Dopamine reuptake and inhibitory mechanisms in human dopamine transporter.

The dopamine transporter has a crucial role in regulation of dopaminergic neurotransmission by uptake of dopamine into neurons and contributes to the abuse potential of psychomotor stimulants1-3. Despite decades of study, the structure, substrate binding, conformational transitions and drug-binding poses of human dopamine transporter remain unknown. Here we report structures of the human dopamine transporter in its apo state, and in complex with the substrate dopamine, the attention deficit hyperactivity disorder drug methylphenidate, and the dopamine-uptake inhibitors GBR12909 and benztropine. The dopamine-bound structure in the occluded state precisely illustrates the binding position of dopamine and associated ions. The structures bound to drugs are captured in outward-facing or inward-facing states, illuminating distinct binding modes and conformational transitions during substrate transport. Unlike the outward-facing state, which is stabilized by cocaine, GBR12909 and benztropine stabilize the dopamine transporter in the inward-facing state, revealing previously unseen drug-binding poses and providing insights into how they counteract the effects of cocaine. This study establishes a framework for understanding the functioning of the human dopamine transporter and developing therapeutic interventions for dopamine transporter-related disorders and cocaine addiction.

Transport and inhibition mechanisms of the human noradrenaline transporter.

The noradrenaline transporter (also known as norepinephrine transporter) (NET) has a critical role in terminating noradrenergic transmission by utilizing sodium and chloride gradients to drive the reuptake of noradrenaline (also known as norepinephrine) into presynaptic neurons1-3. It is a pharmacological target for various antidepressants and analgesic drugs4,5. Despite decades of research, its structure and the molecular mechanisms underpinning noradrenaline transport, coupling to ion gradients and non-competitive inhibition remain unknown. Here we present high-resolution complex structures of NET in two fundamental conformations: in the apo state, and bound to the substrate noradrenaline, an analogue of the χ-conotoxin MrlA (χ-MrlAEM), bupropion or ziprasidone. The noradrenaline-bound structure clearly demonstrates the binding modes of noradrenaline. The coordination of Na+ and Cl- undergoes notable alterations during conformational changes. Analysis of the structure of NET bound to χ-MrlAEM provides insight into how conotoxin binds allosterically and inhibits NET. Additionally, bupropion and ziprasidone stabilize NET in its inward-facing state, but they have distinct binding pockets. These structures define the mechanisms governing neurotransmitter transport and non-competitive inhibition in NET, providing a blueprint for future drug design.

Ablation of Brg1 in fibroblast/myofibroblast lineages attenuates renal fibrosis in mice with diabetic nephropathy.

AIMS: Diabetic nephropathy (DN) is one of the most common complications of diabetes and represents a prototypical form of chronic kidney disease (CKD). Interstitial fibrosis is a key pathological feature of DN. During DN-associated renal fibrosis, resident fibroblasts trans-differentiate into myofibroblasts to remodel the extracellular matrix, the underlying epigenetic mechanism of which is not entirely clear. METHODS: Diabetic nephropathy was induced in C57B6/j mice by a single injection with streptozotocin (STZ). Gene expression was examined by quantitative PCR and Western blotting. Renal fibrosis was evaluated by PicroSirius Red staining. RESULTS: We report that expression of Brg1, a chromatin remodeling protein, in renal fibroblasts was up-regulated during DN pathogenesis as assessed by single-cell RNA-seq. Treatment with high glucose similarly augmented Brg1 expression in primary renal fibroblasts in vitro. Importantly, Brg1 ablation in quiescent renal fibroblasts or in mature myofibroblasts equivalently attenuated renal fibrosis in the context of diabetic nephropathy in mice. Additionally, administration with a small-molecule Brg1 inhibitor PFI-3 ameliorated renal fibrosis and improved renal function in mice induced to develop DN. SIGNIFICANCE: In conclusion, our data provide novel genetic evidence that links Brg1 to fibroblast-myofibroblast transition and renewed rationale for targeting Brg1 in the intervention of DN-associated renal fibrosis.

Transport mechanism and pharmacology of the human GlyT1.

The glycine transporter 1 (GlyT1) plays a crucial role in the regulation of both inhibitory and excitatory neurotransmission by removing glycine from the synaptic cleft. Given its close association with glutamate/glycine co-activated NMDA receptors (NMDARs), GlyT1 has emerged as a central target for the treatment of schizophrenia, which is often linked to hypofunctional NMDARs. Here, we report the cryo-EM structures of GlyT1 bound with substrate glycine and drugs ALX-5407, SSR504734, and PF-03463275. These structures, captured at three fundamental states of the transport cycle-outward-facing, occluded, and inward-facing-enable us to illustrate a comprehensive blueprint of the conformational change associated with glycine reuptake. Additionally, we identified three specific pockets accommodating drugs, providing clear insights into the structural basis of their inhibitory mechanism and selectivity. Collectively, these structures offer significant insights into the transport mechanism and recognition of substrate and anti-schizophrenia drugs, thus providing a platform to design small molecules to treat schizophrenia.

Structural bases of inhibitory mechanism of CaV1.2 channel inhibitors.

The voltage-gated calcium channel CaV1.2 is essential for cardiac and vessel smooth muscle contractility and brain function. Accumulating evidence demonstrates that malfunctions of CaV1.2 are involved in brain and heart diseases. Pharmacological inhibition of CaV1.2 is therefore of therapeutic value. Here, we report cryo-EM structures of CaV1.2 in the absence or presence of the antirheumatic drug tetrandrine or antihypertensive drug benidipine. Tetrandrine acts as a pore blocker in a pocket composed of S6II, S6III, and S6IV helices and forms extensive hydrophobic interactions with CaV1.2. Our structure elucidates that benidipine is located in the DIII-DIV fenestration site. Its hydrophobic sidechain, phenylpiperidine, is positioned at the exterior of the pore domain and cradled within a hydrophobic pocket formed by S5DIII, S6DIII, and S6DIV helices, providing additional interactions to exert inhibitory effects on both L-type and T-type voltage gated calcium channels. These findings provide the structural foundation for the rational design and optimization of therapeutic inhibitors of voltage-gated calcium channels.

Suv39h1 contributes to activation of hepatic stellate cells in non-alcoholic fatty liver disease by enabling anaerobic glycolysis.

AIMS: Non-alcoholic fatty liver disease (NAFLD) has become a global epidemic. Excessive fibrogenesis, characterized by activation of hepatic stellate cells (HSCs), is a hallmark event in late stages of NAFLD. HSC activation is metabolically programmed by anaerobic glycolysis. In the present study we investigated the involvement of suppressor of variegation 3-9 homolog 1 (Suv39h1), a lysine methyltransferase, in NAFLD-associated liver fibrosis. METHODS AND MATERIALS: Liver fibrosis was induced by feeding the mice with a methionine-and-choline deficient (MCD) diet for 8 weeks. RESULTS: We report that germline deletion of Suv39h1 attenuated liver fibrosis in mice fed an MCD diet. In addition, HSC conditional deletion of Suv39h1 similarly ameliorated liver fibrosis in the NAFLD mice. Interestingly, co-culturing with hepatocytes exposed to palmitate promoted glycolysis in wild type HSCs but not in Suv39h1 deficient HSCs. Mechanistically, Suv39h1 facilitated the recruitment of hypoxia induced factor (HIF-1α) to stimulate the transcription of hexokinase 2 (HK2) in HSCs thereby enhancing glycolysis. Importantly, a positive correlation between Suv39h1, HK2, and myofibroblast markers was identified in liver specimens from NAFLD patients. SIGNIFICANCE: In conclusion, our data identify a novel pathway that contributes to the liver fibrosis and points to the possibility of targeting Suv39h1 for the intervention of liver fibrosis in NAFLD.

Regulation of interfacial Dzyaloshinskii-Moriya interaction in ferromagnetic multilayers.

Interfacial Dzyaloshinskii-Moriya interaction (i-DMI) exists in the film materials with inversion symmetry breaking, which can stabilize a series of nonlinear spin structures and control their chirality, such as Néel-type domain wall, magnetic skyrmion and spin spiral. In addition, the strength and chirality of i-DMI are directly related to the dynamic behavior of these nonlinear spin structures. Therefore, regulating the strength and chirality of i-DMI not only has an important scientific significance for enriching spintronics and topological physics, but also has a significant practical value for constructing a new generation of memorizer, logic gate, and brain-like devices with low-power. This review summarizes the research progress on the regulation of i-DMI in ferromagnetic films and provides some prospects for future research.

Chemical basis of microbiome preference in the nematode C. elegans.

Animals are exposed to many microbes in their environment, some of which have been shown to colonize various tissues including the intestine. The composition of the intestinal microbiota affects many aspects of the host's physiology and health. Despite this, very little is known about whether host behavior contributes to the colonization. We approach this question in the nematode C. elegans, which feeds on bacteria and also harbors an intestinal microbiome. We examined the behavior of C. elegans towards CeMbio, a simplified microbiome consisting of twelve strains that represent the bacteria found in the animal's natural environment. We observed that C. elegans raised on E. coli shows a strong preference for three members of CeMbio (Lelliottia amnigena JUb66, Enterobacter hormaechei CEent1, and Pantoea nemavictus BIGb0393) compared to E. coli. Previously, these three bacterial strains have been shown to support faster C. elegans development time than E. coli OP50 and are low colonizers compared to eight other members of CeMbio. We then used gas chromatography coupled to mass spectrometry to identify that these three bacteria release isoamyl alcohol, a previously described C. elegans chemoattractant. We suggest that C. elegans seeks bacteria that release isoamyl alcohol and support faster growth.

Association of Mean Upper Cervical Spinal Cord Cross-Sectional Area With Cerebral Small Vessel Disease: A Community-Based Cohort Study.

BACKGROUND: The purpose of this study was to investigate the association between the mean upper cervical spinal cord cross-sectional area (MUCCA) and the risk and severity of cerebral small vessel disease (CSVD). METHODS: Community-dwelling residents in Lishui City, China, from the cross-sectional survey in the PRECISE cohort study (Polyvascular Evaluation for Cognitive Impairment and Vascular Events) conducted from 2017 to 2019. We included 1644 of 3067 community-dwelling adults in the PRECISE study after excluding those with incorrect, incomplete, insufficient, or missing clinical or imaging data. Total and modified total CSVD scores, as well as magnetic resonance imaging features, including white matter hyperintensity, lacunes, cerebral microbleeds, enlarged perivascular spaces, and brain atrophy, were assessed at the baseline. The Spinal Cord Toolbox was used to measure the upper cervical spinal cord cross-sectional area of the C1 to C3 segments of the spinal cord and its average value was taken as MUCCA. Participants were divided into 4 groups according to quartiles of MUCCA. Associations were analyzed using linear regression models adjusted for age, sex, current smoking and drinking, medical history, intracranial volume, and total cortical volume. RESULTS: The means±SD age of the participants was 61.4±6.5 years, and 635 of 1644 participants (38.6%) were men. The MUCCA was smaller in patients with CSVD than those without CSVD. Using the total CSVD score as a criterion, the MUCCA was 61.78±6.12 cm2 in 504 of 1644 participants with CSVD and 62.74±5.94 cm2 in 1140 of 1644 participants without CSVD. Using the modified total CSVD score, the MUCCA was 61.81±6.04 cm2 in 699 of 1644 participants with CSVD and 62.91±5.94 cm2 in 945 of 1644 without CSVD. There were statistical differences between the 2 groups after adjusting for covariates in 3 models. The MUCCA was negatively associated with the total and modified total CSVD scores (adjusted ß value, -0.009 [95% CI, -0.01 to -0.003] and -0.007 [95% CI, -0.01 to -0.0006]) after adjustment for covariates. Furthermore, the MUCCA was negatively associated with the white matter hyperintensity burden (adjusted ß value, -0.01 [95% CI, -0.02 to -0.003]), enlarged perivascular spaces in the basal ganglia (adjusted ß value, -0.005 [95% CI, -0.009 to -0.001]), lacunes (adjusted ß value, -0.004 [95% CI, -0.007 to -0.0007]), and brain atrophy (adjusted ß value, -0.009 [95% CI, -0.01 to -0.004]). CONCLUSIONS: The MUCCA and CSVD were correlated. Spinal cord atrophy may serve as an imaging marker for CSVD; thus, small vessel disease may involve the spinal cord in addition to being intracranial.

Nature-Inspired Wet Drug Delivery Platforms.

Nature has created various organisms with unique chemical components and multi-scale structures (e.g., foot proteins, toe pads, suckers, setose gill lamellae) to achieve wet adhesion functions to adapt to their complex living environments. These organisms can provide inspirations for designing wet adhesives with mediated drug release behaviors in target locations of biological surfaces. They exhibit conformal and enhanced wet adhesion, addressing the bottleneck of weaker tissue interface adhesion in the presence of body fluids. Herein, it is focused on the research progress of different wet adhesion and bioinspired fabrications, including adhesive protein-based adhesion and inspired adhesives (e.g., mussel adhesion); capillarity and Stefan adhesion and inspired adhesive surfaces (e.g., tree frog adhesion); suction-based adhesion and inspired suckers (e.g., octopus' adhesion); interlocking and friction-based adhesion and potential inspirations (e.g., mayfly larva and teleost adhesion). Other secreted protein-induced wet adhesion is also reviewed and various suckers for other organisms and their inspirations. Notably, one representative application scenario of these bioinspired wet adhesives is highlighted, where they function as efficient drug delivery platforms on target tissues and/or organs with requirements of both controllable wet adhesion and optimized drug release. Finally, the challenges of these bioinspired wet drug delivery platforms in the future is presented.

Design, Synthesis and Antifungal Activities of Novel Pyrazole Analogues Containing the Aryl Trifluoromethoxy Group.

On the basis of the three-component synthetic methodology developed by us, a total of twenty-six pyrazole compounds bearing aryl OCF3 were designed and synthesized. Their chemical structures were characterized by 1H and 13C nuclear magnetic resonance and high-resolution mass spectrometry. These compounds were evaluated systematically for antifungal activities in vitro against six plant pathogenic fungi by the mycelium growth rate method. Most of the compounds showed some activity against each of the fungi at 100 µg/mL. Compounds 1t and 1v exhibited higher activity against all the tested fungi, and 1v displayed the highest activity against F. graminearum with an EC50 value of 0.0530 µM, which was comparable with commercial pyraclostrobin. Structure-activity relationship analysis showed that, with respect to the R1 substituent, the straight chain or cycloalkyl ring moiety was a key structural moiety for the activity, and the R2 substituent on the pyrazole ring could have significant effects on the activity. Simple and readily available pyrazoles with potent antifungal activity were obtained, which are ready for further elaboration to serve as a pharmacophore in new potential antifungal agents.

Hip subluxation in children with spinal cord injury: Incidence and influencing factors.

OBJECTIVE: Hip subluxation is a common complication in children with spinal cord injury. This study aimed to investigate the incidence and influencing factors of hip subluxation and discuss prevention strategies. METHODS: Medical records of children with spinal cord injury were reviewed. The inclusion criteria were as follows: (1) the patient was younger than 18 years old when injured; (2) absence of traumatic or congenital pathological changes of the hip at the time of injury. The migration percentage and acetabular index were selected to evaluate hip stability and acetabulum development. Influencing factors of sex, age, injury duration, severity, level, and spasticity were analyzed. RESULTS: A total of 146 children were enrolled. Twenty-eight children presented with hip subluxation and were significantly younger at the time of injury than those with normal hips (P = 0.002). The incidence of hip subluxation increased with the prolonged injury duration. Injury before age 6, complete injury, and flaccid lower extremities were significant influencing factors (P = 0.003, 0.004, and 0.015, respectively). The risk of hip subluxation decreased by 18% for every year older in injury age (P = 0.031) and decreased by 85% in children with spasticity (P = 0.018) than those without. However, the risk of hip subluxation in children with injury duration longer than 1 year was 7.1 times higher than those with shorter injury duration (P < 0.001). CONCLUSIONS: The incidence of hip subluxation in children with spinal cord injury increased with the injury duration. Younger children had immature hip development. Due to complete injury and flaccid muscle, lack of protection around the hip may lead to subluxation. Follow-up and prevention of hip subluxation need the joint effort of medical staff and families.

Local Manipulation of Skyrmion Nucleation in Microscale Areas of a Thin Film with Nitrogen-Ion Implantation.

Precise manipulation of skyrmion nucleation in microscale or nanoscale areas of thin films is a critical issue in developing high-efficient skyrmionic memories and logic devices. Presently, the mainstream controlling strategies focus on the application of external stimuli to tailor the intrinsic attributes of charge, spin, and lattice. This work reports effective skyrmion manipulation by controllably modifying the lattice defect through ion implantation, which is potentially compatible with large-scale integrated circuit technology. By implanting an appropriate dose of nitrogen ions into a Pt/Co/Ta multilayer film, the defect density was effectively enhanced to induce an apparent modulation of magnetic anisotropy, consequently boosting the skyrmion nucleation. Furthermore, the local control of skyrmions in microscale areas of the macroscopic film was realized by combining the ion implantation with micromachining technology, demonstrating a potential application in both binary storage and multistate storage. These findings provide a new approach to advancing the functionalization and application of skyrmionic devices.

Prognosis of traumatic spinal cord injury in children: Follow-up of 86 patients.

PURPOSE: The long-term situation of children with spinal cord injury (SCI) was investigated, and suggestions for helping them better return to the society were provided. METHODS: SCI patients less than 18 years old hospitalized in Beijing Boai Hospital from January 2011 to December 2020 were retrospectively analyzed. Information including motor function, complications, characteristic changes, self-care abilities, school attendance and social participation were collected by telephone interview and electronic questionnaire. All the answers were statistically analyzed. RESULTS: A total of 86 cases were enrolled, 77 girls and 9 boys, with a median injury age of 6 years and 2 months. The follow-up time was 3-130 months. The main cause of trauma in these children was sport injury (66.3%), the thoracic spinal cord was involved the most (91.9%), and complete SCIs accounted for the majority (76.7%). In terms of complications, children with complete SCIs were more likely to have urinary incontinence, constipation and characteristic changes (p < 0.05); whereas the incomplete SCIs often have spasticity (p < 0.05). As to the daily living abilities, children with incomplete lumbar SCIs were more capable to accomplish personal hygiene, transfer, and bathing independently than those with complete injuries, or cervical/thoracic SCIs, respectively (p < 0.05). Moreover, children older than 9 years care more able to dress and transfer independently than the youngers (p < 0.05). Wheelchair users accounted for 84.9% and more than half of them were able to propel wheelchair independently, and those who move passively in wheelchairs were mostly introverted kids (p < 0.05). Almost all (93.8%) children with incomplete injuries were able to walk independently. Most (79.1%) children continued to attending school, and 41.9% participated in interest classes. Unfortunately, 67.4% of the children spent less time playing with their peers than before the injury. CONCLUSION: SCIs impair physical structures and function of children, affect their independence in daily living, and restrict school attendance and social interaction. Comprehensive rehabilitation after injury is a systematic work. Medical staff and caregivers should not only pay attention to neurological function, but also help them improve self-care abilities. It is also important to balance rehabilitation training and school work and social participation.

The Global Atlas of Bamboo and Rattan (GABR) Phase II: new resources for sustainable development.

Bamboo, the fast-growing grass plant, and rattan, the spiky climbing palm, are both essential forest resources that have been closely linked with human lives, livelihoods and material culture since ancient times. To promote genetic and genomic research in bamboo and rattan, a comprehensive and coordinated international project, the Genome Atlas of Bamboo and Rattan (GABR), was launched in 2017. GABR achieved great success during Phase I (2017-2022). We will focus on investigating and protecting bamboo and rattan germplasm resources in Phase II ( 2022-2027). Here, we briefly review the achievements of Phase I and introduce the goals of Phase II.

Clinical characteristics of pediatric traumatic spinal cord injury in China: A single center retrospective study.

OBJECTIVE: To investigate the clinical characteristics of children with traumatic spinal cord injury (SCI) admitted to a research rehabilitation center between 2011 and 2020, with a view to generate crucial data for understanding and prevention of pediatric traumatic SCI. DESIGN: Retrospective cohort study. SETTING: The National Rehabilitation Research Center of China, Beijing, China. PARTICIPANTS: Medical records and imaging data of children with traumatic SCI admitted to the rehabilitation research center from 2011 to 2020. INTERVENTIONS: Not applicable. OUTCOME MEASURES: Data on age, sex, cause of injury, neurological level of injury, impairment scale of SCI and details of spine fracture or dislocation were all collected and analyzed. RESULTS: A total of 351 patients were included in the study, including 133 males (37.9%) and 218 females (62.1%). There were 231 cases (65.8%) without spine fracture or dislocation. SCI without fracture or dislocation (SCIWORA) was the most common in children between the age of 5 and 14 years (77.9%), and injuries caused by sports were the most common in girls (90.8%). Among sports injuries, those due to a special dance movement called "Xia-Yao" in Chinese, which involves hyperextension of the trunk, constituted the majority, with the neurological level of injuries located predominantly in the middle (34.6%) and lower (44.2%) thoracic levels. CONCLUSION: Girls between the ages of 5 and 14 years constituted the majority of SCIWORA injuries at the thoracic levels, which were caused mainly by "Xia-Yao". Overall, careful attention should be paid to prevent this kind of injury in children.

Movie Events Detecting Reveals Inter-Subject Synchrony Difference of Functional Brain Activity in Autism Spectrum Disorder.

Recently, movie-watching fMRI has been recognized as a novel method to explore brain working patterns. Previous researchers correlated natural stimuli with brain responses to explore brain functional specialization by "reverse correlation" methods, which were based on within-group analysis. However, what external stimuli drove significantly different brain responses in two groups of different subjects were still unknown. To address this, sliding time windows technique combined with inter-Subject functional correlation (ISFC) was proposed to detect movie events with significant group differences between autism spectrum disorder (ASD) and typical development (TD) subjects. Then, using inter-Subject correlation (ISC) and ISFC analysis, we found that in three movie events involving character emotions, the ASD group showed significantly lower ISC in the middle temporal gyrus, temporal pole, cerebellum, caudate, precuneus, and showed decreased functional connectivity between large scale networks than that in TD. Under the movie event focusing on objects and scenes shot, the dorsal and ventral attentional networks of ASD had a strong synchronous response. Meanwhile, ASD also displayed increased functional connectivity between the frontoparietal network (FPN) and dorsal attention network (DAN), FPN, and sensorimotor network (SMN) than TD. ASD has its own unique synchronous response rather than being "unresponsive" in natural movie-watching. Our findings provide a new method and valuable insight for exploring the inconsistency of the brain "tick collectively" to same natural stimuli. This analytic approach has the potential to explore pathological mechanisms and promote training methods of ASD.

Coupled deep-mantle carbon-water cycle: Evidence from lower-mantle diamonds.

Diamonds form in a variety of environments between subducted crust, lithospheric and deep mantle. Recently, deep source diamonds with inclusions of the high-pressure H2O-phase ice-VII were discovered. By correlating the pressures of ice-VII inclusions with those of other high-pressure inclusions, we assess quantitatively the pressures and temperatures of their entrapment. We show that the ice-VII-bearing diamonds formed at depths down to 800 ± 60 km but at temperatures 200-500 K below average mantle temperature that match the pressure-temperature conditions of decomposing dense hydrous mantle silicates. Our work presents strong evidence for coupled recycling of water and carbon in the deep mantle based on natural samples.

Pressure-Induced Polymerization and Disproportionation of Li2C2 Accompanied with Irreversible Conductivity Enhancement.

Li2C2 has the highest theoretical capacity (1400 mA·h·g-1) as the electrode material for Li-ion battery, but suffers from low conductivity. Here we found that under external pressure its conductivity was irreversibly enhanced by 109-fold. To explain that, we performed X-ray diffraction, Raman, IR, gas chromatography-mass spectrometry, and theoretical investigations under external pressure. We found that the C22- anions approached to each other and polymerized upon compression, which is responsible for the irreversible enhancement of conductivity. The polymer has a ribbon structure and disproportionates into Li3C4 (Li2-0.5C2) ribbon structure, Li6C3 (Li propenide) and Li4C3 (Li allenide) upon decompression, implying that the carbon skeletal is highly electrochemically active. Our work reported polymerized Li2C2 for the first time, demonstrated that applying pressure is an effective method to prepare novel Li-C frameworks, and hence shed light on the search for novel carbon-based electrode materials.