Tafa-2 plays an essential role in neuronal survival and neurobiological function in mice

FAM19A5 in vascular aging and osteoporosis: Mechanisms and the "calcification paradox"

Aging induces a progressive decline in the vasculature's structure and function. Vascular aging is a determinant factor for vascular ailments in the elderly. FAM19A5, a recently identified adipokine, has demonstrated involvement in multiple vascular aging-related pathologies, including atherosclerosis, cardio-cerebral vascular diseases and cognitive deficits. This review summarizes the current understanding of FAM19A5' role and explores its putative regulatory mechanisms in various aging-related disorders, including cardiovascular diseases (CVDs), metabolic diseases, neurodegenerative diseases and malignancies. Importantly, we provide novel insights into the underlying therapeutic value of FAM19A5 in osteoporosis. Finally, we outline future perspectives on the diagnostic and therapeutic potential of FAM19A5 in vascular aging-related diseases.

Postnatal maternal care moderates the effects of prenatal bisphenol exposure on offspring neurodevelopmental, behavioral, and transcriptomic outcomes

Bisphenols (BP), including BPA and "BPA-free" structural analogs, are commonly used plasticizers that are present in many plastics and are known endocrine disrupting chemicals. Prenatal exposure to BPA has been associated with negative neurodevelopmental and behavioral outcomes in children and in rodent models. Prenatal BPA exposure has also been shown to impair postnatal maternal care provisioning, which can also affect offspring neurodevelopment and behavior. However, there is limited knowledge regarding the biological effects of prenatal exposure to bisphenols other than BPA and the interplay between prenatal bisphenol exposure and postnatal maternal care on adult behavior. The purpose of the current study was to determine the interactive impact of prenatal bisphenol exposure and postnatal maternal care on neurodevelopment and behavior in rats. Our findings suggest that the effects of prenatal bisphenol exposure on eye-opening, adult attentional set shifting and anxiety-like behavior in the open field are dependent on maternal care in the first five days of life. Interestingly, maternal care might also attenuate the effects of prenatal bisphenol exposure on eye opening and adult attentional set shifting. Finally, transcriptomic profiles in male and female medial prefrontal cortex and amygdala suggest that the interactive effects of prenatal bisphenol exposure and postnatal maternal care converge on estrogen receptor signaling and are involved in biological processes related to gene expression and protein translation and synthesis. Overall, these findings indicate that postnatal maternal care plays a critical role in the expression of the effects of prenatal bisphenol exposure on neurodevelopment and adult behavior. Understanding the underlying biological mechanisms involved might allow us to identify potential avenues to mitigate the adverse effects of prenatal bisphenol exposure and improve health and well-being in human populations.

The origin, evolution, and molecular diversity of the chemokine system

Chemokine signalling performs key functions in cell migration via chemoattraction, such as attracting leukocytes to the site of infection during host defence. The system consists of a ligand, the chemokine, usually secreted outside the cell, and a chemokine receptor on the surface of a target cell that recognises the ligand. Several noncanonical components interact with the system. These include a variety of molecules that usually share some degree of sequence similarity with canonical components and, in some cases, are known to bind to canonical components and/or to modulate cell migration. Whereas canonical components have been described in vertebrate lineages, the distribution of the noncanonical components is less clear. Uncertainty over the relationships between canonical and noncanonical components hampers our understanding of the evolution of the system. We used phylogenetic methods, including gene-tree to species-tree reconciliation, to untangle the relationships between canonical and noncanonical components, identify gene duplication events, and clarify the origin of the system. We found that unrelated ligand groups independently evolved chemokine-like functions. We found noncanonical ligands outside vertebrates, such as TAFA "chemokines" found in urochordates. In contrast, all receptor groups are vertebrate-specific and all-except ACKR1-originated from a common ancestor in early vertebrates. Both ligand and receptor copy numbers expanded through gene duplication events at the base of jawed vertebrates, with subsequent waves of innovation occurring in bony fish and mammals.

Neuronal survival factor TAFA2 suppresses apoptosis through binding to ADGRL1 and activating cAMP/PKA/CREB/BCL2 signaling pathway

AIMS

TAFA2, a cytokine specifically expressed in the central nervous system, plays a vital role in neuronal cell survival. TAFA2 deficiency has been correlated to various neurological disorders in mice and humans. However, the underlying mechanism remains elusive, especially its membrane-binding receptor through which TAFA2 functions. This study aimed to identify the specific binding receptor responsible for the anti-apoptotic effects of TAFA2.

MAIN METHOD

Co-immunoprecipitation (Co-IP) and quantitative mass spectrometry-based proteomic analysis were employed to identify potential TAFA2 binding proteins in V5 knockin mouse brain lysates. Subsequent validation involved in vitro and in vivo Co-IP and pull-down using specific antibodies. The functional analysis included evaluating the effects of ADGRL1 knockout, overexpression, and Lectin-like domain (Lec) deletion mutant on TAFA2's anti-apoptotic activity and analyzing the intracellular signaling pathways mediated by TAFA2 through ADGRL1.

KEY FINDINGS

Our study identified ADGRL1 as a potential receptor for TAFA2, which directly binds to TAFA2 through its lectin-like domain. Overexpression ADGRL1, but not ADGRL1ΔLec, induced apoptosis, which could be effectively suppressed by recombinant TAFA2 (rTAFA2). In ADGRL1-/- cells or re-introducing with ADGRL1ΔLec, responses to rTAFA2 in suppressing cell apoptosis were compromised. Increased cAMP, p-PKA, p-CREB, and BCL2 levels were also observed in response to rTAFA2 treatment, with these responses attenuated in ADGRL1-/- or ADGRL1ΔLec-expressing cells.

SIGNIFICANCE

Our results demonstrated that TAFA2 directly binds to the lectin-like domain of ADGRL1, activating cAMP/PKA/CREB/BCL2 signaling pathway, which is crucial in preventing cell death. These results implicate TAFA2 and its receptor ADGRL1 as potential therapeutic targets for neurological disorders.

Postnatal maternal care moderates the effects of prenatal bisphenol exposure on offspring neurodevelopmental, behavioral, and transcriptomic outcomes

Bisphenols (BPs), including BPA and "BPA-free" structural analogs, are commonly used plasticizers that are present in many plastics and are known endocrine disrupting chemicals. Prenatal exposure to BPA has been associated with negative neurodevelopmental and behavioral outcomes in children and rodent models. Prenatal BPA exposure has also been shown to impair postnatal maternal care provisioning, which can also affect offspring neurodevelopment and behavior. However, there is limited knowledge regarding the biological effects of prenatal exposure to bisphenols other than BPA and the interplay between prenatal BP exposure and postnatal maternal care on adult behavior. The purpose of the current study was to determine the interactive impact of prenatal BP exposure and postnatal maternal care on neurodevelopment and behavior. Our findings suggest that the effects of prenatal BP exposure on eye-opening, adult attentional set shifting and anxiety-like behavior in the open field are dependent on maternal care in the first five days of life. Interestingly, maternal care might also attenuate the effects of prenatal BP exposure on eye opening and adult attentional set shifting. Finally, transcriptomic profiles in male and female medial prefrontal cortex and amygdala suggest that the interactive effects of prenatal BP exposure and postnatal maternal care converge on estrogen receptor signaling and are involved in biological processes related to gene expression and protein translation and synthesis. Overall, these findings indicate that postnatal maternal care plays a critical role in the expression of the effects of prenatal BP exposure on neurodevelopment and adult behavior. Understanding the underlying biological mechanisms involved might allow us to identify potential avenues to mitigate the adverse effects of prenatal BP exposure and improve health and well-being in human populations.

Molecular Structure, Expression and Role of TAFA4 and its Receptor FPR1 in the Spinal Cord

TAFA chemokine like family member 4 (TAFA4, also named FAM19A4) is a member of the TAFA chemokine like ligand or FAM19A family, which includes TAFA1, TAFA2, TAFA3, TAFA4, and TAFA5 (or FAM19A1, FAM19A2, FAM19A3, FAM19A4, and FAM19A5). They are also referred to as neurokines and are involved in the regulation of a diverse range of cellular processes, including chemotaxis of macrophages, phagocytosis, and release of reactive oxygen species (ROS). TAFA4 is a marker of C-low-threshold mechanoreceptors and is expressed predominantly in nociceptors, such as dorsal root ganglia (DRG). TAFA4 has been implicated in the sensory perception of pain in the spinal cord. Mice with deficiency of TAFA4 demonstrate altered excitability in lamina IIi neurons in DRG in addition to increased mechanical and chemical nociception following inflammation or injury. As a secreted protein, TAFA4 binds to cell surface receptor formyl peptide receptor 1 (FPR1), a G protein-coupled receptor to mediate the chemoattraction of macrophages, phagocytosis, and the inflammatory profile of macrophages. It also interacts with cell surface neurexin to mediate signalling across the synapse. Further understanding the mechanisms by which this conserved protein family regulates diverse biological processes such as in neuronal functions, inflammation, and tissue fibrosis will help to design therapeutic targets for the treatment of TAFA related diseases such as spinal cord injury and neuro-inflammatory disorders.

Peptide ligands targeting FGF receptors promote recovery from dorsal root crush injury via AKT/mTOR signaling

Background: Fibroblast growth factor receptors (FGFRs) are key targets for nerve regeneration and repair. The therapeutic effect of exogenous recombinant FGFs in vivo is limited due to their high molecular weight. Small peptides with low molecular weight, easy diffusion, low immunogenicity, and nontoxic metabolite formation are potential candidates. The present study aimed to develop a novel low-molecular-weight peptide agonist of FGFR to promote nerve injury repair.

Methods: Phage display technology was employed to screen peptide ligands targeting FGFR2. The peptide ligand affinity for FGFRs was detected by isothermal titration calorimetry. Structural biology-based computer virtual analysis was used to characterize the interaction between the peptide ligand and FGFR2. The peptide ligand effect on axon growth, regeneration, and behavioral recovery of sensory neurons was determined in the primary culture of sensory neurons and dorsal root ganglia (DRG) explants in vitro and a rat spinal dorsal root injury (DRI) model in vivo. The peptide ligand binding to other membrane receptors was characterized by surface plasmon resonance (SPR) and liquid chromatography-mass spectrometry (LC-MS)/MS. Intracellular signaling pathways primarily affected by the peptide ligand were characterized by phosphoproteomics, and related pathways were verified using specific inhibitors.

Results: We identified a novel FGFR-targeting small peptide, CH02, with seven amino acid residues. CH02 activated FGFR signaling through high-affinity binding with the extracellular segment of FGFRs and also had an affinity for several receptor tyrosine kinase (RTK) family members, including VEGFR2. In sensory neurons cultured in vitro, CH02 maintained the survival of neurons and promoted axon growth. Simultaneously, CH02 robustly enhanced nerve regeneration and sensory-motor behavioral recovery after DRI in rats. CH02-induced activation of FGFR signaling promoted nerve regeneration primarily via AKT and ERK signaling downstream of FGFRs. Activation of mTOR downstream of AKT signaling augmented axon growth potential in response to CH02.

Conclusion: Our study revealed the significant therapeutic effect of CH02 on strengthening nerve regeneration and suggested a strategy for treating peripheral and central nervous system injuries.

Baicalin ameliorates chronic unpredictable mild stress-induced depression through the BDNF/ERK/CREB signaling pathway

Brain-derived neurotrophic factor (BDNF) can activate the extracellular regulated protein kinase (ERK)/cAMP response element binding protein (CREB) cascade revealing an important role in antidepressant effects. Here, we studied the neuroprotective effect of baicalin (BA) in mice with chronic unpredictable mild stress (CUMS)-induced via a BDNF/ERK/CREB signaling pathway. Depression was induced via six weeks of CUMS in male ICR mice, and drug therapy was given simultaneously for the last three weeks. Cognitive dysfunctions were then evaluated via sucrose preference test (SPT), open field test (OFT), Morris water maze test (MWM), tail suspension test (TST), and novelty suppressed feeding test (NSF). Western blot and real-time PCR were then used to detect the relative expression of ERK, CREB, p-ERK, and p-CREB. Integrated optical density (IOD) tests of p-ERK and p-CREB were then evaluated via immunofluorescence. The behavior results showed that the cognitive dysfunctions increased in the CUMS group versus the control (CON) group (p < 0.01). There were decreases in fluoxetine (FLU) and BA groups (p < 0.05, p < 0.01). The protein ratios of p-ERK/ERK, p-CREB/CREB and ERK mRNA, and CREB mRNA expression decreased in the CUMS group (p < 0.01) and markedly increased in the FLU and BA groups (p < 0.05, p < 0.01). The IOD value of the p-ERK and p-CREB in the CUMS group was decreased versus the CON group (p < 0.01), and these changes were improved via BA and FLU treatment (p < 0.05, p < 0.01). This study indicated that BA can improve cognitive functions and has antidepressant effects in mice, which may be associated with activation of the BDNF/ERK/CREB signaling pathway in the hippocampus.

FAM19A5/TAFA5, a novel neurokine, plays a crucial role in depressive-like and spatial memory-related behaviors in mice

FAM19A5/TAFA5 is a member of the family with sequence similarity 19 with unknown function in emotional and cognitive regulation. Here, we reported that FAM19A5 was highly expressed in the embryonic and postnatal mouse brain, especially in the hippocampus. Behaviorally, genetic deletion of Fam19a5 resulted in increased depressive-like behaviors and impaired hippocampus-dependent spatial memory. These behavioral alterations were associated with the decreased expression of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors and N-methyl-D-aspartic acid receptors, as well as significantly reduced glutamate release and neuronal activity in the hippocampus. Subsequently, these changes led to the decreased density of dendritic spines. In recent years, the roles of chronic stress participating in the development of depression have become increasingly clear, but the mechanism remains to be elucidated. We found that the levels of FAM19A5 in plasma and hippocampus of chronic stress-treated mice were significantly decreased whereas overexpression of human FAM19A5 selectively in the hippocampus could attenuate chronic stress-induced depressive-like behaviors. Taken together, our results revealed for the first time that FAM19A5 plays a key role in the regulation of depression and spatial cognition in the hippocampus. Furthermore, our study provided a new mechanism for chronic stress-induced depression, and also provided a potential biomarker for the diagnosis and a new strategy for the treatment of depression.

FAM19A (TAFA): An Emerging Family of Neurokines with Diverse Functions in the Central and Peripheral Nervous System

Cytokines and chemokines have diverse and pleiotropic functions in peripheral tissues and in the brain. Recent studies uncovered a novel family of neuron-derived secretory proteins, or neurokines, distantly related to chemokines. The FAM19A family comprises five ∼12-15 kDa secretory proteins (FAM19A1-5), also known as TAFA1-5, that are predominantly detected in the central and peripheral nervous system. FAM19A expression in the central nervous system is dynamically regulated during development and in the postnatal brain. As secreted ligands, FAM19A proteins appear to bind to different classes of cell surface receptors (e.g., GPCRs and neurexins). Functional studies using gain- and loss-of-function mouse models established nonredundant roles for each FAM19A family member in regulating diverse physiological processes ranging from locomotor activity and food intake to learning and memory, anxiety- and depressive-like behaviors, social communication, repetitive behaviors, and somatosensory functions. This review summarizes major advances as well as the limitations and knowledge gaps in understanding the regulation and diverse biological functions of this conserved family of neurokines.

The high frequency of chromosomal copy number variations and candidate genes in epilepsy patients

OBJECTIVE

Epilepsy is a chronic brain disease and is estimated to affect more than 50 million people worldwide.Epilepsy is a polygenic and multifactorial disease.Genetic causes play a major role in 40-60 % of all epilepsies.Copy number variations(CNVs) have been reported in approximately 5-12 % of patients with different types of epilepsy.Here we aimed to determine the diagnostic yield of the aCGH in epilepsy and to reveal new candidate genes and CNVs by analyzing aCGH data retrospectively.

METHODS

The clinical data of 80 patients with the diagnosis of epilepsy were examined retrospectively and the raw data of aCGH of these patients were reanalyzed in the light of current literature.

RESULTS

Pathogenic/likely pathogenic CNVs were detected in 14 of 80 patients and 12 of these CNVs (15 %) were associated with epilepsy phenotype. In addition, 18 CNVs in 16 different chromosomal loci that were evaluated as the variant of unknown clinical significance(VOUS). In four cases (5%), CNVs associated with epilepsy were less than 100 kb and these accounted for 13.3 % of all epilepsy associated CNVs.

CONCLUSION

The diagnostic yield of aCGH in epilepsy patients was found to be higher than most studies in the literature. MACROD2,ADGRB3(BAI3),SOX8,HIP1,PARK2 and TAFA2 genes were evaluated as potential epilepsy-related genes and NEDD9,RASAL2 and TNR genes thought to be the candidate genes for epilepsy. Our study showed that the diagnostic efficiency of aCGH in epilepsy is high and with more comprehensive studies, it will contribute to the elucidation of genes involved in genetic etiology in epilepsy patients.

Association of Serum FAM19A5 with Cognitive Impairment in Vascular Dementia

Objective

Family with sequence similarity 19 member A5 (FAM19A5), a novel chemokine-like peptide, is a secreted protein mainly expressed in the brain. FAM19A5 was recently found to be involved in a variety of neurological diseases; however, its correlation with vascular dementia (VaD) remains unclear. The aim of the study is to explore the association between serum FAM19A5 and cognitive impairment in subjects with VaD.

Method

136 VaD subjects and 81 normal controls were recruited in the study. Their demographic and clinical baseline data were collected on admission. All subjects received Mini-Mental State Examination (MMSE) evaluation, which was used to test their cognitive functions. A sandwich enzyme-linked immunosorbent assay (ELISA) was applied to detect the serum levels of FAM19A5.

Results

No significant differences were found between the two groups regarding the demographic and clinical baseline data (p > 0.05). The serum FAM19A5 levels were significantly higher compared to normal controls (p < 0.001). The Spearman correlation analysis indicated that serum FAM19A5 levels and MMSE scores have a significant negative correlation in VaD patients (r = −0.414, <0.001). Further multiple regression analysis indicated that serum FAM19A5 levels were independent risk predictors for cognitive functions in VaD (β = 0.419, p = 0.031).

Conclusion

The serum FAM19A5 level of VaD patients is significantly increased, which may serve as a biomarker to predict cognitive function of VaD.

The unique expression profile of FAM19A1 in the mouse brain and its association with hyperactivity, long-term memory and fear acquisition

Neurodevelopment and mature brain function are spatiotemporally regulated by various cytokines and chemokines. The chemokine-like neuropeptide FAM19A1 is a member of family with sequence similarity 19 (FAM19), which is predominantly expressed in the brain. Its highly conserved amino acid sequence among vertebrates suggests that FAM19A1 may play important physiological roles in neurodevelopment and brain function. Here we used a LacZ reporter gene system to map the expression pattern of the FAM19A1 gene in the mouse brain. The FAM19A1 expression was observed in several brain regions starting during embryonic brain development. As the brain matured, the FAM19A1 expression was detected in the pyramidal cells of cortical layers 2/3 and 5 and in several limbic areas, including the hippocampus and the amygdala. FAM19A1-deficient mice were used to evaluate the physiological contribution of FAM19A1 to various brain functions. In behavior analysis, FAM19A1-deficient mice exhibited several abnormal behaviors, including hyperactive locomotor behavior, long-term memory deficits and fear acquisition failure. These findings provide insight into the potential contributions of FAM19A1 to neurodevelopment and mature brain function.

FAM19A1, a brain-enriched and metabolically responsive neurokine, regulates food intake patterns and mouse behaviors

Cytokines and chemokines play diverse roles in different organ systems. Family with sequence similarity 19, member A1-5 (FAM19A1-A5; also known as TAFA1-5) is a group of conserved chemokine-like proteins enriched in the CNS of mice and humans. Their functions are only beginning to emerge. Here, we show that the expression of Fam19a1-a5 in different mouse brain regions are induced or suppressed by unfed and refed states. The striking nutritional regulation of Fam19a family members in the brain suggests a potential central role in regulating metabolism. Using a knockout (KO) mouse model, we show that loss of FAM19A1 results in sexually dimorphic phenotypes. In male mice, FAM19A1 deficiency alters food intake patterns during the light and dark cycle. Fam19a1 KO mice are hyperactive, and locomotor hyperactivity is more pronounced in female KO mice. Behavior tests indicate that Fam19a1 KO female mice have reduced anxiety and sensitivity to pain. Spatial learning and exploration, however, is preserved in Fam19a1 KO mice. Altered behaviors are associated with elevated norepinephrine and dopamine turnover in the striatum. Our results establish an in vivo function of FAM19A1 and highlight central roles for this family of neurokines in modulating animal physiology and behavior.-Lei, X., Liu, L., Terrillion, C. E., Karuppagounder, S. S., Cisternas, P., Lay, M., Martinelli, D. C., Aja, S., Dong, X., Pletnikov, M. V., Wong, G. W. FAM19A1, a brain-enriched and metabolically responsive neurokine, regulates food intake patterns and mouse behaviors.

TAFA5 promotes proliferation and migration in gastric cancer

TAFA chemokine like family member 5 (TAFA5), a TAFA family member that encodes small secreted proteins in the central nervous system, has been demonstrated to have increased expression in human malignancies. However, the expression and function of TAFA5 in gastric cancer (GC) remains unclear. In the present study, public datasets and human GC samples were used to determine the TAFA5 expression levels. The results revealed that TAFA5 was upregulated in GC when compared with adjacent normal tissues. Overexpression of TAFA5 in GC was associated with poor differentiation, and worse tumor, nodal and metastasis stages. In addition, high TAFA5 expression was correlated with unfavorable patient prognoses. In vitro experiments indicated that downregulation of TAFA5 inhibited the proliferation and migration of GC cell lines. Finally, the results from gene set enrichment analysis using data from The Cancer Genome Atlas revealed that TAFA5 expression was significantly correlated with genes associated with epithelial-mesenchymal transition, which was further confirmed by western blot analysis. In conclusion, the results of the present study suggested that TAFA5 had significant effects on GC progression, suggesting that it may serve as a potential therapeutic target for GC therapy.