Tcf4 dysfunction alters dorsal and ventral cortical neurogenesis in Pitt-Hopkins syndrome mouse model showing sexual dimorphism

Pitt-Hopkins syndrome (PTHS) is a neurodevelopmental disorder caused by haploinsufficiency of transcription factor 4 (TCF4). In this work, we focused on the cerebral cortex and investigated in detail the progenitor cell dynamics and the outcome of neurogenesis in a PTHS mouse model. Labeling and quantification of progenitors and newly generated neurons at various time points during embryonic development revealed alterations affecting the dynamic of cortical progenitors since the earliest stages of cortex formation in PTHS mice. Consequently, establishment of neuronal populations and layering of the cortex were found to be altered in heterozygotes subjects at birth. Interestingly, defective layering process of pyramidal neurons was partially rescued by reintroducing TCF4 expression using focal in utero electroporation in the cerebral cortex. Coincidentally with a defective dorsal neurogenesis, we found that ventral generation of interneurons was also defective in this model, which may lead to an excitation/inhibition imbalance in PTHS. Overall, sex-dependent differences were detected with more marked effects evidenced in males compared with females. All of this contributes to expand our understanding of PTHS, paralleling the advances of research in autism spectrum disorder and further validating the PTHS mouse model as an important tool to advance preclinical studies.

Impaired communication at the neuromotor axis during Degenerative Cervical Myelopathy

Degenerative Cervical Myelopathy (DCM) is a progressive neurological condition characterized by structural alterations in the cervical spine, resulting in compression of the spinal cord. While clinical manifestations of DCM are well-documented, numerous unanswered questions persist at the molecular and cellular levels. In this study, we sought to investigate the neuromotor axis during DCM. We use a clinically relevant mouse model, where after 3 months of DCM induction, the sensorimotor tests revealed a significant reduction in both locomotor activity and muscle strength compared to the control group. Immunohistochemical analyses showed alterations in the gross anatomy of the cervical spinal cord segment after DCM. These changes were concomitant with the loss of motoneurons and a decrease in the number of excitatory synaptic inputs within the spinal cord. Additionally, the DCM group exhibited a reduction in the endplate surface, which correlated with diminished presynaptic axon endings in the supraspinous muscles. Furthermore, the biceps brachii (BB) muscle exhibited signs of atrophy and impaired regenerative capacity, which inversely correlated with the transversal area of remnants of muscle fibers. Additionally, metabolic assessments in BB muscle indicated an increased proportion of oxidative skeletal muscle fibers. In line with the link between neuromotor disorders and gut alterations, DCM mice displayed smaller mucin granules in the mucosa layer without damage to the epithelial barrier in the colon. Notably, a shift in the abundance of microbiota phylum profiles reveals an elevated Firmicutes-to-Bacteroidetes ratio-a consistent hallmark of dysbiosis that correlates with alterations in gut microbiota-derived metabolites. Additionally, treatment with short-chain fatty acids stimulated the differentiation of the motoneuron-like NSC34 cell line. These findings shed light on the multifaceted nature of DCM, resembling a synaptopathy that disrupts cellular communication within the neuromotor axis while concurrently exerting influence on other systems. Notably, the colon emerges as a focal point, experiencing substantial perturbations in both mucosal barrier integrity and the delicate balance of intestinal microbiota.

Degenerative Cervical Myelopathy induces sex-specific dysbiosis in mice

Degenerative Cervical Myelopathy (DCM) is the most common cause of spinal cord impairment in elderly populations. It describes a spectrum of disorders that cause progressive spinal cord compression, neurological impairment, loss of bladder and bowel functions, and gastrointestinal dysfunction. The gut microbiota has been recognized as an environmental factor that can modulate both the function of the central nervous system and the immune response through the microbiota-gut-brain axis. Changes in gut microbiota composition or microbiota-producing factors have been linked to the progression and development of several pathologies. However, little is known about the potential role of the gut microbiota in the pathobiology of DCM. Here, DCM was induced in C57BL/6 mice by implanting an aromatic polyether material underneath the C5-6 laminae. The extent of DCM-induced changes in microbiota composition was assessed by 16S rRNA sequencing of the fecal samples. The immune cell composition was assessed using flow cytometry. To date, several bacterial members have been identified using BLAST against the largest collection of metagenome-derived genomes from the mouse gut. In both, female and males DCM caused gut dysbiosis compared to the sham group. However, dysbiosis was more pronounced in males than in females, and several bacterial members of the families Lachnospiraceae and Muribaculaceae were significantly altered in the DCM group. These changes were also associated with altered microbe-derived metabolic changes in propionate-, butyrate-, and lactate-producing bacterial members. Our results demonstrate that DCM causes dynamic changes over time in the gut microbiota, reducing the abundance of butyrate-producing bacteria, and lactate-producing bacteria to a lesser extent. Genome-scale metabolic modeling using gapseq successfully identified pyruvate-to-butanoate and pyruvate-to-propionate reactions involving genes such as Buk and ACH1, respectively. These results provide a better understanding of the sex-specific molecular effects of changes in the gut microbiota on DCM pathobiology.

Gut Microbiota Interaction with the Central Nervous System throughout Life

During the last years, accumulating evidence has suggested that the gut microbiota plays a key role in the pathogenesis of neurodevelopmental and neurodegenerative diseases via the gut-brain axis. Moreover, current research has helped to elucidate different communication pathways between the gut microbiota and neural tissues (e.g., the vagus nerve, tryptophan production, extrinsic enteric-associated neurons, and short chain fatty acids). On the other hand, altering the composition of gut microbiota promotes a state known as dysbiosis, where the balance between helpful and pathogenic bacteria is disrupted, usually stimulating the last ones. Herein, we summarize selected findings of the recent literature concerning the gut microbiome on the onset and progression of neurodevelopmental and degenerative disorders, and the strategies to modulate its composition in the search for therapeutical approaches, focusing mainly on animal models studies. Readers are advised that this is a young field, based on early studies, that is rapidly growing and being updated as the field advances.

[DISCREPA study: treatment of advanced Parkinson's disease and use of second-line treatments in Catalonia]

INTRODUCTION

The treatment of Parkinson's disease (PD) is complex, and the establishment of second-line therapies in advanced PD remains controversial.

AIM

To analyze the assistance of patients with PD in Catalonia, with special attention to the use of second-line therapies in advanced PD.

SUBJECTS AND METHODS

Online self-administered survey to neurologists in Catalonia who treated patients with PD, through the Catalan Society of Neurology.

RESULTS

72 neurologists who visited a monthly average of 38 PD patients (37.3% motor complications) participated. 86% routinely asked about motor. The main reasons for indicating second-line therapies were disability in off (83.1%), impact of dyskinesias (76.9%), impact of time in off (75.4%) and time in off (73.8%). 70% of neurologists declared limitations to establish second-line therapies: lack of resources in their hospital, lack of time to visit the patient or to perform administrative tasks and lack nursing support. Second-line therapies is not used in 72% of patients who could potentially be candidates, especially due to patient rejection (37.9%).

CONCLUSIONS

The majority of neurologists in Catalonia who visit patients with PD routinely ask about motor complications without using specific tools. Although neurologists are well aware of the indications for the establishment of second-line therapies, the refusal of the patient, the lack of time and the lack of defined care protocols to refer patients, they can contribute to a lower use of second-line therapies in advanced PD.

Management of Parkinson's disease and other movement disorders in women of childbearing age: Part 2

INTRODUCTION

Many diseases associated with hyperkinetic movement disorders manifest in women of childbearing age. It is important to understand the risks of these diseases during pregnancy, and the potential risks of treatment for the fetus.

OBJECTIVES

This study aims to define the clinical characteristics and the factors affecting the lives of women of childbearing age with dystonia, chorea, Tourette syndrome, tremor, and restless legs syndrome, and to establish guidelines for management of pregnancy and breastfeeding in these patients.

RESULTS

This consensus document was developed through an exhaustive literature search and a discussion of the content by a group of movement disorder experts from the Spanish Society of Neurology.

CONCLUSIONS

We must evaluate the risks and benefits of treatment in all women with hyperkinetic movement disorders, whether pre-existing or with onset during pregnancy, and aim to reduce effective doses as much as possible or to administer drugs only when necessary. In hereditary diseases, families should be offered genetic counselling. It is important to recognise movement disorders triggered during pregnancy, such as certain types of chorea and restless legs syndrome.

91 Invivo- and invitro-produced bovine embryos have different microRNA profiles after invitro individual culture

Invivo- and invitro-produced bovine embryos have different metabolic characteristics, embryonic development, and gene transcription. Additionally, pregnancy rates at 30 days (on average 51% and 34% when using fixed-time AI and invitro production, respectively) are different in beef cattle. Between Days 8 and 17 of the oestrous cycle, concurrent with embryo-maternal recognition, is when 40% of embryonic losses occur. These losses may occur due to altered embryo-maternal cross-talk. MicroRNA (miRNA) can be involved in this communication; however, its potentially regulated pathways in invivo and invitro embryos on Day 9 are unknown. Our hypothesis is that bovine embryos produced invivo and invitro contain different miRNA profiles, even after invivo bovine embryo were invitro cultured. Cows had the follicular wave synchronized and were superovulated to produce invivo or invitro bovine embryos. For the invitro group, on Day −8 of the protocol, the dominant follicles were recovered by ovum pickup, and invitro embryo production was performed to obtain embryos. For the invivo group, on Day −8, the cows were inseminated 12 and 24h after GnRH analogue application and on Day 7 after expected oestrus, uterine flushing was performed to obtain the embryos. Embryos from both groups were individually cultured for 48h. Three pools (of 5 embryos each) per group were used for reverse transcription of miRNAs from total RNA using miScript II RT Kit (Qiagen). Relative levels of 383 bovine miRNAs were determined using the geometric mean of miR-99b, RNU43 snoRNA, and Hm/Ms/Rt U1 snRNA by RT-qPCR. Differences in relative levels of miRNAs were determined by Student's t-test. A total of 210 miRNAs were detected in invivo and invitro embryos, and 13 out of 210 were differently identified between the groups. In invivo embryos, 6 miRNAs were up-regulated, whereas 7 miRNAs were up-regulated in invitro embryos. TARGETSCAN software was used to identify genes predicted as modulated by each miRNA. The top 100 genes predicted were used to identify enriched pathways according to DAVID Bioinformatics Resources. The miRNAs (miR-129, miR-132, miR-155, miR-192, miR-215, and miR-377) up-regulated in invivo embryos modulated pathways that include signaling pathways regulating pluripotency of stem cells (16 genes), TGF-β (11), hippo (10), oestrogen (8), and cell cycle (7). Moreover, miR-23a, miR-338, miR-34a, miR-491, miR-92b, miR-940, and miR-1271, which were increased in invitro embryos, regulate PI3K-Akt (17 genes), signaling pathways regulating pluripotency of stem cells (10), oestrogen (9), toll-like receptor (9), Wnt (9), and HIF-1 (7). The results demonstrate that even after 48h of invitro culture, bovine embryos produced invivo and invitro have different miRNA profiles that modulate pathways associated with embryonic development on Day 9. Furthermore, these results suggest that bioactive molecules, such as miRNAs, can modify embryo-maternal cross-talk, depending on the environment where the embryos are produced. Funding was provided by FAPESP 2017/19681-9, 2014/22887-0, and 2018/13155-6.

Early Actions of Neurotransmitters During Cortex Development and Maturation of Reprogrammed Neurons

The development of the brain is shaped by a myriad of factors among which neurotransmitters play remarkable roles before and during the formation and maturation of synaptic circuits. Cellular processes such as neurogenesis, morphological development, synaptogenesis and maturation of synapses are temporary and spatially regulated by the local or distal influence of neurotransmitters in the developing cortex. Thus, research on this area has contributed to the understanding of fundamental mechanisms of brain development and to shed light on the etiology of various human neurodevelopmental disorders such as autism and Rett syndrome (RTT), among others. Recently, the field of neuroscience has been shaken by an explosive advance of experimental approaches linked to the use of induced pluripotent stem cells and reprogrammed neurons. This new technology has allowed researchers for the first time to model in the lab the unique events that take place during early human brain development and to explore the mechanisms that cause synaptopathies. In this context, the role of neurotransmitters during early stages of cortex development is beginning to be re-evaluated and a revision of the state of the art has become necessary in a time when new protocols are being worked out to differentiate stem cells into functional neurons. New perspectives on reconsidering the function of neurotransmitters include opportunities for methodological advances, a better understanding of the origin of mental disorders and the potential for development of new treatments.

Enhanced mesoscale climate projections in TAR and AR5 IPCC scenarios: a case study in a Mediterranean climate (Araucanía Region, south central Chile)

Climate change scenarios are computed on a large scale, not accounting for local variations presented in historical data and related to human scale. Based on historical records, we validate a baseline (1962–1990) and correct the bias of A2 and B2 regional projections for the end of twenty-first century (2070–2100) issued from a high resolution dynamical downscaled (using PRECIS mesoscale model, hereinafter DGF-PRECIS) of Hadley GCM from the IPCC 3rd Assessment Report (TAR). This is performed for the Araucanía Region (Chile; 37°–40°S and 71°–74°W) using two different bias correction methodologies. Next, we study high-resolution precipitations to find monthly patterns such as seasonal variations, rainfall months, and the geographical effect on these two scenarios. Finally, we compare the TAR projections with those from the recent Assessment Report 5 (AR5) to find regional precipitation patterns and update the Chilean `projection. To show the effects of climate change projections, we compute the rainfall climatology for the Araucanía Region, including the impact of ENSO cycles (El Niño and La Niña events). The corrected climate projection from the high-resolution dynamical downscaled model of the TAR database (DGF-PRECIS) show annual precipitation decreases: B2 (−19.19 %, −287 ± 42 mm) and A2 (−43.38 %, −655 ± 27.4 mm per year. Furthermore, both projections increase the probability of lower rainfall months (lower than 100 mm per month) to 64.2 and 72.5 % for B2 and A2, respectively.