Utilizing human cerebral organoids to model breast cancer brain metastasis in culture.

BACKGROUND: Metastasis, the spread, and growth of malignant cells at secondary sites within a patient's body, accounts for over 90% of cancer-related mortality. Breast cancer is the most common tumor type diagnosed and the leading cause of cancer lethality in women in the United States. It is estimated that 10-16% breast cancer patients will have brain metastasis. Current therapies to treat patients with breast cancer brain metastasis (BCBM) remain palliative. This is largely due to our limited understanding of the fundamental molecular and cellular mechanisms through which BCBM progresses, which represents a critical barrier for the development of efficient therapies for affected breast cancer patients. METHODS: Previous research in BCBM relied on co-culture assays of tumor cells with rodent neural cells or rodent brain slice ex vivo. Given the need to overcome the obstacle for human-relevant host to study cell-cell communication in BCBM, we generated human embryonic stem cell-derived cerebral organoids to co-culture with human breast cancer cell lines. We used MDA-MB-231 and its brain metastatic derivate MDA-MB-231 Br-EGFP, other cell lines of MCF-7, HCC-1806, and SUM159PT. We leveraged this novel 3D co-culture platform to investigate the crosstalk of human breast cancer cells with neural cells in cerebral organoid. RESULTS: We found that MDA-MB-231 and SUM159PT breast cancer cells formed tumor colonies in human cerebral organoids. Moreover, MDA-MB-231 Br-EGFP cells showed increased capacity to invade and expand in human cerebral organoids. CONCLUSIONS: Our co-culture model has demonstrated a remarkable capacity to discern the brain metastatic ability of human breast cancer cells in cerebral organoids. The generation of BCBM-like structures in organoid will facilitate the study of human tumor microenvironment in culture.

Nontoxic, Biodegradable Hyperbranched Poly(ß-amino ester)s for Efficient siRNA Delivery and Gene Silencing.

RNA interference (RNAi)-mediated gene silencing is a promising therapeutic approach to treat various diseases, but safe and efficient delivery remains a major challenge to its clinical application. Non-viral gene vectors, such as poly(ß-amino esters) (pBAEs), have emerged as a potential candidate due to their biodegradability, low toxicity profile, ease of synthesis, and high gene transfection efficiency for both DNA and siRNA delivery. However, achieving significant gene silencing using pBAEs often requires a large amount of polymer carrier (with polymer/siRNA weight ratio >100) or high siRNA dose (>100 nM), which might potentially exacerbate toxicity concerns during delivery. To overcome these barriers, we designed and optimized a series of hyperbranched pBAEs capable of efficiently condensing siRNA and achieving excellent silencing efficiency at a lower polymer/siRNA weight ratio (w/w) and siRNA dose. Through modulation of monomer combinations and branching density, we identified the top-performing hyperbranched pBAEs, named as h(A2B3)-1, which possess good siRNA condensation ability, low cytotoxicity, and high cellular uptake efficiency. Compared with Lipofectamine 2000, h(A2B3)-1 achieved lower cytotoxicity and higher siRNA silencing efficiency in HeLa cells at a polymer/siRNA weight ratio of 30 and 30 nM siRNA dose. Notably, h(A2B3)-1 enhanced the gene uptake in primary neural cells and effectively silenced the target gene in hard-to-transfect primary cortical neurons and oligodendrocyte progenitor cells, with gene knockdown efficiencies of 34.8 and 53.4% respectively. By incorporating a bioreducible disulfide compartment into the polymer backbone, the cytocompatibility of the h(A2B3)-1 was greatly enhanced while maintaining their good transfection efficiency. Together, the low cytotoxicity and high siRNA transfection efficiency of hyperbranched h(A2B3)-1 in this study demonstrated their great potential as a non-viral gene vector for efficient siRNA delivery and RNAi-mediated gene silencing. This provides valuable insight into the future development of safe and efficient non-viral siRNA delivery systems as well as their translation into clinical applications.

Developmental toxicity of pyriproxyfen induces changes in the ultrastructure of neural cells and in the process of skull ossification.

Some studies relate the use of pyriproxyfen (PPF) in drinking water with damage to embryonic neurodevelopment, including a supposed association with cases of microcephaly. However, the effects on neural cells and skull ossification in embryos remain unclear. This study aims to investigate the effects of PPF on the structure and ultrastructure of brain cells and its influence on the skull ossification process during embryonic development. Chicken embryos, used as an experimental model, were exposed to concentrations of 0.01 and 10 mg/l PPF at E1. The findings demonstrated that PPF led to notable ultrastructural alterations such as reduced cilia and microvilli of ependymal cells and damage to mitochondria, endoplasmic reticulum, Golgi bodies, and cell membranes in neural cells. The frequency of changes and the degree of these cell damage between the forebrain and midbrain were similar. PPF induced a reduction in fox3 transcript levels, specific for differentiation of neurons, and a reduction in the NeuN protein content related to mature neurons and dendritic branches. PPF impacted the ossification process of the skull, as evidenced by the increase in the ossified area and the decrease in inter-bone spacing. In conclusion, this study highlights the ability of PPF to affect neurodevelopmental processes by inducing ultrastructural damage to neural cells, concomitant with a reduction in NeuN and fox3 expression. This detrimental impact coupled with deficiencies in skull ossification can prevent the proper growth and development of the brain.

Hybrid hydrogels support neural cell culture development under magnetic actuation at high frequency.

The combination of hydrogels and magnetic nanoparticles, scarcely explored to date, offers a wide range of possibilities for innovative therapies. Herein, we have designed hybrid 3D matrices integrating natural polymers, such as collagen, chitosan (CHI) and hyaluronic acid (HA), to provide soft and flexible 3D networks mimicking the extracellular matrix of natural tissues, and iron oxide nanoparticles (IONPs) that deliver localized heat when exposed to an alternating magnetic field (AMF). First, colloidally stable nanoparticles with a hydrodynamic radius of ∼20 nm were synthesized and coated with either CHI (NPCHI) or HA (NPHA). Then, collagen hydrogels were homogeneously loaded with these coated-IONPs resulting in soft (E0 ∼ 2.6 kPa), biodegradable and magnetically responsive matrices. Polymer-coated IONPs in suspension preserved primary neural cell viability and neural differentiation even at the highest dose (0.1 mg Fe/mL), regardless of the coating, even boosting neuronal interconnectivity at lower doses. Magnetic hydrogels maintained high neural cell viability and sustained the formation of highly interconnected and differentiated neuronal networks. Interestingly, those hydrogels loaded with the highest dose of NPHA (0.25 mgFe/mg polymer) significantly impaired non-neuronal differentiation with respect to those with NPCHI. When evaluated under AMF, cell viability slightly diminished in comparison with control hydrogels magnetically stimulated, but not compared to their counterparts without stimulation. Neuronal differentiation under AMF was only affected on collagen hydrogels with the highest dose of NPHA, while non-neuronal differentiation regained control values. Taken together, NPCHI-loaded hydrogels displayed a superior performance, maybe benefited from their higher nanomechanical fluidity. STATEMENT OF SIGNIFICANCE: Hydrogels and magnetic nanoparticles are undoubtedly useful biomaterials for biomedical applications. Nonetheless, the combination of both has been scarcely explored to date. In this study, we have designed hybrid 3D matrices integrating both components as promising magnetically responsive platforms for neural therapeutics. The resulting collagen scaffolds were soft (E0 ∼ 2.6 kPa) and biodegradable hydrogels with capacity to respond to external magnetic stimuli. Primary neural cells proved to grow on these substrates, preserving high viability and neuronal differentiation percentages even under the application of a high-frequency alternating magnetic field. Importantly, those hydrogels loaded with chitosan-coated iron oxide nanoparticles displayed a superior performance, likely related to their higher nanomechanical fluidity.

The application of human-derived cell lines in neurotoxicity studies of environmental pollutants.

As industrial and societal advancements progress, an increasing number of environmental pollutants linked to human existence have been substantiated to elicit neurotoxicity and developmental neural toxicity. For research in this field, human-derived neural cell lines have become excellent in vitro models. This study examines the utilization of immortalized cell lines, specifically the SH-SY5Y human neuroblastoma cell line, and neural cells derived from human pluripotent stem cells, in the investigation of neurotoxicity and developmental neural toxicity caused by environmental pollutants. The study also explores the culturing techniques employed for these cell lines and provides an overview of the standardized assays used to assess various biological endpoints. The environmental pollutants involved include a variety of organic compounds, heavy metals, and microplastics. The utilization of cell lines derived from human sources holds significant significance in elucidating the neurotoxic effects of environmental pollutants and the underlying mechanisms. Finally, we propose the possibility of improving the in vitro model of the human nervous system and the toxicity detection methods.

Synergy of Nanotopography and Electrical Conductivity of PEDOT/PSS for Enhanced Neuronal Development.

Biomaterials able to promote neuronal development and neurite outgrowth are highly desired in neural tissue engineering for the repair of damaged or disrupted neural tissue and restoring the axonal connection. For this purpose, the use of either electroactive or micro- and nanostructured materials has been separately investigated. Here, the use of a nanomodulated conductive poly(3,4-ethylendioxithiophene) poly(styrenesulfonate) (PEDOT/PSS) substrate that exhibits instructive topographical and electrical cues at the same time was investigated for the first time. In particular, thin films featuring grooves with sizes comparable with those of neuronal neurites (NanoPEDOT) were fabricated by electrochemical polymerization of PEDOT/PSS on a nanomodulated polycarbonate template. The ability of NanoPEDOT to support neuronal development and direct neurite outgrowth was demonstrated by assessing cell viability and proliferation, expression of neuronal markers, average neurite length, and direction of neuroblastoma N2A cells induced to differentiate on this novel support. In addition to the beneficial effect of the nanogrooved topography, a 30% increase was shown in the average length of neurites when differentiating cells were subjected to an electrical stimulation of a few microamperes for 6 h. The results reported here suggest a favorable effect on the neuronal development of the synergistic combination of nanotopography and electrical stimulation, supporting the use of NanoPEDOT in neural tissue engineering to promote physical and functional reconnection of impaired neural networks.

NGLY1 mutations cause protein aggregation in human neurons.

Biallelic mutations in the gene that encodes the enzyme N-glycanase 1 (NGLY1) cause a rare disease with multi-symptomatic features including developmental delay, intellectual disability, neuropathy, and seizures. NGLY1's activity in human neural cells is currently not well understood. To understand how NGLY1 gene loss leads to the specific phenotypes of NGLY1 deficiency, we employed direct conversion of NGLY1 patient-derived induced pluripotent stem cells (iPSCs) to functional cortical neurons. Transcriptomic, proteomic, and functional studies of iPSC-derived neurons lacking NGLY1 function revealed several major cellular processes that were altered, including protein aggregate-clearing functionality, mitochondrial homeostasis, and synaptic dysfunctions. These phenotypes were rescued by introduction of a functional NGLY1 gene and were observed in iPSC-derived mature neurons but not astrocytes. Finally, laser capture microscopy followed by mass spectrometry provided detailed characterization of the composition of protein aggregates specific to NGLY1-deficient neurons. Future studies will harness this knowledge for therapeutic development.

Expression of Human L-Dopa Decarboxylase (DDC) under Conditions of Oxidative Stress.

Oxidative stress is known to influence mRNA levels, translation, and proteolysis. The importance of oxidative stress has been demonstrated in several human diseases, including neurodegenerative disorders. L-Dopa decarboxylase (DDC) is the enzyme that converts L-Dopa to dopamine (DA). In spite of a large number of studies, little is known about the biological significance of the enzyme under physiological and pathological conditions. Here, we investigated the relationship between DDC expression and oxidative stress in human neural and non-neural cells. Oxidative stress was induced by treatment with H2O2. Our data indicated that mRNA and protein expression of DDC was enhanced or remained stable under conditions of ROS induction, despite degradation of total RNA and increased cytotoxicity and apoptosis. Moreover, DDC silencing caused an increase in the H2O2-induced cytotoxicity. The current study suggests that DDC is involved in the mechanisms of oxidative stress.

Effect of methanol fixation on single-cell RNA sequencing of the murine dentate gyrus.

Single-cell RNA sequencing (scRNA-seq) provides a powerful tool to evaluate the transcriptomic landscape and heterogeneity of thousands of cells in parallel. However, complex study designs or the unavailability of in-house instruments require the temporal disconnection between sample preparation and library construction, raising the need for efficient sample preservation methods which are compatible with scRNA-seq downstream analysis. Several studies evaluated the effect of methanol fixation as preservation method, yet none of them deeply assessed its effect on adult primary dissociated brain tissue. Here, we evaluated its effect on murine dentate gyrus (DG) single cell suspensions and on subsequent scRNA-seq downstream analysis by performing SOrting and Robot-assisted Transcriptome SEQuencing (SORT-seq), a partially robotized version of the CEL-seq2 protocol. Our results show that MeOH fixation preserves RNA integrity and has no apparent effects on cDNA library construction. They also suggest that fixation protects from sorting-induced cell stress and increases the proportion of high-quality cells. Despite evidence of mRNA leakage in fixed cells, their relative gene expression levels correlate well with those of fresh cells and fixation does not significantly affect the variance of the dataset. Moreover, it allows the identification of all major DG cell populations, including neural precursors, granule neurons and different glial cell types, with a tendency to preserve more neurons that are underrepresented in fresh samples. Overall, our data show that MeOH fixation is suitable for preserving primary neural cells for subsequent single-cell RNA profiling, helping to overcome challenges arising from complex workflows, improve experimental flexibility and facilitate scientific collaboration.

Interfacing neural cells with typical microelectronics materials for future manufacturing.

The biocompatibility of materials used in electronic devices is critical for the development of implantable devices like pacemakers and neuroprosthetics, as well as in future biomanufacturing. Biocompatibility refers to the ability of these materials to interact with living cells and tissues without causing an adverse response. Therefore, it is essential to evaluate the biocompatibility of metals and semiconductor materials used in electronic devices to ensure their safe use in medical applications. Here, we evaluated the biocompatibility of a collection of diced silicon chips coated with a variety of metal thin films, interfacing them with different cell types, including murine mastocytoma cells in suspension culture, adherent NIH 3T3 fibroblasts, and human induced pluripotent stem cell (iPSC)-derived neural progenitor cells (NPCs). All materials tested were biocompatible and showed the potential to support neural differentiation of iPSC-NPCs, creating an opportunity to use these materials in a scalable production of a range of biohybrid devices such as electronic devices to study neural behaviors and neuropathies.

SAM/SAH Mediates Parental Folate Deficiency-Induced Neural Cell Apoptosis in Neonatal Rat Offspring: The Expression of Bcl-2, Bax, and Caspase-3.

Research demonstrated that folate deficiency in either the mother or father could impact the biological functions of the offspring's of neural cells. Folate deficiency can also impair the methionine cycle, thus contributing to the conversion of S-adenosylmethionine (SAM) to S-adenosylhomocysteine (SAH), which could potentially cause damage to the central nervous system. The study focused on the effect of parental folate deficiency on neural cell apoptosis in offspring neonatal rats and whether it is mediated by the levels of SAM and SAH in brains. The experimental design was conducted by feeding female and male Sprague Dawley (SD) rats with either folate-deficient or folate-normal diets, sacrificing the offspring within 24 h and isolating their brain tissue. Rats were divided into four groups: the maternal-folate-deficient and paternal-folate-deficient (D-D) group; the maternal-folate-deficient and paternal-folate-normal (D-N) group; the maternal-folate-normal and paternal-folate-deficient (N-D) group; and the maternal-folate-normal and paternal-folate-normal (N-N) group. There was down-regulation of B-cell lymphoma 2 (Bcl-2) expression, up-regulation of Bcl-2-associated X protein (Bax) and Caspase-3 expression of neural cells, and pathological changes in the brain ultrastructure, as well as decreased SAM levels, increased SAH levels, and a decreased SAM/SAH ratio in the rat fetal brain via parental folate deficiency. In conclusion, parental folate deficiency could induce the apoptosis of neural cells in neonatal offspring rats, while biparental folate deficiency had the greatest effect on offspring, and the unilateral effect was greater in mothers than in fathers. This process may be mediated by the levels of SAM and SAH in the rat fetal brain.

Assembling Spheroids of Rat Primary Neurons Using a Stress-Free 3D Culture System.

Neural injuries disrupt the normal functions of the nervous system, whose complexities limit current treatment options. Because of their enhanced therapeutic effects, neurospheres have the potential to advance the field of regenerative medicine and neural tissue engineering. Methodological steps can pose challenges for implementing neurosphere assemblies; for example, conventional static cultures hinder yield and throughput, while the presence of the necrotic core, time-consuming methodology, and high variability can slow their progression to clinical application. Here we demonstrate the optimization of primary neural cell-derived neurospheres, developed using a high-throughput, stress-free, 3D bioreactor. This process provides a necessary baseline for future studies that could develop co-cultured assemblies of stem cells combined with endothelial cells, and/or biomaterials and nanomaterials for clinical therapeutic use. Neurosphere size and neurite spreading were evaluated under various conditions using Image J software. Primary neural cells obtained from the hippocampi of three-day-old rat pups, when incubated for 24 h in a reactor coated with 2% Pluronic and seeded on Poly-D-Lysine-coated plates establish neurospheres suitable for therapeutic use within five days. Most notably, neurospheres maintained high cell viability of ≥84% and expressed the neural marker MAP2, neural marker ß-Tubulin III, and glial marker GFAP at all time points when evaluated over seven days. Establishing these factors reduces the variability in developing neurospheres, while increasing the ease and output of the culture process and maintaining viable cellular constructs.

Microfluidic Systems for Neural Cell Studies.

Whereas the axons of the peripheral nervous system (PNS) spontaneously regenerate after an injury, the occurring regeneration is rarely successful because axons are usually directed by inappropriate cues. Therefore, finding successful ways to guide neurite outgrowth, in vitro, is essential for neurogenesis. Microfluidic systems reflect more appropriately the in vivo environment of cells in tissues such as the normal fluid flow within the body, consistent nutrient delivery, effective waste removal, and mechanical stimulation due to fluid shear forces. At the same time, it has been well reported that topography affects neuronal outgrowth, orientation, and differentiation. In this review, we demonstrate how topography and microfluidic flow affect neuronal behavior, either separately or in synergy, and highlight the efficacy of microfluidic systems in promoting neuronal outgrowth.

Electroacupuncture attenuates chronic inflammatory pain and depression comorbidity by inhibiting hippocampal neuronal apoptosis via the PI3K/Akt signaling pathway.

In chronic inflammatory pain (CIP) and depression, neuroapoptosis has been identified as a contributing factor. Electroacupuncture (EA) shows promise as an alternative therapy for this comorbidity. However, the underlying mechanism remains unclear. This study aimed to investigate the effects of EA on hippocampal neuronal apoptosis in rats with CIP and depression. Rats received plantar injections of complete Freund's adjuvant (CFA) on days 0 and 14. They were then divided into groups: sham operation, model, EA, and duloxetine. EA was administered at Hegu (LI4) and Taichong (LR3) from days 15 to 28, while the duloxetine group received duloxetine and distilled water daily (0.1 mg/ml). Pain behavior was assessed using the mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) tests. Depression-like behavior was evaluated through the sucrose preference test (SPT), open-field test (OFT), and forced swim test (FST). Hematoxylin and eosin (HE) staining was employed to assess pathological changes in the hippocampus. Nerve cell apoptosis was determined using TUNEL fluorescence staining. Western blot analysis was conducted to measure the protein expression of Bcl-2, Bax, p-PI3K/PI3K, and p-Akt/Akt. EA demonstrated significant pain intensity reduction and alleviation of pain-related depressive symptoms. Our findings from the HE staining confirmed that CIP induced by CFA led to morphological changes in the hippocampus, while EA effectively reversed these pathological alterations. Moreover, EA intervention remarkably reduced neuronal apoptosis and exhibited an upregulation of Bcl-2 protein expression accompanied by a decrease in Bax expression. Additionally, EA activated the PI3K/Akt signaling pathway. Overall, our study suggests that EA holds the potential to improve pain and depressive behaviors in rats with CIP and depression comorbidity, potentially mediated through the activation of the PI3K/Akt pathway, leading to a reduction in hippocampal neuronal apoptosis.

Unique Chirality Selection in Neural Cells for D-Matrix Enabling Specific Manipulation of Cell Behaviors.

Manipulating neural cell behaviors is a critical issue to various therapies for neurological diseases and damages, where matrix chirality has long been overlooked despite the proven adhesion and proliferation improvement of multiple non-neural cells by L-matrixes. Here, it is reported that the D-matrix chirality specifically enhances cell density, viability, proliferation, and survival in four different types of neural cells, contrasting its inhibition in non-neural cells. This universal impact on neural cells is defined as "chirality selection for D-matrix" and is achieved through the activation of JNK and p38/MAPK signaling pathways by the cellular tension relaxation resulting from the weak interaction between D-matrix and cytoskeleton proteins, particularly actin. Also, D-matrix promotes sciatic nerve repair effectively, both with or without non-neural stem cell implantation, by improving the population, function, and myelination of autologous Schwann cells. D-matrix chirality, as a simple, safe, and effective microenvironment cue to specifically and universally manipulate neural cell behaviors, holds extensive application potential in addressing neurological issues such as nerve regeneration, neurodegenerative disease treatment, neural tumor targeting, and neurodevelopment.

Evaluation of Poly(N-Ethyl Pyrrolidine Methacrylamide) (EPA) and Derivatives as Polymeric Vehicles for miRNA Delivery to Neural Cells.

MicroRNAs (miRNAs) are endogenous, short RNA oligonucleotides that regulate the expression of hundreds of proteins to control cells' function in physiological and pathological conditions. miRNA therapeutics are highly specific, reducing the toxicity associated with off-target effects, and require low doses to achieve therapeutic effects. Despite their potential, applying miRNA-based therapies is limited by difficulties in delivery due to their poor stability, fast clearance, poor efficiency, and off-target effects. To overcome these challenges, polymeric vehicles have attracted a lot of attention due to their ease of production with low costs, large payload, safety profiles, and minimal induction of the immune response. Poly(N-ethyl pyrrolidine methacrylamide) (EPA) copolymers have shown optimal DNA transfection efficiencies in fibroblasts. The present study aims to evaluate the potential of EPA polymers as miRNA carriers for neural cell lines and primary neuron cultures when they are copolymerized with different compounds. To achieve this aim, we synthesized and characterized different copolymers and evaluated their miRNA condensation ability, size, charge, cytotoxicity, cell binding and internalization ability, and endosomal escape capacity. Finally, we evaluated their miRNA transfection capability and efficacy in Neuro-2a cells and rat primary hippocampal neurons. The results indicate that EPA and its copolymers, incorporating ß-cyclodextrins with or without polyethylene glycol acrylate derivatives, can be promising vehicles for miRNA administration to neural cells when all experiments on Neuro-2a cells and primary hippocampal neurons are considered together.

Surface grafting of poly-L-lysine via diazonium chemistry to enhance cell adhesion to biomedical electrodes.

The ability to study and regulate cell behavior at a biomaterial interface requires a strict control over its surface chemistry. Significance of studying cell adhesion in vitro and in vivo has become increasingly important, particularly in the field of tissue engineering and regenerative medicine. A promising surface modification route assumes using organic layers prepared by the method of electrografting of diazonium salts and their further functionalization with biologically active molecules as cell adhesion promoters. This work reports the modification of platinum electrodes with selected diazonium salts and poly-L-lysine to increase the number of sites available for cell adhesion. As-modified electrodes were characterized in terms of their chemical and morphological properties, as well as wettability. In order to monitor the process of cell attachment, biofunctionalized electrodes were used as substrates for culturing human neuroblastoma SH-SY5Y cells. The experiments revealed that cell adhesion is favored on the surface of diazonium-modified and poly-L-lysine coated electrodes, indicating proposed modification route as a valuable strategy enhancing the integration between bioelectronic devices and neural cells.

Mitochondrial, cell cycle control and neuritogenesis alterations in an iPSC-based neurodevelopmental model for schizophrenia.

Schizophrenia is a severe psychiatric disorder of neurodevelopmental origin that affects around 1% of the world's population. Proteomic studies and other approaches have provided evidence of compromised cellular processes in the disorder, including mitochondrial function. Most of the studies so far have been conducted on postmortem brain tissue from patients, and therefore, do not allow the evaluation of the neurodevelopmental aspect of the disorder. To circumvent that, we studied the mitochondrial and nuclear proteomes of neural stem cells (NSCs) and neurons derived from induced pluripotent stem cells (iPSCs) from schizophrenia patients versus healthy controls to assess possible alterations related to energy metabolism and mitochondrial function during neurodevelopment in the disorder. Our results revealed differentially expressed proteins in pathways related to mitochondrial function, cell cycle control, DNA repair and neuritogenesis and their possible implication in key process of neurodevelopment, such as neuronal differentiation and axonal guidance signaling. Moreover, functional analysis of NSCs revealed alterations in mitochondrial oxygen consumption in schizophrenia-derived cells and a tendency of higher levels of intracellular reactive oxygen species (ROS). Hence, this study shows evidence that alterations in important cellular processes are present during neurodevelopment and could be involved with the establishment of schizophrenia, as well as the phenotypic traits observed in adult patients. Neural stem cells (NSCs) and neurons were derived from induced pluripotent stem cells (iPSCs) from schizophrenia patients and controls. Proteomic analyses were performed on the enriched mitochondrial and nuclear fractions of NSCs and neurons. Whole-cell proteomic analysis was also performed in neurons. Our results revealed alteration in proteins related to mitochondrial function, cell cycle control, among others. We also performed energy pathway analysis and reactive oxygen species (ROS) analysis of NSCs, which revealed alterations in mitochondrial oxygen consumption and a tendency of higher levels of intracellular ROS in schizophrenia-derived cells.

Anisotropic 3D scaffolds for spinal cord guided repair: Current concepts.

A spinal cord injury (SCI) can be caused by unforeseen events such as a fall, a vehicle accident, a gunshot, or a malignant illness, which has a significant impact on the quality of life of the patient. Due to the limited regenerative potential of the central nervous system (CNS), SCI is one of the most daunting medical challenges of modern medicine. Great advances have been made in tissue engineering and regenerative medicine, which include the transition from two-dimensional (2D) to three-dimensional (3D) biomaterials. Combinatory treatments that use 3D scaffolds may significantly enhance the repair and regeneration of functional neural tissue. In an effort to mimic the chemical and physical properties of neural tissue, scientists are researching the development of the ideal scaffold made of synthetic and/or natural polymers. Moreover, in order to restore the architecture and function of neural networks, 3D scaffolds with anisotropic properties that replicate the native longitudinal orientation of spinal cord nerve fibres are being designed. In an effort to determine if scaffold anisotropy is a crucial property for neural tissue regeneration, this review focuses on the most current technological developments relevant to anisotropic scaffolds for SCI. Special consideration is given to the architectural characteristics of scaffolds containing axially oriented fibres, channels, and pores. By analysing neural cell behaviour in vitro and tissue integration and functional recovery in animal models of SCI, the therapeutic efficacy is evaluated for its successes and limitations.

Research Progress of Low-Intensity Pulsed Ultrasound in the Repair of Peripheral Nerve Injury.

Peripheral nerve injury (PNI) is a common disease that has profound impact on the health of patients, but has poor prognosis. The gold standard for the treatment of peripheral nerve defects is autologous nerve grafting; notwithstanding, due to the extremely high requirement for surgeons and medical facilities, there is great interest in developing better treatment strategies for PNI. Low-intensity pulsed ultrasound (LIPUS) is a noninterventional stimulation method characterized by low-intensity pulsed waves. It has good therapeutic effect on fractures, inflammation, soft tissue regeneration, and nerve regulation, and can participate in PNI repair from multiple perspectives. This review concentrates on the effects and mechanisms of LIPUS in the repair of PNI from the perspective of LIPUS stimulation of neural cells and stem cells, modulation of neurotrophic factors, signaling pathways, proinflammatory cytokines, and nerve-related molecules. In addition, the effects of LIPUS on nerve conduits are reviewed, as nerve conduits are expected to be a successful alternative treatment for PNI with the development of tissue engineering. Overall, the application advantages and prospects of LIPUS in the repair of PNI are highlighted by summarizing the effects of LIPUS on seed cells, neurotrophic factors, and nerve conduits for neural tissue engineering.