Diabetes Primes Neutrophils for Neutrophil Extracellular Trap Formation through Trained Immunity

Neutrophils are primed for neutrophil extracellular trap (NET) formation during diabetes, and excessive NET formation from primed neutrophils compromises wound healing in patients with diabetes. Here, we demonstrate that trained immunity mediates diabetes-induced NET priming in neutrophils. Under diabetic conditions, neutrophils exhibit robust metabolic reprogramming comprising enhanced glycolysis via the pentose phosphate pathway and fatty acid oxidation, which result in the accumulation of acetyl-coenzyme A. Adenosine 5'-triphosphate-citrate lyase-mediated accumulation of acetyl-coenzyme A and histone acetyltransferases further induce the acetylation of lysine residues on histone 3 (AcH3K9, AcH3K14, and AcH3K27) and histone 4 (AcH4K8). The pharmacological inhibition of adenosine 5'-triphosphate-citrate lyase and histone acetyltransferases completely inhibited high-glucose-induced NET priming. The trained immunity of neutrophils was further confirmed in neutrophils isolated from patients with diabetes. Our findings suggest that trained immunity mediates functional changes in neutrophils in diabetic environments, and targeting neutrophil-trained immunity may be a potential therapeutic target for controlling inflammatory complications of diabetes.

Acid sphingomyelinase as a pathological and therapeutic target in neurological disorders: focus on Alzheimer's disease

Over the past decade, numerous studies have highlighted the importance of acid sphingomyelinase (ASM) in disease treatment in humans. This enzyme functions primarily to generate ceramide, maintain the cellular membrane, and regulate cellular function. However, in the blood and brain of patients with neurological disorders, including major depression, ischemic stroke, amyotrophic lateral sclerosis, multiple sclerosis, and Alzheimer's disease (AD), elevated ASM levels significantly suggest disease onset or progression. In these diseases, increased ASM is profoundly involved in neuronal death, abnormal autophagy, neuroinflammation, blood-brain barrier disruption, hippocampal neurogenesis loss, and immune cell dysfunction. Moreover, genetic and pharmacological inhibition of ASM can prevent or ameliorate various diseases. The therapeutic effects of ASM inhibition have prompted the urgent need to develop ASM inhibitors, and several ASM inhibitors have been identified. In this review, we summarize the current knowledge on the critical roles and mechanisms of ASM in brain cells and blood that are associated with different neuropathological features, especially those observed in AD. Furthermore, we elucidate the potential possibility and limitations of existing ASM-targeting drugs according to experimental studies in neurological disorder mouse models.

Role of NCKAP1 in the Defective Phagocytic Function of Microglia-Like Cells Derived from Rapidly Progressing Sporadic ALS

Microglia plays a key role in determining the progression of amyotrophic lateral sclerosis (ALS), yet their precise role in ALS has not been identified in humans. This study aimed to identify a key factor related to the functional characteristics of microglia in rapidly progressing sporadic ALS patients using the induced microglia model, although it is not identical to brain resident microglia. After confirming that microglia-like cells (iMGs) induced by human monocytes could recapitulate the main signatures of brain microglia, step-by-step comparative studies were conducted to delineate functional differences using iMGs from patients with slowly progressive ALS [ALS(S), n = 14] versus rapidly progressive ALS [ALS(R), n = 15]. Despite an absence of significant differences in the expression of microglial homeostatic genes, ALS(R)-iMGs preferentially showed defective phagocytosis and an exaggerated pro-inflammatory response to LPS stimuli compared to ALS(S)-iMGs. Transcriptome analysis revealed that the perturbed phagocytosis seen in ALS(R)-iMGs was closely associated with decreased NCKAP1 (NCK-associated protein 1)-mediated abnormal actin polymerization. NCKAP1 overexpression was sufficient to rescue impaired phagocytosis in ALS(R)-iMGs. Post-hoc analysis indicated that decreased NCKAP1 expression in iMGs was correlated with the progression of ALS. Our data suggest that microglial NCKAP1 may be an alternative therapeutic target in rapidly progressive sporadic ALS.

Immunotherapy targeting plasma ASM is protective in a mouse model of Alzheimer's disease

Acid sphingomyelinase (ASM) has been implicated in neurodegenerative disease pathology, including Alzheimer's disease (AD). However, the specific role of plasma ASM in promoting these pathologies is poorly understood. Herein, we explore plasma ASM as a circulating factor that accelerates neuropathological features in AD by exposing young APP/PS1 mice to the blood of mice overexpressing ASM, through parabiotic surgery. Elevated plasma ASM was found to enhance several neuropathological features in the young APP/PS1 mice by mediating the differentiation of blood-derived, pathogenic Th17 cells. Antibody-based immunotherapy targeting plasma ASM showed efficient inhibition of ASM activity in the blood of APP/PS1 mice and, interestingly, led to prophylactic effects on neuropathological features by suppressing pathogenic Th17 cells. Our data reveals insights into the potential pathogenic mechanisms underlying AD and highlights ASM-targeting immunotherapy as a potential strategy for further investigation.

Acid sphingomyelinase inhibition improves motor behavioral deficits and neuronal loss in an amyotrophic lateral sclerosis mouse model

Amyotrophic lateral sclerosis (ALS) is an incurable neurodegenerative disease characterized by the degeneration of motor neurons in the spinal cord. Main symptoms are manifested as weakness, muscle loss, and muscle atrophy. Some studies have reported that alterations in sphingolipid metabolism may be intimately related to neurodegenerative diseases, including ALS. Acid sphingomyelinase (ASM), a sphingolipid-metabolizing enzyme, is considered an important mediator of neurodegenerative diseases. Herein, we show that ASM activity increases in samples from patients with ALS and in a mouse model. Moreover, genetic inhibition of ASM improves motor function impairment and spinal neuronal loss in an ALS mouse model. Therefore, these results suggest the role of ASM as a potentially effective target and ASM inhibition may be a possible therapeutic approach for ALS. [BMB Reports 2022; 55(12): 621-626].

Diverse Roles of Ceramide in the Progression and Pathogenesis of Alzheimer’s Disease

Alzheimer’s disease (AD) is the most common neurodegenerative disorder, and is associated with several pathophysiological features, including cellular dysfunction, failure of neurotransmission, cognitive impairment, cell death, and other clinical consequences. Advanced research on the pathogenesis of AD has elucidated a mechanistic framework and revealed many therapeutic possibilities. Among the mechanisms, sphingolipids are mentioned as distinctive mediators to be associated with the pathology of AD. Reportedly, alteration in the metabolism of sphingolipids and their metabolites result in the dysfunction of mitochondria, autophagy, amyloid beta regulation, and neuronal homeostasis, which exacerbates AD progression. Considering the importance of sphingolipids, in this review, we discuss the role of ceramide, a bioactive sphingolipid metabolite, in the progression and pathogenesis of AD. Herein, we describe the ceramide synthesis pathway and its involvement in the dysregulation of homeostasis, which eventually leads to AD. Furthermore, this review references different therapeutics proposed to modulate the ceramide pathway to maintain ceramide levels and prevent the disease progression.

Impact on capsule formation for three different types of implant surface tomography

Although capsular contracture remains one of the major problems following silicone breast implantation, the associated mechanism has yet to be determined. This study thus aimed to investigate capsule formation and capsular contracture using three types of implants with different surface topographies in vivo. Three types of implants (i.e., smooth, macrotexture, and nanotexture) with different surface topographies were inserted in a total of 48 Wistar rats. After 4 and 12 weeks, the samples were analyzed via histological, immunohistochemical, and Western blot examination. To identify implant movement, the degree to which implant position changed was measured. And the surface topography was characterized using scanning electron microscopy. Hematoxylin–eosin staining showed that the nanotexture type implant promoted significant decreases in capsule thickness at 12 weeks (P < 0.05), while Masson trichrome staining showed decreased collagen fiber density with the same implant type. Immunohistochemical and Western blot examination revealed reduced fibrosis markers (myofibroblast, and transforming growth factor beta-1) in the nanotexture surface implant. Meanwhile, implant location evaluation found that the nanotexture and smooth surface implants had significantly increased movement (P < 0.05). The nanotexture surface implant had been found to reduce capsule formation given that it minimizes the effects of factors related to foreign body reaction.

Clinical and genetic features of four patients with Pearson syndrome: An observational study

Pearson syndrome (PS) is a multisystem mitochondrial cytopathy arising from deletions in mitochondrial DNA. Pearson syndrome is a sporadic disease that affects the hematopoietic system, pancreas, eyes, liver, and heart and the prognosis is poor. Causes of morbidity include metabolic crisis, bone marrow dysfunction, sepsis, and liver failure in early infancy or childhood. Early diagnosis may minimize complications, but suspicion of the disease is difficult and only mitochondrial DNA gene testing can identify mutations. There is no specific treatment for PS, which remains supportive care according to symptoms; however, hematopoietic stem cell transplantation may be considered in cases of bone marrow failure.We herein describe the clinical and genetic characteristics of four patients with PS. One patient presented with hypoglycemia, two developed pancytopenia, and the final patient had hypoglycemia and acute hepatitis as the primary manifestation. All patients had lactic acidosis. Additionally, all patients showed a variety of clinical features including coagulation disorder, pancreatic, adrenal, and renal tubular insufficiencies. Two patients with pancytopenia died in their early childhood. Our experience expands the phenotypic spectrum associated with PS and its clinical understanding.

The blood cerebrospinal fluid barrier orchestrates immunosurveillance, immunoprotection, and immunopathology in the central nervous system

Once characterized as an immune privileged area, recent scientific advances have demonstrated that the central nervous system (CNS) is both immunologically active and a specialized site. The anatomical and cellular features of the brain barriers, the glia limitans, and other superficial coverings of the CNS endow the brain with specificity for immune cell entry and other macro- and micro-elements to the brain. Cellular trafficking via barriers comprised of tightly junctioned non-fenestrated endothelium or tightly regulated fenestrated epithelium results in different phenotypic and cellular changes in the brain, that is, inflammatory versus regulatory changes. Based on emerging evidence, we described the unique ability of the blood cerebrospinal fluid barrier (BCSFB) to recruit, skew, and suppress immune cells. Additionally, we sum up the current knowledge on both cellular and molecular mechanisms governed by the choroid plexus and the cerebrospinal fluid at the BCSFB for immunosurveillance, immunoprotection, and immunopathology.

Extracellular vesicles from dHL-60 cells as delivery vehicles for diverse therapeutics

Extracellular vesicles (EVs) are membrane-derived heterogeneous vesicles that mediate intercellular communications. They have recently been considered as ideal vehicles for drug-delivery systems, and immune cells are suggested as a potential source for drug-loaded EVs. In this study, we investigated the possibility of neutrophils as a source for drug-loaded EVs. Neutrophil-like differentiated human promyelocytic leukemia cells (dHL-60) produced massive amounts of EVs within 1 h. The dHL-60 cells are also easily loaded with various cargoes such as antibiotics (penicillin), anticancer drug (paclitaxel), chemoattractant (MCP-1), miRNA, and Cas9. The EVs derived from the dHL-60 cells showed efficient incorporation of these cargoes and significant effector functions, such as bactericidal activity, monocyte chemotaxis, and macrophage polarization. Our results suggest that neutrophils or neutrophil-like promyelocytic cells could be an attractive source for drug-delivery EVs.

Nucleocapsid and Spike Proteins of SARS-CoV-2 Drive Neutrophil Extracellular Trap Formation

Patients with severe coronavirus disease 2019 (COVID-19) demonstrate dysregulated immune responses including exacerbated neutrophil functions. Massive neutrophil infiltrations accompanying neutrophil extracellular trap (NET) formations are also observed in patients with severe COVID-19. However, the mechanism underlying severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-induced NET formation has not yet been elucidated. Here we show that 2 viral proteins encoded by SARS-CoV-2, the nucleocapsid protein and the whole spike protein, induce NET formation from neutrophils. NET formation was ROS-independent and was completely inhibited by the spleen tyrosine kinase inhibition. The inhibition of p38 MAPK, protein kinase C, and JNK signaling pathways also inhibited viral protein-induced NET formation. Our findings demonstrate one method by which SARS-CoV-2 evades innate immunity and provide a potential target for therapeutics to treat patients with severe COVID-19.

Neutrophil-derived trail is a proinflammatory subtype of neutrophil-derived extracellular vesicles

Aims: Extracellular vesicles (EVs) are membrane-derived vesicles that mediate intercellular communications. Neutrophils produce different subtypes of EVs during inflammatory responses. Neutrophil-derived trails (NDTRs) are generated by neutrophils migrating toward inflammatory foci, whereas neutrophil-derived microvesicles (NDMVs) are thought to be generated by neutrophils that have arrived at the inflammatory foci. However, the physical and functional characteristics of neutrophil-derived EVs are incompletely understood. In this study, we aimed to investigate the differences between NDTRs and NDMVs. Methods: The generation of neutrophil-derived EVs were visualized by live-cell fluorescence images and the physical characteristics were further analyzed using nanotracking analysis assay, scanning electron microscopic analysis, and marker expressions. Functional characteristics of neutrophil-derived EVs were analyzed using assays for bactericidal activity, monocyte chemotaxis, phenotype polarization of macrophages, and miRNA sequencing. Finally, the effects of neutrophil-derived EVs on the acute and chronic inflammation were examined in vivo. Results: Both EVs share similar characteristics including stimulators, surface marker expression, bactericidal activity, and chemoattractive effect on monocytes via MCP-1. However, the integrin-mediated physical interaction was required for generation of NDTRs whereas NDMV generation was dependent on PI3K pathway. Interestingly, NDTRs contained proinflammatory miRNAs such as miR-1260, miR-1285, miR-4454, and miR-7975, while NDMVs contained anti-inflammatory miRNAs such as miR-126, miR-150, and miR-451a. Although both EVs were easily uptaken by monocytes, NDTRs enhanced proinflammatory macrophage polarization whereas NDMVs induced anti-inflammatory macrophage polarization. Moreover, NDTRs showed protective effects against lethality in a murine sepsis model and pathological changes in a murine chronic colitis model. Conclusion: These results suggest that NDTR is a proinflammatory subtype of neutrophil-derived EVs distinguished from NDMV.

A Glycosylated Prodrug to Attenuate Neuroinflammation and Improve Cognitive Deficits in Alzheimer's Disease Transgenic Mice

We report a prodrug, Glu-DAPPD, to overcome the shortcomings of an anti-neuroinflammatory molecule, N,N'-diacetyl-p-phenylenediamine (DAPPD), in biological applicability for potential therapeutic applications. We suspect that Glu-DAPPD can release DAPPD through endogenous enzymatic bioconversion. Consequently, Glu-DAPPD exhibits in vivo efficacies in alleviating neuroinflammation, reducing amyloid-β aggregate accumulation, and improving cognitive function in Alzheimer's disease transgenic mice. Our studies demonstrate that the prodrug approach is suitable and effective toward developing drug candidates against neurodegeneration.

Sphingolipids in neuroinflammation: a potential target for diagnosis and therapy

Sphingolipids are ubiquitous building blocks of eukaryotic cell membranes that function as signaling molecules for regulating a diverse range of cellular processes, including cell proliferation, growth, survival, immune-cell trafficking, vascular and epithelial integrity, and inflammation. Recently, several studies have highlighted the pivotal role of sphingolipids in neuroinflammatory regulation. Sphingolipids have multiple functions, including induction of the expression of various inflammatory mediators and regulation of neuroinflammation by directly effecting the cells of the central nervous system. Accumulating evidence points to sphingolipid engagement in neuroinflammatory disorders, including Alzheimer’s and Parkinson’s diseases. Abnormal sphingolipid alterations, which involves an increase in ceramide and a decrease in sphingosine kinase, are observed during neuroinflammatory disease. These trends are observed early during disease development, and thus highlight the potential of sphingolipids as a new therapeutic and diagnostic target for neuroinflammatory diseases.

Pharmacologic properties of high-dose ambroxol in four patients with Gaucher disease and myoclonic epilepsy

Background

Ambroxol (ABX) has been suggested as an augmentative pharmacological agent for neuronopathic Gaucher disease (nGD). This study assessed the long-term safety and efficacy of combined therapy with high-dose ABX and enzyme replacement therapy (ERT) in nGD.

Methods

ABX+ERT therapy was administered for 4.5 years in four patients with nGD. ABX was initiated at a dose of 1.5 mg/kg/day, and the dose was escalated up to 27 mg/kg/day. The target plasma level was 10 µmol/L or less. The changes in glucocerebrosidase activity, biochemical, safety and neurocognitive findings were assessed.

Results

Enhanced residual GCcase activity was observed in all patients, as evidenced in both in vitro and in vivo studies. During the first 2 years of study with ABX (up to 21 mg/kg/day), mean seizure frequencies and neurocognitive function worsened. After ABX dosage was increased up to 27 mg/kg/day of ABX, its trough plasma concentration was 3.2–8.8 µmol/L. Drug-to-drug interaction, especially with antiepileptic drug significantly affected the pharmacokinetic parameters of ABX. Importantly, at 27 mg/kg/day of ABX, the seizure frequencies markedly decreased from the baseline, and the neurocognitive function was improved. In addition, Lyso-Gb1, a biomarker for the severity and progression of GD, was normalised in all patients. High-dose ABX was well-tolerated with no severe adverse events.

Conclusions

Long-term treatment with high-dose ABX+ERT was safe and might help to arrest the progression of the neurological manifestations in GD.

Vascular endothelial growth factor improves the therapeutic effects of cyclodextrin in Niemann-Pick type C mice

Niemann-Pick type C disease (NP-C) is a fatal neurodegenerative disorder caused by a deficiency in the function of the NPC1 gene. Malfunction of this gene/protein leads to progressive accumulation of unesterified cholesterol and sphingolipids in many organs, including the brain. To date, drugs that target pivotal stages in the pathogenic cascade have been tested as monotherapies or in combination with a second agent, showing additive benefits. In this study, we have investigated the effects of combining centrally and systemically administered therapies in a mouse model of NP-C, i.e. overexpression of brain-specific vascular endothelial growth factor (VEGF) in combination with systemic administration of 2-hydroxypropyl-β-cyclodextrin (CD). We found that animals treated using a combination of VEGF and CD showed an improvement in pathophysiology compared to those treated with CD alone or brain VEGF overexpression alone, or non-treated NP-C mice. Combination therapy increased the time period over which NP-C mice maintained their body-weight and motor function, and decreased the abnormal accumulation of lipids. In addition, combination therapy delayed the onset of Purkinje cell loss and reduced neuroinflammation. Taken together, our results demonstrate that combination therapy using VEGF and CD is a promising therapeutic modality for treating NP-C, and suggest that it represents a potential strategy for the treatment of diseases that cause both visceral and brain pathologies.

Tunable regulatory activities of 1,10-phenanthroline derivatives towards acid sphingomyelinase and Zn(ii)-amyloid-β

We report a new series of small molecules able to achieve the tunability of modulatory activities against acid sphingomyelinase (ASM) and Zn(ii)-bound amyloid-β [Zn(ii)-Aβ], two pathological targets found in the brain affected by Alzheimer's disease. Rational tuning of the hydrophobicity and Zn(ii) binding affinity of the 1,10-phenanthroline (phen) framework successfully yielded compounds as chemical modulators for ASM (4 and 5), Zn(ii)-Aβ (phen, 1, and 2), or both (3).

Characterization of the Subventricular-Thalamo-Cortical Circuit in the NP-C Mouse Brain, and New Insights Regarding Treatment

Gliosis in Niemann-Pick type C (NP-C) disease is characterized by marked changes in microglia and astrocytes. However, the gliosis onset and progression in NP-C has not been systematically studied, nor has the mechanism underlying this finding. Here, we found early gliosis in the subventricular zone (SVZ) of NP-C mice. Neural progenitor damage by Npc1 mutation suppressed vascular endothelial growth factor (VEGF) expression and further induced microglia activation followed by astrogliosis. Interestingly, excessive astrogliosis in the SVZ induced neural progenitor retention and/or migration into thalamus via astrocyte-derived VEGF, resulting in acceleration of thalamic and cortical gliosis through thalamo-cortical pathways. Transplantation of VEGF-overexpressing neural stem cells into the SVZ improved whole-brain pathology of NP-C mice. Overall, our data provide a new pathological perspective on NP-C neural pathology, revealing abnormalities in the subventricular-thalamo-cortical circuit of NP-C mouse brain and highlighting the importance of the SVZ microenvironment as a therapeutic target for NP-C disease.

Effects of Stromal Vascular Fraction on Breast Cancer Growth and Fat Engraftment in NOD/SCID Mice

BACKGROUND

To overcome unpredictable fat graft resorption, cell-assisted lipotransfer using stromal vascular fraction (SVF) has been introduced. However, its effect on cancer growth stimulation and its oncological safety are debatable. We investigated the effect of SVF on adjacent breast cancer and transplanted fat in a mouse model.

METHODS

A breast cancer xenograft model was constructed by injecting 2 × 10⁶ MDA-MB-231-luc breast cancer cells into the right lower back of 40 NOD/SCID mice. Two weeks later, cancer size was sorted according to signal density using an in vivo optical imaging system, and 36 mice were included. Human fat was extracted from the abdomen, and SVFs were isolated using a component isolator. The mice were divided into four groups: A, controls; B, injected with 30 μl SVF; C, injected with 0.5 ml fat and 30 μl saline; group D, injected with 0.5 ml fat and 30 μl SVF. Magnetic resonance imaging and three-dimensional micro-computed tomography volumetric analysis were performed at 4 and 8 weeks.

RESULTS

Tumor volume was 43.6, 42.3, 48.7, and 42.4 mm³ at the initial time point and 6780, 5940, 6080, and 5570 mm³ at 8 weeks in groups A, B, C, and D, respectively. Fat graft survival volume after 8 weeks was 49.32% and 62.03% in groups C and D, respectively. At 2-month follow-up after fat grafting in the xenograft model, SVF injection showed an increased fat survival rate and did not increase the adjacent tumor growth significantly.

CONCLUSION

Fat grafting with SVF yields satisfactory outcome in patients who undergo breast reconstruction surgery.

NO LEVEL ASSIGNED

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Immune inflammatory modulation as a potential therapeutic strategy of stem cell therapy for ALS and neurodegenerative diseases

With emerging evidence on the importance of non-cell autonomous toxicity in neurodegenerative diseases, therapeutic strategies targeting modulation of key immune cells. including microglia and Treg cells, have been designed for treatment of ALS and other neurodegenerative diseases. Strategy switching the patient’s environment from a pro-inflammatory toxic to an anti-inflammatory, and neuroprotective condition, could be potential therapy for neurodegenerative diseases. Mesenchymal stem cells (MSCs) regulate innate and adaptive immune cells, through release of soluble factors such as TGF- β and elevation of regulatory T cells (Tregs) and T helper-2 cells (Th2 cells), would play important roles, in the neuroprotective effect on motor neuronal cell death mechanisms in ALS. Single cycle of repeated intrathecal injections of BM-MSCs demonstrated a clinical benefit lasting at least 6 months, with safety, in ALS patients. Cytokine profiles of CSF provided evidence that BM-MSCs, have a role in switching from pro-inflammatory to anti-inflammatory conditions. Inverse correlation of TGF-β1 and MCP-1 levels, could be a potential biomarker to responsiveness. Thus, additional cycles of BM-MSC treatment are required, to confirm long-term efficacy and safety.

A Novel and Selective p38 Mitogen-Activated Protein Kinase Inhibitor Attenuates LPS-Induced Neuroinflammation in BV2 Microglia and a Mouse Model

Neuroinflammation is an important pathological feature in neurodegenerative diseases. Accumulating evidence has suggested that neuroinflammation is mainly aggravated by activated microglia, which are macrophage like cells in the central nervous system. Therefore, the inhibition of microglial activation may be considered for treating neuroinflammatory diseases. p38 mitogen-activated protein kinase (MAPK) has been identified as a crucial enzyme with inflammatory roles in several immune cells, and its activation also relates to neuroinflammation. Considering the proinflammatory roles of p38 MAPK, its inhibitors can be potential therapeutic agents for neurodegenerative diseases relating to neuroinflammation initiated by microglia activation. This study was designed to evaluate whether NJK14047, a recently identified novel and selective p38 MAPK inhibitor, could modulate microglia-mediated neuroinflammation by utilizing lipopolysaccharide (LPS)-stimulated BV2 cells and an LPS-injected mice model. Our results showed that NJK14047 markedly reduced the production of nitric oxide and prostaglandin E₂ by downregulating the expression of various proinflammatory mediators such as nitric oxide synthase, cyclooxygenase-2, tumor necrosis factor-α and interleukin-1β in LPS-induced BV2 microglia. Moreover, NJK14047 significantly reduced microglial activation in the brains of LPS-injected mice. Overall, these results suggest that NJK14047 significantly reduces neuroinflammation in cellular/vivo model and would be a therapeutic candidate for various neuroinflammatory diseases.

Vascular and Neurogenic Rejuvenation in Aging Mice by Modulation of ASM

Although many reports have revealed dysfunction of endothelial cells in aging, resulting in blood-brain barrier (BBB) breakdown, the underlying mechanism or mechanisms remain to be explored. Here, we find that acid sphingomyelinase (ASM) is a critical factor for regulating brain endothelial barrier integrity. ASM is increased in brain endothelium and/or plasma of aged humans and aged mice, leading to BBB disruption by increasing caveolae-mediated transcytosis. Genetic inhibition and endothelial-specific knockdown of ASM in mice ameliorated BBB breakdown and neurocognitive impairment during aging. Using primary mouse brain endothelial cells, we found that ASM regulated the caveolae-cytoskeleton interaction through protein phosphatase 1-mediated ezrin/radixin/moesin (ERM) dephosphorylation and apoptosis. Moreover, mice with conditional ASM overexpression in brain endothelium accelerated significant BBB impairment and neurodegenerative change. Overall, these results reveal a novel role for ASM in the control of neurovascular function in aging, suggesting that ASM may represent a new therapeutic target for anti-aging.

Enhancement of Virus Infection Using Dynamic Cell Culture in a Microchannel

With increasing interest in induced pluripotent stem cells (iPSCs) in the field of stem cell research, highly efficient infection of somatic cells with virus factors is gaining importance. This paper presents a method of employing microfluidic devices for dynamic cell culture and virus infection in a microchannel. The closed space in the microchannel provided a better environment for viruses to diffuse and contact cell surfaces to infect cells. The microfluidic devices were fabricated by photolithography and soft lithography. NIH/3T3 fibroblast cells were cultured in the microfluidic device in static and dynamic conditions and compared with the conventional culture method of using Petri dishes. Virus infection was evaluated using an enhanced green fluorescent protein virus as a model. Dynamic culture in the microchannel showed similar growth of cells to that in Petri dish culture, but the virus infection efficiency was four-times higher. The proposed dynamic culture system could be useful in iPSC research by providing efficient virus infection tools.

Novel peptides derived from neuropeptide Y prevent chemotherapy-induced bone marrow damage by regulating hematopoietic stem cell microenvironment

Chemotherapy-induced bone marrow damage is accompanied by acute nerve injury in the bone marrow (BM), resulting in sensory and autonomic neuropathy. Cisplatin, a popular chemotherapy drugs, induces the impairment of hematopoietic stem cells (HSCs) and bone marrow regeneration, leading to chronic bone marrow abnormalities. Previously, we reported the protective roles of neuropeptide Y (NPY) against cisplatin-induced bone marrow impairment. In this study, we identified novel peptides, generated from full-length NPY that rescued cisplatin-induced sensory neuropathy and HSC suppression by regulating cell survival in the BM microenvironment. One of these peptides, especially, showed a better protective property against these impairments compared to that seen in full-length NPY. Therefore, we suggest the NPY sequences most effective against the chemotherapy-induced bone marrow dysfunction that could be potentially useful as therapeutic agents for patients receiving chemotherapy.

The role of Purkinje cell-derived VEGF in cerebellar astrogliosis in Niemann-Pick type C mice

Niemann-Pick type C disease (NP-C) is a fatal neurodegenerative disorder caused by a deficiency of NPC1 gene function, which leads to severe neuroinflammation such as astrogliosis. While reports demonstrating neuroinflammation are prevalent in NP-C, information about the onset and progression of cerebellar astrogliosis in this disorder is lacking. Using gene targeting, we generated vascular endothelial growth factor (VEGF) conditional null mutant mice. Deletion of VEGF in cerebellar Purkinje neurons (PNs) led to a significant increase of astrogliosis in the brain of NP-C mice in addition to the loss of PNs, suggesting PN-derived VEGF as an important factor in NP-C pathology. Moreover, replenishment of VEGF in neurons improved brain pathology in NP-C mice. Overall, our data provide a new pathological perspective on cerebellar astrogliosis in NP-C and suggest the importance of VEGF as a therapeutic target for this disease. [BMB Reports 2018; 51(2): 79-84].

Piperlongumine inhibits neuroinflammation via regulating NF-κB signaling pathways in lipopolysaccharide-stimulated BV2 microglia cells

Inflammatory processes in the central nervous system are feature among biological reactions to harmful stimuli such as pathogens and damaged cells. In resting conditions, microglia are involved in immune surveillance and brain homeostasis. However, the activation of abnormal microglia can be detrimental to neurons, even resulting in neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease and Huntington's disease. Therefore, normalization of microglial activation is considered a promising strategy for developing drugs that can treat or prevent inflammation-related brain diseases. In the present study, we investigated the effects of piperlongumine, an active component of Piper longum, on lipopolysaccharide (LPS)-induced neuroinflammation using BV2 microglial cells. We found that piperlongumine significantly inhibited the production of nitric oxide and prostaglandin E2 induced by LPS. Piperlongumine also reduced the expression of inducible nitric oxide synthase and cyclooxygenase-2 as well as proinflammatory cytokines such as tumor necrosis factor-α and interleukin-6. Piperlongumine exerted its anti-neuroinflammatory effects by suppressing the nuclear factor kappa B signaling pathway. These findings suggest that piperlongumine could be a candidate agent for the treatment of inflammation-related neurodegenerative diseases.

Neuropeptide Y improves cisplatin-induced bone marrow dysfunction without blocking chemotherapeutic efficacy in a cancer mouse model

Cisplatin is the most effective and widely used chemo-therapeutic agent for many types of cancer. Unfortunately, its clinical use is limited by its adverse effects, notably bone marrow suppression leading to abnormal hematopoiesis. We previously revealed that neuropeptide Y (NPY) is responsible for the maintenance of hematopoietic stem cell (HSC) function by protecting the sympathetic nervous system (SNS) fibers survival from chemotherapy-induced bone marrow impairment. Here, we show the NPY-mediated protective effect against bone marrow dysfunction due to cisplatin in an ovarian cancer mouse model. During chemotherapy, NPY mitigates reduction in HSC abundance and destruction of SNS fibers in the bone marrow without blocking the anticancer efficacy of cisplatin, and it results in the restoration of blood cells and amelioration of sensory neuropathy. Therefore, these results suggest that NPY can be used as a potentially effective agent to improve bone marrow dysfunction during cisplatin-based cancer therapy.

Neuropeptide Y-based recombinant peptides ameliorate bone loss in mice by regulating hematopoietic stem/progenitor cell mobilization

Ovariectomy-induced bone loss is related to an increased deposition of osteoclasts on bone surfaces. We reported that the 36-amino-acid-long neuropeptide Y (NPY) could mobilize hematopoietic stem/progenitor cells (HSPCs) from the bone marrow to the peripheral blood by regulating HSPC maintenance factors and that mobilization of HSPCs ameliorated low bone density in an ovariectomy-induced osteoporosis mouse model by reducing the number of osteoclasts. Here, we demonstrated that new NPY peptides, recombined from the cleavage of the full-length NPY, showed better functionality for HSPC mobilization than the full-length peptide. These recombinant peptides mediated HSPC mobilization with greater efficiency by decreasing HSPC maintenance factors. Furthermore, treatment with these peptides reduced the number of osteoclasts and relieved ovariectomy-induced bone loss in mice more effectively than treatment with full-length NPY. Therefore, these results suggest that peptides recombined from full-length NPY can be used to treat osteoporosis.

Neuropeptide Y protects kidney against cisplatin-induced nephrotoxicity by regulating p53-dependent apoptosis pathway

Cisplatin is a platinum-based chemotherapeutic drug for treating various types of cancers. However, the use of cisplatin is limited by its negative effect on normal tissues, particularly nephrotoxicity. Various mechanisms such as DNA adduct formation, mitochondrial dysfunction, oxidative stress, and apoptosis are involved in the adverse effect induced by cisplatin treatment. Several studies have suggested that neuropeptide Y (NPY) is involved in neuroprotection as well as restoration of bone marrow dysfunction from chemotherapy induced nerve injury. However, the role of NPY in chemotherapy-induced nephrotoxicity has not been studied. Here, we show that NPY rescues renal dysfunction by reducing the expression of pro-apoptotic proteins in cisplatin induced nephrotoxicity through Y1 receptor, suggesting that NPY can protect kidney against cisplatin nephrotoxicity as a possible useful agent to prevent and treat cisplatin-induced nephrotoxicity. [BMB Reports 2016; 49(5): 288-292]

Highly efficient reprogramming and characterization of induced pluripotent stem cells by using a microwell array

Reprogramming of human somatic cells to induced pluripotent stem cells (iPSCs) enables the possibility of generating patient-specific cells. However, the low efficiency issue associated with iPSCs generation has limited iPSCs usage in research and clinical applications. In this study, we developed a high efficiency system to generate iPSCs by using a polydimethylsiloxane stencil. This device could be applied to the localization and reprogramming of human fibroblasts. Herein, a well-defined culture system based on a stencil, which supported efficient reprogramming of fibroblasts into iPSCs with 2-4 fold increase in efficacy over conventional methods, is presented. Subsequently, we prepared a multiple analysis system, which used a micro-patterned scissile microarray to characterize iPSCs. The results showed that iPSCs could be cultured into micro-patterns in a precisely controlled manner on the scissile poly(ethylene terephthalate) sheet, which was cut into pieces for subsequent analyses, indicating that this method allows multiple analyses to establish iPSC pluripotency in the same sample. Our approach provides a simple, cost-effective, but highly efficient system for the generation and characterization of iPSCs, and will serve as a powerful tool for establishing patient- and disease-specific pluripotent stem cells.

Electronic Supplementary Material

Supplementary material is available for this article at 10.1007/s13770-016-0015-0 and is accessible for authorized users.

Role of neuropeptide Y in the bone marrow hematopoietic stem cell microenvironment

The sympathetic nervous system (SNS) or neurotransmitters in the bone marrow microenvironment has been known to regulate hematopoietic stem cell (HSC) functions such as self-renewal, proliferation and differentiation. However, the specific role of neuropeptide Y (NPY) in this process remains relatively unexplored. In this study, we demonstrated that NPY deficient mice have significantly reduced HSC numbers and impaired bone marrow regeneration due to apoptotic destruction of SNS fibers and/or endothelial cells. Moreover, NPY treatment prevented bone marrow impairments in a mouse model of chemotherapy-induced SNS injury, while conditional knockout mice lacking the Y1 receptor in macrophages did not restore bone marrow dysfunction in spite of NPY injection. Transforming growth factor-beta (TGF-β) secreted by NPY-mediated Y1 receptor stimulation in macrophages plays a key role in neuroprotection and HSC survival in the bone marrow. Therefore, this study reveals a new role of NPY in bone marrow HSC microenvironment, and provides an insight into the therapeutic application of this neuropeptide. [BMB Reports 2015; 48(12): 645-646]

Two Siblings with Adolescent/Adult Onset Niemann-Pick Disease Type C in Korea

Niemann-Pick disease, type C (NP-C), is caused by NPC1 or NPC2 gene mutations. Progressive neurological, psychiatric, and visceral symptoms are characteristic. Here, we present cases of a brother (Case 1) and sister (Case 2) in their mid-20s with gait disturbance and psychosis. For the Case 1, neurological examination revealed dystonia, ataxia, vertical supranuclear-gaze palsy (VSGP), and global cognitive impairment. Case 2 showed milder, but similar symptoms, with cortical atrophy. Abdominal computed tomography showed hepatosplenomegaly in both cases. NPC1 gene sequencing revealed compound heterozygote for exon 9 (c.1552C>T [R518W]) and exon 18 (c.2780C>T [A927V]). Filipin-staining tests were also positive. When a young patient with ataxia or dystonia shows VSGP, NP-C should be considered.

Neuropeptide Y Induces Hematopoietic Stem/Progenitor Cell Mobilization by Regulating Matrix Metalloproteinase-9 Activity Through Y1 Receptor in Osteoblasts

Hematopoietic stem/progenitor cell (HSPC) mobilization is an essential homeostatic process regulated by the interaction of cellular and molecular components in bone marrow niches. It has been shown by others that neurotransmitters released from the sympathetic nervous system regulate HSPC egress from bone marrow to peripheral blood. In this study, we investigate the functional role of neuropeptide Y (NPY) on this process. NPY deficient mice had significantly impaired HSPC mobilization due to increased expression of HSPC maintenance factors by reduction of matrix metalloproteinase-9 (MMP-9) activity in bone marrow. Pharmacological or endogenous elevation of NPY led to decrease of HSPC maintenance factors expression by activating MMP-9 in osteoblasts, resulting in HSPC mobilization. Mice in which the Y1 receptor was deleted in osteoblasts did not exhibit HSPC mobilization by NPY. Furthermore, NPY treatment in ovariectomized mice caused reduction of bone loss due to HSPC mobilization. These results suggest a new role of NPY on HSPC mobilization, as well as the potential therapeutic application of this neuropeptide for stem cell-based therapy. Stem Cells 2016;34:2145-2156.

Defective Self-Renewal and Differentiation of GBA-Deficient Neural Stem Cells Can Be Restored By Macrophage Colony-Stimulating Factor

Gaucher disease (GD) is an autosomal recessive lysosomal storage disorder caused by mutations in the glucocerebrosidase gene (GBA), which encodes the lysosomal enzyme glucosylceramidase (GCase). Deficiency in GCase leads to characteristic visceral pathology and lethal neurological manifestations in some patients. Investigations into neurogenesis have suggested that neurodegenerative disorders, such as GD, could be overcome or at least ameliorated by the generation of new neurons. Bone marrow-derived mesenchymal stem cells (BM-MSCs) are potential candidates for use in the treatment of neurodegenerative disorders because of their ability to promote neurogenesis. Our objective was to examine the mechanism of neurogenesis by BM-MSCs in GD. We found that neural stem cells (NSCs) derived from a neuronopathic GD model exhibited decreased ability for self-renewal and neuronal differentiation. Co-culture of GBA-deficient NSCs with BM-MSCs resulted in an enhanced capacity for self-renewal, and an increased ability for differentiation into neurons or oligodendrocytes. Enhanced proliferation and neuronal differentiation of GBA-deficient NSCs was associated with elevated release of macrophage colony-stimulating factor (M-CSF) from BM-MSCs. Our findings suggest that soluble M-CSF derived from BM-MSCs can modulate GBA-deficient NSCs, resulting in their improved proliferation and neuronal differentiation.

AMD3100 improves ovariectomy-induced osteoporosis in mice by facilitating mobilization of hematopoietic stem/progenitor cells

Inhibition of an increase of osteoclasts has become the most important treatment for osteoporosis. The CXCR4 antagonist, AMD3100, plays an important role in the mobilization of osteoclast precursors within bone marrow (BM). However, the actual therapeutic impact of AMD3100 in osteoporosis has not yet been ascertained. Here we demonstrate the therapeutic effect of AMD3100 in the treatment of ovariectomy-induced osteoporosis in mice. We found that treatment with AMD3100 resulted in direct induction of release of SDF-1 from BM to blood and mobilization of hematopoietic stem/progenitor cells (HSPCs) in an osteoporosis model. AMD3100 prevented bone density loss after ovariectomy by mobilization of HSPCs, suggesting a therapeutic strategy to reduce the number of osteoclasts on bone surfaces. These findings support the hypothesis that treatment with AMD3100 can result in efficient mobilization of HSPCs into blood through direct blockade of the SDF-1/CXCR4 interaction in BM and can be considered as a potential new therapeutic intervention for osteoporosis. [BMB Reports 2014; 47(8): 439-444]

Neuropeptide Y regulates the hematopoietic stem cell microenvironment and prevents nerve injury in the bone marrow

Many reports have revealed the importance of the sympathetic nervous system (SNS) in the control of the bone marrow environment. However, the specific role of neuropeptide Y (NPY) in this process has not been systematically studied. Here we show that NPY-deficient mice have significantly reduced hematopoietic stem cell (HSC) numbers and impaired regeneration in bone marrow due to apoptotic destruction of SNS fibers and/or endothelial cells. Furthermore, pharmacological elevation of NPY prevented bone marrow impairments in a mouse model of chemotherapy-induced SNS injury, while NPY injection into conditional knockout mice lacking the Y1 receptor in macrophages did not relieve bone marrow dysfunction. These results indicate that NPY promotes neuroprotection and restores bone marrow dysfunction from chemotherapy-induced SNS injury through the Y1 receptor in macrophages. They also reveal a new role of NPY as a regulator of the bone marrow microenvironment and highlight the potential therapeutic value of this neuropeptide.

CCL2 induces neural stem cell proliferation and neuronal differentiation in Niemann-Pick type C mice

Niemann-Pick type C disease (NP-C) is a rare and ultimately fatal lysosomal storage disorder with variable neurologic symptoms. Loss of neuronal function and neuronal cell death occur in the NP-C brain, similar to the findings for other neurodegenerative diseases. Targeting of neuronal cells in the brain therefore represents a potential clinical intervention strategy to reduce the rate of disease progression and improve the quality of life. We previously reported that bone marrow stem cells show a neurogenic effect through CCL2 (also known as monocyte chemoattractant protein-1, MCP-1) secretion in the brains of NP-C mice. However, the direct effect of CCL2 on neurogenesis has not been ascertained. Here, to define neurogenic effects of CCL2 in NP-C, we applied human recombinant CCL2 to neural stem cells (NSCs) derived from NP-C mice. CCL2-treated NSCs showed significantly increased capacity for self-renewal, proliferation and neuronal differentiation. Similar results were observed in the subventricular zone of NP-C mice after CCL2 treatment. Furthermore, infusion of CCL2 into the NP-C mouse brain resulted in reduction of neuroinflammation. Taken together, our results demonstrate that CCL2 is a potential new therapeutic agent for NP-C.

Highly reproducible quantification of apoptotic cells using micropatterned culture of neurons

The quantification of apoptotic cells is an integral component of many cell-based assays in biological studies. However, current methods for quantifying apoptotic cells using conventional random cultures have shown great limitations, especially for the quantification of primary neurons. Randomly distributed neurons under primary culture conditions can lead to biased estimates, and vastly different estimates of cell numbers can be produced within the same experiment. In this study, we developed a simple, accurate, and reliable technique for quantifying apoptotic neurons by means of micropatterned cell cultures. A polydimethylsiloxane (PDMS) microstencil was used as a physical mask for micropatterning cell cultures, and primary granular neurons (GNs) were successfully cultured within the micropattern-confined regions and homogeneously distributed over the entire field of each pattern. As compared with the conventional method based on random cultures, the micropatterned culture method allowed for highly reproducible quantification of apoptotic cells. These results were also confirmed by using GNs derived from mice with neurodegeneration. We hope that this micropatterning method based on the use of a PDMS microstencil can overcome the technical obstacles existing in current biological studies and will serve as a powerful tool for facilitating the study of apoptosis-involved diseases.

Acid sphingomyelinase modulates the autophagic process by controlling lysosomal biogenesis in Alzheimer's disease

Acid sphingomyelinase activity is increased in brain and plasma of mice and patients with Alzheimer’s disease and its inhibition represents a potential new therapeutic intervention for this disease.

In Alzheimer’s disease (AD), abnormal sphingolipid metabolism has been reported, although the pathogenic consequences of these changes have not been fully characterized. We show that acid sphingomyelinase (ASM) is increased in fibroblasts, brain, and/or plasma from patients with AD and in AD mice, leading to defective autophagic degradation due to lysosomal depletion. Partial genetic inhibition of ASM (ASM^+/−) in a mouse model of familial AD (FAD; amyloid precursor protein [APP]/presenilin 1 [PS1]) ameliorated the autophagocytic defect by restoring lysosomal biogenesis, resulting in improved AD clinical and pathological findings, including reduction of amyloid-β (Aβ) deposition and improvement of memory impairment. Similar effects were noted after pharmacologic restoration of ASM to the normal range in APP/PS1 mice. Autophagic dysfunction in neurons derived from FAD patient induced pluripotent stem cells (iPSCs) was restored by partial ASM inhibition. Overall, these results reveal a novel mechanism of ASM pathogenesis in AD that leads to defective autophagy due to impaired lysosomal biogenesis and suggests that partial ASM inhibition is a potential new therapeutic intervention for the disease.

Inhibition of GM3 synthase attenuates neuropathology of Niemann-Pick disease Type C. by affecting sphingolipid metabolism

In several lysosomal storage disorders, including Niemann-Pick disease Type C (NP-C), sphingolipids, including glycosphingolipids, particularly gangliosides, are the predominant storage materials in the brain, raising the possibility that accumulation of these lipids may be involved in the NP-C neurodegenerative process. However, correlation of these accumulations and NP-C neuropathology has not been fully characterized. Here we derived NP-C mice with complete and partial deletion of the Siat9 (encoding GM3 synthase) gene in order to investigate the role of ganglioside in NP-C pathogenesis. According to our results, NPC mice with homozygotic deletion of GM3 synthase exhibited an enhanced neuropathological phenotype and died significantly earlier than NP-C mice. Notably, in contrast to complete depletion, NP-C mice with partial deletion of the GM3 synthase gene showed ameliorated NP-C neuropathology, including motor disability, demyelination, and abnormal accumulation of cholesterol and sphingolipids. These findings indicate the crucial role of GM3 synthesis in the NP-C phenotype and progression of CNS pathologic abnormality, suggesting that well-controlled inhibition of GM3 synthesis could be used as a therapeutic strategy.

Bone marrow-derived mesenchymal stem cells contribute to the reduction of amyloid-β deposits and the improvement of synaptic transmission in a mouse model of pre-dementia Alzheimer's disease

The remarkable potentiality of bone marrow-derived mesenchymal stem cells (BM-MSCs) after transplantation to models of neurological disease and injury has been described. We have previously published data confirming the influence of BM-MSCs on β-amyloid (Aβ) deposition in an Alzheimer's disease (AD) mouse model. However, therapeutic approaches in neurological diseases such as AD, including those for BM-MSCs, are increasingly centered on the potential for prophylactic therapy in pro-dromal states where the underlying cause of the disease is apparent but functional deficits are not. In order to investigate whether BM-MSCs could have a beneficial effect in high-risk pre-dementia AD individuals, we treated young AD mice, at an age at which they display neuropathological, but not cognitive features of AD. Following a single intra-cerebral injection of BM-MSCs, interestingly, we found a significant decrease in the cerebral Aβ deposition compared with controls treated with PBS that was sustained up to 2 months post-injection. Expression of dynamin 1 and Synapsin 1, key pre-synaptic proteins associated with synaptic transmission, which are typically decreased in brains of AD patients, were considerably enhanced in the brains of AD mice treated with BM-MSCs and this response was sustained beyond 2 months. These data demonstrate that BM-MSCs produce an acute reduction in Aβ deposits and facilitate changes in key proteins required for synaptic transmission. These findings suggest that BM-MSC transplantation warrants further investigation as a potential therapy for early intervention in pro-dromal AD.

Bone-marrow-derived mesenchymal stem cells promote proliferation and neuronal differentiation of Niemann-Pick type C mouse neural stem cells by upregulation and secretion of CCL2

Niemann-Pick type C (NP-C) disease is a neurodegenerative disorder characterized neuropathologically by ballooned neurons distended with lipid storage and widespread neuronal loss. Neural stem cells (NSC) derived from NP-C disease models have decreased ability for self-renewal and neuronal differentiation. Investigation of neurogenesis in the adult brain has suggested that NP-C disease can be overcome, or at least ameliorated, by the generation of new neurons. Bone-marrow-derived mesenchymal stem cells (BM-MSCs) are regarded as potential candidates for use in the treatment of neurodegenerative disorders because of their ability to promote neurogenesis. The underlying mechanisms of BM-MSC-induced promotion of neurogenesis, however, have not been resolved. The aim of the present study was to examine the mechanism of neurogenesis by BM-MSCs in NP-C disease. Coculture of embryonic NSCs from NP-C mice that exhibit impaired ability for self-renewal and decreased rates of neuronal differentiation with BM-MSCs resulted in an enhanced capacity for self-renewal and an increased ability for differentiation into neurons or oligodendrocytes. In addition, results of in vivo studies have demonstrated that transplantation of intracerebral BM-MSCs resulted in stimulated proliferation and neuronal differentiation of NSCs within the subventricular zone. Of particular interest, enhanced proliferation and neuronal differentiation of endogenous NP-C mouse NSCs showed an association with elevated release of the chemokine (C-C motif) ligand 2 (CCL2) from BM-MSCs. These effects suggest that soluble CCL2 derived from BM-MSCs can modulate endogenous NP-C NSCs, resulting in their improved proliferation and neuronal differentiation in mice.