Human Nucleus Research Articles

A Causal Role for the Human Subthalamic Nucleus in Non-Selective Cortico-Motor Inhibition

A Causal Role for the Human Subthalamic Nucleus in Non-Selective Cortico-Motor Inhibition

Revisiting miR-155 in intervertebral disc degeneration: blood cell signature and local cell-free profiles

We unraveled the expression profiles of coding-noncoding RNAs in intervertebral disc degeneration (IDD). However, it remains elusive regarding miR-155 expression in peripheral blood mononuclear cells (PBMCs) and local extracellular space in IDD. The study aimed for investigating the miR-155 expression of PBMCs, extracellular miRNAs (ex-miRNAs) of human nucleus pulposus (NP) tissues, and morphological changes of cell death in the IDD process. Here, we harvested peripheral blood and NP samples from scoliosis and IDD patients as control and degenerative groups, respectively. Then standard Ficoll density-gradient centrifugation was used to isolate PBMCs. The two subpopulations of PBMCs were divided based on the cellular difference in adherence, i.e., monocytes/ macrophages and lymphocytes. Quantitative real-time PCR was used to evaluate miR-155 relative expression in PBMCs. ex-miRNAs were screened by comparison between GSE19943, GSE63492, and extracellular RNA (exRNA) atlas. The morphological changes of cell death subtypes in IDD were observed in transmission electron microscopy (TEM). Results indicate that the lower expression of miR-155 in PBMCs from IDD patients ascribed to alterations in monocytes/macrophages. Moreover, we identified 594 shared hsa-miRNAs as the intracellular miRNA expression profile and 258 miRNAs as the ex-miRNA expression profile in human NP tissue. miR-155 was amongst intracellular miRNAs in NP. TEM observation presented multiple endocytic secretory vesicles within human NP cells, implicating exosome transporting machinery. Typical necroptosis and pyroptosis were noted in human NP. Collectively, this study reveals miR-155 expression in PBMCs from IDD patients. Moreover, we propose ex-miRNA expression profile and necroptosis/pyroptosis in human NP tissue, shedding novel light on the etiology of IDD.

The investigation of diverse physiological and therapeutic impact of cellular-based products derived from human cumulus cells.

Particular somatic cells, namely cumulus cells (CCs) that support the oocyte maturation, fertility, and viability by providing the nutrients and energy to the oocyte envelop the mammalian oocyte. In this study, discarded human cumulus tissues were used to reveal the value of hyaluronic acid-rich CCs on several cellular events, including differentiation. Conditioned media, recovered from the primary culture of CCs, were introduced to the human nucleus pulposus cells (hNPCs) which were functionally distorted because of the loss of chondrogenecity. Enlightening the impact of cumulus conditioned media (CCM) on wound healing and angiogenesis was also investigated. In line with these goals, differentiation of hNPCs into chondrocytes with CCM as the basal medium containing traditional differentiation agents was induced upon isolation and characterization of hCCs and hNPCs. The effects were detected by differentiation-specific cell stains and gene expression analyses. Scratch and tube formation assays were performed to detect the effect of CCM on wound healing and angiogenesis. Our results showed that cumulus cell-conditioned media promoted the chondrogenesis and osteogenesis of hNPCs. A significant increase in angiogenesis and ability for wound closure was detected only in groups cultured in CCM compared to the control. These findings demonstrated that CCM might be used in therapeutics.

Circ0007042 alleviates intervertebral disc degeneration by adsorbing miR-369 to upregulate BMP2 and activate the PI3K/AKt pathway

BackgroundTo identify regulatory ncRNA molecules that can cause differential expression of CDH2 in intervertebral disc degeneration (IDD) and explore whether there are other ways to affect the progression of IDD.MethodsA primary culture of human nucleus pulposus (NP) cells was established and identified by immunofluorescence. An in vitro IDD model was constructed by compressing human NP cells, and the MTT assay was used to measure cell viability. Changes in the ncRNA group were analysed by RNA-seq. The expression levels of hsa_circ_7042, CDH2, and miR-369-3p were detected by qPCR. Cell apoptosis, senescence, and extracellular matrix (ECM) metabolism were detected by flow cytometry, β-galactosidase staining, and Western blotting. hsa_circ_7042, miR-369-3p, and bone morphogenetic protein 2 (BMP2) were verified by luciferase and RNA immunoprecipitation (RIP) analyses. The PI3K/Akt pathway was validated by transfection of BMP2 siRNA. Furthermore, a mouse model of lumbar spine instability was constructed. circ_7042 adenovirus was packaged and injected into the intervertebral discs of mice, and the influence of circ_7042 overexpression on intervertebral disc degeneration was determined.ResultsWestern blotting, qPCR, and flow cytometry analyses confirmed that overexpression of circ_7042 could downregulate miR-369-3p and upregulate the expression of CDH2 and BMP2 in IDD cell and animal models. Additionally, the levels of apoptotic and senescent cells decreased, and ECM degradation decreased. The PI3K/Akt pathway was significantly activated after circ_7042 was overexpressed. The injection of circ_7042-overexpressing adenovirus effectively reduced ECM degradation and the level of apoptosis in NP tissue.Conclusionscirc_7042 could upregulate the expression of CDH2 and BMP2 by absorbing miR-369-3p, and the increased BMP2 activated the PI3K/Akt pathway, thus improving IDD.

Revisiting miR-155 in intervertebral disc degeneration: blood cell signature and local cell-free profiles

We unraveled the expression profiles of coding-noncoding RNAs in intervertebral disc degeneration (IDD). However, it remains elusive regarding miR-155 expression in peripheral blood mononuclear cells (PBMCs) and local extracellular space in IDD. The study aimed for investigating the miR-155 expression of PBMCs, extracellular miRNAs (ex-miRNAs) of human nucleus pulposus (NP) tissues, and morphological changes of cell death in the IDD process. Here, we harvested peripheral blood and NP samples from scoliosis and IDD patients as control and degenerative groups, respectively. Then standard Ficoll density-gradient centrifugation was used to isolate PBMCs. The two subpopulations of PBMCs were divided based on the cellular difference in adherence, i.e., monocytes/ macrophages and lymphocytes. Quantitative real-time PCR was used to evaluate miR-155 relative expression in PBMCs. ex-miRNAs were screened by comparison between GSE19943, GSE63492, and extracellular RNA (exRNA) atlas. The morphological changes of cell death subtypes in IDD were observed in transmission electron microscopy (TEM). Results indicate that the lower expression of miR-155 in PBMCs from IDD patients ascribed to alterations in monocytes/macrophages. Moreover, we identified 594 shared hsa-miRNAs as the intracellular miRNA expression profile and 258 miRNAs as the ex-miRNA expression profile in human NP tissue. miR-155 was amongst intracellular miRNAs in NP. TEM observation presented multiple endocytic secretory vesicles within human NP cells, implicating exosome transporting machinery. Typical necroptosis and pyroptosis were noted in human NP. Collectively, this study reveals miR-155 expression in PBMCs from IDD patients. Moreover, we propose ex-miRNA expression profile and necroptosis/pyroptosis in human NP tissue, shedding novel light on the etiology of IDD.

LncRNA HOTAIR influences cell proliferation via miR-130b/PTEN/AKT axis in IDD

ABSTRACT Intervertebral disc degeneration (IDD) constitutes the pathological foundation of most musculoskeletal disorders of the spine. Previous studies have noted that cell proliferation is a common feature of IDD. Bioinformatics indicated that aberrantly expressed long non-coding RNAs (lncRNAs) were involved in the development of IDD. In this study, we aimed to investigate the function of lncRNA HOTAIR in the proliferation of human nucleus pulposus (NP) cells of IDD in vitro and further clarified its mechanism. The expression of HOTAIR and miR-130b was quantified by qRT-PCR in nucleus pulposus (NP) tissues. Furthermore, NP cells proliferation were assayed by CCK8 and Immunostaining. Dual-luciferase reporter and RIP assay were used to examine the expression of HOTAIR, PTEN, and their co-target gene miR-130b. Western blotting was used to test AKT expression. Our in vitro experiments on human normal NP cells observed that HOTAIR was significantly dysregulated in IDD. Further, HOTAIR can suppress proliferation by directly targeting miR-130b. In addition, Both HOTAIR and PTEN were confirmed to target miR-130b, and miR-130b upregulation reversed the phenomenon of ectopic expression of HOTAIR. More importantly, HOTAIR upregulation significantly reduced CyclinD1 protein expression by PTEN/AKT signaling pathway. Our findings suggest that HOTAIR may bind to miR-130b and subsequently increased CyclinD1 expression via PTEN/Akt pathway. Thereby, HOTAIR could become a potential target for the treatment of IDD. Abbreviations : IDD; intervertebral disc degenerationncRNAs; non-coding RNAslncRNAs; long non-coding RNAsmiRNAs; microRNAsNP; nucleus pulposusqRT-PCR; quantitative reverse transcription–PCR LBP; Low back pain ORF; open reading frame HOTAIR; Hox transcript antisense intergenic RNA FAF1; Fas-associated protein factor-1Erk; extracellular signal-regulated kinase TUG1; Taurine Up-regulated Gene 1 HIF1A hypoxia-inducible factor 1-alpha PI3K; phosphoinositide-3 kinase AIS; adolescent idiopathic scoliosis ECM; extracellular matrix LN;lupus nephritis CT;computed tomography MRI; magnetic resonance imaging PBS; phosphate-buffered salin PBS; phosphate-buffered salin PVDF; polyvinylidene fluoride TBST; Tris-buffered saline Tween ECL; enhanced chemiluminescenceRIP; RNA immunoprecipitation

The protective effects of dezocine on interleukin-1β-induced inflammation, oxidative stress and apoptosis of human nucleus pulposus cells and the possible mechanisms

ABSTRACT Intervertebral disc degeneration (IDD) is a natural problem linked to the inflammation. We aimed to investigate the role of dezocine (DEZ) in the development of IDD. Human nucleus pulposus cells (HNPCs) induced by interleukin (IL)-1β was used as a cellular model of IDD. After treatment with DEZ, HNPCs viability was evaluated with a CCK-8 assay. Then, the levels of inflammatory factors, including IL-6 and tumor necrosis factor-α (TNF-α), and oxidative stress-related markers, including reactive oxygen species (ROS), malondialdehyde (MDA) and reduced glutathione (GSH), were tested by RT-qPCR or kits. TUNEL staining was employed to detect cell apoptosis and Western blot was used to determine the expression of proteins related to inflammation, oxidative stress, apoptosis, endoplasmic reticulum stress (ERS) and MAPK signaling. Afterward, PMA, a MAPK signaling pathway agonist, was adopted for exploring the regulatory effects of DEZ on MAPK pathway. Results indicated that DEZ enhanced cell viability of HNPCs after IL-1β exposure. DEZ alleviated the inflammation and oxidative stress, evidenced by decreased levels of IL-6, TNF-α, ROS, MDA, p-NF-κB p65, NF-κB p65 in nucleus, cox-2 and increased levels of NF-κB p65 in cytoplasm, GSH, SOD1 and SOD2. Moreover, DEZ notably inhibited IL-1β-induced apoptosis of HNPCs. Furthermore, DEZ suppressed the levels of ERS-related proteins. The levels of related proteins in MAPK signaling including p-P38 and p-ERK1/2 were remarkably reduced after DEZ administration. By contrast, PMA crippled the impacts of DEZ on inflammation, oxidative stress and apoptosis of HNPCs induced by IL-1β. Collectively, DEZ ameliorates IL-1β-induced HNPCs injury via inhibiting MAPK signaling.

Melatonin reverses tumor necrosis factor-alpha-induced metabolic disturbance of human nucleus pulposus cells via MTNR1B/Gαi2/YAP signaling.

Background: Intervertebral disc degeneration (IDD), the main cause of low back pain, is closely related to the inflammatory microenvironment in the nucleus pulposus (NP). Tumor necrosis factor-α (TNF-α) plays an important role in inflammation-related metabolic disturbance of NP cells. Melatonin has been proven to regulate the metabolism of NP cells, but whether it can protect NP cells from TNF-α-induced damage is still unclear. Therefore, this study aims to investigate the role and specific mechanism of melatonin on regulating the metabolism of NP cells in the inflammatory microenvironment.Methods: Western blotting, RT-qPCR and immunohistochemistry were used to detect the expression of melatonin membrane receptors (MTNR1A/B) and TNF-α in human NP tissues. In vitro, human primary NP cells were treated with or without vehicle, TNF-α and melatonin. And the metabolic markers were also detected by western blotting and RT-qPCR. The activity of NF-κB signaling and Hippo/YAP signaling were assessed by western blotting and immunofluorescence. Membrane receptors inhibitors, pathway inhibitors, lentiviral infection, plasmids transfection and immunoprecipitation were used to explore the specific mechanism of melatonin. In vivo, the rat IDD model was constructed and melatonin was injected intraperitoneally to evaluate its therapeutical effect on IDD.Results: The upregulation of TNF-α and downregulation of melatonin membrane receptors (MTNR1A/B) were observed in degenerative NP tissues. Then we demonstrated that melatonin could alleviate the development of IDD in a rat model and reverse TNF-α-impaired metabolism of NP cells in vitro. Further investigation revealed that the protective effects of melatonin on NP cells mainly rely on MTNR1B, which subsequently activates Gαi2 protein. The activation of Gαi2 could upregulate the yes-associated protein (YAP) level, resulting in anabolic enhancement of NP cells. In addition, melatonin-mediated YAP upregulation increased the expression of IκBα and suppressed the TNF-α-induced activation of the NF-κB pathway, thereby inhibiting the catabolism of NP cells.Conclusions: Our results revealed that melatonin can reverse TNF-α-impaired metabolism of NP cells via the MTNR1B/Gαi2/YAP axis and suggested that melatonin can be used as a potential therapeutic drug in the treatment of IDD.

Hypoxia Modulates Regenerative Potential of Fetal Stem Cells.

Adult mesenchymal stem cells (MSCs) are prone to senescence, which limits the scope of their use in tissue engineering and regeneration and increases the likelihood of post-implantation failure. As a robust alternative cell source, fetal stem cells can prevent an immune reaction and senescence. However, few studies use this cell type. In this study, we sought to characterize fetal cells' regenerative potential in hypoxic conditions. Specifically, we examined whether hypoxic exposure during the expansion and differentiation phases would affect human fetal nucleus pulposus cell (NPC) and fetal synovium-derived stem cell (SDSC) plasticity and three-lineage differentiation potential. We concluded that fetal NPCs represent the most promising cell source for chondrogenic differentiation, as they are more responsive and display stronger phenotypic stability, particularly when expanded and differentiated in hypoxic conditions. Fetal SDSCs have less potential for chondrogenic differentiation compared to their adult counterpart. This study also indicated that fetal SDSCs exhibit a discrepancy in adipogenic and osteogenic differentiation in response to hypoxia.

Genipin Cross-Linked Decellularized Nucleus Pulposus Hydrogel-Like Cell Delivery System Induces Differentiation of ADSCs and Retards Intervertebral Disc Degeneration

Intervertebral disc degeneration (IDD) is the pathological basis of disc degenerative diseases (DDD). Reduction in the number of cells and degeneration of the extracellular matrix (ECM) in the nucleus pulposus (NP) are characteristics of IDD. Bio-hydrogel combined with stem cell transplantation is a promising treatment. Injectable ECM hydrogels have good biological activity and in-situ gelatinization. However, its biomechanics and stability are insufficient to provide adequate mechanical support for intervertebral discs and to maintain the long-term differential stimulus for seeded stem cells. In our study, we developed genipin cross-linked decellularized nucleus pulposus hydrogel (GDH) as delivery system. We evaluated the mechanical properties, stability, biocompatibility, and differentiation induction of GDH cross-linked with different concentrations of genipin in vitro. The GDH-loaded adipose-derived mesenchymal stem cells (ADSCs) (GDHA) were injected into the rat degenerated coccygeal intervertebral disc. The effect of intervertebral disc regeneration in vivo was evaluated. The results showed that GDH with 0.02% of genipin had similar elastic modulus to human nucleus pulposus, good biocompatibility, and inducibility of expressing NP-related genes. In vivo studies showed that GDHA improved the survival of ADSCs and improved the intervertebral height, MRI index, and histological grading score. In conclusion, GDH, as an outstanding bio-hydrogel cell delivery system, has the therapeutic potential for retarding IDD.

The Stereological Analysis and Spatial Distribution of Neurons in the Human Subthalamic Nucleus.

The subthalamic nucleus (STN) is a small, ovoid structure, and an important site of deep brain stimulation (DBS) for the treatment of Parkinson’s disease. Although the STN is a clinically important structure, there are many unresolved issues with regard to it. These issues are especially related to the anatomical subdivision, neuronal phenotype, neuronal composition, and spatial distribution. In this study, we have examined the expression pattern of 8 neuronal markers [nNOS, NeuN, parvalbumin (PV), calbindin (CB), calretinin (CR), FOXP2, NKX2.1, and PAX6] in the adult human STN. All of the examined markers, except CB, were present in the STN. To determine the neuronal density, we have performed stereological analysis on Nissl-stained and immunohistochemical slides of positive markers. The stereology data were also used to develop a three-dimensional map of the spatial distribution of neurons within the STN. The nNOS population exhibited the largest neuronal density. The estimated total number of nNOS STN neurons is 281,308 ± 38,967 (± 13.85%). The STN neuronal subpopulations can be divided into two groups: one with a neuronal density of approximately 3,300 neurons/mm3 and the other with a neuronal density of approximately 2,200 neurons/mm3. The largest density of STN neurons was observed along the ventromedial border of the STN and the density gradually decreased toward the dorsolateral border. In this study, we have demonstrated the presence of 7 neuronal markers in the STN, three of which were not previously described in the human STN. The human STN is a collection of diverse, intermixed neuronal subpopulations, and our data, as far as the cytoarchitectonics is concerned, did not support the tripartite STN subdivision.

Small extracellular vesicles from hypoxic mesenchymal stem cells alleviate intervertebral disc degeneration by delivering miR-17-5p

Minimally invasive repair strategies are a very promising approach for the treatment of intervertebral disc degeneration (IDD). In recent years, small extracellular vesicles (sEVs) secreted from mesenchymal stem cells (MSCs) have been shown great potential in alleviating IDD. However, in vitro experiments, MSCs are usually exposed to a normoxic micro-environment, which differs greatly from the hypoxic micro-environment in vivo. The primary purpose of our research was to determine whether sEVs isolated from MSCs under hypoxic status (H-sEVs) exhibit a more beneficial effect on protecting IDD compared with sEVs derived from MSCs under normoxic status (N-sEVs). A tail IDD rat model and a series of experiments in vitro were conducted to compare the beneficial effects of PBS, N-sEVs, and H-sEVs treatment. Then, to validate the role of sEVs miRNAs in IDD, a miRNA microarray sequencing analysis and a series of rescue experiments were conducted. Luciferase activity, RNA-ChIP and western blot were performed to explore the potential mechanisms. The results indicate that sEVs alleviate IDD by ameliorating the homeostatic imbalance between anabolism and catabolism in vivo and in vitro. Microarray sequencing result shows that miR-17-5p is maximally enriched in H-sEVs. Toll-like receptor 4 (TLR4) was determined to be a target downstream gene of miR-17-5p. Finally, it was found that H-sEVs miR-17-5p may modulate proliferation and synthesis of human nucleus pulposus cells (HNPCs) matrix via TLR4 pathway. In conclusion, H-sEVs miR-17-5p alleviate IDD via promoting HNPCs matrix proliferation and synthesis, providing new therapeutic targets for IDD. Statement of significanceIntervertebral disc degeneration (IDD) is the primary cause of low back pain (LBP), which is a huge burden to society. Our research demonstrates for the first time that hypoxic pretreatment of small extracellular vesicles (H-sEVs) effectively alleviated the progress of IDD. In short, in the present research, we found that H-sEVs miR-17-5p could modulate proliferation and synthesis of nucleus pulposus cells (NPCs) matrix via TLR4/PI3K/AKT pathway. Therefore, hypoxic pre-treatment is a prospective and efficient method to optimize the therapeutic effect of MSCs-derived sEVs. miRNA and MSCs-derived sEVs combination may be a promising therapeutic approach for IDD.

Functional Topography of the Human Subthalamic Nucleus: Relevance for Subthalamotomy in Parkinson's Disease.

The subthalamic nucleus (STN) is considered a key structure in motor, behavioral, and emotional control. Although identification of the functional topography of the STN has therapeutic implications in the treatment of the motor features of Parkinson's disease (PD), the details of its functional and somatotopic organization in humans are not well understood. The aim of this study was to characterize the functional organization of the STN and its correlation with the motor outcomes induced by subthalamotomy. We used diffusion-weighted imaging to assess STN connectivity patterns in 23 healthy control subjects and 86 patients with PD, of whom 39 received unilateral subthalamotomy. Analytical tractography was used to reconstruct structural cortico-subthalamic connectivity. A diffusion-weighted imaging/functional magnetic resonance imaging-driven somatotopic parcellation of the STN was defined to delineate the representation of the upper and lower limb in the STN. We confirmed a connectional gradient to sensorimotor, supplementary-motor, associative, and limbic cortical regions, spanning from posterior-dorsal-lateral to anterior-ventral-medial portions of the STN, with intermediate overlapping zones. Functional magnetic resonance imaging-driven parcellation demonstrated dual segregation of motor cortico-subthalamic projections in humans. Moreover, the relationship between lesion topography and functional anatomy of the STN explains specific improvement in bradykinesia, rigidity, and tremor induced by subthalamotomy. Our results support an interplay between segregation and integration of cortico-subthalamic projections, suggesting the coexistence of parallel and convergent information processing. Identifying the functional topography of the STN will facilitate better definition of the optimal location for functional neurosurgical approaches, that is, electrode placement and lesion location, and improve specific cardinal features in PD. © 2021 International Parkinson and Movement Disorder Society.

Cell type-specific Alzheimer's disease polygenic risk scores are associated with distinct disease processes in preclinical Alzheimer's disease.

Conventional polygenic risk score (PRS) summarizes genetic risk throughout the genome and lacks biological specificity. Here, leveraging human brain single nucleus RNA sequencing (sNuc-Seq) data, we introduce a new method to capture cell-type specific Alzheimer's disease (AD) PRS, and implicate different cell types in distinct disease processes in preclinical AD. Cognitively unimpaired (CU) older adults of European descent who participated in the Anti-Amyloid Treatment in Asymptomatic Alzheimer's (A4) study screening PET were included in this study. Cortical amyloid-β burden (Aβ) was quantified as cortical composite SUVR from the florbetapir PET. Screening cognition was measured with Preclinical Alzheimer Cognitive Composite (PACC). We defined cell type-specific genes as genes expressed higher in a given cell type (FDR<0.05) compared to other cell types in a published human neocortex sNucSeq study, for eight major cell types identified from the same study. Published AD genome-wide association study results were processed with PRS-CS to infer posterior effect size of each genetic variant, and we derived cell type-specific ADPRS by weighted summation and standardization of the genetic risk of AD localized to cell type-specific genes. We excluded the APOE region from ADPRS, and adjusted for APOE ε4, ε2, age, sex, and the first three genotype principal components in all analyses. In CU older adults from the A4 screen data (n=2961; 71.3±4.8 years old), microglia-specific ADPRS had the strongest association with higher Aβ (beta=0.018, p=2.0×10-8 ), while neuron-specific ADPRSs showed weaker associations (Figure 1A). By contrast, excitatory neuron-specific ADPRS had the strongest association with lower PACC (additionally adjusted for years of education; beta=-0.16, p=1.0×10-4 ; Figure 1B), and this association remained significant even after adjusting for Aβ (beta=-0.14, p=6.1×10-4 ). The excitatory neuron-specific ADPRS was negatively associated with years of education (beta=-0.12, p=0.018), suggesting a shared heritability between neuron-specific AD risk and lower cognitive reserve. These results further implicate microglia in fibrillar Aβ accumulation and support the neuronal role in cognitive reserve. Cell type-specific ADPRSs derived using our novel method demonstrate specific relationships with AD pathology and cognition, and may improve power to predict progression during the preclinical stages of AD.

Fractal analysis of chromatin condensation in the human sperm nuclei

Fractal analysis of chromatin condensation in the human sperm nuclei

Deep learning enables genetic analysis of the human thoracic aorta.

Enlargement or aneurysm of the aorta predisposes to dissection, an important cause of sudden death. We trained a deep learning model to evaluate the dimensions of the ascending and descending thoracic aorta in 4.6 million cardiac magnetic resonance images from the UK Biobank. We then conducted genome-wide association studies in 39,688 individuals, identifying 82 loci associated with ascending and 47 with descending thoracic aortic diameter, of which 14 loci overlapped. Transcriptome-wide analyses, rare-variant burden tests, and human aortic single nucleus RNA sequencing prioritized genes including SVIL, which was strongly associated with descending aortic diameter. A polygenic score for ascending aortic diameter was associated with thoracic aortic aneurysm in 385,621 UK Biobank participants (HR = 1.43 per s.d.; CI 1.32-1.54; P = 3.3 × 10−20). Our results illustrate the potential for rapidly defining quantitative traits with deep learning, an approach that can be broadly applied to biomedical images.

Machine learning algorithm for decoding multiple subthalamic spike trains for speech brain–machine interfaces

Objective. The goal of this study is to decode the electrical activity of single neurons in the human subthalamic nucleus (STN) to infer the speech features that a person articulated, heard or imagined. We also aim to evaluate the amount of subthalamic neurons required for high accuracy decoding suitable for real-life speech brain-machine interfaces (BMI). Approach. We intraoperatively recorded single-neuron activity in the STN of 21 neurosurgical patients with Parkinson’s disease undergoing implantation of deep brain stimulator while patients produced, perceived or imagined the five monophthongal vowel sounds. Our decoder is based on machine learning algorithms that dynamically learn specific features of the speech-related firing patterns. Main results. In an extensive comparison of algorithms, our sparse decoder (‘SpaDe’), based on sparse decomposition of the high dimensional neuronal feature space, outperformed the other algorithms in all three conditions: production, perception and imagery. For speech production, our algorithm, Spade, predicted all vowels correctly (accuracy: 100%; chance level: 20%). For perception accuracy was 96%, and for imagery: 88%. The accuracy of Spade showed a linear behavior in the amount of neurons for the perception data, and even faster for production or imagery. Significance. Our study demonstrates that the information encoded by single neurons in the STN about the production, perception and imagery of speech is suitable for high-accuracy decoding. It is therefore an important step towards BMIs for restoration of speech faculties that bears an enormous potential to alleviate the suffering of completely paralyzed (‘locked-in’) patients and allow them to communicate again with their environment. Moreover, our research indicates how many subthalamic neurons may be necessary to achieve each level of decoding accuracy, which is of supreme importance for a neurosurgeon planning the implantation of a speech BMI.

Reducing Inflammation and Vascular Invasion in Intervertebral Disc Degeneration via Cystathionine-γ-Lyase Inhibitory Effect on E-Selectin.

The incidence of degenerative spinal diseases, such as cervical spondylosis and thoracic and lumbar disc herniation, is increasing. These health problems have adversely affected human life and work. Surgical intervention is effective when intervertebral disc degeneration (IDD) causes nerve compression and/or severely limits daily activity. Early IDD patients generally do not require surgery. However, there is no effective method of impeding IDD progression. Thus, novel approaches to alleviating IDD deterioration are urgently required. Cystathionine-γ-lyase (CSE) and E-selectin (CD62E) are vital factors regulating vascular function and inflammation. However, their effects on IDD and vascular invasion in intervertebral discs (IVDs) are pending further exploration. Here, bioinformatics and human nucleus pulposus (NP) tissues analyses revealed that CSE was significantly downregulated and CD62E was upregulated in the NP tissues of IDD patients. We demonstrated that CSE overexpression, CD62E downregulation, and NF-κB (P65) inhibition mitigate inflammation and recover metabolic function in NP cells. Similarly, CSE attenuated vascular invasion induced by inflammatory irritation. Using a rat IDD model, we showed that CSE improved degeneration, inflammation, and microvascular invasion in NP tissue, whereas CD62E had the opposite effect. Taken together, our results indicated that the CSE/CD62E pathway could effectively improve the inflammatory environment and vascular invasion in IVD. Hence, the findings of this study propose a promising and valuable strategy for the treatment of patients with early IDD as well as postoperative adjuvant therapy in patients with severe IDD.

Evidence-Based Network Modelling to Simulate Nucleus Pulposus Multicellular Activity in Different Nutritional and Pro-Inflammatory Environments.

Initiation of intervertebral disc degeneration is thought to be biologically driven. This reflects a process, where biochemical and mechanical stimuli affect cell activity (CA) that compromise the tissue strength over time. Experimental research enhanced our understanding about the effect of such stimuli on different CA, such as protein synthesis or mRNA expression. However, it is still unclear how cells respond to their native environment that consists of a “cocktail” of different stimuli that might locally vary. This work presents an interdisciplinary approach of experimental and in silico research to approximate Nucleus Pulposus CA within multifactorial biochemical environments. Thereby, the biochemical key stimuli glucose, pH, and the proinflammatory cytokines TNF-α and IL1β were considered that were experimentally shown to critically affect CA. To this end, a Nucleus Pulposus multicellular system was modelled. It integrated experimental findings from in vitro studies of human or bovine Nucleus Pulposus cells, to relate the individual effects of targeted stimuli to alterations in CA. Unknown stimulus-CA relationships were obtained through own experimental 3D cultures of bovine Nucleus Pulposus cells in alginate beads. Translation of experimental findings into suitable parameters for network modelling approaches was achieved thanks to a new numerical approach to estimate the individual sensitivity of a CA to each stimulus type. Hence, the effect of each stimulus type on a specific CA was assessed and integrated to approximate a multifactorial stimulus environment. Tackled CA were the mRNA expressions of Aggrecan, Collagen types I & II, MMP3, and ADAMTS4. CA was assessed for four different proinflammatory cell states; non-inflamed and inflamed for IL1β, TNF-α or both IL1β&TNF-α. Inflamed cell clusters were eventually predicted in a multicellular 3D agent-based model. Experimental results showed that glucose had no significant impact on proinflammatory cytokine or ADAMTS4 mRNA expression, whereas TNF-α caused a significant catabolic shift in most explored CA. In silico results showed that the presented methodology to estimate the sensitivity of a CA to a stimulus type importantly improved qualitative model predictions. However, more stimuli and/or further experimental knowledge need to be integrated, especially regarding predictions about the possible progression of inflammatory environments under adverse nutritional conditions. Tackling the multicellular level is a new and promising approach to estimate manifold responses of intervertebral disc cells. Such a top-down high-level network modelling approach allows to obtain information about relevant stimulus environments for a specific CA and could be shown to be suitable to tackle complex biological systems, including different proinflammatory cell states. The development of this methodology required a close interaction with experimental research. Thereby, specific experimental needs were derived from systematic in silico approaches and obtained results were directly used to enhance model predictions, which reflects a novelty in this research field. Eventually, the presented methodology provides modelling solutions suitable for multiscale approaches to contribute to a better understanding about dynamics over multiple spatial scales. Future work should focus on an amplification of the stimulus environment by integrating more key relevant stimuli, such as mechanical loading parameters, in order to better approximate native physiological environments.

Beneficial effects of hypotaurine supplementation in preparation and freezing media on human sperm cryo-capacitation and DNA quality

BackgroundAlthough widely used, slow freezing considerably modifies the functions of human spermatozoa. Cryopreservation induces nuclear sperm alterations and cryo-capacitation, reducing the chances of pregnancy. Hypotaurine is naturally present in the male and female genital tracts and has capacitating, osmolytic and anti-oxidant properties. The analysis were performed on surplus semen of men with normal (n = 19) or abnormal (n = 14) sperm parameters. Spermatozoa were selected by density gradient centrifugation before slow freezing. For each sample, these steps were performed in parallel with (“H+” arm) or without (“H-” arm) hypotaurine supplementation. After thawing, we measured total and progressive mobility, vitality, acrosome integrity, markers of capacitation signaling pathway and nuclear quality. For the latter, we focused on sperm chromatin packaging, DNA fragmentation and the presence of vacuoles in the sperm nucleus.ResultsPost-thaw spermatozoa selected and frozen in the presence of hypotaurine had a higher vitality (+ 16.7%, p < 0.001), progressive and total motility (+ 39.9% and + 21.6% respectively, p < 0.005) than spermatozoa from the control “H-” arm. Hypotaurine also reduced the non-specific phosphorylation of the capacitation protein markers P110 and P80 (p < 0.01), indicating a decrease in cryo-capacitation. Hypotaurine supplementation reduced chromatin decondensation, measured by chromomycin A3 (− 16.1%, p < 0.05), DNA fragmentation (− 18.7%, p < 0.05) and nuclear vacuolization (− 20.8%, p < 0.05).ConclusionOur study is the first to demonstrate beneficial effects of hypotaurine supplementation in preparation and freezing procedures on human spermatozoa sperm fertilization capacity and nucleus quality. Hypotaurine supplementation limited cryo-capacitation, increased the proportion of live and progressively motile spermatozoa and reduces the percentage of spermatozoa showing chromatin decondensation, DNA fragmentation and nuclear vacuolation.Trial registrationClinical Trial, NCT04011813. Registered 19 May 2019 - Retrospectively registered.