Loss of mGlu5 receptors in somatostatin-expressing neurons alters negative emotional states.

Subtype 5 metabotropic glutamate receptors (mGlu5) are known to play an important role in regulating cognitive, social and valence systems. However, it remains largely unknown at which circuits and neuronal types mGlu5 act to influence these behavioral domains. Altered tissue- or cell-specific expression or function of mGlu5 has been proposed to contribute to the exacerbation of neuropsychiatric disorders. Here, we examined how these receptors regulate the activity of somatostatin-expressing (SST+) neurons, as well as their influence on behavior and brain rhythmic activity. Loss of mGlu5 in SST+ neurons elicited excitatory synaptic dysfunction in a region and sex-specific manner together with a range of emotional imbalances including diminished social novelty preference, reduced anxiety-like behavior and decreased freezing during retrieval of fear memories. In addition, the absence of mGlu5 in SST+ neurons during fear processing impaired theta frequency oscillatory activity in the medial prefrontal cortex and ventral hippocampus. These findings reveal a critical role of mGlu5 in controlling SST+ neurons excitability necessary for regulating negative emotional states.

Global financial crisis and COVID-19: Industrial reactions.

We study industrial reactions to both the global financial crisis of 2008 and the COVID-19 pandemic. Although most industries in the U.S. suffered from the two events, the stock performance of most industries started to recover following the announcements of quantitative easing. Our results indicate that quantitative easing is effective in boosting investor confidence. We also find that the effect of quantitative easing in 2020 on stock performance is more significant for the industries that are more affected by the pandemic.

Coacervate-Filled Lipid Vesicles for Protein Delivery.

Macromolecularly crowded coacervate is useful in protein delivery for tissue engineering and regenerative medicine. However, coacervate tends to aggregate easily, which impedes their application. Here, this work presents a method to prepare coacervate with enhanced stability. This work assembles phospholipids on the surface of a coacervate to form lipocoacervate (LipCo). The resultant LipCo possesses a discrete spherical structure with a coacervate interior and phospholipid outer shell. The size of LipCo does not change over the four-week observation window, whereas coacervate coalesced into one bulk phase within 30 min. This work uses vascular endothelial growth factor-C (VEGF-C) and fibroblast growth factor-2 (FGF-2) as examples to test LipCo's ability to maintain protein bioactivity. The in vitro lymphangiogenesis assay demonstrates that human dermal lymphatic endothelial cells (LECs) formed increased network of cord in VEGF-C and FGF-2 loaded LipCo group compared to free proteins and proteins loaded in coacervate. Overall, LipCo could serve as a protein delivery vehicle with improved colloidal stability.

RECLUSIVE CHANDELIERS: FUNCTIONAL ISOLATION OF DENTATE AXO-AXONIC CELLS AFTER EXPERIMENTAL STATUS EPILEPTICUS.

Axo-axonic cells (AACs) provide specialized inhibition to the axon initial segment (AIS) of excitatory neurons and can regulate network output and synchrony. Although hippocampal dentate AACs are structurally altered in epilepsy, physiological analyses of dentate AACs are lacking. We demonstrate that parvalbumin neurons in the dentate molecular layer express PTHLH, an AAC marker, and exhibit morphology characteristic of AACs. Dentate AACs show high-frequency, non-adapting firing but lack persistent firing in the absence of input and have higher rheobase than basket cells suggesting that AACs can respond reliably to network activity. Early after pilocarpine-induced status epilepticus (SE), dentate AACs receive fewer spontaneous excitatory and inhibitory synaptic inputs and have significantly lower maximum firing frequency. Paired recordings and spatially localized optogenetic stimulation revealed that SE reduced the amplitude of unitary synaptic inputs from AACs to granule cells without altering reliability, short-term plasticity, or AIS GABA reversal potential. These changes compromised AAC-dependent shunting of granule cell firing in a multicompartmental model. These early post-SE changes in AAC physiology would limit their ability to receive and respond to input, undermining a critical brake on the dentate throughput during epileptogenesis.

Reclusive chandeliers: Functional isolation of dentate axo-axonic cells after experimental status epilepticus.

Axo-axonic cells (AACs) provide specialized inhibition to the axon initial segment (AIS) of excitatory neurons and can regulate network output and synchrony. Although hippocampal dentate AACs are structurally altered in epilepsy, physiological analyses of dentate AACs are lacking. We demonstrate that parvalbumin neurons in the dentate molecular layer express PTHLH, an AAC marker, and exhibit morphology characteristic of AACs. Dentate AACs show high-frequency, non-adapting firing but lack persistent firing in the absence of input and have higher rheobase than basket cells suggesting that AACs can respond reliably to network activity. Early after pilocarpine-induced status epilepticus (SE), dentate AACs receive fewer spontaneous excitatory and inhibitory synaptic inputs and have significantly lower maximum firing frequency. Paired recordings and spatially localized optogenetic stimulation revealed that SE reduced the amplitude of unitary synaptic inputs from AACs to granule cells without altering reliability, short-term plasticity, or AIS GABA reversal potential. These changes compromised AAC-dependent shunting of granule cell firing in a multicompartmental model. These early post-SE changes in AAC physiology would limit their ability to receive and respond to input, undermining a critical brake on the dentate throughput during epileptogenesis.

WNK1 promotes water homeostasis by acting as a central osmolality sensor for arginine vasopressin release.

Maintaining internal osmolality constancy is essential for life. Release of arginine vasopressin (AVP) in response to hyperosmolality is critical. Current hypotheses for osmolality sensors in circumventricular organs (CVOs) of the brain focus on mechanosensitive membrane proteins. The present study demonstrated that intracellular protein kinase WNK1 was involved. Focusing on vascular-organ-of-lamina-terminalis (OVLT) nuclei, we showed that WNK1 kinase was activated by water restriction. Neuron-specific conditional KO (cKO) of Wnk1 caused polyuria with decreased urine osmolality that persisted in water restriction and blunted water restriction-induced AVP release. Wnk1 cKO also blunted mannitol-induced AVP release but had no effect on osmotic thirst response. The role of WNK1 in the osmosensory neurons in CVOs was supported by neuronal pathway tracing. Hyperosmolality-induced increases in action potential firing in OVLT neurons was blunted by Wnk1 deletion or pharmacological WNK inhibitors. Knockdown of Kv3.1 channel in OVLT by shRNA reproduced the phenotypes. Thus, WNK1 in osmosensory neurons in CVOs detects extracellular hypertonicity and mediates the increase in AVP release by activating Kv3.1 and increasing action potential firing from osmosensory neurons.

Effects of oligo-fucoidan on the immune response, inflammatory status and pulmonary function in patients with asthma: a randomized, double-blind, placebo-controlled trial.

Asthma is a common disease occurring worldwide. The clinical treatment of asthma is constantly revised and updated; however, it is associated with side effects. Our previous in vitro and ex vivo studies found that oligo-fucoidan can improve allergic immune responses and reduce airway inflammation. The purpose of this clinical trial was to investigate the effects of oligo-fucoidan on the immune status, inflammatory response, and pulmonary function of patients with asthma. Twenty asthmatic patients were randomly divided into two groups: (1) control group: receiving regular asthma treatment and supplementation with placebo; (2) fucoidan group: receiving regular asthma treatment and supplementation with oligo-fucoidan. Pulmonary function tests, the "Asthma Control Questionnaire" survey, biochemical data, inflammatory factors, and immune cell subtypes were detected. During treatment, the levels of WBC (p = 0.038) and creatinine (p = 0.012 and p = 0.008 at 12th and 24th weeks) were significantly decreased in the fucoidan group. Lung function (FEV1/FVC pr) significantly increased in the fucoidan group (p = 0.046). Regarding the proportion of immune cells, the level of IFN+ and CD4+IFN+cells in the fucoidan group was significantly increased during the treatment period (P < 0.05), while the proportions of CD3+CD4+ cells (p = 0.048) and CD3+CD8+ cells (p = 0.009) in the fucoidan group were significantly decreased during the treatment period. Regarding cytokines, the level of interleukin-8 (IL-8) was also significantly reduced in the fucoidan group during the treatment period.

Involvement of a BH3-only apoptosis sensitizer gene Blm-s in hippocampus-mediated mood control.

Mood disorders are an important public health issue and recent advances in genomic studies have indicated that molecules involved in neurodevelopment are causally related to mood disorders. BLM-s (BCL-2-like molecule, small transcript isoform), a BH3-only proapoptotic BCL-2 family member, mediates apoptosis of postmitotic immature neurons during embryonic cortical development, but its role in the adult brain is unknown. To better understand the physiological role of Blm-s gene in vivo, we generated a Blm-s-knockout (Blm-s-/-) mouse. The Blm-s-/- mice breed normally and exhibit grossly normal development. However, global depletion of Blm-s is highly associated with depression- and anxiety-related behaviors in adult mutant mice with intact learning and memory capacity. Functional magnetic resonance imaging of adult Blm-s-/- mice reveals reduced connectivity mainly in the ventral dentate gyrus (vDG) of the hippocampus with no alteration in the dorsal DG connectivity and in total hippocampal volume. At the cellular level, BLM-s is expressed in DG granule cells (GCs), and Blm-s-/- mice show reduced dendritic complexity and decreased spine density in mature GCs. Electrophysiology study uncovers that mature vGCs in adult Blm-s-/- DG are intrinsically more excitable. Interestingly, certain genetic variants of the human Blm homologue gene (VPS50) are significantly associated with depression traits from publicly resourced UK Biobank data. Taken together, BLM-s is required for the hippocampal mood control function. Loss of BLM-s causes abnormality in the electrophysiology and morphology of GCs and a disrupted vDG neural network, which could underlie Blm-s-null-associated anxiety and depression.

Morpho-physiological properties and connectivity of vasoactive intestinal polypeptide-expressing interneurons in the mouse hippocampal dentate gyrus.

The hippocampus is a key brain structure for cognitive and emotional functions. Among the hippocampal subregions, the dentate gyrus (DG) is the first station that receives multimodal sensory information from the cortex. Local-circuit inhibitory GABAergic interneurons (INs) regulate the excitation-inhibition balance in the DG principal neurons (PNs) and therefore are critical for information processing. Similar to PNs, GABAergic INs also receive distinct inhibitory inputs. Among various classes of INs, vasoactive intestinal polypeptide-expressing (VIP+ ) INs preferentially target other INs in several brain regions and thereby directly modulate the GABAergic system. However, the morpho-physiological characteristics and postsynaptic targets of VIP+ INs in the DG are poorly understood. Here, we report that VIP+ INs in the mouse DG are highly heterogeneous based on their morpho-physiological characteristics. In approximately two-thirds of morphologically reconstructed cells, their axons ramify in the hilus. The remaining cells project their axons exclusively to the molecular layer (15%), to both the molecular layer and hilus (10%), or throughout the entire DG layers (8%). Generally, VIP+ INs display variable intrinsic properties and discharge patterns without clear correlation with their morphologies. Finally, VIP+ INs are recruited with a long latency in response to theta-band cortical inputs and preferentially innervate GABAergic INs over glutamatergic PNs. In summary, VIP+ INs in the DG are composed of highly diverse subpopulations and control the DG output via disinhibition.

Inhibition of the Proliferation and Invasion of C6 Glioma Cells by Tricin via the Upregulation of Focal-Adhesion-Kinase-Targeting MicroRNA-7.

Tricin, a natural flavonoid present in large amounts in rice bran, was investigated for the mechanisms by which it exhibited antiproliferation and anti-invasion in C6 glioma cells. The results indicated that treatment with 5, 10, 25, and 50 µM tricin for 48 h significantly ( p < 0.05) inhibited cell numbers and colony numbers with values of 134.3 ± 5.5, 114.6 ± 2.5, 106.3 ± 3.2, and 57.3 ± 10.2, respectively. Tricin also inhibited C6-cell motility, migration, and invasion. Tricin changed the cytoskeletal organization, reduced matrix-metalloproteinase (MMP) expression, and upregulated E-cadherin. Tricin decreased FAK protein levels and suppressed focal-adhesion-kinase (FAK)-downstream-signal activation. Most importantly, tricin dose-dependently upregulated microRNA-7 (miR-7). Transfection with an miR-7 inhibitor suppressed miR-7 expression, increased FAK expression, and promoted the proliferation and invasion in C6 cells. The data support a novel anticancer mechanism of tricin that involves upregulation of FAK-targeting miR-7 in C6 glioma cells.

Effects of an injectable functionalized self-assembling nanopeptide hydrogel on angiogenesis and neurogenesis for regeneration of the central nervous system.

Brain injury is a devastating medical condition and represents a major health problem. Tissue and organ reconstruction have been regarded as promising therapeutic strategies. Here, we propose a regenerative methodology focusing on the provision of functionalized nanopeptide scaffolds to facilitate angiogenesis and neurogenesis at the brain injury site. The peptide RADA16-SVVYGLR undergoes self-assembly to construct an interconnected network with intertwining nanofibers, and can be controlled to display various physicochemical properties by the adjustment of microenvironmental factors such as pH and ion concentration. Such scaffolds can support endothelial cells to form tube-like structures and neural stem cells to survive and proliferate. In an in vivo zebrafish brain injury model, sprouting angiogenesis and developmental neurogenesis were achieved, and functional recovery of the severed optic tectum was enhanced in RADA16-SVVYGLR hydrogel-implanted zebrafish. This nanopeptide hydrogel was non-toxic to zebrafish embryos during early developmental stages. This angiogenic self-assembling peptide hydrogel had programmable physical properties, good biocompatibility, and regenerative ability for functional recovery in the injured brain. We suggest that functionalized self-assembling peptides encapsulated with neural stem cells or used alone could be an attractive and effective therapeutic modality for brain injury and diseases (e.g., trauma, stroke, tumor, degenerative neurological disorders, etc.).

Development of biomimetic micro-patterned device incorporated with neurotrophic gradient and supportive Schwann cells for the applications in neural tissue engineering.

In these years, the artificial nerve guidance conduit (NGC) has been developed as an alternative way to repair peripheral nerve injury. Unlike autologous nerve graft, the artificial NGC without proper stimulating factors and guidance cues still cannot obtain satisfactory prognosis for clinical patients. In this study, a biodegradable polymer-based implantable device has been developed and characterized. By incorporating three stimulating factors: (1) micro-patterned surface that can directionally guide the axon as physical cue; (2) neurotrophic gradient membrane that can continually attract axon outgrowth from the proximal to distal stump as chemical cue; (3) Schwann cells (SCs) that can support the growth of neurite and form myelin sheath around axon as biological cue, we expect that this construct can be used as a promising NGC for peripheral nerve regeneration. The results showed that the micro-patterned surface with specific dimension of channels and chambers can be precisely fabricated by laser ablation. Attachment and directional extension of differentiated neural stem cells (NSCs) were observed in micro-channels. The gradient distribution of nerve growth factor 7S on gelatin membrane was successfully achieved. Significant improvement in neurite length and increase in neuronal gene expressions were also noticed in higher concentration region. When co-culturing with SCs, NSCs can differentiate toward neuronal cells with strong expression of mature neuronal markers: ßIII tubulin and microtubule-associated protein-2 (Map 2). Meanwhile, myelin basic protein was also observed, suggesting that SCs can provide biological support to neuronal cells in vitro. In the future, this advanced artificial NGC may be used as implantable prosthesis for the treatment of peripheral nerve injury with better functional recovery.

Enzyme-crosslinked gene-activated matrix for the induction of mesenchymal stem cells in osteochondral tissue regeneration.

The development of osteochondral tissue engineering is an important issue for the treatment of traumatic injury or aging associated joint disease. However, the different compositions and mechanical properties of cartilage and subchondral bone show the complexity of this tissue interface, making it challenging for the design and fabrication of osteochondral graft substitute. In this study, a bilayer scaffold is developed to promote the regeneration of osteochondral tissue within a single integrated construct. It has the capacity to serve as a gene delivery platform to promote transfection of human mesenchymal stem cells (hMSCs) and the functional osteochondral tissues formation. For the subchondral bone layer, the bone matrix with organic (type I collagen, Col) and inorganic (hydroxyapatite, Hap) composite scaffold has been developed through mineralization of hydroxyapatite nanocrystals oriented growth on collagen fibrils. We also prepare multi-shell nanoparticles in different layers with a calcium phosphate core and DNA/calcium phosphate shells conjugated with polyethyleneimine to act as non-viral vectors for delivery of plasmid DNA encoding BMP2 and TGF-ß3, respectively. Microbial transglutaminase is used as a cross-linking agent to crosslink the bilayer scaffold. The ability of this scaffold to act as a gene-activated matrix is demonstrated with successful transfection efficiency. The results show that the sustained release of plasmids from gene-activated matrix can promote prolonged transgene expression and stimulate hMSCs differentiation into osteogenic and chondrogenic lineages by spatial and temporal control within the bilayer composite scaffold. This improved delivery method may enhance the functionalized composite graft to accelerate healing process for osteochondral tissue regeneration. STATEMENT OF SIGNIFICANCE: In this study, a gene-activated matrix (GAM) to promote the growth of both cartilage and subchondral bone within a single integrated construct is developed. It has the capacity to promote transfection of human mesenchymal stem cells (hMSCs) and the functional osteochondral tissues formation. The results show that the sustained release of plasmids including TGF-beta and BMP-2 from GAM could promote prolonged transgene expression and stimulate hMSCs differentiation into the osteogenic and chondrogenic lineages by spatial control manner. This improved delivery method should enhance the functionalized composite graft to accelerate healing process in vitro and in vivo for osteochondral tissue regeneration.

Tailored design of multifunctional and programmable pH-responsive self-assembling polypeptides as drug delivery nanocarrier for cancer therapy.

Breast cancer has become the second leading cause of cancer-related mortality in female wherein more than 90% of breast cancer-related death results from cancer metastasis to distant organs at advanced stage. The purpose of this study is to develop biodegradable nanoparticles composed of natural polypeptides and calcium phosphate (CaP) with sequential pH-responsivity to tumor microenvironments for active targeted drug delivery. Two different amphiphilic copolymers, poly(ethylene glycol)3400-aconityl linkage-poly(l-glutamic acid)15-poly(l-histidine)10-poly(l-leucine)10 and LyP1-poly(ethylene glycol)1100-poly(l-glutamic acid)15-poly(l-histidine)10-poly(l-leucine)10, were exploited to self-assemble into micelles in aqueous phase. The bio-stable nanoparticles provide three distinct functional domains: the anionic PGlu shell for CaP mineralization, the protonation of PHis segment for facilitating anticancer drug release at target site, and the hydrophobic core of PLeu for encapsulation of anticancer drugs. Furthermore, the hydrated PEG outer corona is used for prolonging circulation time, while the active targeting ligand, LyP-1, is served to bind to breast cancer cells and lymphatic endothelial cells in tumor for inhibiting metastasis. Mineralized DOX-loaded nanoparticles (M-DOX NPs) efficiently prevent the drug leakage at physiological pH value and facilitate the encapsulated drug release at acidic condition when compared to DOX-loaded nanoparticles (DOX NPs). M-DOX NPs with LyP-1 targeting ligand effectively accumulated in MDA-MB-231 breast cancer cells. The inhibition effect on cell proliferation also enhances with time, illustrating the prominent anti-tumor efficacy. Moreover, the in vitro metastatic inhibition model shows the profound inhibition effect of inhibitory nanoparticles. In brief, this self-assembling peptide-based drug delivery nanocarrier with multifunctionality and programmable pH-sensitivity is of great promise and potential for anti-cancer therapy. STATEMENT OF SIGNIFICANCE: This tailored-design polypeptide-based nanoparticles with self-assembling and programmable stimulus-responsive properties enable to 1) have stable pH in physiological value with a low level of drug loss and effectively release the encapsulated drug with pH variations according to the tumor microenvironment, 2) enhance targeting ability to hard-to-treat breast cancer cells and activate endothelial cells (tumor region), 3) significantly inhibit the growth and prevent from malignant metastasis of cancer cells in consonance with promising anti-tumor efficacy, and 4) make tumors stick to localized position so that these confined solid tumors can be more accessible by different treatment modalities. This work contributes to designing a programmable pH-responsive drug delivery system based on the tailor-designed polypeptides.