A soy protein Lunasin can ameliorate amyloid-beta 42 mediated neurodegeneration in Drosophila eye

Expressing miR-282 mitigates Aβ42-induced neurodegeneration in Alzheimer's model in Drosophila

Alzheimer's disease is a complex neurodegenerative condition characterized by the accumulation of amyloid beta plaques, leading to memory loss, cognitive decline, and impaired autonomous behavior. Despite extensive research, an effective treatment remains elusive. The buildup of amyloid beta plaques (Aβ42) in the brain causes oxidative stress and disrupts normal molecular signaling, adversely affecting neuron function. Previous research has identified factors that can either exacerbate or mitigate neurodegenerative diseases. Our study aimed to uncover new factors involved in the pathogenesis of Alzheimer's disease. Using Drosophila as a model organism, we employed the Gal4/UAS system to express human Aβ42 in the flies' retinal neurons which led to neurodegenerative changes in their compound eyes. To identify genetic modifiers, we conducted a screen by co-expressing microRNAs and found that miR-282 acts as a suppressor. Overexpressing miR-282 in the GMR > Aβ42 background reduced Aβ42-induced neurodegeneration. Further analysis using prediction tools and RNA interference experiments identified three potential downstream targets of miR-282: calpain-B, knot, and scabrous. Downregulating these genes via RNA interference in the GMR > Aβ42 background mitigated neurodegeneration. Our research highlights miR-282 as a novel molecule that may influence the progression of Alzheimer's disease, offering potential avenues for future therapeutic or diagnostic developments.

Alzheimer's disease pathophysiology in the Retina

The retina is an emerging CNS target for potential noninvasive diagnosis and tracking of Alzheimer's disease (AD). Studies have identified the pathological hallmarks of AD, including amyloid β-protein (Aβ) deposits and abnormal tau protein isoforms, in the retinas of AD patients and animal models. Moreover, structural and functional vascular abnormalities such as reduced blood flow, vascular Aβ deposition, and blood-retinal barrier damage, along with inflammation and neurodegeneration, have been described in retinas of patients with mild cognitive impairment and AD dementia. Histological, biochemical, and clinical studies have demonstrated that the nature and severity of AD pathologies in the retina and brain correspond. Proteomics analysis revealed a similar pattern of dysregulated proteins and biological pathways in the retina and brain of AD patients, with enhanced inflammatory and neurodegenerative processes, impaired oxidative-phosphorylation, and mitochondrial dysfunction. Notably, investigational imaging technologies can now detect AD-specific amyloid deposits, as well as vasculopathy and neurodegeneration in the retina of living AD patients, suggesting alterations at different disease stages and links to brain pathology. Current and exploratory ophthalmic imaging modalities, such as optical coherence tomography (OCT), OCT-angiography, confocal scanning laser ophthalmoscopy, and hyperspectral imaging, may offer promise in the clinical assessment of AD. However, further research is needed to deepen our understanding of AD's impact on the retina and its progression. To advance this field, future studies require replication in larger and diverse cohorts with confirmed AD biomarkers and standardized retinal imaging techniques. This will validate potential retinal biomarkers for AD, aiding in early screening and monitoring.

miR-277 targets the proapoptotic gene-hid to ameliorate Aβ42-mediated neurodegeneration in Alzheimer's model

Alzheimer's disease (AD), an age-related progressive neurodegenerative disorder, exhibits reduced cognitive function with no cure to date. One of the reasons for AD is the accumulation of Amyloid-beta 42 (Aβ42) plaque(s) that trigger aberrant gene expression and signaling, which results in neuronal cell death by an unknown mechanism(s). Misexpression of human Aβ42 in the developing retina of Drosophila exhibits AD-like neuropathology. Small non-coding RNAs, microRNAs (miRNAs), post-transcriptionally regulate the expression of their target genes and thereby regulate different signaling pathways. In a forward genetic screen, we identified miR-277 (human ortholog is hsa-miR-3660) as a genetic modifier of Aβ42-mediated neurodegeneration. Loss-of-function of miR-277 enhances the Aβ42-mediated neurodegeneration. Whereas gain-of-function of miR-277 in the GMR > Aβ42 background downregulates cell death to maintain the number of neurons and thereby restores the retinal axonal targeting defects indicating the functional rescue. In addition, gain-of-function of miR-277 rescues the eclosion- and climbing assays defects observed in GMR > Aβ42 background. Thus, gain-of-function of miR-277 rescues both structurally as well as functionally the Aβ42-mediated neurodegeneration. Furthermore, we identified head involution defective (hid), an evolutionarily conserved proapoptotic gene, as one of the targets of miR-277 and validated these results using luciferase- and qPCR -assays. In the GMR > Aβ42 background, the gain-of-function of miR-277 results in the reduction of hid transcript levels to one-third of its levels as compared to GMR > Aβ42 background alone. Here, we provide a novel molecular mechanism where miR-277 targets and downregulates proapoptotic gene, hid, transcript levels to rescue Aβ42-mediated neurodegeneration by blocking cell death. These studies shed light on molecular mechanism(s) that mediate cell death response following Aβ42 accumulation seen in neurodegenerative disorders in humans and provide new therapeutic targets for neurodegeneration.

Exploring the efficient natural products for Alzheimer's disease therapy via Drosophila melanogaster (fruit fly) models

Alzheimer's disease (AD) is a grievous neurodegenerative disorder and a major form of senile dementia, which is partially caused by abnormal amyloid-beta peptide deposition and Tau protein phosphorylation. But until now, the exact pathogenesis of AD and its treatment strategy still need to investigate. Fortunately, natural products have shown potential as therapeutic agents for treating symptoms of AD due to their neuroprotective activity. To identify the excellent lead compounds for AD control from natural products of herbal medicines, as well as, detect their modes of action, suitable animal models are required. Drosophila melanogaster (fruit fly) is an important model for studying genetic and cellular biological pathways in complex biological processes. Various Drosophila AD models were broadly used for AD research, especially for the discovery of neuroprotective natural products. This review focused on the research progress of natural products in AD disease based on the fruit fly AD model, which provides a reference for using the invertebrate model in developing novel anti-AD drugs.

N-Acetyltransferase 9 ameliorates Aβ42-mediated neurodegeneration in the Drosophila eye

Alzheimer's disease (AD), a progressive neurodegenerative disorder, manifests as accumulation of amyloid-beta-42 (Aβ42) plaques and intracellular accumulation of neurofibrillary tangles (NFTs) that results in microtubule destabilization. Targeted expression of human Aβ42 (GMR > Aβ42) in developing Drosophila eye retinal neurons results in Aβ42 plaque(s) and mimics AD-like extensive neurodegeneration. However, there remains a gap in our understanding of the underlying mechanism(s) for Aβ42-mediated neurodegeneration. To address this gap in information, we conducted a forward genetic screen, and identified N-acetyltransferase 9 (Mnat9) as a genetic modifier of GMR > Aβ42 neurodegenerative phenotype. Mnat9 is known to stabilize microtubules by inhibiting c-Jun-N- terminal kinase (JNK) signaling. We found that gain-of-function of Mnat9 rescues GMR > Aβ42 mediated neurodegenerative phenotype whereas loss-of-function of Mnat9 exhibits the converse phenotype of enhanced neurodegeneration. Here, we propose a new neuroprotective function of Mnat9 in downregulating the JNK signaling pathway to ameliorate Aβ42-mediated neurodegeneration, which is independent of its acetylation activity. Transgenic flies expressing human NAT9 (hNAT9), also suppresses Aβ42-mediated neurodegeneration thereby suggesting functional conservation in the interaction of fly Mnat9 or hNAT9 with JNK-mediated neurodegeneration. These studies add to the repertoire of molecular mechanisms that mediate cell death response following accumulation of Aβ42 and may provide new avenues for targeting neurodegeneration.

Stem Cells and Natural Agents in the Management of Neurodegenerative Diseases: A New Approach

Neurodegenerative diseases refer to a group of neurological disorders as a consequence of various destructive illnesses, that predominantly impact neurons in the central nervous system, resulting in impairments in certain brain functions. Alzheimer's disease, Parkinson's disease, Huntington's disease, multiple sclerosis, and other neurodegenerative disorders represent a major risk to human health. In order to optimize structural and functional recovery, reconstructive methods integrate many approaches now, to address the complex and multivariate pathophysiology of neurodegenerative disorders. Stem cells, with their unique property of regeneration, offer new possibilities in regenerative and reconstructive medicine. Concurrently, there is an important role for natural products in controlling many health sufferings and they can delay or even prevent the onset of various diseases. In addition, due to their therapeutic properties, they have been used as neuroprotective agents to treat neurodegenerative disorders. After decades of intensive research, scientists made advances in treating these disorders so far, but current therapies are still not capable of preventing the illnesses from progressing. Therefore, in this review, we focused on a new perspective combining stem cells and natural products as an innovative therapy option in the management of neurodegenerative diseases.

A Drosophila model of HPV16-induced cancer reveals conserved disease mechanism

High-risk human papillomaviruses (HR-HPVs) cause almost all cervical cancers and a significant number of vaginal, vulvar, penile, anal, and oropharyngeal cancers. HPV16 and 18 are the most prevalent types among HR-HPVs and together cause more than 70% of all cervical cancers. Low vaccination rate and lack of molecularly-targeted therapeutics for primary therapy have led to a slow reduction in cervical cancer incidence and high mortality rate. Hence, creating new models of HPV-induced cancer that can facilitate understanding of the disease mechanism and identification of key cellular targets of HPV oncogenes are important for development of new interventions. Here in this study, we used the tissue-specific expression technique, Gal4-UAS, to establish the first Drosophila model of HPV16-induced cancer. Using this technique, we expressed HPV16 oncogenes E5, E6, E7 and the human E3 ligase (hUBE3A) specifically in the epithelia of Drosophila eye, which allows simple phenotype scoring without affecting the viability of the organism. We found that, as in human cells, hUBE3A is essential for cellular abnormalities caused by HPV16 oncogenes in flies. Several proteins targeted for degradation by HPV16 oncoproteins in human cells were also reduced in the Drosophila epithelial cells. Cell polarity and adhesion were compromised, resulting in impaired epithelial integrity. Cells did not differentiate to the specific cell types of ommatidia, but instead were transformed into neuron-like cells. These cells extended axon-like structures to connect to each other and exhibited malignant behavior, migrating away to distant sites. Our findings suggest that given the high conservation of genes and signaling pathways between humans and flies, the Drosophila model of HPV16- induced cancer could serve as an excellent model for understanding the disease mechanism and discovery of novel molecularly-targeted therapeutics.

Jatamansinol from Nardostachys jatamansi (D.Don) DC. Protects Aβ42-induced Neurotoxicity in Alzheimer's Disease Drosophila Model

Nardostachys jatamansi (D. Don) DC. is an essential plant used in Indian Ayurveda to treat neurological disorders, and it enhances memory. Its active phytochemical(s) responsible for neuroprotection is not yet studied. One of the neurological disorders, namely Alzheimer's disease (AD) causes dementia, is not having pharmacological strategies to effectively prevent the onset of AD, cure or reverse AD progression, and treat cognitive symptoms. Here is an attempt to analyze the neuroprotective effect of jatamansinol isolated from N. jatamansi against Aβ₄₂ protein-induced neurotoxicity using the Aβ₄₂ protein expressed Drosophila Alzheimer's disease (AD) model. Oregon-K (OK) and AD flies were reared on regular or jatamansinol supplemented food and analyzed their lifespan, locomotor activity, learning and memory, eye degeneration, oxidative stress levels, antioxidant activities, cholinesterase activities, Aβ₄₂ protein, and Aβ₄₂ gene expression. Jatamansinol extends the lifespan, improves locomotor activity, enhances learning and memory, and reduces Aβ₄₂ protein levels in AD flies. Jatamansinol boosts the antioxidant enzyme activities, prevents Aβ₄₂ protein-induced oxidative stress, ameliorates eye degeneration, and inhibits cholinesterase activities in the AD model. This study evidences the protective effect of jatamansinol against the Aβ₄₂ protein-induced neurotoxicity in the AD Drosophila model, suggesting its possible therapeutic potential against AD.

Protocol to study cell death using TUNEL assay in Drosophila imaginal discs

Cell death maintains tissue homeostasis by eliminating dispensable cells. Misregulation of cell death is seen in diseases like cancer, neurodegeneration, etc. Therefore, cell death assays like TUNEL have become reliable tools, where fragmented DNA of dying cells gets fluorescently labeled and can be detected under microscope. We used TUNEL assay in Drosophila melanogaster third-instar larval eye-antennal imaginal discs to label and quantify cell death. This assay is sensitive to detect DNA fragmentation, an important event, during apoptosis in retinal neurons.

For complete details on the use and execution of this profile, please refer to Wang et al. (1999), Tare et al. (2011), and Mehta et al. (2021).

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Combines immunohistochemistry and TUNEL assay to measure cell death

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Marks the fragmented DNA to quantify dying cells in specific regions of the tissue

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This protocol can be adapted to assay cell death in other tissues as well

Newt regeneration genes regulate Wingless signaling to restore patterning in Drosophila eye

Newts utilize their unique genes to restore missing parts by strategic regulation of conserved signaling pathways. Lack of genetic tools poses challenges to determine the function of such genes. Therefore, we used the Drosophila eye model to demonstrate the potential of 5 unique newt (Notophthalmus viridescens) gene(s), viropana1-viropana5 (vna1-vna5), which were ectopically expressed in L 2 mutant and GMR-hid, GMR-GAL4 eye. L 2 exhibits the loss of ventral half of early eye and head involution defective (hid) triggers cell-death during later eye development. Surprisingly, newt genes significantly restore missing photoreceptor cells both in L 2 and GMR>hid background by upregulating cell-proliferation and blocking cell-death, regulating evolutionarily conserved Wingless (Wg)/Wnt signaling pathway and exhibit non-cell-autonomous rescues. Further, Wg/Wnt signaling acts downstream of newt genes. Our data highlights that unique newt proteins can regulate conserved pathways to trigger a robust restoration of missing photoreceptor cells in Drosophila eye model with weak restoration capability.

Unbiased automated quantitation of ROS signals in live retinal neurons of Drosophila using Fiji/ImageJ

Numerous imaging modules are utilized to study changes that occur during cellular processes. Besides qualitative (immunohistochemical) or semiquantitative (Western blot) approaches, direct quantitation method(s) for detecting and analyzing signal intensities for disease(s) biomarkers are lacking. Thus, there is a need to develop method(s) to quantitate specific signals and eliminate noise during live tissue imaging. An increase in reactive oxygen species (ROS) such as superoxide (O2•-) radicals results in oxidative damage of biomolecules, which leads to oxidative stress. This can be detected by dihydroethidium staining in live tissue(s), which does not rely on fixation and helps prevent stress on tissues. However, the signal-to-noise ratio is reduced in live tissue staining. We employ the Drosophila eye model of Alzheimer's disease as a proof of concept to quantitate ROS in live tissue by adapting an unbiased method. The method presented here has a potential application for other live tissue fluorescent images.

Role of Retinal Amyloid-β in Neurodegenerative Diseases: Overlapping Mechanisms and Emerging Clinical Applications

Amyloid-β (Aβ) accumulations have been identified in the retina for neurodegeneration-associated disorders like Alzheimer's disease (AD), glaucoma, and age-related macular degeneration (AMD). Elevated retinal Aβ levels were associated with progressive retinal neurodegeneration, elevated cerebral Aβ accumulation, and increased disease severity with a decline in cognition and vision. Retinal Aβ accumulation and its pathological effects were demonstrated to occur prior to irreversible neurodegeneration, which highlights its potential in early disease detection and intervention. Using the retina as a model of the brain, recent studies have focused on characterizing retinal Aβ to determine its applicability for population-based screening of AD, which warrants a further understanding of how Aβ manifests between these disorders. While current treatments directly targeting Aβ accumulations have had limited results, continued exploration of Aβ-associated pathological pathways may yield new therapeutic targets for preserving cognition and vision. Here, we provide a review on the role of retinal Aβ manifestations in these distinct neurodegeneration-associated disorders. We also discuss the recent applications of retinal Aβ for AD screening and current clinical trial outcomes for Aβ-associated treatment approaches. Lastly, we explore potential future therapeutic targets based on overlapping mechanisms of pathophysiology in AD, glaucoma, and AMD.

Hippo signaling: bridging the gap between cancer and neurodegenerative disorders

During development, regulation of organ size requires a balance between cell proliferation, growth and cell death. Dysregulation of these fundamental processes can cause a variety of diseases. Excessive cell proliferation results in cancer whereas excessive cell death results in neurodegenerative disorders. Many signaling pathways known-to-date have a role in growth regulation. Among them, evolutionarily conserved Hippo signaling pathway is unique as it controls both cell proliferation and cell death by a variety of mechanisms during organ sculpture and development. Neurodegeneration, a complex process of progressive death of neuronal population, results in fatal disorders with no available cure to date. During normal development, cell death is required for sculpting of an organ. However, aberrant cell death in neuronal cell population can result in neurodegenerative disorders. Hippo pathway has gathered major attention for its role in growth regulation and cancer, however, other functions like its role in neurodegeneration are also emerging rapidly. This review highlights the role of Hippo signaling in cell death and neurodegenerative diseases and provide the information on the chemical inhibitors employed to block Hippo pathway. Understanding Hippo mediated cell death mechanisms will aid in development of reliable and effective therapeutic strategies in future.

A Two-Clone Approach to Study Signaling Interactions among Neuronal Cells in a Pre-clinical Alzheimer's Disease Model

To understand the progression of Alzheimer's disease, studies often rely on ectopic expression of amyloid-beta 42 (Aβ42) throughout an entire tissue. Uniform ectopic expression of Aβ42 may obscure cell-cell interactions that contribute to the progression of the disease. We developed a two-clone system to study the signaling cross talk between GFP-labeled clones of Aβ42-expressing neurons and wild-type neurons simultaneously generated from the same progenitor cell by a single recombination event. Surprisingly, wild-type clones are reduced in size as compared with Aβ42-producing clones. We found that wild-type cells are eliminated by the induction of cell death. Furthermore, aberrant activation of c-Jun-N-terminal kinase (JNK) signaling in Aβ42-expressing neurons sensitizes neighboring wild-type cells to undergo progressive neurodegeneration. Blocking JNK signaling in Aβ42-producing clones restores the size of wild-type clones.

An E3 ubiquitin ligase, cullin-4 regulates retinal differentiation in Drosophila eye

During organogenesis, cell proliferation is followed by the differentiation of specific cell types to form an organ. Any aberration in differentiation can result in developmental defects, which can result in a partial to a near-complete loss of an organ. We employ the Drosophila eye model to understand the genetic and molecular mechanisms involved in the process of differentiation. In a forward genetic screen, we identified, cullin-4 (cul-4), which encodes an E3 ubiquitin ligase, to play an important role in retinal differentiation. During development, cul-4 is known to be involved in protein degradation, regulation of genomic stability, and regulation of cell cycle. Previously, we have reported that cul-4 regulates cell death during eye development by downregulating Wingless (Wg)/Wnt signaling pathway. We found that loss-of-function of cul-4 results in a reduced eye phenotype, which can be due to onset of cell death. However, we found that loss-of-function of cul-4 also affects retinal development by downregulating retinal determination (RD) gene expression. Early markers of retinal differentiation are dysregulated in cul-4 loss of function conditions, indicating that cul-4 is necessary for differentiation. Furthermore, loss-of-function of cul-4 ectopically induces expression of negative regulators of eye development like Wg and Homothorax (Hth). During eye development, Wg is known to block the progression of a synchronous wave of differentiation referred to as Morphogenetic furrow (MF). In cul-4 loss-of-function background, expression of dpp-lacZ, a MF marker, is significantly downregulated. Our data suggest a new role of cul-4 in retinal differentiation. These studies may have significant bearings on our understanding of early eye development.

Pharmacological Treatment of Alzheimer's Disease: Insights from Drosophila melanogaster

Aging is an ineluctable law of life. During the process of aging, the occurrence of neurodegenerative disorders is prevalent in the elderly population and the predominant type of dementia is Alzheimer’s disease (AD). The clinical symptoms of AD include progressive memory loss and impairment of cognitive functions that interfere with daily life activities. The predominant neuropathological features in AD are extracellular β-amyloid (Aβ) plaque deposition and intracellular neurofibrillary tangles (NFTs) of hyperphosphorylated Tau. Because of its complex pathobiology, some tangible treatment can only ameliorate the symptoms, but not prevent the disease altogether. Numerous drugs during pre-clinical or clinical studies have shown no positive effect on the disease outcome. Therefore, understanding the basic pathophysiological mechanism of AD is imperative for the rational design of drugs that can be used to prevent this disease. Drosophilamelanogaster has emerged as a highly efficient model system to explore the pathogenesis and treatment of AD. In this review we have summarized recent advancements in the pharmacological research on AD using Drosophila as a model species, discussed feasible treatment strategies and provided further reference for the mechanistic study and treatment of age-related AD.

Inactivation of Hippo and cJun-N-terminal Kinase (JNK) signaling mitigate FUS mediated neurodegeneration in vivo

Amyotrophic Lateral Sclerosis (ALS), a late-onset neurodegenerative disorder characterized by the loss of motor neurons in the central nervous system, has no known cure to-date. Disease causing mutations in human Fused in Sarcoma (FUS) leads to aggressive and juvenile onset of ALS. FUS is a well-conserved protein across different species, which plays a crucial role in regulating different aspects of RNA metabolism. Targeted misexpression of FUS in Drosophila model recapitulates several interesting phenotypes relevant to ALS including cytoplasmic mislocalization, defects at the neuromuscular junction and motor dysfunction. We screened for the genetic modifiers of human FUS-mediated neurodegenerative phenotype using molecularly defined deficiencies. We identified hippo (hpo), a component of the evolutionarily conserved Hippo growth regulatory pathway, as a genetic modifier of FUS mediated neurodegeneration. Gain-of-function of hpo triggers cell death whereas its loss-of-function promotes cell proliferation. Downregulation of the Hippo signaling pathway, using mutants of Hippo signaling, exhibit rescue of FUS-mediated neurodegeneration in the Drosophila eye, as evident from reduction in the number of TUNEL positive nuclei as well as rescue of axonal targeting from the retina to the brain. The Hippo pathway activates c-Jun amino-terminal (NH₂) Kinase (JNK) mediated cell death. We found that downregulation of JNK signaling is sufficient to rescue FUS-mediated neurodegeneration in the Drosophila eye. Our study elucidates that Hippo signaling and JNK signaling are activated in response to FUS accumulation to induce neurodegeneration. These studies will shed light on the genetic mechanism involved in neurodegeneration observed in ALS and other associated disorders.

A Positive Feedback Loop of Hippo- and c-Jun-Amino-Terminal Kinase Signaling Pathways Regulates Amyloid-Beta-Mediated Neurodegeneration

Alzheimer's disease (AD, OMIM: 104300) is an age-related disorder that affects millions of people. One of the underlying causes of AD is generation of hydrophobic amyloid-beta 42 (Aβ42) peptides that accumulate to form amyloid plaques. These plaques induce oxidative stress and aberrant signaling, which result in the death of neurons and other pathologies linked to neurodegeneration. We have developed a Drosophila eye model of AD by targeted misexpression of human Aβ42 in the differentiating retinal neurons, where an accumulation of Aβ42 triggers a characteristic neurodegenerative phenotype. In a forward deficiency screen to look for genetic modifiers, we identified a molecularly defined deficiency, which suppresses Aβ42-mediated neurodegeneration. This deficiency uncovers hippo (hpo) gene, a member of evolutionarily conserved Hippo signaling pathway that regulates growth. Activation of Hippo signaling causes cell death, whereas downregulation of Hippo signaling triggers cell proliferation. We found that Hippo signaling is activated in Aβ42-mediated neurodegeneration. Downregulation of Hippo signaling rescues the Aβ42-mediated neurodegeneration, whereas upregulation of Hippo signaling enhances the Aβ42-mediated neurodegeneration phenotypes. It is known that c-Jun-amino-terminal kinase (JNK) signaling pathway is upregulated in AD. We found that activation of JNK signaling enhances the Aβ42-mediated neurodegeneration, whereas downregulation of JNK signaling rescues the Aβ42-mediated neurodegeneration. We tested the nature of interactions between Hippo signaling and JNK signaling in Aβ42-mediated neurodegeneration using genetic epistasis approach. Our data suggest that Hippo signaling and JNK signaling, two independent signaling pathways, act synergistically upon accumulation of Aβ42 plaques to trigger cell death. Our studies demonstrate a novel role of Hippo signaling pathway in Aβ42-mediated neurodegeneration.

Neuroprotective protein hydrolysates from hemp (Cannabis sativa L.) seeds

Hemp (Cannabis sativa L.) seeds are well known for their potential use as a source of nutrients, fiber, and bioactive compounds. A hemp protein isolate, prepared from defatted hemp flour, was hydrolyzed by alcalase and flavourzyme under specific conditions. The resulting hydrolysates were evaluated for the selection of potentially bioactive hemp protein hydrolysates (HPHs) owing to their DPPH scavenging and ferric reducing antioxidant power activity. In vitro cell-free experiments led to the identification of two bioactive HPHs, HPH20A and HPH60A + 15AF, which were used at 50 and 100 μg mL-1 on BV-2 microglial cells in order to evaluate the anti-neuroinflammatory activities. Our results showed that HPH20A and HPH60A + 15AF down-regulated TNF-α, IL-1β, and IL-6 mRNA transcriptional levels in LPS-stimulated BV-2 microglial cells. In addition, HPH20A and HPH60A + 15AF up-regulated the gene expression of anti-inflammatory cytokine IL-10. This study suggests for the first time that HPHs may improve the neuroinflammatory and inflammatory states, supporting the nutraceutical value of hemp seeds.

Insights into regeneration tool box: An animal model approach

For ages, regeneration has intrigued countless biologists, clinicians, and biomedical engineers. In recent years, significant progress made in identification and characterization of a regeneration tool kit has helped the scientific community to understand the mechanism(s) involved in regeneration across animal kingdom. These mechanistic insights revealed that evolutionarily conserved pathways like Wnt, Notch, Hedgehog, BMP, and JAK/STAT are involved in regeneration. Furthermore, advancement in high throughput screening approaches like transcriptomic analysis followed by proteomic validations have discovered many novel genes, and regeneration specific enhancers that are specific to highly regenerative species like Hydra, Planaria, Newts, and Zebrafish. Since genetic machinery is highly conserved across the animal kingdom, it is possible to engineer these genes and regeneration specific enhancers in species with limited regeneration properties like Drosophila, and mammals. Since these models are highly versatile and genetically tractable, cross-species comparative studies can generate mechanistic insights in regeneration for animals with long gestation periods e.g. Newts. In addition, it will allow extrapolation of regenerative capabilities from highly regenerative species to animals with low regeneration potential, e.g. mammals. In future, these studies, along with advancement in tissue engineering applications, can have strong implications in the field of regenerative medicine and stem cell biology.

Comparative transcriptomic analysis and structure prediction of novel Newt proteins

Notophthalmus viridescens (Red-spotted Newt) possess amazing capabilities to regenerate their organs and other tissues. Previously, using a de novo assembly of the newt transcriptome combined with proteomic validation, our group identified a novel family of five protein members expressed in adult tissues during regeneration in Notophthalmus viridescens. The presence of a putative signal peptide suggests that all these proteins are secretory in nature. Here we employed iterative threading assembly refinement (I-TASSER) server to generate three-dimensional structure of these novel Newt proteins and predicted their function. Our data suggests that these proteins could act as ion transporters, and be involved in redox reaction(s). Due to absence of transgenic approaches in N. viridescens, and conservation of genetic machinery across species, we generated transgenic Drosophila melanogaster to misexpress these genes. Expression of 2775 transcripts were compared between these five newly identified Newt genes. We found that genes involved in the developmental process, cell cycle, apoptosis, and immune response are among those that are highly enriched. To validate the RNA Seq. data, expression of six highly regulated genes were verified using real time Quantitative Polymerase Chain Reaction (RT-qPCR). These graded gene expression patterns provide insight into the function of novel protein family identified in Newt, and layout a map for future studies in the field.

Peptides as epigenetic modulators: therapeutic implications

Peptides originating from different sources (endogenous, food derived, environmental, and synthetic) are able to influence different aspects of epigenetic regulation. Endogenous short peptides, resulting from proteolytic cleavage of proteins or upon translation of non-annotated out of frame transcripts, can block DNA methylation and hereby regulate gene expression. Peptides entering the body by digestion of food-related proteins can modulate DNA methylation and/or histone acetylation while environmental peptides, synthesized by bacteria, fungi, and marine sponges, mainly inhibit histone deacetylation. In addition, synthetic peptides that reverse or inhibit different epigenetic modifications of both histones and the DNA can be developed as well. Next to these DNA and histone modifications, peptides can also influence the expression of non-coding RNAs such as lncRNAs and the maturation of miRNAs.

Seen the advantages over small molecules, the development of peptide therapeutics is an interesting approach to treat diseases with a strong epigenetic basis like cancer and Alzheimer’s disease. To date, only a limited number of drugs with a proven epigenetic mechanism of action have been approved by the FDA of which two (romidepsin and nesiritide) are peptides. A large knowledge gap concerning epigenetic effects of peptides is present, and this class of molecules deserves more attention in the development as epigenetic modulators. In addition, none of the currently approved peptide drugs are under investigation for their potential effects on epigenetics, hampering drug repositioning of these peptides to other indications with an epigenetic etiology.

Label-free distribution of anti-amyloid D-AIP in Drosophila melanogaster: prevention of Aβ42-induced toxicity without side effects in transgenic flies

Soluble oligomers of the 42-amino acid amyloid beta (Aβ42) peptide are highly toxic and suspected as the causative agent of synaptic dysfunction and neuronal loss in Alzheimer's disease (AD). Previously, we have shown that a small, D-amino acid Aβ42-oligomer interacting peptide (D-AIP) can neutralize human Aβ42-mediated toxicity using in vitro and cell-based assays. In the present longitudinal study using a transgenic Drosophila melanogaster model, advanced live confocal imaging and mass spectrometry imaging (MALDI-MSI) showed that the eight amino acid D-AIP can attenuate Aβ42-induced toxicity in vivo. By separating male and female flies into distinct groups, the resultant distribution of ingested D-AIP was different between the sexes. The Aβ42-induced 'rough eye' phenotype could be rescued in the female transgenics, likely because of the co-localization of D-AIP with human Aβ42 in the female fly heads. Interestingly, the phenotype could not be rescued in the male transgenics, likely because of the co-localization of D-AIP with a confounding male-specific sex peptide (Acp70A candidate in MSI spectra) in the gut of the male flies. As a novel, more cost-effective strategy to prevent toxic amyloid formation during the early stages of AD (i.e. neutralization of toxic low-order Aβ42 oligomers without creating larger aggregates in the process), our longitudinal study establishes that D-AIP is a stable and highly effective neutralizer of toxic Aβ42 peptides in vivo. Cover Image for this issue: doi: 10.1111/jnc.14512.

Proximal fate marker homothorax marks the lateral extension of stalk-eyed fly Cyrtodopsis whitei

The placement of eyes on insect head is an important evolutionary trait. The stalk-eyed fly, Cyrtodopsis whitei, exhibits a hypercephaly phenotype where compound eyes are located on lateral extension from the head while the antennal segments are placed inwardly on this stalk. This stalk-eyed phenotype is characteristic of the family Diopsidae in the Diptera order and dramatically deviates from other dipterans, such as Drosophila. Like other insects, the adult eye and antenna of stalk-eyed fly develop from a complex eye-antennal imaginal disc. We analyzed the markers involved in proximo-distal (PD) axis of the developing eye imaginal disc of the stalk-eyed flies. We used homothorax (hth) and distalless (dll), two highly conserved genes as the marker for proximal and distal fate, respectively. We found that lateral extensions between eye and antennal field of the stalk-eyed fly's eye-antennal imaginal disc exhibit robust Hth expression. Hth marks the head specific fate in the eye- and proximal fate in the antenna-disc. Thus, the proximal fate marker Hth expression evolves in the stalk-eyed flies to generate lateral extensions for the placement of the eye on the head. Moreover, during pupal eye metamorphosis, the lateral extension folds back on itself to place the antenna inside and the adult compound eye on the distal tip. Interestingly, the compound eye in other insects does not have a prominent PD axis as observed in the stalk-eyed fly.

Current state of art after twenty years of the discovery of bioactive peptide lunasin

Non-communicable diseases have become the medical challenge of the 21st century because of their high incidence and mortality rates. Accumulating evidence has suggested that the modulation of diet and other lifestyle habits is the best strategy for the prevention of these diseases. An increasing number of dietary compounds have been found to exert health promoting benefits beyond their nutritional effects. Among them, lunasin is considered one of the most studied bioactive peptides. Since its discovery in soybean twenty years ago, many researchers around the world have focused their studies on demonstrating the chemopreventive and chemotherapeutic activity of lunasin. Moreover, in the last years, promising protective effects of this peptide against hypercholesterolemia, obesity, metabolic syndrome and associated cardiovascular disorders, and inflammatory and immune-regulated diseases have been described. This review summarizes recent remarkable advances on the use of peptide lunasin as a potential functional ingredient to provide health benefits. Moreover, novel aspects related to the influence of lunasin's digestion and bioavailability, the mechanisms of action proposed to explain the underlying biological properties, and the incorporation of this peptide into nutritional supplements are critically discussed.

Exploring the efficacy of natural products in alleviating Alzheimer's disease

Alzheimer’s disease (hereafter AD) is a progressive neurodegenerative disorder that affects the central nervous system. There are multiple factors that cause AD, viz., accumulation of extracellular Amyloid-beta 42 plaques, intracellular hyper-phosphorylated Tau tangles, generation of reactive oxygen species due to mitochondrial dysfunction and genetic mutations. The plaques and tau tangles trigger aberrant signaling, which eventually cause cell death of the neurons. As a result, there is shrinkage of brain, cognitive defects, behavioral and psychological problems. To date, there is no direct cure for AD. Thus, scientists have been testing various strategies like screening for the small inhibitor molecule library or natural products that may block or prevent onset of AD. Historically, natural products have been used in many cultures for the treatment of various diseases. The research on natural products have gained importance as the active compounds extracted from them have medicinal values with reduced side effects, and they are bioavailable. The natural products may target the proteins or members of signaling pathways that get altered in specific diseases. Many natural products are being tested in various animal model systems for their role as a potential therapeutic target for AD, and to address questions about how these natural products can rescue AD or other neurodegenerative disorders. Some of these products are in clinical trials and results are promising because of their neuroprotective, anti-inflammatory, antioxidant, anti-amyloidogenic, anticholinesterase activities and easy availability. This review summarizes the use of animal model systems to identify natural products, which may serve as potential therapeutic targets for AD.