Selective Inhibition of the Interaction between SARS-CoV-2 Spike S1 and ACE2 by SPIDAR Peptide Induces Anti-Inflammatory Therapeutic Responses

Peptide S4 is an entry inhibitor of SARS-CoV-2 infection

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses a significant socioeconomic burden, and combating COVID-19 is imperative. Blocking the SARS-CoV-2 RBD-ACE2 interaction is a promising therapeutic approach for viral infections, as SARS-CoV-2 binds to the ACE2 receptors of host cells via the RBD of spike proteins to infiltrate these cells. We used computer-aided drug design technology and cellular experiments to screen for peptide S4 with high affinity and specificity for the human ACE2 receptor through structural analysis of SARS-CoV-2 and ACE2 interactions. Cellular experiments revealed that peptide S4 effectively inhibited SARS-CoV-2 and HCoV-NL63 viruses from infecting host cells and was safe for cells at effective concentrations. Based on these findings, peptide S4 may be a potential pharmaceutical agent for clinical application in the treatment of the ongoing SARS-CoV-2 pandemic.

Muscle-building supplement β-hydroxy β-methylbutyrate stimulates the maturation of oligodendroglial progenitor cells to oligodendrocytes

Oligodendrocytes are the myelinating cells in the CNS and multiple sclerosis (MS) is a demyelinating disorder that is characterized by progressive loss of myelin. Although oligodendroglial progenitor cells (OPCs) should be differentiated into oligodendrocytes, for multiple reasons, OPCs fail to differentiate into oligodendrocytes in MS. Therefore, increasing the maturation of OPCs to oligodendrocytes may be of therapeutic benefit for MS. The β-hydroxy β-methylbutyrate (HMB) is a muscle-building supplement in humans and this study underlines the importance of HMB in stimulating the maturation of OPCs to oligodendrocytes. HMB treatment upregulated the expression of different maturation markers including PLP, MBP, and MOG in cultured OPCs. Double-label immunofluorescence followed by immunoblot analyses confirmed the upregulation of OPC maturation by HMB. While investigating mechanisms, we found that HMB increased the maturation of OPCs isolated from peroxisome proliferator-activated receptor β-/- (PPARβ-/-) mice, but not PPARα-/- mice. Similarly, GW6471 (an antagonist of PPARα), but not GSK0660 (an antagonist of PPARβ), inhibited HMB-induced maturation of OPCs. GW9662, a specific inhibitor of PPARγ, also could not inhibit HMB-mediated stimulation of OPC maturation. Furthermore, PPARα agonist GW7647, but neither PPARβ agonist GW0742 nor PPARγ agonist GW1929, alone increased the maturation of OPCs. Finally, HMB treatment of OPCs led to the recruitment of PPARα, but neither PPARβ nor PPARγ, to the PLP gene promoter. These results suggest that HMB stimulates the maturation of OPCs via PPARα and that HMB may have therapeutic prospects in remyelination.

Identification of Cinnamein, a Component of Balsam of Tolu/Peru, as a New Ligand of PPARα for Plaque Reduction and Memory Protection in a Mouse Model of Alzheimer's Disease

Background

Despite intense investigations, no effective treatment is yet available to reduce plaques and protect memory and learning in patients with Alzheimer's disease (AD), the most common neurodegenerative disorder. Therefore, it is important to identify a non-toxic, but effective, treatment option for AD.

Objective

Cinnamein, a nontoxic compound, is naturally available in Balsam of Peru and Tolu Balsam. We examined whether cinnamein treatment could decrease plaques and improve cognitive functions in 5XFAD mouse model of AD.

Methods

We employed in silico analysis, time-resolved fluorescence energy transfer assay, thermal shift assay, primary neuron isolation, western blot, immunostaining, immunohistochemistry, Barnes maze, T maze, and open field behavior.

Results

Oral administration of cinnamein led to significant reduction in amyloid-β plaque deposits in the brain and protection of spatial learning and memory in 5XFAD mice. Peroxisome proliferator-activated receptor alpha (PPARα), a nuclear hormone receptor, is involved in plaque lowering and increase in hippocampal plasticity. While investigating underlying mechanisms, we found that cinnamein served as a ligand of PPARα. Accordingly, oral cinnamein upregulated the level of PPARα, but not PPARβ, in the hippocampus, and remained unable to decrease plaques from the hippocampus and improve memory and learning in 5XFAD mice lacking PPARα. While A disintegrin and metalloproteinase domain-containing protein 10 (ADAM10) is one of the drivers of nonamyloidogenic pathway, transcription factor EB (TFEB) is considered as the master regulator of autophagy. Cinnamein treatment was found to upregulate both ADAM10 and TFEB in the brain of 5XFAD mice via PPARα.

Conclusions

Our results suggest that this balsam component may have therapeutic importance in AD.

A Piecewise Design Approach to Engineering a Miniature ACE2 Mimic to Bind SARS-CoV-2

As the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues its global spread, the exploration of novel therapeutic and diagnostic strategies is still needed. The virus enters host cells by binding the angiotensin-converting enzyme 2 (ACE2) receptor through the spike protein. Here, we develop an engineered, small, stable, and catalytically inactive version of ACE2, termed miniature ACE2 (mACE2), designed to bind the spike protein with high affinity. Employing a magnetic nanoparticle-based assay, we harnessed the strong binding affinity of mACE2 to develop a sensitive and specific platform for the detection or neutralization of SARS-CoV-2. Our findings highlight the potential of engineered mACE2 as a valuable tool in the fight against SARS-CoV-2. The success of developing such a small reagent based on a piecewise molecular design serves as a proof-of-concept approach for the rapid deployment of such agents to diagnose and fight other viral diseases.

Design and Characterization of a New Formulation for the Delivery of COVID-19-mRNA Vaccine to the Nasal Mucosa

Chitosan, a natural polysaccharide derived from chitin, possesses biocompatibility, biodegradability, and mucoadhesive characteristics, making it an attractive material for the delivery of mRNA payloads to the nasal mucosa and promoting their uptake by target cells such as epithelial and immune cells (e.g., dendritic cells and macrophages). In this project, we aimed at developing novel lipid-based nanoformulations for mRNA delivery to counteract the pandemic caused by SARS-CoV-2 virus. The formulations achieved a mRNA encapsulation efficiency of ~80.2% with chitosan-lipid nanoparticles, as measured by the RiboGreen assay. Furthermore, the evaluation of SARS-CoV-2 Spike (S) receptor-binding domain (RBD) expression via ELISA for our vaccine formulations showed transfection levels in human embryonic kidney cells (HEK 293), lung carcinoma cells (A549), and dendritic cells (DC 2.4) equal to 9.9 ± 0.1 ng/mL (174.7 ± 1.1 fold change from untreated cells (UT)), 7.0 ± 0.2 ng/mL (128.1 ± 4.9 fold change from UT), and 0.9 ± 0.0 ng/mL (18.0 ± 0.1 fold change from UT), respectively. Our most promising vaccine formulation was also demonstrated to be amenable to lyophilization with minimal degradation of loaded mRNA, paving the way towards a more accessible and stable vaccine. Preliminary in vivo studies in mice were performed to assess the systemic and local immune responses. Nasal bronchoalveolar lavage fluid (BALF) wash showed that utilizing the optimized formulation resulted in local antibody concentrations and did not trigger any systemic antibody response. However, if further improved and developed, it could potentially contribute to the management of COVID-19 through nasopharyngeal immunization strategies.

Cinnamic acid, a natural plant compound, exhibits neuroprotection in a mouse model of Sandhoff disease via PPARα

Tay-Sachs disease (TSD) and its severe form Sandhoff disease (SD) are autosomal recessive lysosomal storage metabolic disorders, which often result into excessive GM2 ganglioside accumulation predominantly in lysosomes of nerve cells. Although patients with these diseases appear normal at birth, the progressive accumulation of undegraded GM2 gangliosides in neurons leads to early death accompanied by manifestation of motor difficulties and gradual loss of behavioral skills. Unfortunately, there is still no effective treatment available for TSD/SD. The present study highlights the importance of cinnamic acid (CA), a naturally occurring aromatic fatty acid present in a number of plants, in inhibiting the disease process in a transgenic mouse model of SD. Oral administration of CA significantly attenuated glial activation and inflammation and reduced the accumulation of GM2 gangliosides/glycoconjugates in the cerebral cortex of Sandhoff mice. Besides, oral CA also improved behavioral performance and increased the survival of Sandhoff mice. While assessing the mechanism, we found that oral administration of CA increased the level of peroxisome proliferator-activated receptor α (PPARα) in the brain of Sandhoff mice and that oral CA remained unable to reduce glycoconjugates, improve behavior and increase survival in Sandhoff mice lacking PPARα. Our results indicate a beneficial function of CA that utilizes a PPARα-dependent mechanism to halt the progression of SD and thereby increase the longevity of Sandhoff mice.

Lipid-Lowering Drug Gemfibrozil Protects Mice from Tay-Sachs Disease via Peroxisome Proliferator-Activated Receptor α

Tay-Sachs disease (TSD) is a progressive heritable neurodegenerative disorder characterized by the deficiency of the lysosomal β-hexosaminidase enzyme (Hex-/-) and the storage of GM2 ganglioside, as well as other related glycoconjugates. Along with motor difficulties, TSD patients also manifest a gradual loss of skills and behavioral problems, followed by early death. Unfortunately, there is no cure for TSD; however, research on treatments and therapeutic approaches is ongoing. This study underlines the importance of gemfibrozil (GFB), an FDA-approved lipid-lowering drug, in inhibiting the disease process in a transgenic mouse model of Tay-Sachs. Oral administration of GFB significantly suppressed glial activation and inflammation, while also reducing the accumulation of GM2 gangliosides/glycoconjugates in the motor cortex of Tay-Sachs mice. Furthermore, oral GFB improved behavioral performance and increased the life expectancy of Tay-Sachs mice. While investigating the mechanism, we found that oral administration of GFB increased the level of peroxisome proliferator-activated receptor α (PPARα) in the brain of Tay-Sachs mice, and that GFB remained unable to reduce glycoconjugates and improve behavior and survival in Tay-Sachs mice lacking PPARα. Our results indicate a beneficial function of GFB that employs a PPARα-dependent mechanism to halt the progression of TSD and increase longevity in Tay-Sachs mice.

Efficacies of S-nitrosoglutathione (GSNO) and GSNO reductase inhibitor in SARS-CoV-2 spike protein induced acute lung disease in mice

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which initially surfaced in late 2019, often triggers severe pulmonary complications, encompassing various disease mechanisms such as intense lung inflammation, vascular dysfunction, and pulmonary embolism. Currently, however, there's no drug addressing all these mechanisms simultaneously. This study explored the multi-targeting potential of S-nitrosoglutathione (GSNO) and N6022, an inhibitor of GSNO reductase (GSNOR) on markers of inflammatory, vascular, and thrombotic diseases related to COVID-19-induced acute lung disease. For this, acute lung disease was induced in C57BL/6 mice through intranasal administration of recombinant SARS-CoV-2 spike protein S1 domain (SP-S1). The mice exhibited fever, body weight loss, and increased blood levels and lung expression of proinflammatory cytokines (e.g., TNF-α and IL-6) as well as increased vascular inflammation mediated by ICAM-1 and VCAM-1 and lung infiltration by immune cells (e.g., neutrophils, monocytes, and activated cytotoxic and helper T cells). Further, the mice exhibited increased lung hyperpermeability (lung Evans blue extravasation) leading to lung edema development as well as elevated blood coagulation factors (e.g., fibrinogen, thrombin, activated platelets, and von Willebrand factor) and lung fibrin deposition. Similar to the patients with COVID-19, male mice showed more severe disease than female mice, along with higher GSNOR expression in the lungs. Optimization of GSNO by treatment with exogenous GSNO or inhibition of GSNOR by N6022 (or GSNO knockout) protects against SP-S1-induced lung diseases in both genders. These findings provide evidence for the potential efficacies of GSNO and GSNOR inhibitors in addressing the multi-mechanistic nature of SARS-CoV-2 SP-associated acute-lung disease.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Spike Protein S1 Induces Methylglyoxal-Derived Hydroimidazolone/Receptor for Advanced Glycation End Products (MG-H1/RAGE) Activation to Promote Inflammation in Human Bronchial BEAS-2B Cells

The pathogenesis of coronavirus disease 2019 (COVID-19) is associated with a hyperinflammatory response. The mechanisms of SARS-CoV-2-induced inflammation are scantly known. Methylglyoxal (MG) is a glycolysis-derived byproduct endowed with a potent glycating action, leading to the formation of advanced glycation end products (AGEs), the main one being MG-H1. MG-H1 exerts strong pro-inflammatory effects, frequently mediated by the receptor for AGEs (RAGE). Here, we investigated the involvement of the MG-H1/RAGE axis as a potential novel mechanism in SARS-CoV-2-induced inflammation by resorting to human bronchial BEAS-2B and alveolar A549 epithelial cells, expressing different levels of the ACE2 receptor (R), exposed to SARS-CoV-2 spike protein 1 (S1). Interestingly, we found in BEAS-2B cells that do not express ACE2-R that S1 exerted a pro-inflammatory action through a novel MG-H1/RAGE-based pathway. MG-H1 levels, RAGE and IL-1β expression levels in nasopharyngeal swabs from SARS-CoV-2-positive and -negative individuals, as well as glyoxalase 1 expression, the major scavenging enzyme of MG, seem to support the results obtained in vitro. Altogether, our findings reveal a novel mechanism involved in the inflammation triggered by S1, paving the way for the study of the MG-H1/RAGE inflammatory axis in SARS-CoV-2 infection as a potential therapeutic target to mitigate COVID-19-associated pathogenic inflammation.

Tau fibrils induce glial inflammation and neuropathology via TLR2 in Alzheimer's disease-related mouse models

Glial activation and inflammation coincide with neurofibrillary tangle (NFT) formation in neurons. However, the mechanism behind the interaction between tau fibrils and glia is poorly understood. Here, we found that tau preformed fibrils (PFFs) caused induction of inflammation in microglia by specifically activating the TLR2/MyD88, but not the TLR4/MyD88, pathway. Accordingly, the WT TLR2-interacting domain of MyD88 (wtTIDM) peptide inhibited tau PFF-induced activation of the TLR2/MyD88/NF-κB pathway, resulting in reduced inflammation. Nasal administration of wtTIDM in P301S tau-expressing PS19 mice was found to inhibit gliosis and inflammatory markers, as well as to reduce pathogenic tau in the hippocampus, resulting in improved cognitive behavior in PS19 mice. The inhibitory effect of wtTIDM on tau pathology was absent in PS19 mice lacking TLR2, reinforcing the essential involvement of TLR2 in wtTIDM-mediated effects in vivo. Studying the mechanism further, we found that the tau promoter harbored a potential NF-κB-binding site and that proinflammatory molecules increased transcription of tau in neurons via NF-κB. These results suggest that tau-induced neuroinflammation and neuropathology require TLR2 and that neuroinflammation directly upregulates tau in neurons via NF-κB, highlighting a direct connection between inflammation and tauopathy.

Association of Obesity with SARS-CoV-2 and Its Relationship with the Humoral Response Prior to Vaccination in the State of Mexico: A Cross-Sectional Study

Obesity is associated with an increased risk of contracting infections. This study aimed to estimate the risk of COVID-19 infection associated with obesity and to assess its role in the specific antibody response against SARS-CoV-2 in 2021. This study included 980 participants from the State of Mexico who participated in a serological survey where they were tested for SARS-CoV-2 IgG anti-S1/S2 and anti-RBD antibodies and asked for height, weight, and previous infection data via a questionnaire. Of the cohort of 980 participants, 451 (46.02%) were seropositive at the time of recruitment (45.2% symptomatic and 54.8% asymptomatic). The risk of SARS-CoV-2 infection with obesity was 2.18 (95% CI: 1.51-3.16), 2.58 (95% CI: 1.63-4.09), and 1.88 (95% CI: 1.18-2.98) for seropositive, asymptomatic, and symptomatic individuals, respectively, compared to those with normal weight. Anti-S1/S2 and anti-RBD IgG antibodies tended to be higher in overweight and obese participants in the seropositive group and stratified by different obesity classes. Additionally, there was a positive correlation between anti-S1/S2 and anti-RBD IgG antibodies and BMI in both men and women in the seropositive group. Obesity is an independent risk factor for SARS-CoV-2 infection when adjusted for confounding variables; however, the relationship between BMI and anti-S1/S2 and anti-RBD IgG antibody levels differed markedly in the presence or absence of symptoms.

Muscle-building supplement β-hydroxy β-methylbutyrate binds to PPARα to improve hippocampal functions in mice

This study underlines the importance of β-hydroxy β-methylbutyrate (HMB), a muscle-building supplement in human, in increasing mouse hippocampal plasticity. Detailed proteomic analyses reveal that HMB serves as a ligand of peroxisome proliferator-activated receptor α (PPARα), a nuclear hormone receptor involved in fat metabolism, via interaction with the Y314 residue. Accordingly, HMB is ineffective in increasing plasticity of PPARα-/- hippocampal neurons. While lentiviral establishment of full-length PPARα restores the plasticity-promoting effect of HMB in PPARα-/- hippocampal neurons, lentiviral transduction of Y314D-PPARα remains unable to do that, highlighting the importance of HMB's interaction with the Y314 residue. Additionally, oral HMB improves spatial learning and memory and reduces plaque load in 5X familial Alzheimer's disease (5XFAD) mice, but not in 5XFADΔPPARα mice (5XFAD lacking PPARα), indicating the involvement of PPARα in HMB-mediated neuroprotection in 5XFAD mice. These results delineate neuroprotective functions of HMB and suggest that this widely used supplement may be repurposed for AD.

Prenol, but Not Vitamin C, of Fruit Binds to SARS-CoV-2 Spike S1 to Inhibit Viral Entry: Implications for COVID-19

Fruit consumption may be beneficial for fighting infection. Although vitamin C is the celebrity component of fruit, its role in COVID-19 is unclear. Because spike S1 of SARS-CoV-2 binds to angiotensin-converting enzyme 2 (ACE2) on host cells to enter the cell and initiate COVID-19, using an α-screen-based assay, we screened vitamin C and other components of fruit for inhibiting the interaction between spike S1 and ACE2. We found that prenol, but neither vitamin C nor other major components of fruit (e.g., cyanidin and rutin), reduced the interaction between spike S1 and ACE2. Thermal shift assays indicated that prenol associated with spike S1, but not ACE2, and that vitamin C remained unable to do so. Although prenol inhibited the entry of pseudotyped SARS-CoV-2, but not vesicular stomatitis virus, into human ACE2-expressing HEK293 cells, vitamin C blocked the entry of pseudotyped vesicular stomatitis virus, not SARS-CoV-2, indicating the specificity of the effect. Prenol, but not vitamin C, decreased SARS-CoV-2 spike S1-induced activation of NF-κB and the expression of proinflammatory cytokines in human A549 lung cells. Moreover, prenol also decreased the expression of proinflammatory cytokines induced by spike S1 of N501Y, E484K, Omicron, and Delta variants of SARS-CoV-2. Finally, oral treatment with prenol reduced fever, decreased lung inflammation, enhanced heart function, and improved locomotor activities in SARS-CoV-2 spike S1-intoxicated mice. These results suggest that prenol and prenol-containing fruits, but not vitamin C, may be more beneficial for fighting against COVID-19.

Advances in developing ACE2 derivatives against SARS-CoV-2

Extensive immune evasion of SARS-CoV-2 rendered therapeutic antibodies ineffective in the COVID-19 pandemic. Propagating SARS-CoV-2 variants are characterised by immune evasion capacity through key amino acid mutations, but can still bind human angiotensin-converting enzyme 2 (ACE2) through the spike protein and are, thus, sensitive to ACE2-mimicking decoys as inhibitors. In this Review, we examine advances in the development of ACE2 derivatives from the past 3 years, including the recombinant ACE2 proteins, ACE2-loaded extracellular vesicles, ACE2-mimicking antibodies, and peptide or mini-protein mimetics of ACE2. Several ACE2 derivatives are granted potent neutralisation efficacy against SARS-CoV-2 variants that rival or surpass endogenous antibodies by various auxiliary techniques such as chemical modification and practical recombinant design. The derivatives also represent enhanced production efficiency and improved bioavailability. In addition to these derivatives of ACE2, new effective therapeutics against SARS-CoV-2 variants are expected to be developed.

Activation of PPARα Exhibits Therapeutic Efficacy in a Mouse Model of Juvenile Neuronal Ceroid Lipofuscinosis

Juvenile neuronal ceroid lipofuscinosis (JNCL) is a fatal inherited neurodegenerative disease of children that occurs because of defective function of the lysosomal membrane glycoprotein CLN3. JNCL features glial activation and accumulation of autofluorescent storage material containing subunit c of mitochondrial ATP synthase (SCMAS), ultimately resulting into neuronal loss. Until now, no effective therapy is available for JNCL. This study underlines the possible therapeutic importance of gemfibrozil, an activator of peroxisome proliferator-activated receptor α (PPARα) and a lipid-lowering drug approved by the Food and Drug Administration in an animal model of JNCL. Oral gemfibrozil treatment reduced microglial and astroglial activation, attenuated neuroinflammation, restored the level of transcription factor EB (TFEB; the master regulator of lysosomal biogenesis), and decreased the accumulation of storage material SCMAS in somatosensory barrel field (SBF) cortex of Cln3Δex7/8 (Cln3ΔJNCL) mice of both sexes. Accordingly, gemfibrozil treatment also improved locomotor activities of Cln3ΔJNCL mice. While investigating the mechanism, we found marked loss of PPARα in the SBF cortex of Cln3ΔJNCL mice, which increased after gemfibrozil treatment. Oral gemfibrozil also stimulated the recruitment of PPARα to the Tfeb gene promoter in vivo in the SBF cortex of Cln3ΔJNCL mice, indicating increased transcription of Tfeb in the CNS by gemfibrozil treatment via PPARα. Moreover, disease pathologies aggravated in Cln3ΔJNCL mice lacking PPARα (Cln3ΔJNCLΔPPARα) and gemfibrozil remained unable to decrease SCMAS accumulation, reduce glial activation, and improve locomotor performance of Cln3ΔJNCLΔPPARα mice. These results suggest that activation of PPARα may be beneficial for JNCL and that gemfibrozil may be repurposed for the treatment of this incurable disease.SIGNIFICANCE STATEMENT Despite intense investigations, no effective therapy is available for JNCL, an incurable inherited lysosomal storage disorder. Here, we delineate that oral administration of gemfibrozil, a lipid-lowering drug, decreases glial inflammation, normalizes and/or upregulates TFEB, and reduces accumulation of autofluorescent storage material in SBF cortex to improve locomotor activities in Cln3Δex7/8 (Cln3ΔJNCL) mice. Aggravation of disease pathology in Cln3ΔJNCL mice lacking PPARα (Cln3ΔJNCLΔPPARα) and inability of gemfibrozil to decrease SCMAS accumulation, reduce glial activation, and improve locomotor performance of Cln3ΔJNCLΔPPARα mice delineates an important role of PPARα in this process. These studies highlight a new property of gemfibrozil and indicate its possible therapeutic use in JNCL patients.

Variants of SARS-CoV-2: Influences on the Vaccines' Effectiveness and Possible Strategies to Overcome Their Consequences

The immune response elicited by the current COVID-19 vaccinations declines with time, especially among the immunocompromised population. Furthermore, the emergence of novel SARS-CoV-2 variants, particularly the Omicron variant, has raised serious concerns about the efficacy of currently available vaccines in protecting the most vulnerable people. Several studies have reported that vaccinated people get breakthrough infections amid COVID-19 cases. So far, five variants of concern (VOCs) have been reported, resulting in successive waves of infection. These variants have shown a variable amount of resistance towards the neutralising antibodies (nAbs) elicited either through natural infection or the vaccination. The spike (S) protein, membrane (M) protein, and envelope (E) protein on the viral surface envelope and the N-nucleocapsid protein in the core of the ribonucleoprotein are the major structural vaccine target proteins against COVID-19. Among these targets, S Protein has been extensively exploited to generate effective vaccines against COVID-19. Hence, amid the emergence of novel variants of SARS-CoV-2, we have discussed their impact on currently available vaccines. We have also discussed the potential roles of S Protein in the development of novel vaccination approaches to contain the negative consequences of the variants' emergence and acquisition of mutations in the S Protein of SARS-CoV-2. Moreover, the implications of SARS-CoV-2's structural proteins were also discussed in terms of their variable potential to elicit an effective amount of immune response.

Treadmill workout activates PPARα in the hippocampus to upregulate ADAM10, decrease plaques and improve cognitive functions in 5XFAD mouse model of Alzheimer's disease

Although liver is rich in peroxisome proliferator-activated receptor α (PPARα), recently we have described the presence of PPARα in hippocampus where it is involved in non-amyloidogenic metabolism of amyloid precursor protein (APP) via ADAM10, decreasing amyloid plaques and improving memory and learning. However, mechanisms to upregulate PPARα in vivo in the hippocampus are poorly understood. Regular exercise has multiple beneficial effects on human health and here, we describe the importance of regular mild treadmill exercise in upregulating PPARα in vivo in the hippocampus of 5XFAD mouse model of Alzheimer's disease. We also demonstrate that treadmill exercise remained unable to stimulate ADAM10, reduce plaque pathology and improve cognitive functions in 5XFADΔPPARα mice (5XFAD mice lacking PPARα). On the other hand, treadmill workout increased ADAM10, decreased plaque pathology and protected memory and learning in 5XFADΔPPARβ mice (5XFAD mice lacking PPARβ). Moreover, the other PPAR (PPARγ) also did not play any role in the transcription of ADAM10 in vivo in the hippocampus of treadmill exercised 5XFAD mice. These results underline an important role of PPARα in which treadmill exercise remains unable to exhibit neuroprotection in the hippocampus in the absence of PPARα.

Upregulation of DJ-1 in Dopaminergic Neurons by a Physically-Modified Saline: Implications for Parkinson's Disease

Parkinson's disease (PD) is the second most common neurodegenerative disorder in human and loss-of-functions DJ-1 mutations are associated with a familial form of early onset PD. Functionally, DJ-1 (PARK7), a neuroprotective protein, is known to support mitochondria and protect cells from oxidative stress. Mechanisms and agents by which the level of DJ-1 could be increased in the CNS are poorly described. RNS60 is a bioactive aqueous solution created by exposing normal saline to Taylor-Couette-Poiseuille flow under high oxygen pressure. Recently we have described neuroprotective, immunomodulatory and promyelinogenic properties of RNS60. Here we delineate that RNS60 is also capable of increasing the level of DJ-1 in mouse MN9D neuronal cells and primary dopaminergic neurons, highlighting another new neuroprotective effect of RNS60. While investigating the mechanism we found the presence of cAMP response element (CRE) in DJ-1 gene promoter and stimulation of CREB activation in neuronal cells by RNS60. Accordingly, RNS60 treatment increased the recruitment of CREB to the DJ-1 gene promoter in neuronal cells. Interestingly, RNS60 treatment also induced the enrollment of CREB-binding protein (CBP), but not the other histone acetyl transferase p300, to the promoter of DJ-1 gene. Moreover, knockdown of CREB by siRNA led to the inhibition of RNS60-mediated DJ-1 upregulation, indicating an important role of CREB in DJ-1 upregulation by RNS60. Together, these results indicate that RNS60 upregulates DJ-1 in neuronal cells via CREB-CBP pathway. It may be of benefit for PD and other neurodegenerative disorders.

Regression of Lung Cancer in Mice by Intranasal Administration of SARS-CoV-2 Spike S1

This study underlines the importance of SARS-CoV-2 spike S1 in prompting death in cultured non-small cell lung cancer (NSCLC) cells and in vivo in lung tumors in mice. Interestingly, we found that recombinant spike S1 treatment at very low doses led to death of human A549 NSCLC cells. On the other hand, boiled recombinant SARS-CoV-2 spike S1 remained unable to induce death, suggesting that the induction of cell death in A549 cells was due to native SARS-CoV-2 spike S1 protein. SARS-CoV-2 spike S1-induced A549 cell death was also inhibited by neutralizing antibodies against spike S1 and ACE2. Moreover, our newly designed wild type ACE2-interacting domain of SARS-CoV-2 (wtAIDS), but not mAIDS, peptide also attenuated SARS-CoV-2 spike S1-induced cell death, suggesting that SARS-CoV-2 spike S1-induced death in A549 NSCLC cells depends on its interaction with ACE2 receptor. Similarly, recombinant spike S1 treatment also led to death of human H1299 and H358 NSCLC cells. Finally, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) intoxication led to the formation tumors in lungs of A/J mice and alternate day intranasal treatment with low dose of recombinant SARS-CoV-2 spike S1 from 22-weeks of NNK insult (late stage) induced apoptosis and tumor regression in the lungs. These studies indicate that SARS-CoV-2 spike S1 may have implications for lung cancer treatment.

The SARS-CoV-2 S1 Spike Protein Promotes MAPK and NF-kB Activation in Human Lung Cells and Inflammatory Cytokine Production in Human Lung and Intestinal Epithelial Cells

The coronavirus disease 2019 (COVID-19) pandemic began in January 2020 in Wuhan, China, with a new coronavirus designated SARS-CoV-2. The principal cause of death from COVID-19 disease quickly emerged as acute respiratory distress syndrome (ARDS). A key ARDS pathogenic mechanism is the “Cytokine Storm”, which is a dramatic increase in inflammatory cytokines in the blood. In the last two years of the pandemic, a new pathology has emerged in some COVID-19 survivors, in which a variety of long-term symptoms occur, a condition called post-acute sequelae of COVID-19 (PASC) or “Long COVID”. Therefore, there is an urgent need to better understand the mechanisms of the virus. The spike protein on the surface of the virus is composed of joined S1–S2 subunits. Upon S1 binding to the ACE2 receptor on human cells, the S1 subunit is cleaved and the S2 subunit mediates the entry of the virus. The S1 protein is then released into the blood, which might be one of the pivotal triggers for the initiation and/or perpetuation of the cytokine storm. In this study, we tested the hypothesis that the S1 spike protein is sufficient to activate inflammatory signaling and cytokine production, independent of the virus. Our data support a possible role for the S1 spike protein in the activation of inflammatory signaling and cytokine production in human lung and intestinal epithelial cells in culture. These data support a potential role for the SARS-CoV-2 S1 spike protein in COVID-19 pathogenesis and PASC.

Treadmill exercise reduces α-synuclein spreading via PPARα

This study underlines the importance of treadmill exercise in reducing α-synuclein (α-syn) spreading in the A53T brain and protecting nigral dopaminergic neurons. Preformed α-syn fibril (PFF) seeding in the internal capsule of young A53T α-syn mice leads to increased spreading of α-syn to substantia nigra and motor cortex and concomitant loss of nigral dopaminergic neurons. However, regular treadmill exercise decreases α-syn spreading in the brain and protects nigral dopaminergic neurons in PFF-seeded mice. Accordingly, treadmill exercise also mitigates α-synucleinopathy in aged A53T mice. While investigating this mechanism, we have observed that treadmill exercise induces the activation of peroxisome proliferator-activated receptor α (PPARα) in the brain to stimulate lysosomal biogenesis via TFEB. Accordingly, treadmill exercise remains unable to stimulate TFEB and reduce α-synucleinopathy in A53T mice lacking PPARα, and fenofibrate, a prototype PPARα agonist, reduces α-synucleinopathy. These results delineate a beneficial function of treadmill exercise in reducing α-syn spreading in the brain via PPARα.

Medha Plus - A novel polyherbal formulation ameliorates cognitive behaviors and disease pathology in models of Alzheimer's disease

Alzheimer's disease (AD) is a multi-faceted neurodegenerative disorder that leads to drastic cognitive impairments culminating in death. Pathologically, it is characterized by amyloid-β (Aβ) plaques, neurofibrillary tangles and neurodegeneration in brain. Complete cure of AD remains elusive to date. Available synthetic drugs only provide symptomatic reliefs targeting single molecule, hence, are unable to address the multi-factorial aspects in AD pathogenesis. It is imperative to develop combinatorial drugs that address the multiple molecular targets in AD. We show a unique polyherbal formulation of Brahmi, Mandukaparni, Shankhpushpi, Yastimadhu, Kokilaksha and Shunthi called 'Medha Plus' (MP), conventionally used for improving memory and reducing anxiety, was able to ameliorate cognitive deficits and associated pathological hallmarks of AD. Viability assays revealed that MP prevented Aβ-induced loss of neurites as well as neuronal apoptosis in cellular models. An array of behavioral studies showed that MP was able to recover AD-associated memory deficits in both Aβ-injected rats and 5XFAD mice. Immunohistochemical studies further revealed that MP treatment reduced Aβ depositshpi and decreased apoptotic cell death in the hippocampus. Enzymatic assays demonstrated anti-oxidative and anti-acetyl cholinesterase properties of MP especially in hippocampus of Aβ-injected rats. An underlying improvement in synaptic plasticity was observed with MP treatment in 5XFAD mice along with an increased expression of phospho-Akt at serine 473 indicating a role of PI3K/Akt signaling in correcting these synaptic deficits. Thus, our strong experiment-driven approach shows that MP is an incredible combinatorial drug that targets multiple molecular targets with exemplary neuroprotective properties and is proposed for clinical trial.