific imaging of large molecules such as peptides, proteins, and mRNA, a task that has been, to date, difficult for any MS analysis. Together with the strength of the analytical performance of ToF-SIMS in the label-free tissue imaging of small biomolecules, the proposed strategy allows one to simultaneously obtain integrated information of spatial distribution of metabolites, lipids, peptides, proteins, and mRNA at a high resolution in a single measurement. As part of the suggested strategy, we present a sample preparation method suitable for MS imaging. Because a comprehensive method to examine the spatial distribution of multiple biomolecules in tissues has remained elusive, our strategy can be a useful tool to support the understanding of the interactions of biomolecules in tissues as well as pathological mechanisms.
Proceedings of the National Academy of Sciences of the United States of America
Gamal El-Din, TM;Lantin, T;Tschumi, CW;Juarez, B;Quinlan, M;Hayano, JH;Li, J;Zweifel, LS;Catterall, WA;
PMID: 34728568 | DOI: 10.1073/pnas.2112666118
Autism spectrum disorder (ASD) adversely impacts >1% of children in the United States, causing social interaction deficits, repetitive behaviors, and communication disorders. Genetic analysis of ASD has advanced dramatically through genome sequencing, which has identified >500 genes with mutations in ASD. Mutations that alter arginine gating charges in the voltage sensor of the voltage-gated potassium (KV) channel KV7 (KCNQ) are among those frequently associated with ASD. We hypothesized that these gating charge mutations would induce gating pore current (also termed ω-current) by causing an ionic leak through the mutant voltage sensor. Unexpectedly, we found that wild-type KV7 conducts outward gating pore current through its native voltage sensor at positive membrane potentials, owing to a glutamine in the third gating charge position. In bacterial and human KV7 channels, gating charge mutations at the R1 and R2 positions cause inward gating pore current through the resting voltage sensor at negative membrane potentials, whereas mutation at R4 causes outward gating pore current through the activated voltage sensor at positive potentials. Remarkably, expression of the KV7.3/R2C ASD-associated mutation in vivo in midbrain dopamine neurons of mice disrupts action potential generation and repetitive firing. Overall, our results reveal native and mutant gating pore current in KV7 channels and implicate altered control of action potential generation by gating pore current through mutant KV7 channels as a potential pathogenic mechanism in autism.
Saxena, A;Sharma, V;Muthuirulan, P;Neufeld, SJ;Tran, MP;Gutierrez, HL;Chen, KD;Erberich, JM;Birmingham, A;Capellini, TD;Cobb, J;Hiller, M;Cooper, KL;
PMID: 34793695 | DOI: 10.1016/j.cub.2021.10.063
Despite the great diversity of vertebrate limb proportion and our deep understanding of the genetic mechanisms that drive skeletal elongation, little is known about how individual bones reach different lengths in any species. Here, we directly compare the transcriptomes of homologous growth cartilages of the mouse (Mus musculus) and bipedal jerboa (Jaculus jaculus), the latter of which has "mouse-like" arms but extremely long metatarsals of the feet. Intersecting gene-expression differences in metatarsals and forearms of the two species revealed that about 10% of orthologous genes are associated with the disproportionately rapid elongation of neonatal jerboa feet. These include genes and enriched pathways not previously associated with endochondral elongation as well as those that might diversify skeletal proportion in addition to their known requirements for bone growth throughout the skeleton. We also identified transcription regulators that might act as "nodes" for sweeping differences in genome expression between species. Among these, Shox2, which is necessary for proximal limb elongation, has gained expression in jerboa metatarsals where it has not been detected in other vertebrates. We show that Shox2 is sufficient to increase mouse distal limb length, and a nearby putative cis-regulatory region is preferentially accessible in jerboa metatarsals. In addition to mechanisms that might directly promote growth, we found evidence that jerboa foot elongation may occur in part by de-repressing latent growth potential. The genes and pathways that we identified here provide a framework to understand the modular genetic control of skeletal growth and the remarkable malleability of vertebrate limb proportion.
Cell death and differentiation
Wang, T;Tomas, D;Perera, ND;Cuic, B;Luikinga, S;Viden, A;Barton, SK;McLean, CA;Samson, AL;Southon, A;Bush, AI;Murphy, JM;Turner, BJ;
PMID: 34857917 | DOI: 10.1038/s41418-021-00910-z
Amyotrophic lateral sclerosis (ALS) is caused by selective degeneration of motor neurons in the brain and spinal cord; however, the primary cell death pathway(s) mediating motor neuron demise remain elusive. We recently established that necroptosis, an inflammatory form of regulated cell death, was dispensable for motor neuron death in a mouse model of ALS, implicating other forms of cell death. Here, we confirm these findings in ALS patients, showing a lack of expression of key necroptotic effector proteins in spinal cords. Rather, we uncover evidence for ferroptosis, a recently discovered iron-dependent form of regulated cell death, in ALS. Depletion of glutathione peroxidase 4 (GPX4), an anti-oxidant enzyme and central repressor of ferroptosis, occurred in post-mortem spinal cords of both sporadic and familial ALS patients. GPX4 depletion was also an early and universal feature of spinal cords and brains of transgenic mutant superoxide dismutase 1 (SOD1G93A), TDP-43 and C9orf72 mouse models of ALS. GPX4 depletion and ferroptosis were linked to impaired NRF2 signalling and dysregulation of glutathione synthesis and iron-binding proteins. Novel BAC transgenic mice overexpressing human GPX4 exhibited high GPX4 expression localised to spinal motor neurons. Human GPX4 overexpression in SOD1G93A mice significantly delayed disease onset, improved locomotor function and prolonged lifespan, which was attributed to attenuated lipid peroxidation and motor neuron preservation. Our study discovers a new role for ferroptosis in mediating motor neuron death in ALS, supporting the use of anti-ferroptotic therapeutic strategies, such as GPX4 pathway induction and upregulation, for ALS treatment.