Intracellular magnesium optimizes transmission efficiency and plasticity of hippocampal synapses by reconfiguring their connectivity.

Synapses at dendritic branches exhibit specific properties for information processing. However, how the synapses are orchestrated to dynamically modify their properties, thus optimizing information processing, remains elusive. Here, we observed at hippocampal dendritic branches diverse configurations of synaptic connectivity, two extremes of which are characterized by low transmission efficiency, high plasticity and coding capacity, or inversely. The former favors information encoding, pertinent to learning, while the latter prefers information storage, relevant to memory. Presynaptic intracellular Mg2+ crucially mediates the dynamic transition continuously between the two extreme configurations. Consequently, varying intracellular Mg2+ levels endow individual branches with diverse synaptic computations, thus modulating their ability to process information. Notably, elevating brain Mg2+ levels in aging animals restores synaptic configuration resembling that of young animals, coincident with improved learning and memory. These findings establish intracellular Mg2+ as a crucial factor reconfiguring synaptic connectivity at dendrites, thus optimizing their branch-specific properties in information processing.

CRISPR/Cas9-based toolkit for rapid marker recycling and combinatorial libraries in Komagataella phaffii.

Komagataella phaffii, a nonconventional yeast, is increasingly attractive to researchers owing to its posttranslational modification ability, strict methanol regulatory mechanism, and lack of Crabtree effect. Although CRISPR-based gene editing systems have been established in K. phaffii, there are still some inadequacies compared to the model organism Saccharomyces cerevisiae. In this study, a redesigned gRNA plasmid carrying red and green fluorescent proteins facilitated plasmid construction and marker recycling, respectively, making marker recycling more convenient and reliable. Subsequently, based on the knockdown of Ku70 and DNA ligase IV, we experimented with integrating multiple DNA fragments at a single locus. A 26.5-kb-long DNA fragment divided into 11 expression cassettes for lycopene synthesis could be successfully integrated into a single locus at one time with a success rate of 57%. A 27-kb-long DNA fragment could also be precisely knocked out with a 50% positive rate in K. phaffii by introducing two DSBs simultaneously. Finally, to explore the feasibility of rapidly balancing the expression intensity of multiple genes in a metabolic pathway, a yeast combinatorial library was successfully constructed in K. phaffii using lycopene as an indicator, and an optimal combination of the metabolic pathway was identified by screening, with a yield titer of up to 182.73 mg/L in shake flask fermentation. KEY POINTS: • Rapid marker recycling based on the visualization of a green fluorescent protein • One-step multifragment integration and large fragment knockout in the genome • A random assembly of multiple DNA elements to create yeast libraries in K. phaffii.

Construction and stable gene expression of AGR2xPD1 bi-specific antibody that enhances attachment between T-Cells and lung tumor cells, suppress tumor cell migration and promoting CD8 expression in cytotoxic T-cells.

There has been a substantial and consistent rise in the number of clinical trials to develop advanced and potent bispecific antibodies (BsAb) over the past two decades with multiple targets to improve the efficacy or tissue specificity of monoclonal antibodies (mAb) treatment for diseases with multiple determining factors or widely-expressed targets. In this study, we designed and synthesized BsAb AGR2xPD1 targeting extracellular AGR2, a paracrine signal, and PD1, an immune checkpoint protein. Our design is intended to use AGR2 binding to guide PD1 targeting for AGR2+cancer. We used this construction to produce AGR2xPD1 BsAb by generating clonally selected stable 293F cell line with high expression. Applying this BsAb in a T cell-Tumor cell co-culture system showed that targeting both PD1 and AGR2 with this BsAb induces the attachment of TALL-104 (CD8+ T-lymphocytes) cells onto co-cultured H460 AGR2+ Lung tumor cells and significantly reduces migration of H460 cells. T-cell expression of CD8 and IFNγ is also synergistically enhanced by the AGR2xPD1 BsAb treatment in the AGR2+H460 co-culture system. These effects are significantly reduced with AGR2 expression negative WI38 cells. Our results demonstrate that the AGR2xPD1 BsAb could be a potential therapeutic agent to provide better solid tumor targeting and synergetic efficacy for treating AGR2+ cancer by blocking AGR2 paracrine signaling to reduce tumor survival, and redirecting cytotoxic T-cells into AGR2+ cancer cells.

A high efficient FVIII variant corrects bleeding in hemophilia A mouse model.

Hemophilia A is a bleeding disorder caused by quantitative or qualitative deficiencies in coagulation factor VIII (FVIII). Low FVIII expression due to its unstable mRNA and binding with immunoglobulin-binding protein (BiP) compromises gene therapy endeavors in hemophilia A. Site-directed mutagenesis have demonstrated an improvement in the expression of FVIII proteins. In this study, a targeted point mutation of Pro at position 290 to Thr (P290T) enhances the in vitro specific activity of B-domain-deleted factor VIII (BDD-FVIII). Hydrodynamic gene delivery of P290T cDNA into FVIII-deficient (FVIII-/-) mice corrected bleeding symptoms. P290T variant resulted in high plasma FVIII coagulant activity 24 h post-gene delivery. Furthermore, bleeding time and average blood loss was significantly reduced in FVIII-/- mice injected with P290T variant, whereas BDD-FVIII and PBS-injected mice experienced prolonged bleeding and excessive blood loss. Histological analysis of the liver biopsies revealed no apparent signs of liver damage. No signs of potential toxicity were seen in mice following mice bodyweights assessment. Altogether, our results demonstrate that the introduction of P290T mutation increases both in vitro and in vivo FVIII coagulant activity, supporting ongoing efforts to develop more effective replacement therapy for hemophilia A.

MoS2/LaF3 for enhanced photothermal therapy performance of poorly-differentiated hepatoma.

Photothermal therapy (PTT) based on nanoparticle had been widely used to antitumor treatment. However, low photothermal conversion efficiency (PCE) is the main hurdle for antitumor treatment. To improve the PCE and gain ideal clinical the nanoparticle with higher photothermal conversion efficiency, we have developed a highly efficient solar absorber with MoS2/LaF3/ polydimethylsiloxane(PDMS) which can enhance the absorption of solar irradiation engergy, however, its photothermal effect irradiated by near-infrared light has not yet been investigated. The knowledge absence in photothermal effect will impede MoS2/LaF3/PDMS to be used for cancer therapy in clinic. In this study, we applied LaF3-loaded, MoS2-based photothermal conversion agents (PTAs) for improved photothermal cancer therapy. The study showed that the MoS2/LaF3 nanoflowers showed higher photothermal conversion efficiency (PCE, 42.5%) and could more effectively inhibit cancer cell proliferation compared to MoS2-based PTT agents in vitro. In vivo, the results further revealed that photothermal therapy using MoS2/LaF3 nanoflowers could significantly inhibit solid tumor growth. The study clearly demonstrated that MoS2/LaF3 could work at under low power NIR Laser in vitro and in vivo, resulting in a very impressive therapeutic effect in tumor-bearing mice. The MoS2/LaF3 nanoflowers will be prominent candidate nanoparticle for effective inhibiting tumor growth by photothermal therapy.

Extracellular AGR2 activates neighboring fibroblasts through endocytosis and direct binding to ß-catenin that requires AGR2 dimerization and adhesion domains.

Anterior gradient 2 (AGR2) is often overexpressed in several types of cancer. AGR2 is cytoplasmic or secreted as an extracellular signal. Intracellular AGR2 properties and role in cancer have been well studied, but its extracellular function is largely unclear. It has been shown that extracellular AGR2 activates endothelial cells and fibroblasts in culture, but the mechanism of AGR2 signaling is not well elucidated. Here, we report that tumor secreted or externally added AGR2 translocates into cytoplasm by endocytosis, binds to ß-catenin and further co-translocates to the nucleus in NIH3T3 fibroblasts. Externally added AGR2 also increased ß-catenin expression, stability, and accumulation in the nucleus in both fibroblasts and cancer cells. External AGR2 rescued the expression of ß-catenin, which was suppressed by EGFR inhibitor AG1478 indicating an alternative pathway to regulate ß-catenin independent of EGFR signal. These effects were abolished when a monoclonal antibody against AGR2 was added to the experiments, confirming the effects are caused by AGR2 only. Putting together, our results show that extracellular AGR2 signaling pathway involves endocytosis mediated cellular translocation, direct binding and regulating ß-catenin nuclear accumulation. It is also a target against tumor initiated AGR2 signaling to form and maintain tumor microenvironment.

Metabolic Engineering of Saccharomyces cerevisiae To Overproduce Squalene.

Squalene has wide applications in the food and pharmaceutical industries. Engineering microbes to produce squalene is a promising alternative for traditional production approaches. In this study, squalene production was enhanced to 978.24 mg/L through stepwise overexpression of the enzymes that catalyze acetyl-CoA to squalene. Subsequently, to increase the activity of HMG-CoA reductase and alleviate the high dependence on NADPH, the HMG-CoA reductase (NADH-HMGR) from Silicibacter pomeroyi, highly specific for NADH, was introduced, which increased squalene production to 1086.31 mg/L. Native ethanol dehydrogenase ADH2 and acetaldehyde dehydrogenase ADA from Dickeya zeae were further overexpressed, which enhanced the capability to utilize ethanol for squalene synthesis and endowed the engineered strain with greater adaptability to high ethanol concentrations. Finally, a remarkable squalene production of 9472 mg/L was obtained from ethanol via carbon source-controlled fed-batch fermentation. This study will greatly accelerate the process of developing microbial cell factories for squalene production.

The yeast peroxisome: A dynamic storage depot and subcellular factory for squalene overproduction.

Engineering microbes to produce terpenes from renewable feedstock is a promising alternative to traditional production approaches. Generally, terpenes are not readily secreted by microbial cells, and their distribution within cells is usually obscure and often a restricting factor for the overproduction of terpenes due to the storage limitation. Here, we determined that squalene overproduced in the cytoplasm of Saccharomyces cerevisiae was distributed in a form similar to oil droplets. Interestingly, these suspected oil droplets were confirmed to be inflated peroxisomes that were swollen along with the production of squalene, indicating that peroxisomes in S. cerevisiae are dynamic depots for the storage of squalene. In view of this, harnessing peroxisomes as subcellular compartments for squalene synthesis was performed, achieving a 138-fold improvement in squalene titer (1312.82 mg/L) relative to the parent strain, suggesting that the peroxisome of S. cerevisiae is an efficient subcellular factory for the synthesis of terpenes. By dual modulation of cytoplasmic and peroxisomal engineering, the squalene titer was further improved to 1698.02 mg/L. After optimizing a two-stage fed-batch fermentation method, the squalene titer reached 11.00 g/L, the highest ever reported. This provides new insight into the synthesis and storage of squalene in peroxisomes and reveals the potential of harnessing peroxisomes to overproduce terpenes in S. cerevisiae through dual cytoplasmic-peroxisomal engineering.

A Direct Quantitative Analysis of Erythrocyte Intracellular Ionized Magnesium in Physiological and Pathological Conditions.

Magnesium (Mg2+) is an endogenous cation that is involved in many essential biological reactions. Abnormal Mg2+ metabolisms in the body affect important physiological and pathological processes. However, most endogenous Mg2+ markers fail to represent body Mg2+ status; they are disadvantageous in terms of representational capacity, applied range, operational convenience, etc. In this article, we evaluated some of the most popular Mg2+ marker candidates. A logical model of the blood Mg2+ compartments was established, which consisted of unstable Mg2+ pools, representative Mg2+ pools, and conserved Mg2+ pools. These pools were based on the metabolic efficiency of Mg2+ in an acute Mg2+ intake test. The results of this study showed that only the erythrocyte intracellular ionized Mg2+ (RBC [Mg2+]i), a representative Mg2+ pool, could effectively represent abnormal body Mg2+ metabolisms in various conditions, including dietary Mg2+ adjustments, aging and metabolic syndrome. These results suggest that RBC [Mg2+]i might be a widely applicable marker of body Mg2+ levels. On unified technology platform and evaluation system, this research compared the representative capacities of RBC [Mg2+]i, plasma Mg2+ concentration (plasma [Mg2+]), erythrocyte intracellular total Mg (RBC [Mg]total) and Mg retention in rats and mice under various Mg2+-metabolism-related physiological and pathological conditions. Our technique for the direct quantitative analysis of RBC [Mg2+]i may prove valuable for basic physiological research, dietary Mg2+ regulation, as well as clinical monitoring/intervention of Mg2+-metabolism-related pathology.

MAGT1-mediated disturbance of Mg2+ homeostasis lead to exhausted of HBV-infected NK and CD8+ T cells.

The magnesium transporter 1 (MAGT1) is a critical regulator of basal intracellular free magnesium ([Mg2+]i) levels. It has been shown that MAGT1 was involved in the disorder in Mg2+ homeostasis after Epstein-Barr virus (EBV) infection. Here, we identified the effects of MAGT1-mediated disturbance of Mg2+ homeostasis on chronic hepatitis B virus (HBV)-infected natural killer (NK) and CD8+ T cells. The expression of MAGT1 was gradually decreased with the increase of infected time in CD8+ T cells, but not with that in NK cells, of the patients. Decreased level of intracellular free Mg2+ ([Mg2+]i) leads to defective expression of programmed cell death 1 (PD-1) and the NK activating receptor (NKG2D) in NK and CD8+ T cells. Our data illustrate that [Mg2+]i plays a key role in control of HBV infection.

Novel Application of Magnetic Protein: Convenient One-Step Purification and Immobilization of Proteins.

Recently, a magnetic protein was discovered, and a multimeric magnetosensing complex was validated, which may form the basis of magnetoreception. In this study, the magnetic protein was firstly used in biotechnology application, and a novel convenient one-step purification and immobilization method was established. A universal vector and three linker patterns were developed for fusion expression of magnetic protein and target protein. The magnetic protein was absorbed by iron beads, followed by target protein aggregation, purification, and immobilization. GFP, employed as a reporter protein, was successfully purified from cell lysate. Subsequently, three enzymes (lipase, α-L-arabinofuranosidase, pullulanase) with different molecular sizes testified the versatility of this magnetic-based approach. The specific activities of the purified enzymes were distinctly higher than those of the traditionally purified enzymes using affinity chromatography. The lipase immobilized on iron beads presented improved thermostability and enhanced pH tolerance compared to the free enzyme. The immobilized lipase could be easily recovered and reused for maximum utilization. After 20 cycles of reutilization, the magnetically immobilized lipase retained 71% of its initial activity. This investigation may help introduce magnetic protein into biotechnology applications, and the one-step purification and immobilization method may serve to illustrate an economically viable process for industry.

Oral Application of Magnesium-L-Threonate Attenuates Vincristine-induced Allodynia and Hyperalgesia by Normalization of Tumor Necrosis Factor-α/Nuclear Factor-κB Signaling.

BACKGROUND: Antineoplastic agents, including vincristine, often induce neuropathic pain and magnesium deficiency clinically, but the causal link between them has not been determined. No drug is available for treating this form of neuropathic pain. METHODS: Injection of vincristine (0.1 mg · kg · day, intraperitoneally, for 10 days) was used to induce nociceptive sensitization, which was accessed with von Frey hairs and the plantar tester in adult male Sprague-Dawley rats. Magnesium-L- threonate was administered through drinking water (604 mg · kg · day). Extracellular and intracellular free Mg were measured by Calmagite chromometry and flow cytometry. Molecular biologic and electrophysiologic experiments were performed to expose the underlying mechanisms. RESULTS: Vincristine injection induced allodynia and hyperalgesia (n = 12), activated tumor necrosis factor-α/nuclear factor-κB signaling, and reduced free Mg in cerebrospinal fluid by 21.7 ± 6.3% (mean ± SD; n = 13) and in dorsal root ganglion neurons by 27 ± 6% (n = 11). Reducing Mg activated tumor necrosis factor-α/nuclear factor-κB signaling in cultured dorsal root ganglion neurons. Oral application of magnesium-L-threonate prevented magnesium deficiency and attenuated both activation of tumor necrosis factor-α/nuclear factor-κB signaling and nociceptive sensitization (n = 12). Mechanistically, vincristine induced long-term potentiation at C-fiber synapses, up-regulated N-methyl-D-aspartate receptor type 2B subunit of N-methyl-D-aspartate receptor, and led to peptidergic C-fiber sprouting in spinal dorsal horn (n = 6 each). The vincristine-induced pathologic plasticity was blocked by intrathecal injection of nuclear factor-κB inhibitor (n = 6), mimicked by tumor necrosis factor-α, and substantially prevented by oral magnesium-L-threonate (n = 5). CONCLUSIONS: Vincristine may activate tumor necrosis factor-α/nuclear factor-κB pathway by reduction of intracellular magnesium, leading to spinal pathologic plasticity and nociceptive sensitization. Oral magnesium-L-threonate that prevents the magnesium deficiency is a novel approach to prevent neuropathic pain induced by chemotherapy.

Erythrocyte intracellular Mg(2+) concentration as an index of recognition and memory.

Magnesium (Mg(2+)) plays an important role in the neural system, and yet scarcely any research has quantitatively analyzed the link between endogenous Mg(2+) level and memory. Using our original technique, we measured erythrocyte intracellular ionized Mg(2+) concentration (RBC [Mg(2+)]i), which linearly correlated to recognition and spatial memory in normal aging rats. In the brain, RBC [Mg(2+)]i significantly correlated to hippocampus extracellular fluid Mg(2+) concentration, and further correlated to hippocampal synapse density. Elevation of Mg(2+) intake in aged rats demonstrated an association between RBC [Mg(2+)]i increase and memory recovery. The therapeutic effect of Mg(2+) administration was inversely correlated to individual basal RBC [Mg(2+)]i. In summary, we provide a method to measure RBC [Mg(2+)]i, an ideal indicator of body Mg(2+) level. RBC [Mg(2+)]i represents rodent memory performance in our study, and might further serve as a potential biomarker for clinical differential diagnosis and precise treatment of Mg(2+)-deficiency-associated memory decline during aging.

Regulation of structural and functional synapse density by L-threonate through modulation of intraneuronal magnesium concentration.

Oral administration of the combination of L-threonate (threonate) and magnesium (Mg(2+)) in the form of L-Threonic acid Magnesium salt (L-TAMS) can enhance learning and memory in young rats and prevent memory decline in aging rats and in Alzheimer's disease model mice. Recent results from a human clinical trial demonstrate the efficacy of L-TAMS in restoring global cognitive abilities of older adults. Previously, we reported that neuronal intracellular Mg(2+) serves as a critical signaling molecule for controlling synapse density, a key factor that determines cognitive ability. The elevation of brain Mg(2+) by oral administration of L-TAMS in intact animals plays a significant role in mediating the therapeutic effects of L-TAMS. The current study sought to elucidate the unique role of threonate. We aimed to understand if threonate acts directly to elevate intraneuronal Mg(2+), and why Mg(2+) given without threonate is ineffective for enhancing learning and memory ability. We discovered that threonate is naturally present in cerebrospinal fluid (CSF) and oral treatment with L-TAMS elevated CSF threonate. In cultured hippocampal neurons, threonate treatment directly induced an increase in intracellular Mg(2+) concentration. Functionally, elevating threonate upregulated expression of NR2B-containing NMDAR, boosted mitochondrial membrane potential (ΔΨm), and increased functional synapse density in neuronal cultures. These effects are unique to threonate, as other common Mg(2+) anions failed to have the same results. Mechanistically, threonate's effects were specifically mediated through glucose transporters (GLUTs). We also evaluated the effects of threonate in human neural stem cell-derived neurons, and found it was equally effective at upregulating synapse density. The current study provides an explanation for why threonate is an essential component of L-TAMS and supports the use of L-TAMS to promote cognitive abilities in human.

Efficacy and Safety of MMFS-01, a Synapse Density Enhancer, for Treating Cognitive Impairment in Older Adults: A Randomized, Double-Blind, Placebo-Controlled Trial.

BACKGROUND: Cognitive impairment is a major problem in elderly, affecting quality of life. Pre-clinical studies show that MMFS-01, a synapse density enhancer, is effective at reversing cognitive decline in aging rodents. OBJECTIVE: Since brain atrophy during aging is strongly associated with both cognitive decline and sleep disorder, we evaluated the efficacy of MMFS-01 in its ability to reverse cognitive impairment and improve sleep. METHODS: We conducted a randomized, double-blind, placebo-controlled, parallel-designed trial in older adult subjects (age 50-70) with cognitive impairment. Subjects were treated with MMFS-01 (n = 23) or placebo (n = 21) for 12 weeks and cognitive ability, sleep quality, and emotion were evaluated. Overall cognitive ability was determined by a composite score of tests in four major cognitive domains. RESULTS: With MMFS-01 treatment, overall cognitive ability improved significantly relative to placebo (p = 0.003; Cohen's d = 0.91). Cognitive fluctuation was also reduced. The study population had more severe executive function deficits than age-matched controls from normative data and MMFS-01 treatment nearly restored their impaired executive function, demonstrating that MMFS-01 may be clinically significant. Due to the strong placebo effects on sleep and anxiety, the effects of MMFS-01 on sleep and anxiety could not be determined. CONCLUSIONS: The current study demonstrates the potential of MMFS-01 for treating cognitive impairment in older adults.

The distinct role of NR2B subunit in the enhancement of visual plasticity in adulthood.

BACKGROUND: Experience-dependent plasticity is confined to the critical period of early postnatal life, and declines dramatically thereafter. This attenuation promotes the stabilization of cortical circuits, but also limits functional recovery of several brain diseases. The cognitive functions and synaptic plasticity in the hippocampus and prefrontal cortex are elevated following chronic magnesium treatment. Here, we explored the effect of magnesium treatment on visual plasticity and the potential clinical significance. RESULTS: Visual plasticity in adult mice was dramatically enhanced following magnesium treatment, which was concurrent with an increase in the expression of NR2 subunits of N-methyl-D-aspartate receptors. Blockade of NR2B activity in both the induction and expression periods of plasticity prevented this reinstatement. However, the plasticity restored via a decrease in cortical inhibition was independent on the activation of NR2B, indicating a different underlying mechanism. The functional excitatory synapses on layer 2/3 pyramidal neurons were increased following magnesium supplementation. Moreover, the synaptic and neuronal responses were reminiscent of that within the critical period, and this rejuvenation of adult visual cortex facilitated the recovery of visual functions in amblyopia. CONCLUSIONS: Collectively, our data reveal two distinct mechanisms underlying the restoration of visual plasticity in adulthood, and the rejuvenation of adult visual cortex following magnesium treatment provides a new avenue to develop clinical therapies for adult amblyopia, as well as to explore plasticity-based treatment of other brain diseases, such as stroke and aphasia.

Regulation of density of functional presynaptic terminals by local energy supply.

BACKGROUND: The density of functional synapses is an important parameter in determining the efficacy of synaptic transmission. However, how functional presynaptic terminal density is regulated under natural physiological conditions is still poorly understood. RESULTS: We studied the factors controlling the density of presynaptic functional terminals at single dendritic branches of hippocampal neurons and found that elevation of intracellular Mg(2+) concentration was effective in increasing the density of functional terminals. Interestingly, the upregulation was not due to synaptogenesis, but to the conversion of a considerable proportion of presynaptic terminals from nonfunctional to functional. Mechanistic studies revealed that the nonfunctional terminals had inadequate Ca(2+)-sensitivity-related proteins, resulting in very low Ca(2+) sensitivity within their vesicle release machinery. We identified energy-dependent axonal transport as a primary factor controlling the amount of Ca(2+)-sensitivity-related proteins in terminals. The elevation of intracellular Mg(2+) enhanced local energy supply and promoted the increase of Ca(2+)-sensitivity-related proteins in terminals, leading to increased functional terminal density. CONCLUSIONS: Our study suggests that local energy supply plays a critical role in controlling the density of functional presynaptic terminals, demonstrating the link between energy supply and efficacy of synaptic transmission.

Molecular cloning, characterization, and expression of sheep FGF5 gene.

The fibroblast growth factor 5 gene (FGF5) is a member of the FGF gene family, and represents a candidate gene for hair length because of its role in the regulation of the hair follicle growth cycle. In our current study, we cloned, sequenced, and characterized the full-length FGF5 cDNA of Chinese Merino sheep. We obtained the complete genomic sequence of the FGF5 gene from sheep blood samples, and compared it to other FGF5 sequences in GenBank. We found that the FGF5 gene spanned 21,743bp of genomic DNA, and consisted of 3 exons and 2 introns, both of which differed from those of a previously annotated FGF5 genomic sequence from sheep. We also identified a previously undescribed FGF5 mRNA splicing variant, FGF5S, and the western blot analysis showed that the molecular weights of the FGF5 (34kDa) and FGF5s (17kDa) proteins were consistent with the estimates based on the genomic and cDNA sequence data. We examined the expression of both FGF5 mRNAs in various tissues of sheep, and found that the expression of the FGF5S mRNA was restricted to the brain, spleen, and skin tissue. The single-nucleotide polymorphism analysis of the genomic sequence revealed 72 genetic variants of the FGF5 gene. Our findings provide insight into the functions of the FGF5 gene in Chinese Merino.

Elevation of brain magnesium prevents synaptic loss and reverses cognitive deficits in Alzheimer's disease mouse model.

BACKGROUND: Profound synapse loss is one of the major pathological hallmarks associated with Alzheimer's disease, which might underlie memory impairment. Our previous work demonstrates that magnesium ion is a critical factor in controlling synapse density/plasticity. Here, we tested whether elevation of brain magnesium, using a recently developed compound (magnesium-L-threonate, MgT), can ameliorate the AD-like pathologies and cognitive deficits in the APPswe/PS1dE9 mice, a transgenic mouse model of Alzheimer's disease. RESULTS: MgT treatment reduced Aß-plaque, prevented synapse loss and memory decline in the transgenic mice. Strikingly, MgT treatment was effective even when the treatment was given to the mice at the end-stage of their Alzheimer's disease-like pathological progression. To explore how elevation of brain magnesium ameliorates the AD-like pathologies in the brain of transgenic mice, we studied molecules critical for APP metabolism and signaling pathways implicated in synaptic plasticity/density. In the transgenic mice, the NMDAR signaling pathway was downregulated, while the BACE1 expression were upregulated. MgT treatment prevented the impairment of these signaling pathways, stabilized BACE1 expression and reduced sAPPß and ß-CTF in the transgenic mice. At the molecular level, elevation of extracellular magnesium prevented the high Aß-induced reductions in synaptic NMDARs by preventing calcineurin overactivation in hippocampal slices. CONCLUSIONS: Our results suggest that elevation of brain magnesium exerts substantial synaptoprotective effects in a mouse model of Alzheimer's disease, and hence it might have therapeutic potential for treating Alzheimer's disease.