Bone morphogenetic proteins in the nervous system

Role of HDAC5 Epigenetics in Chronic Craniofacial Neuropathic Pain

The information provided from the papers reviewed here about the role of epigenetics in chronic craniofacial neuropathic pain is critically important because epigenetic dysregulation during the development and maintenance of chronic neuropathic pain is not yet well characterized, particularly for craniofacial pain. We have noted that gene expression changes reported vary depending on the nerve injury model and the reported sample collection time point. At a truly chronic timepoint of 10 weeks in our model of chronic neuropathic pain, functional groupings of genes examined include those potentially contributing to anti-inflammation, nerve repair/regeneration, and nociception. Genes altered after treatment with the epigenetic modulator LMK235 are discussed. All of these differentials are key in working toward the development of diagnosis-targeted therapeutics and likely for the timing of when the treatment is provided. The emphasis on the relevance of time post-injury is reiterated here.

Identity and Maturity of iPSC-Derived Oligodendrocytes in 2D and Organoid Systems

Oligodendrocytes originating in the brain and spinal cord as well as in the ventral and dorsal domains of the neural tube are transcriptomically and functionally distinct. These distinctions are also reflected in the ultrastructure of the produced myelin, and the susceptibility to myelin-related disorders, which highlights the significance of the choice of patterning protocols in the differentiation of induced pluripotent stem cells (iPSCs) into oligodendrocytes. Thus, our first goal was to survey the different approaches applied to the generation of iPSC-derived oligodendrocytes in 2D culture and in organoids, as well as reflect on how these approaches pertain to the regional and spatial fate of the generated oligodendrocyte progenitors and myelinating oligodendrocytes. This knowledge is increasingly important to disease modeling and future therapeutic strategies. Our second goal was to recap the recent advances in the development of oligodendrocyte-enriched organoids, as we explore their relevance to a regional specification alongside their duration, complexity, and maturation stages of oligodendrocytes and myelin biology. Finally, we discuss the shortcomings of the existing protocols and potential future explorations.

Does type of bone graft matter? A retrospective review of the use of biological bone grafts in patients undergoing elective 1-3 level spinal interbody fusion

OBJECTIVE

There is a lack of strong evidence for use of expensive bone substitutes. This study compares perioperative data and patient reported quality-of-life outcomes across the varied types of bone graft extenders. The study analyzes the existing Quality and Outcomes Database and evaluates patient reported outcomes for 1-3 level lumbar fusion procedures comparing across different types of biologics bone graft.

METHODS

We retrospectively analyzed a prospectively collected data registry. Bone graft implant data were collected and grouped into the following categories: (1) Autograft with basic allograft (2) Enhanced, synthetic, or cellular allograft (3) Use of BMP. Preoperative and 1 year patient reported outcomes and perioperative data from the prospective collected registry were analyzed.

RESULTS

There were 384 patients included in this study. There were 168 (43.8%) patients in group 1, 133 (34.6%) patients in group 2, and 83 (21.6%) in group 3. There were no group differences in baseline or 1 year back pain, leg pain, ODI, or EQ-5D. The GLM Repeated Measures results indicate a significant difference within each of the three groups between the preoperative and postoperative measures for back pain, leg pain, ODI, and EQ-5D. The change over time was not significantly different between the groups.

CONCLUSIONS

Bone graft extenders are a significant contributor to the cost of lumbar fusion. This study demonstrates no difference in preoperative, and 1 year patient reported outcomes between the three groups. There was no significant difference in rate of reoperations across the three groups.

Development of a Single-Neurosphere Culture to Assess Radiation Toxicity and Pre-Clinical Cancer Combination Therapy Safety

Radiation therapy (RT) is a crucial treatment modality for central nervous system (CNS) tumors but toxicity to healthy CNS tissues remains a challenge. Additionally, environmental exposure to radiation during nuclear catastrophes or space travel presents a risk of CNS toxicity. However, the underlying mechanisms of radiation-induced CNS toxicity are not fully understood. Neural progenitor cells (NPCs) are highly radiosensitive, resulting in decreased neurogenesis in the hippocampus. This study aimed to characterize a novel platform utilizing rat NPCs cultured as 3D neurospheres (NSps) to screen the safety and efficacy of experimental drugs with and without radiation exposure. The effect of radiation on NSp growth and differentiation was assessed by measuring sphere volume and the expression of neuronal differentiation markers Nestin and GFAP and proliferation marker Ki67. Radiation exposure inhibited NSp growth, decreased proliferation, and increased GFAP expression, indicating astrocytic differentiation. RNA sequencing analysis supported these findings, showing upregulation of Notch, BMP2/4, S100b, and GFAP gene expression during astrogenesis. By recapitulating radiation-induced toxicity and astrocytic differentiation, this single-NSp culture system provides a high-throughput preclinical model for assessing the effects of various radiation modalities and evaluates the safety and efficacy of potential therapeutic interventions in combination with radiation.

Transplantation of Chemical Compound-Induced Cells from Human Fibroblasts Improves Locomotor Recovery in a Spinal Cord Injury Rat Model

The development of regenerative medicine using cell therapy is eagerly awaited for diseases such as spinal cord injury (SCI), for which there has been no radical cure. We previously reported the direct conversion of human fibroblasts into neuronal-like cells using only chemical compounds; however, it is unclear whether chemical compound-induced neuronal-like (CiN) cells are clinically functional. In this study, we partially modified the method of inducing CiN cells (termed immature CiN cells) and examined their therapeutic efficacy, in a rat model of SCI, to investigate whether immature CiN cells are promising for clinical applications. Motor function recovery, after SCI, was assessed using the Basso, Beattie, and Bresnahan (BBB) test, as well as the CatWalk analysis. We found that locomotor recovery, after SCI in the immature CiN cell-transplanted group, was partially improved compared to that in the control group. Consistent with these results, magnetic resonance imaging (MRI) and histopathological analyses revealed that nerve recovery or preservation improved in the immature CiN cell-transplanted group. Furthermore, transcriptome analysis revealed that immature CiN cells highly express hepatocyte growth factor (HGF), which has recently been shown to be a promising therapeutic agent against SCI. Our findings suggest that immature CiN cells may provide an alternative strategy for the regenerative therapy of SCI.

Decrease levels of bone morphogenetic protein 6 and noggin in chronic schizophrenia elderly

Objective

Bone morphogenetic protein 6 (BMP6) and noggin both have been implicated in the pathophysiology of chronic dementia, and chronic schizophrenia (SCZ) has high risk for progressing to dementia in later life. The current study investigated the relationship between blood BMP6/noggin levels and cognitive function in chronic SCZ elderly.

Methods

A total of 159 chronic SCZ elderly and 171 community normal controls (NC) were involved in the present study. Blood cytokines including BMP6 and its antagonist-noggin, and cognitive function were measured in all subjects, 157 subjects among them received apolipoprotein E (APOE) genotype test, and 208 subjects received cognitive assessment at 1-year follow-up.

Results

Chronic SCZ elderly had decreased levels of blood BMP6 and noggin compared to healthy controls, especially in the subgroup of chronic SCZ with dementia. Blood BMP6 combing with noggin could distinguish chronic SCZ from NC elderly. APOE ε4 carriers had lower levels of BMP6 than APOE non-ε4 carriers under chronic SCZ.

Conclusions

There was a significant relationship of blood BMP6/noggin with cognitive performance in chronic SCZ.

Current progress of cerebral organoids for modeling Alzheimer's disease origins and mechanisms

Alzheimer's disease (AD) is a progressive, neurodegenerative disease that has emerged as a leading risk factor for dementia associated with increasing age. Two-dimensional (2D) cell culture and animal models, which have been used to analyze AD pathology and search for effective treatments for decades, have significantly contributed to our understanding of the mechanism of AD. Despite their successes, 2D and animal models can only capture a fraction of AD mechanisms due to their inability to recapitulate human brain-specific tissue structure, function, and cellular diversity. Recently, the emergence of three-dimensional (3D) cerebral organoids using tissue engineering and induced pluripotent stem cell technology has paved the way to develop models that resemble features of human brain tissue more accurately in comparison to prior models. In this review, we focus on summarizing key research strategies for engineering in vitro 3D human brain-specific models, major discoveries from using AD cerebral organoids, and its future perspectives.

Exploring the growth trait molecular markers in two sheep breeds based on Genome-wide association analysis

Growth traits are quantitative traits controlled by multiple micro-effect genes. we identified molecular markers related to sheep growth traits, which formed the basis of molecular breeding. In this study, we randomly selected 100 Qira Black sheep and 84 German Merino sheep for the blood collection the jugular vein to genotype by using the Illumina Ovine SNP 50K Bead Chip. quality control criteria for statistical analysis were: rejection detection rate < 90% and minimum allele frequency (MAF) < 5%. Then, we performed Genome-wide association studies (GWAS) on sheep body weight, body height, body length, and chest circumference using mixed linear models. After getting 55 SNPs with significant correlation, they were annotated by reference genome of Ovis aries genome (Oar_v4.0) and We obtained a total of 84 candidate genes associated with production traits (BMPR1B, HSD17B3, TMEM63C, etc.). We selected BMPR1B for population validation and found a correlation between the FecB locus and body weight traits. Therefore, this study not only supplements the existing knowledge of molecular markers of sheep growth traits, but also has important theoretical significance and reference value for the mining of functional genes of sheep growth traits.

Generation of Lens Progenitor Cells and Lentoid Bodies from Pluripotent Stem Cells: Novel Tools for Human Lens Development and Ocular Disease Etiology

In vitro differentiation of human pluripotent stem cells (hPSCs) into specialized tissues and organs represents a powerful approach to gain insight into those cellular and molecular mechanisms regulating human development. Although normal embryonic eye development is a complex process, generation of ocular organoids and specific ocular tissues from pluripotent stem cells has provided invaluable insights into the formation of lineage-committed progenitor cell populations, signal transduction pathways, and self-organization principles. This review provides a comprehensive summary of recent advances in generation of adenohypophyseal, olfactory, and lens placodes, lens progenitor cells and three-dimensional (3D) primitive lenses, "lentoid bodies", and "micro-lenses". These cells are produced alone or "community-grown" with other ocular tissues. Lentoid bodies/micro-lenses generated from human patients carrying mutations in crystallin genes demonstrate proof-of-principle that these cells are suitable for mechanistic studies of cataractogenesis. Taken together, current and emerging advanced in vitro differentiation methods pave the road to understand molecular mechanisms of cataract formation caused by the entire spectrum of mutations in DNA-binding regulatory genes, such as PAX6, SOX2, FOXE3, MAF, PITX3, and HSF4, individual crystallins, and other genes such as BFSP1, BFSP2, EPHA2, GJA3, GJA8, LIM2, MIP, and TDRD7 represented in human cataract patients.

The effects of Bone Morphogenetic Protein 4 on adult neural stem cell proliferation, differentiation and survival in an in vitro model of ischemic stroke

The subventricular zone (SVZ) of the lateral ventricles represents a main region where neural stem cells (NSCs) of the mature central nervous system (CNS) reside. Bone Morphogenetic Proteins (BMPs) are the largest subclass of the transforming growth factor-β (TGF-β) superfamily of ligands. BMP4 is one such member and plays important roles in adult NSC differentiation. However, the exact effects of BMP4 on SVZ adult NSCs in CNS ischemia are still unknown. Using oxygen and glucose deprivation (OGD) as an in vitro model of ischemia, we examined the behavior of adult NSCs. We observed that anoxia resulted in reduced viability of adult NSCs, and that BMP4 treatment clearly rescued apoptotic cell death following anoxia. Furthermore, BMP4 treatment exhibited a strong inhibitory effect on cellular proliferation of the adult NSCs in normoxic conditions. Moreover, such inhibitory effects of BMP4 treatment were also found in OGD conditions, despite the enhanced cellular proliferation of the adult NSCs that was observed under such ischemic conditions. Increased neuronal and astroglial commitment of adult NSCs were found in the OGD conditions, whereas a reduction in differentiated neurons and an increase in differentiated astrocytes were observed following BMP4 treatment. The present data indicate that BMP4 modulates proliferation and differentiation of SVZ-derived adult NSCs and promotes cell survival in the in vitro model of ischemic stroke.

Premature Neural Progenitor Cell Differentiation Into Astrocytes in Retinoic Acid-Induced Spina Bifida Rat Model

During embryonic spinal cord development, neural progenitor cells (NPCs) generate three major cell lines: neurons, oligodendrocytes, and astrocytes at precise times and locations within the spinal cord. Recent studies demonstrate early astrogenesis in animal models of spina bifida, which may play a role in neuronal dysfunction associated with this condition. However, to date, the pathophysiological mechanisms related to this early astrocytic response in spina bifida are poorly understood. This study aimed to characterize the development of early astrogliosis over time from Pax6+, Olig2+, or Nkx2.2+ NPCs using a retinoic acid-induced spina bifida rat model. At three gestational ages (E15, E17, and E20), spinal cords from fetuses with retinoic acid-induced spina bifida, their healthy sibling controls, or fetuses treated with the vehicle control were analyzed. Results indicated that premature astrogliosis and astrocytic activation were associated with an altered presence of Pax6+, Olig2+, and Nkx2.2+ NPCs in the lesion compared to the controls. Finally, this response correlated with an elevation in genes involved in the Notch-BMP signaling pathway. Taken together, changes in NPC patterning factor expression with Notch-BMP signaling upregulation may be responsible for the altered astrogenesis patterns observed in the spinal cord in a retinoic acid-induced spina bifida model.

The Cross-Talks Among Bone Morphogenetic Protein (BMP) Signaling and Other Prominent Pathways Involved in Neural Differentiation

The bone morphogenetic proteins (BMPs) are a group of potent morphogens which are critical for the patterning, development, and function of the central nervous system. The appropriate function of the BMP pathway depends on its interaction with other signaling pathways involved in neural differentiation, leading to synergistic or antagonistic effects and ultimately favorable biological outcomes. These opposite or cooperative effects are observed when BMP interacts with fibroblast growth factor (FGF), cytokines, Notch, Sonic Hedgehog (Shh), and Wnt pathways to regulate the impact of BMP-induced signaling in neural differentiation. Herein, we review the cross-talk between BMP signaling and the prominent signaling pathways involved in neural differentiation, emphasizing the underlying basic molecular mechanisms regarding the process of neural differentiation. Knowing these cross-talks can help us to develop new approaches in regenerative medicine and stem cell based therapy. Recently, cell therapy has received significant attention as a promising treatment for traumatic or neurodegenerative diseases. Therefore, it is important to know the signaling pathways involved in stem cell differentiation toward neural cells. Our better insight into the cross-talk of signaling pathways during neural development would improve neural differentiation within in vitro tissue engineering approaches and pre-clinical practices and develop futuristic therapeutic strategies for patients with neurological disease.

Transcriptome Dynamics of Human Neuronal Differentiation From iPSC

The generation and use of induced pluripotent stem cells (iPSCs) in order to obtain all differentiated adult cell morphologies without requiring embryonic stem cells is one of the most important discoveries in molecular biology. Among the uses of iPSCs is the generation of neuron cells and organoids to study the biological cues underlying neuronal and brain development, in addition to neurological diseases. These iPSC-derived neuronal differentiation models allow us to examine the gene regulatory factors involved in such processes. Among these regulatory factors are long non-coding RNAs (lncRNAs), genes that are transcribed from the genome and have key biological functions in establishing phenotypes, but are frequently not included in studies focusing on protein coding genes. Here, we provide a comprehensive analysis and overview of the coding and non-coding transcriptome during multiple stages of the iPSC-derived neuronal differentiation process using RNA-seq. We identify previously unannotated lncRNAs via genome-guided de novo transcriptome assembly, and the distinct characteristics of the transcriptome during each stage, including differentially expressed and stage specific genes. We further identify key genes of the human neuronal differentiation network, representing novel candidates likely to have critical roles in neurogenesis using coexpression network analysis. Our findings provide a valuable resource for future studies on neuronal differentiation.

Biological heterogeneity in idiopathic pulmonary arterial hypertension identified through unsupervised transcriptomic profiling of whole blood

Idiopathic pulmonary arterial hypertension (IPAH) is a rare but fatal disease diagnosed by right heart catheterisation and the exclusion of other forms of pulmonary arterial hypertension, producing a heterogeneous population with varied treatment response. Here we show unsupervised machine learning identification of three major patient subgroups that account for 92% of the cohort, each with unique whole blood transcriptomic and clinical feature signatures. These subgroups are associated with poor, moderate, and good prognosis. The poor prognosis subgroup is associated with upregulation of the ALAS2 and downregulation of several immunoglobulin genes, while the good prognosis subgroup is defined by upregulation of the bone morphogenetic protein signalling regulator NOG, and the C/C variant of HLA-DPA1/DPB1 (independently associated with survival). These findings independently validated provide evidence for the existence of 3 major subgroups (endophenotypes) within the IPAH classification, could improve risk stratification and provide molecular insights into the pathogenesis of IPAH.

Clinical manifestations of patients with GDF2 mutations associated with hereditary hemorrhagic telangiectasia type 5

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant fibrovascular dysplasia caused by mutations in ENG, ACVRL1, and SMAD4. Increasingly, there has been an appreciation for vascular conditions with phenotypic overlap to HHT but which have distinct clinical manifestations and arise from novel or uncharacterized gene variants. This study reported on a cohort of four unrelated probands who were diagnosed with a rare form of GDF2-related HHT5, for which only five prior cases have been described. Two patients harbored heterozygous missense variants not previously annotated as pathogenic (p.Val403Ile; p.Glu355Gln). Clinically, these patients had features resembling HHT1, including cerebrovascular involvement of their disease (first report documenting cerebral involvement of HHT5), but with earlier onset of epistaxis and a unique anatomic distribution of dermal capillary lesions that involved the upper forelimbs, trunk, and head. The other two patients harbored interstitial deletions larger than five megabases between 10q11.22 and 10q11.23 that included GDF2. To our knowledge, this is the first report detailing large genomic deletions leading to HHT5. These patients also demonstrated mucocutaneous capillary dysplasias, including intranasal vascular lesions complicated by childhood-onset epistasis, with a number of extravascular findings related to their 10q11.21q11.23 deletion. In conclusion, patients with GDF2-related HHT may present with a number of unique characteristics that differ from classically reported features of HHT.

Bone morphogenetic proteins (BMPs) in the central regulation of energy balance and adult neural plasticity

The current worldwide obesity pandemic highlights a need to better understand the regulation of energy balance and metabolism, including the role of the nervous system in controlling energy intake and energy expenditure. Neural plasticity in the hypothalamus of the adult brain has been implicated in full-body metabolic health, however, the mechanisms surrounding hypothalamic plasticity are incompletely understood. Bone morphogenetic proteins (BMPs) control metabolic health through actions in the brain as well as in peripheral tissues such as adipose, together regulating both energy intake and energy expenditure. BMP ligands, receptors, and inhibitors are found throughout plastic adult brain regions and have been demonstrated to modulate neurogenesis and gliogenesis, as well as synaptic and dendritic plasticity. This role for BMPs in adult neural plasticity is distinct from their roles in brain development. Existing evidence suggests that BMPs induce weight loss through hypothalamic pathways, and part of the mechanism of action may be through inducing neural plasticity. In this review, we summarize the data regarding how BMPs affect neural plasticity in the adult mammalian brain, as well as the relationship between central BMP signaling and metabolic health.

Tumor cells generate astrocyte-like cells that contribute to SHH-driven medulloblastoma relapse

Astrocytes, a major glial cell type in the brain, play a critical role in supporting the progression of medulloblastoma (MB), the most common malignant pediatric brain tumor. Through lineage tracing analyses and single-cell RNA sequencing, we demonstrate that astrocytes are predominantly derived from the transdifferentiation of tumor cells in relapsed MB (but not in primary MB), although MB cells are generally believed to be neuronal-lineage committed. Such transdifferentiation of MB cells relies on Sox9, a transcription factor critical for gliogenesis. Our studies further reveal that bone morphogenetic proteins (BMPs) stimulate the transdifferentiation of MB cells by inducing the phosphorylation of Sox9. Pharmacological inhibition of BMP signaling represses MB cell transdifferentiation into astrocytes and suppresses tumor relapse. Our studies establish the distinct cellular sources of astrocytes in primary and relapsed MB and provide an avenue to prevent and treat MB relapse by targeting tumor cell transdifferentiation.

Accumulated Knowledge of Activin Receptor-Like Kinase 2 (ALK2)/Activin A Receptor, Type 1 (ACVR1) as a Target for Human Disorders

Activin receptor-like kinase 2 (ALK2), also known as Activin A receptor type 1 (ACVR1), is a transmembrane kinase receptor for members of the transforming growth factor-β family. Wild-type ALK2/ACVR1 transduces osteogenic signaling in response to ligand binding. Fifteen years ago, a gain-of-function mutation in the ALK2/ACVR1 gene was detected in patients with the genetic disorder fibro-dysplasia ossificans progressiva, which is characterized by heterotopic ossification in soft tissues. Additional disorders, such as diffuse intrinsic pontin glioma, diffuse idiopathic skeletal hyperostosis, primary focal hyperhidrosis, and congenital heart defects, have also been found to be associated with ALK2/ACVR1. These findings further expand in vitro and in vivo model system research and promote our understanding of the molecular mechanisms of the pathogenesis and development of novel therapeutics and diagnosis for disorders associated with ALK2/ACVR1. Through aggressive efforts, some of the disorders associated with ALK2/ACVR1 will be overcome in the near future.

Cardiopulmonary and Neurologic Dysfunctions in Fibrodysplasia Ossificans Progressiva

Fibrodysplasia Ossificans Progressiva (FOP) is an ultra-rare but debilitating disorder characterized by spontaneous, progressive, and irreversible heterotopic ossifications (HO) at extraskeletal sites. FOP is caused by gain-of-function mutations in the Activin receptor Ia/Activin-like kinase 2 gene (Acvr1/Alk2), with increased receptor sensitivity to bone morphogenetic proteins (BMPs) and a neoceptor response to Activin A. There is extensive literature on the skeletal phenotypes in FOP, but a much more limited understanding of non-skeletal manifestations of this disease. Emerging evidence reveals important cardiopulmonary and neurologic dysfunctions in FOP including thoracic insufficiency syndrome, pulmonary hypertension, conduction abnormalities, neuropathic pain, and demyelination of the central nervous system (CNS). Here, we review the recent research and discuss unanswered questions regarding the cardiopulmonary and neurologic phenotypes in FOP.

A SMAD1/5-YAP signalling module drives radial glia self-amplification and growth of the developing cerebral cortex

The growth and evolutionary expansion of the cerebral cortex are defined by the spatial-temporal production of neurons, which itself depends on the decision of radial glial cells (RGCs) to self-amplify or to switch to neurogenic divisions. The mechanisms regulating these RGC fate decisions are still incompletely understood. Here, we describe a novel and evolutionarily conserved role of the canonical BMP transcription factors SMAD1/5 in controlling neurogenesis and growth during corticogenesis. Reducing the expression of both SMAD1 and SMAD5 in neural progenitors at early mouse cortical development caused microcephaly and an increased production of early-born cortical neurons at the expense of late-born ones, which correlated with the premature differentiation and depletion of the pool of cortical progenitors. Gain- and loss-of-function experiments performed during early cortical neurogenesis in the chick revealed that SMAD1/5 activity supports self-amplifying RGC divisions and restrains the neurogenic ones. Furthermore, we demonstrate that SMAD1/5 stimulate RGC self-amplification through the positive post-transcriptional regulation of the Hippo signalling effector YAP. We anticipate this SMAD1/5-YAP signalling module to be fundamental in controlling growth and evolution of the amniote cerebral cortex.

A Deletion in GDF7 is Associated with a Heritable Forebrain Commissural Malformation Concurrent with Ventriculomegaly and Interhemispheric Cysts in Cats

An inherited neurologic syndrome in a family of mixed-breed Oriental cats has been characterized as forebrain commissural malformation, concurrent with ventriculomegaly and interhemispheric cysts. However, the genetic basis for this autosomal recessive syndrome in cats is unknown. Forty-three cats were genotyped on the Illumina Infinium Feline 63K iSelect DNA Array and used for analyses. Genome-wide association studies, including a sib-transmission disequilibrium test and a case-control association analysis, and homozygosity mapping, identified a critical region on cat chromosome A3. Short-read whole genome sequencing was completed for a cat trio segregating with the syndrome. A homozygous 7 bp deletion in growth differentiation factor 7 (GDF7) (c.221_227delGCCGCGC [p.Arg74Profs]) was identified in affected cats, by comparison to the 99 Lives Cat variant dataset, validated using Sanger sequencing and genotyped by fragment analyses. This variant was not identified in 192 unaffected cats in the 99 Lives dataset. The variant segregated concordantly in an extended pedigree. In mice, GDF7 mRNA is expressed within the roof plate when commissural axons initiate ventrally-directed growth. This finding emphasized the importance of GDF7 in the neurodevelopmental process in the mammalian brain. A genetic test can be developed for use by cat breeders to eradicate this variant.

Toxic effects of dechlorane plus on the common carp (Cyprinus carpio) embryonic development

Dechlorane Plus (DP) is a widely used chlorinated flame retardant, which has been extensively detected in the environment. Although DP content in the surface water is low, it can pose a continuous exposure risk to aquatic organisms due to its strong bioaccumulation. Considering that the related studies on the toxicity mechanism of DP exposure are limited, the effect of DP on carp embryo development was evaluated. In the present work, carp embryos were exposed to different concentrations (0, 30, 60, and 120 μg/L) of DP at 3 h post-fertilization (hpf). The expression levels of neural and skeletal development-associated genes, such as sox2, sox19a, Mef2c and BMP4, were detected with quantitative PCR, and the changes in different developmental toxicity endpoints were observed. Our results demonstrated that the expression levels of sox2, sox19a, Mef2c and BMP4 were significantly altered and several developmental abnormalities were found in DP-exposed carp embryos, such as DNA damage, increased mortality rate, delayed hatching time, reduced hatching rate, decreased body length, and increased morphological deformities. In addition, the activities of reactive oxygen species and malondialdehyde were remarkably higher in 60 and 120 μg/L DP exposure groups than in control group. These results suggest that DP can exhibit a unique modes of action, which lead to aberration occurrence in the early development stage of common carps, which may be related to some gene damage and oxidative stress. Besides, the parameters evaluated here can be used as tools to access the environmental risk for biota and humans exposed to DP.

Biosynthesis, characterization and evaluation of the supportive properties and biocompatibility of DBM nanoparticles on a tissue-engineered nerve conduit from decellularized sciatic nerve

In this study, we examined the supporting effects of nano-demineralized bone matrix on the cultivation of Wharton's jelly stem cells on acellularized nerve scaffold. Demineralized bone matrix nanoparticles were prepared and characterized by several experiments. Decellularized sciatic nerve scaffolds were prepared and their efficiency was evaluated using histological stainings and biomechanical testing. Results of histological staining indicated that the integrity of the extra cellular matrix components was preserved. Also, the growth and viability of WJSCs on the scaffolds were significantly higher in DBM nanoparticle groups. We conclude that supportive properties of nano-DBM groups showed better cell viability and a suitable microenvironment for proliferation, retention, and adhesion of cells compared with other groups.

Impact of long-lasting spontaneous physical activity on bone morphogenetic protein 4 in the heart and tibia in murine model of heart failure

Bone morphogenetic protein 4 (BMP4) plays an important role in bone remodeling and in heart failure pathogenesis. The aim of this study was to evaluate the effect of spontaneous physical activity on the expression of BMP4 in the heart and tibia of the transgenic (Tgαq*44) mice, representing a model of chronic heart failure. Tgαq*44 and wild-type FVB mice (WT) were randomly assigned either to sedentary or to trained groups undergoing 8 weeks of spontaneous wheel running. The BMP4 protein expression in heart and tibiae was evaluated using Western immunoblotting and the phosphorus and calcium in the tibiae was assessed using the X-ray microanalysis. BMP4 content in the hearts of the Tgαq*44-sedentary mice was by ~490% higher than in the WT-sedentary mice, whereas in tibiae the BMP4 content of the Tgαq*44-sedentary mice was similar to that in the WT-sedentary animals. Tgαq*44 mice revealed by ~28% poorer spontaneous physical activity than the WT mice. No effect of performed physical activity on the BMP4 content in the hearts of either in the Tgαq*44 or WT mice was observed. However, 8-week spontaneous wheel running resulted in a decrease in the BMP4 expression in tibiae (by ~43%) in the group of Tgαq*44 mice only, with no changes in their bone phosphorus and calcium contents. We have concluded that prolonged period of spontaneous physical exercise does not increase the risk of the progression of the BMP4-mediated pathological cardiac hypertrophy and does not affect bone mineral status in the chronic heart failure mice.

Functional Roles of Long Non-coding RNAs in Motor Neuron Development and Disease

Long non-coding RNAs (lncRNAs) have gained increasing attention as they exhibit highly tissue- and cell-type specific expression patterns. LncRNAs are highly expressed in the central nervous system and their roles in the brain have been studied intensively in recent years, but their roles in the spinal motor neurons (MNs) are largely unexplored. Spinal MN development is controlled by precise expression of a gene regulatory network mediated spatiotemporally by transcription factors, representing an elegant paradigm for deciphering the roles of lncRNAs during development. Moreover, many MN-related neurodegenerative diseases, such as amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA), are associated with RNA metabolism, yet the link between MN-related diseases and lncRNAs remains obscure. In this review, we summarize lncRNAs known to be involved in MN development and disease, and discuss their potential future therapeutic applications.

Galectin-3 modulates postnatal subventricular zone gliogenesis

Postnatal subventricular zone (SVZ) neural stem cells generate forebrain glia, namely astrocytes and oligodendrocytes. The cues necessary for this process are unclear, despite this phase of brain development being pivotal in forebrain gliogenesis. Galectin‐3 (Gal‐3) is increased in multiple brain pathologies and thereby regulates astrocyte proliferation and inflammation in injury. To study the function of Gal‐3 in inflammation and gliogenesis, we carried out functional studies in mouse. We overexpressed Gal‐3 with electroporation and using immunohistochemistry surprisingly found no inflammation in the healthy postnatal SVZ. This allowed investigation of inflammation‐independent effects of Gal‐3 on gliogenesis. Loss of Gal‐3 function via knockdown or conditional knockout reduced gliogenesis, whereas Gal‐3 overexpression increased it. Gal‐3 overexpression also increased the percentage of striatal astrocytes generated by the SVZ but decreased the percentage of oligodendrocytes. These novel findings were further elaborated with multiple analyses demonstrating that Gal‐3 binds to the bone morphogenetic protein receptor one alpha (BMPR1α) and increases bone morphogenetic protein (BMP) signaling. Conditional knockout of BMPR1α abolished the effect of Gal‐3 overexpression on gliogenesis. Gain‐of‐function of Gal‐3 is relevant in pathological conditions involving the human forebrain, which is particularly vulnerable to hypoxia/ischemia during perinatal gliogenesis. Hypoxic/ischemic injury induces astrogliosis, inflammation and cell death. We show that Gal‐3 immunoreactivity was increased in the perinatal human SVZ and striatum after hypoxia/ischemia. Our findings thus show a novel inflammation‐independent function for Gal‐3; it is necessary for gliogenesis and when increased in expression can induce astrogenesis via BMP signaling.

Interplay between BMPs and Reactive Oxygen Species in Cell Signaling and Pathology

The integration of cell extrinsic and intrinsic signals is required to maintain appropriate cell physiology and homeostasis. Bone morphogenetic proteins (BMPs) are cytokines that belong to the transforming growth factor-β (TGF-β) superfamily, which play a key role in embryogenesis, organogenesis and regulation of whole-body homeostasis. BMPs interact with membrane receptors that transduce information to the nucleus through SMAD-dependent and independent pathways, including PI3K-AKT and MAPKs. Reactive oxygen species (ROS) are intracellular molecules derived from the partial reduction of oxygen. ROS are highly reactive and govern cellular processes by their capacity to regulate signaling pathways (e.g., NF-κB, MAPKs, KEAP1-NRF2 and PI3K-AKT). Emerging evidence indicates that BMPs and ROS interplay in a number of ways. BMPs stimulate ROS production by inducing NOX expression, while ROS regulate the expression of several BMPs. Moreover, BMPs and ROS influence common signaling pathways, including PI3K/AKT and MAPK. Additionally, dysregulation of BMPs and ROS occurs in several pathologies, including vascular and musculoskeletal diseases, obesity, diabetes and kidney injury. Here, we review the current knowledge on the integration between BMP and ROS signals and its potential applications in the development of new therapeutic strategies.

Activation of the BMP4/Smad1 Pathway Promotes Retinal Ganglion Cell Survival and Axon Regeneration

Purpose

We investigate if the BMP4/Smad1 intracellular signaling pathway is neuroprotective and axogenic in adult rodent retinal ganglion cells (RGC) in vivo and in vitro.

Methods

Adult retinal cultures were prepared from intact and after optic nerve crush (ONC) injured rats that have been stimulated to survive and regenerate using an intravitreal peripheral nerve (PN) graft. Laser capture microdissection (LCM) then was used to isolate RGC with and without neurites. Quantitative RT-PCR determined changes in BMP4/Smad1 signaling pathway mRNA. Immunohistochemistry confirmed localization of BMP4 and activation of Smad1 in ONC+PN-stimulated RGC in vivo. BMP4 peptide was used to stimulate RGC survival and neurite/axon regeneration in vitro and in vivo. Finally, the rapamycin sensitivity of the effects was determined in BMP4-stimulated RGC in vitro and in vivo.

Results

In retinal cultures prepared from intact and ONC+PN-stimulated rats, RGC with neurites had upregulated regeneration-related and BMP4/Smad1 signaling pathway mRNA levels, while low levels of these mRNAs were present in RGC isolated without neurites. An optimal dose of 200 ng/mL BMP4 peptide in vitro promoted approximately 30% RGC survival and disinhibited RGC neurite outgrowth, despite the presence of inhibitory CNS myelin extracts. BMP4 also promoted approximately 30% RGC survival in vivo and stimulated significant RGC axon regeneration at 100, 200, and 400 μm beyond the lesion site. Finally, the response of RGC to BMP4 treatment in vitro and in vivo was rapamycin-insensitive.

Conclusions

Activation of the BMP4/Smad1 pathway promotes survival and axon regeneration independent of mTOR and, therefore, may be of therapeutic interest.

Bcl-2 Overexpression Induces Neurite Outgrowth via the Bmp4/Tbx3/NeuroD1 Cascade in H19-7 Cells

Bcl-2 is overexpressed in the nervous system during neural development and plays an important role in modulating cell survival. In addition to its anti-apoptotic function, it has been suggested previously that Bcl-2 might act as a mediator of neuronal differentiation. However, the mechanism by which Bcl-2 might influence neurogenesis is not sufficiently understood. In this study, we aimed to determine the non-apoptotic functions of Bcl-2 during neuronal differentiation. First, we used microarrays to analyze the whole-genome expression patterns of rat neural stem cells overexpressing Bcl-2 and found that Bcl-2 overexpression induced the expression of various neurogenic genes. Moreover, Bcl-2 overexpression increased the neurite length as well as expression of Bmp4, Tbx3, and proneural basic helix-loop-helix genes, such as NeuroD1, NeuroD2, and Mash1, in H19-7 rat hippocampal precursor cells. To determine the hierarchy of these molecules, we selectively depleted Bmp4, Tbx3, and NeuroD1 in Bcl-2-overexpressing cells. Bmp4 depletion suppressed the upregulation of Tbx3 and NeuroD1 as well as neurite outgrowth, which was induced by Bcl-2 overexpression. Although Tbx3 knockdown repressed Bcl-2-mediated neurite elaboration and downregulated NeuroD1 expression, it did not affect Bcl-2-induced Bmp4 expression. While the depletion of NeuroD1 had no effect on the expression of Bcl-2, Bmp4, or Tbx3, Bcl-2-mediated neurite outgrowth was suppressed. Taken together, these results demonstrate that Bcl-2 regulates neurite outgrowth through the Bmp4/Tbx3/NeuroD1 cascade in H19-7 cells, indicating that Bcl-2 may have a direct role in neuronal development in addition to its well-known anti-apoptotic function in response to environmental insults.

The wonders of BMP9: From mesenchymal stem cell differentiation, angiogenesis, neurogenesis, tumorigenesis, and metabolism to regenerative medicine

Although bone morphogenetic proteins (BMPs) initially showed effective induction of ectopic bone growth in muscle, it has since been determined that these proteins, as members of the TGF-β superfamily, play a diverse and critical array of biological roles. These roles include regulating skeletal and bone formation, angiogenesis, and development and homeostasis of multiple organ systems. Disruptions of the members of the TGF-β/BMP superfamily result in severe skeletal and extra-skeletal irregularities, suggesting high therapeutic potential from understanding this family of BMP proteins. Although it was once one of the least characterized BMPs, BMP9 has revealed itself to have the highest osteogenic potential across numerous experiments both in vitro and in vivo, with recent studies suggesting that the exceptional potency of BMP9 may result from unique signaling pathways that differentiate it from other BMPs. The effectiveness of BMP9 in inducing bone formation was recently revealed in promising experiments that demonstrated efficacy in the repair of critical sized cranial defects as well as compatibility with bone-inducing bio-implants, revealing the great translational promise of BMP9. Furthermore, emerging evidence indicates that, besides its osteogenic activity, BMP9 exerts a broad range of biological functions, including stem cell differentiation, angiogenesis, neurogenesis, tumorigenesis, and metabolism. This review aims to summarize our current understanding of BMP9 across biology and the body.

Plasmonic nano surface for neuronal differentiation and manipulation

Neurodegenerative diseases and traumatic brain injuries can destroy neurons, resulting in sensory and motor function loss. Transplantation of differentiated neurons from stem cells could help restore such lost functions. Plasmonic gold nanorods (AuNR) were integrated in growth surfaces to stimulate and modulate neural cells in order to tune cell physiology. An AuNR nanocomposite system was fabricated, characterized, and then utilized to study the differentiation of embryonic rat neural stem cells (NSCs). Results demonstrated that this plasmonic surface 1) accelerated differentiation, yielding almost twice as many differentiated neural cells as a traditional NSC culture surface coated with poly-D-lysine and laminin for the same time period; and 2) promoted differentiation of NSCs into neurons and astrocytes in a 2:1 ratio, as evidenced by the expression of relevant marker proteins. These results indicate that the design and properties of this AuNR plasmonic surface would be advantageous for tissue engineering to address neural degeneration.

Current Updates on Bone Grafting Biomaterials and Recombinant Human Growth Factors Implanted Biotherapy for Spinal Fusion: A Review of Human Clinical Studies

BACKGROUND

Owing to their great promise in the spinal surgeries, bone graft substitutes have been widely investigated for their safety and clinical potential. By the current advances in the spinal surgery, an understanding of the precise biological mechanism of each bone graft substitute is mandatory for upholding the induction of solid spinal fusion.

OBJECTIVE

The aim of the present review is to critically discuss various surgical implications and level of evidence of most commonly employed bone graft substitutes for spinal fusion.

METHOD

Data was collected via electronic search using "PubMed", "SciFinder", "ScienceDirect", "Google Scholar", "Web of Science" and a library search for articles published in peer-reviewed journals, conferences, and e-books.

RESULTS

Despite having exceptional inherent osteogenic, osteoinductive, and osteoconductive features, clinical acceptability of autografts (patient's own bone) is limited due to several perioperative and postoperative complications i.e., donor-site morbidities and limited graft supply. Alternatively, allografts (bone harvested from cadaver) have shown great promise in achieving acceptable bone fusion rate while alleviating the donor-site morbidities associated with implantation of autografts. As an adjuvant to allograft, demineralized bone matrix (DBM) has shown remarkable efficacy of bone fusion, when employed as graft extender or graft enhancer. Recent advances in recombinant technologies have made it possible to implant growth and differentiation factors (bone morphogenetic proteins) for spinal fusion.

CONCLUSION

Selection of a particular bone grafting biotherapy can be rationalized based on the level of spine fusion, clinical experience and preference of orthopaedic surgeon, and prevalence of donor-site morbidities.

Deciphering the Dynamical Origin of Mixed Population during Neural Stem Cell Development

Neural stem cells (NSCs) often give rise to a mixed population of cells during differentiation. However, the dynamical origin of these mixed states is poorly understood. In this article, our mathematical modeling study demonstrates that the bone morphogenetic protein 2 (BMP2) mediated disparate differentiation dynamics of NSCs in central and peripheral nervous systems essentially function through two distinct bistable switches that are mutually interconnected via a mushroom-like bifurcation. Stochastic simulations of the model reveal that the mixed population originates due to the existence of these bistable switching regulations and that the maintenance of such mixed states depends on the level of stochastic fluctuations of the system. It further demonstrates that due to extrinsic variability, cells in an NSC population can dynamically transit from mushroom to a unique isola kind of bifurcation state, which essentially extends the range of the BMP2-driven mixed population state during differentiation. Importantly, the model predicts that by individually altering the expression level of key regulatory proteins, the NSCs can be converted entirely to a preferred phenotype for BMP2 doses that previously resulted in a mixed population. Our findings show that efficient neuronal regeneration can be achieved by systematically maneuvering the differentiation dynamics.

The Expression of Shh, Ptch1, and Gli1 in the Developing Caudal Spinal Cord of Fetal Rats With Anorectal Malformations

BACKGROUND

Postoperative incontinence and constipation still remain the major complications of anorectal malformations (ARMs), despite improvements in their treatment. One of the most important factors that affect postoperative anorectal function is malformations in the lumbosacral spinal cord. However, far too little attention has been paid to the underlying mechanism that produces these malformations.

MATERIALS AND METHODS

The levels of sonic hedgehog (Shh), patched homolog 1 (Ptch1), and zinc finger-containing transcription factors 1 (Gli1) expression were investigated in the lumbosacral spinal cord in ethylenethiourea-exposed rat fetus with ARMs, and Shh, Ptch1, and Gli1 expression was confirmed with immunohistochemical staining, quantitative real-time polymerase chain reaction, and western blot analyses during lumbosacral spinal cord development both in the ARMs and normal rat embryos.

RESULTS

Our results have shown that Shh, Ptch1, and Gli1 expression in the lumbosacral spinal cord of rat embryos with ARMs was decreased at both the messenger RNA and protein levels, when compared with their expression levels in normal tissues (P < 0.05).

CONCLUSIONS

This study demonstrated that the expression of Shh, Ptch1, and Gli1 in lumbosacral spinal cord was remarkably reduced during late developmental stages in fetal rats with ARMs. These findings offered some important insights into the involvement of the Shh-Ptch1-Gli1 signaling pathway in the pathogenesis of lumbosacral spinal cord maldevelopment in rat fetus with ARMs, which leads to complications after procedures for ARMs.

Bone morphogenetic proteins and inner ear development

Bone morphogenetic proteins (BMPs) are the largest subfamily of the transforming growth factor-β superfamily, and they play important roles in the development of numerous organs, including the inner ear. The inner ear is a relatively small organ but has a highly complex structure and is involved in both hearing and balance. Here, we discuss BMPs and BMP signaling pathways and then focus on the role of BMP signal pathway regulation in the development of the inner ear and the implications this has for the treatment of human hearing loss and balance dysfunction.

Motor axon guidance in Drosophila

The Drosophila motor system starts to assemble during embryonic development. It is composed of 30 muscles per abdominal hemisegment and 36 motor neurons assembling into nerve branches to exit the CNS, navigate within the muscle field and finally establish specific connections with their target muscles. Several families of guidance molecules that play a role controlling this process as well as transcriptional regulators that program the behavior of specific motor neuron have been identified. In this review we summarize the role of both groups of molecules in the motor system as well as their relationship where known. It is apparent that partially redundant guidance protein families and membrane molecules with different functional output direct guidance decisions cooperatively. Some distinct transcriptional regulators seem to control guidance of specific nerve branches globally directing the expression of groups of pathfinding molecules in all motor neurons within the same motor branch.

TGF-β Family Signaling in Neural and Neuronal Differentiation, Development, and Function

Signaling by the transforming growth factor β (TGF-β) family is necessary for proper neural development and function throughout life. Sequential waves of activation, inhibition, and reactivation of TGF-β family members regulate numerous elements of the nervous system from the earliest stages of embryogenesis through adulthood. This review discusses the expression, regulation, and function of TGF-β family members in the central nervous system at various developmental stages, beginning with induction and patterning of the nervous system to their importance in the adult as modulators of inflammatory response and involvement in degenerative diseases.

Neuroprotective Effect of Chitosan Oligosaccharide on Hypoxic-Ischemic Brain Damage in Neonatal Rats

Neonatal hypoxic-ischemic brain damage (HIBD) is one of the leading causes of neonatal mortality and permanent neurological disability worldwide and the effective treatment strategies are not yet available. It has been demonstrated that Chitosan oligosaccharide (COS) exerts protective effect in vitro ischemic brain injury. However, no information is available on possible effects of COS on neonatal HIBD. To investigate the hypothesis of the potential neuroprotective effect of COS on the brain injury due to HIBD, 7-day-old Sprague-Dawley rats were treated with left carotid artery ligation followed by exposure to 8% oxygen (balanced with nitrogen) for 2.5 h at 37 °C. After COS treatment, the cerebral damage was measured by behavior tasks, 2,3,5-triphenyltetrazolium chloride(TTC), Hematoxyline-Eosin(HE), Nissl and Fluoro-Jade B(FJB)staining. In addition, the oxidative stress were assayed with ipsilateral hemisphere homogenates. Immunofluorescence staining were used to examine the activation of the astrocyte and microglia. Expression of inflammatory-related proteins were analyzed by western-blot analysis. In this study we found that administration of COS ameliorated early neurological reflex behavior, significantly reduce brain infarct volume and attenuated neuronal cell injury and degeneration. Furthermore, COS markedly decreased the level of MDA, lactic acid and increased SOD, GSH-Px and T-AOC. COS attenuated hypoxic-ischemic induced up-regulation of expressions of interleukin-1β (IL-1β), tumor necrosis factor alpha (TNF-α), meanwhile it dramatically increased the interleukin-10 (IL-10). These results suggest that COS exerts neuroprotection on hypoxic-ischemic brain damage in neonatal rats, it implies COS might be a potential therapeutic for the treatment of HIBD.

Bone morphogenetic protein-5, a key molecule that mediates differentiation in MC3T3E1 osteoblast cell line

Bone morphogenetic protein-5 (BMP-5) is a member of the TGF receptor-β family with osteoinductive property. However, its physiological role in osteoblast differentiation is not defined. This study highlights the importance of BMP-5 in MC3T3E1 osteoblast differentiation. Pre-osteoblasts exposed to osteogenic media (ascorbic acid, 50 µg/ml and β-glycerophosphate, 10 mM) showed high protein expression of BMP-5 in cell lysates and cell culture supernatants, which peaked during early time-points of differentiation and declined with onset of mineralization. Attenuation of endogenous BMP-5 protein expression by RNA interference downregulated the expression of type I collagen (COLIA1), an early osteoblast differentiation marker but not osteocalcin, a late osteoblast differentiation marker. Further experiments to analyze the cell signaling components revealed that BMP-5 modulates COLIA1 expression via p38-Runx2 axis involving Runx2 (Ser19) phosphorylation. These effects were also observed when recombinant BMP-5 was added to pre-osteoblast cultures reinforcing the fact that BMP-5 is a modulator of COLIA1 expression. We conclude that BMP-5 has stage-specific role to play during MC3T3E1 osteoblast differentiation in part by autocrine p38/Runx2/COLIA1 signaling. © 2017 BioFactors, 43(4):558-566, 2017.

Peptides derived from the knuckle epitope of BMP-9 induce the cholinergic differentiation and inactivate GSk3beta in human SH-SY5Y neuroblastoma cells

The incidence of brain degenerative disorders like Alzheimer's disease (AD) will increase as the world population ages. While there is presently no known cure for AD and current treatments having only a transient effect, an increasing number of publications indicate that growth factors (GF) may be used to treat AD. GFs like the bone morphogenetic proteins (BMPs), especially BMP-9, affect many aspects of AD. However, BMP-9 is a big protein that cannot readily cross the blood-brain barrier. We have therefore studied the effects of two small peptides derived from BMP-9 (pBMP-9 and SpBMP-9). We investigated their capacity to differentiate SH-SY5Y human neuroblastoma cells into neurons with or without retinoic acid (RA). Both peptides induced Smad 1/5 phosphorylation and their nuclear translocation. They increased the number and length of neurites and the expression of neuronal markers MAP-2, NeuN and NSE better than did BMP-9. They also promoted differentiation to the cholinergic phenotype more actively than BMP-9, SpBMP-9 being the most effective as shown by increases in intracellular acetylcholine, ChAT and VAchT. Finally, both peptides activated the PI3K/Akt pathway and inhibited GSK3beta, a current AD therapeutic target. BMP-9-derived peptides, especially SpBMP-9, with or without RA, are promising molecules that warrant further investigation.

Cloning, expression profiling and promoter functional analysis of Bone morphogenetic protein 6 and 7 in tongue sole (Cynoglossus semilaevis)

Bone morphogenetic proteins (BMPs) play crucial roles in vertebrate developmental process and are associated with the mechanisms which drive early skeletal development. As a first approach to elucidating the role of BMPs in regulating fish bone formation and growth, we describe the cloning, expression profiling and promoter functional analysis of bmp6 and bmp7 in tongue sole (Cynoglossus semilaevis). The full length of bmp6 and bmp7 cDNA sequences is 1939 and 1836 bp, which encodes a protein of 428 and 427 amino acids, respectively. Tissue expression distribution of bmp6 and bmp7 was examined in 14 tissues of mature individuals by quantitative real-time PCR (qRT-PCR). The results revealed that bmp6 was predominantly expressed in the gonad, and bmp7 exhibited the highest expression level in the dorsal fin. Further comparison of bmp6 expression levels between female and male gonads showed that the expression in the ovary was significantly higher than in the testis. Moreover, bmp6 and bmp7 expression levels were detected at 15 sampling time points of early developmental stages (egg, larva, juvenile and fingerling stages). The highest expression level of bmp6 was observed in the egg stage (multi-cell and gastrula stage); while bmp7 exhibited the highest expression in the larva stage (1-4 days old). The high expression levels of BMP6 in the ovary as well as at early embryonic stages indicated that the maternally stored transcripts of bmp6 might play a role in early embryonic development. Whole-mount in situ hybridization showed that bmp6 and bmp7 exhibited similar spatial expression patterns. Both bmp6 and bmp7 signals were first detected in the head and anterior regions in newly hatched larvae, and then, the mRNAs appeared in the crown-like larval fin, jaw, operculum and fins (pectoral, dorsal, pelvic and anal) along with early development. Subsequently, we characterized the 5'-flanking regions of bmp6 and bmp7 by testing the promoter activity by luciferase reporter assays. Positive regulatory regions were, respectively, detected at the location of -272 to +28 and -740 to -396 in bmp6 and bmp7 gene. The predicted transcription factor binding sites (CREB, AP1 and methyl-CpG-binding protein) in the regions might participate in the transcriptional regulation of these two genes.

Complications Associated With Bone Morphogenetic Protein in the Lumbar Spine

Complications associated with the use of recombinant human bone morphogenetic protein in the lumbar spine include retrograde ejaculation, ectopic bone formation, vertebral osteolysis and subsidence, postoperative radiculitis, and hematoma and seroma. These complications are controversial and remain widely debated. This article discusses the reported complications and possible implications for the practicing spine surgeon. Understanding the complications associated with the use of recombinant human bone morphogenetic protein and the associated controversies allows for informed decision making by both the patient and the surgeon. [Orthopedics. 2017; 40(2):e229-e237.].

Water temperature induces jaw deformity and bone morphogenetic proteins (BMPs) gene expression in golden pompano Trachinotus ovatus larvae

Golden pompano Trachinotus ovatus larvae were kept at 26, 29 and 33 °C for 15 days from 3-day post hatching (DPH) to 18 DPH to test temperature-dependent growth and jaw malformation. The growth, survival, jaw deformity and the gene expressions of bone morphogenetic proteins (BMPs) were used as criteria to examine the fish response to temperature manipulation. The growth rate of fish at 29 or 33 °C was significantly faster than fish at 26 °C, while fish survival at 29 °C was significantly higher than fish at 33 °C. Jaw deformity was significantly affected by water temperature. The highest jaw deformity occurred on fish at 33 °C, and the lowest jaw deformity was at 26 °C. The expressions of all BMP genes except BMP10 were significantly affected by water temperature. The highest gene expression of BMP2 was on fish at 29 °C, and the lowest expression was at 33 °C. For the BMP4 gene, the highest and lowest expressions were found on fish at 33 and 26 °C, respectively. The present study indicates that jaw deformity of golden pompano larvae increases with increasing temperature, and the gene expression of BMP4 proteins coincides with high jaw deformity and water temperature elevation.

Bone mesenchymal stem cell-conditioned medium induces the upregulation of Smad6, which inhibits the BMP-4/Smad1/5/8 signaling pathway

OBJECTIVES

In this study, we aimed to investigate the effect of bone mesenchymal stem cells (BMSCs) conditioned medium on BMP4-induced activation of the Smad signaling pathway during the process of neural stem cells differentiation.

METHODS

We designed four experimental groups: (A) control group, (B) BMP-4 treatment group, (C) BMSC-CM group, and (D) BMSC-CM (BMSC-conditioned medium) combined with BMP-4 group. The expression of microtube-associated protein-2 (MAP-2) detected by immunocytochemical staining and western blot. The expression of glial fibrillary acidic protein (GFAP) and BMP receptors (BMPRII and BMPRIa) was determined by western blot, while SMAD1/5/8 and SMAD6 mRNA expression was detected by quantitative real-time polymerase chain reaction (Q-RT-PCR).

RESULTS

We found that the expression of microtube-associated protein-2 (MAP-2) increased in group B compared to group A. In group C, the expression of GFAP was increased and the expression of MAP-2 was decreased compared to group A. This phenomenon was weaker in group D. We also demonstrated that BMSC-CM could inhibit the activation of BMP signaling by downregulating the expression of BMPRII and BMPRIa proteins. Moreover, BMSC-CM could upregulate the expression of Smad6 mRNA and inhibit the activation of Smad1/5/8 mRNA.

CONCLUSION

These observations suggest that BMSC-CM could neutralize the effect of BMP-4 on the differentiation of NSCs by upregulating the expression of Smad6 and decrease the expression of GFAP by inhibiting the BMP-4-SMAD1/5/8 signaling pathway, conversely increasing the generation of neurons.

Bone Morphogenetic Protein 4 Signalling in Neural Stem and Progenitor Cells during Development and after Injury

Substantial progress has been made in identifying the extracellular signalling pathways that regulate neural stem and precursor cell biology in the central nervous system (CNS). The bone morphogenetic proteins (BMPs), in particular BMP4, are key players regulating neuronal and glial cell development from neural precursor cells in the embryonic, postnatal, and injured CNS. Here we review recent studies on BMP4 signalling in the generation of neurons, astrocytes, and oligodendroglial cells in the CNS. We also discuss putative mechanisms that BMP4 may utilise to influence glial cell development following CNS injury and highlight some questions for further research.