Lentivirus Production and Purification

Unraveling the Transcriptomic Profiles of Large and Small Donkey Follicles

BACKGROUND

The diameter of mature follicles in donkeys is several times larger than in cattle and sheep, but the key genes responsible for maintaining follicular development and preventing apoptosis remain unclear.

METHODS

This study observed the process of donkey follicular development using ultrasound and analyzed the changes in common reproductive hormones in serum. Granulosa cells (GCs) were collected from large (mature follicles, diameter ≥ 37 mm) and small (atretic follicles, diameter 10-25 mm) follicles for sequencing to screen differentially expressed genes (DEGs) and signaling pathways influencing the development of mature follicles. The roles of selected genes were further validated in in vitro cultured GCs.

RESULTS

Donkey follicles exhibited rapid growth 5-7 days before ovulation, reaching maturity at a diameter of 37 mm. The maximum diameter of ovulatory follicles was approximately 40.7 mm, while non-ovulatory follicles began to undergo atresia when reaching about 25 mm. Serum reproductive hormone levels aligned with follicular developmental status. RNA sequencing identified 3291 DEGs between large and small follicles, with KEGG analysis highlighting enrichment in the PI3K-Akt signaling pathway, focal adhesion, amoebiasis, and cancer pathways. Lentiviral overexpression and interference assays targeting the DEGs EMCN and SYT12 revealed that EMCN positively regulates FOXO3, a key gene in the PI3K-Akt pathway.

CONCLUSIONS

The EMCN gene in mature donkey follicles regulates FOXO3 in the PI3K-Akt signaling pathway, potentially inhibiting apoptosis in follicular granulosa cells and sustaining follicular development until ovulation. This study provides insights into the mechanisms underlying follicular development in donkeys.

Hypoxia and HIF-1 inhibition enhance lentiviral transduction efficiency: a novel strategy for gene delivery optimization

Lentiviral vectors are widely used for stable gene delivery, but their transduction efficiency can be limited by suboptimal experimental conditions. Here, we investigated the role of oxygen concentration and hypoxia-inducible factor 1 (HIF-1) signaling in lentiviral packaging and transduction. We found that packaging lentivirus under hypoxic conditions (10% O₂) significantly increased viral titers and transduction efficiency by approximately 10%. However, hypoxic conditions during viral entry impaired infection efficiency, likely due to HIF-1α-mediated cellular protective mechanisms. Pretreatment of cells with the HIF-1 inhibitor PX-478 reversed this effect, enhancing viral entry and genome integration in a dose-dependent manner. Combining hypoxic virus packaging with PX-478 pretreatment synergistically improved transduction efficiency by 20%. These findings suggest that HIF-1 inhibition and controlled hypoxia significantly enhance lentiviral transduction efficiency, establishing a versatile strategy with broad applicability across viral vector-dependent biomedical applications.

Defining the genome-wide mutagenic impact of APOBEC3 enzymes

Somatic mutations drive cancer initiation and tumor evolution. Therefore, the etiology of mutagenesis in cancer is important to preventative and treatment strategies. Somatic mutagenesis in cancer is a multifactorial process and includes both endogenous and exogenous sources of mutations. One recently recognized source of mutagenesis in cancer is the innate immune APOBEC3 family of enzymes, which catalyze cytosine deamination to restrict viral infection but can aberrantly act on the cellular genome, resulting in mutations. Single base substitution (SBS) signatures, or mutational patterns, identified in cancer genomes have demonstrated widespread mutagenesis caused by APOBEC3 enzymes throughout human tumors. To comprehensively define the consequences of APOBEC3 mutagenesis, we developed an experimental pipeline for prospective analysis of genome-wide mutations caused by APOBEC3 activity. This pipeline can be adapted to analyze additional sources of mutagenesis across a spectrum of cells.

METTL14 depletion induces trophoblast cell dysfunction by inhibiting miR-21-5p processing in an m6A-dependent manner

Spontaneous abortion (SA) is a devastating, but common outcome for expectant parents and their families. However, the mechanism of SA occurrence remains mostly unknown. Herein, we examined human SA villi samples and found decreased N6-methyladenosine (m6A) levels and methyltransferase-like protein 14 (METTL14) expression compared with those in healthy women. Knockdown of METTL14 in trophoblast HTR8 cells induced cellular dysfunction. We identified candidate differentially expressed microRNAs and found that METTL14 accelerated miR-21-5p processing by modulating its m6A modification level. Exogenous miR-21-5p expression attenuated METTL14 knockdown-induced cellular dysfunction. Subsequently, we found that SMAD family member 7 (SMAD7) expression is inhibited by miR-21-5p and that knockdown of SMAD7 rescued the trophoblast cell dysfunction induced by miR-21-5p inhibitors. Then, we revealed that METTL14 can regulate the SMAD7 pathway by modulating miR-21-5p. Finally, we found that exposing pregnant mice to an m6A inhibitor caused embryo loss and reduced expression levels of Mettl14 and miR-21-5p while increasing Smad7 levels. Taken together, this study establishes the involvement of m6A in SA and identified a novel SA signaling pathway. These results reveal the underlying molecular mechanisms of trophoblast cell dysfunction induced by m6A modification and provide new strategies to identify and mitigate SA.

A specific super-enhancer actuated by berberine regulates EGFR-mediated RAS-RAF1-MEK1/2-ERK1/2 pathway to induce nasopharyngeal carcinoma autophagy

Nasopharyngeal carcinoma (NPC), primarily found in the southern region of China, is a malignant tumor known for its highly metastatic characteristics. The high mortality rates caused by the distant metastasis and disease recurrence remain unsolved clinical problems. In clinic, the berberine (BBR) compound has widely been in NPC therapy to decrease metastasis and disease recurrence, and BBR was documented as a main component with multiple anti-NPC effects. However, the mechanism by which BBR inhibits the growth and metastasis of nasopharyngeal carcinoma remains elusive. Herein, we show that BBR effectively inhibits the growth, metastasis, and invasion of NPC via inducing a specific super enhancer (SE). From a mechanistic perspective, the RNA sequencing (RNA-seq) results suggest that the RAS-RAF1-MEK1/2-ERK1/2 signaling pathway, activated by the epidermal growth factor receptor (EGFR), plays a significant role in BBR-induced autophagy in NPC. Blockading of autophagy markedly attenuated the effect of BBR-mediated NPC cell growth and metastasis inhibition. Notably, BBR increased the expression of EGFR by transcription, and knockout of EGFR significantly inhibited BBR-induced microtubule associated protein 1 light chain 3 (LC3)-II increase and p62 inhibition, proposing that EGFR plays a pivotal role in BBR-induced autophagy in NPC. Chromatin immunoprecipitation sequencing (ChIP-seq) results found that a specific SE existed only in NPC cells treated with BBR. This SE knockdown markedly repressed the expression of EGFR and phosphorylated EGFR (EGFR-p) and reversed the inhibition of BBR on NPC proliferation, metastasis, and invasion. Furthermore, BBR-specific SE may trigger autophagy by enhancing EGFR gene transcription, thereby upregulating the RAS-RAF1-MEK1/2-ERK1/2 signaling pathway. In addition, in vivo BBR effectively inhibited NPC cells growth and metastasis, following an increase LC3 and EGFR and a decrease p62. Collectively, this study identifies a novel BBR-special SE and established a new epigenetic paradigm, by which BBR regulates autophagy, inhibits proliferation, metastasis, and invasion. It provides a rationale for BBR application as the treatment regime in NPC therapy in future.

Effects of an indole derivative on cell proliferation, transfection, and alternative splicing in production of lentiviral vectors by transient co-transfection

Lentiviral vectors derived from human immunodeficiency virus type I are widely used to deliver functional gene copies to mammalian cells for research and gene therapies. Post-transcriptional splicing of lentiviral vector transgene in transduced host and transfected producer cells presents barriers to widespread application of lentiviral vector-based therapies. The present study examined effects of indole derivative compound IDC16 on splicing of lentiviral vector transcripts in producer cells and corresponding yield of infectious lentiviral vectors. Indole IDC16 was shown previously to modify alternative splicing in human immunodeficiency virus type I. Human embryonic kidney 293T cells were transiently transfected by 3rd generation backbone and packaging plasmids using polyethyleneimine. Reverse transcription-quantitative polymerase chain reaction of the fraction of unspliced genomes in human embryonic kidney 293T cells increased up to 31% upon the indole's treatment at 2.5 uM. Corresponding yield of infectious lentiviral vectors decreased up to 4.5-fold in a cell transduction assay. Adjusting timing and duration of IDC16 treatment indicated that the indole's disruption of early stages of transfection and cell cycle had a greater effect on exponential time course of lentiviral vector production than its reduction of post-transcriptional splicing. Decrease in transfected human embryonic kidney 293T proliferation by IDC16 became significant at 10 uM. These findings indicated contributions by early-stage transfection, cell proliferation, and post-transcriptional splicing in transient transfection of human embryonic kidney 293T cells for lentiviral vector production.

LncRNA IL21-AS1 facilitates tumour progression by enhancing CD24-induced phagocytosis inhibition and tumorigenesis in ovarian cancer

CD24 is overexpressed in various tumours and considered a regulator of cell migration, invasion, and proliferation. Recent studies have found that CD24 on ovarian cancer (OC) and triple-negative breast cancer cells interacts with the inhibitory receptor sialic-acid-binding Ig-like lectin 10 (Siglec-10) on tumour-associated macrophages (TAMs) to inhibit phagocytosis by macrophages. Because of its multiple roles in regulating the immune response and tumorigenesis, CD24 is a very promising therapeutic target. However, the regulatory mechanism of CD24 in OC remains unclear. Here, we found that the long noncoding RNA (lncRNA) IL21-AS1, which was upregulated in OC, inhibited macrophage-mediated phagocytosis and promoted OC cell proliferation and apoptosis inhibition. More importantly, after IL21-AS1 knockdown, a significant survival advantage was observed in mice engrafted with tumours. Mechanistically, we identified IL21-AS1 as a hypoxia-induced lncRNA. Moreover, IL21-AS1 increased HIF1α-induced CD24 expression under hypoxic conditions. In parallel, we found that IL21-AS1 acted as a competing endogenous RNA (ceRNA) for miR-561-5p to regulate CD24 expression. Finally, IL21-AS1 increased CD24 expression in OC and facilitated OC progression. Our findings provide a molecular basis for the regulation of CD24, thus highlighting a potential strategy for targeted treatment of OC.

PEDF inhibits VEGF-induced vascular leakage through binding to VEGFR2 in acute myocardial infarction

Pigment epithelium-derived factor (PEDF) could bind to vascular endothelial growth factor receptor 2 (VEGFR2) and inhibit its activation induced by VEGF. But how PEDF affects VEGFR2 pathway is still poorly understood. In this study, we elucidated the precise mechanism underlying the interaction between PEDF and VEGFR2, and subsequently corroborated our findings using a rat AMI model. PEDF prevented endocytosis of VE-cadherin induced by hypoxia, thereby protecting the endothelium integrity. A three-dimensional model of the VEGFR2-PEDF complex was constructed by protein-protein docking method. The results showed that the VEGFR2-PEDF complex was stable during the simulation. Hydrogen bonds, binding energy and binding modes were analyzed during molecular dynamics simulations, which indicated that hydrogen bonds and hydrophobic interactions were important for the recognition of VEGFR2 with PEDF. In addition, the results from exudation of fibrinogen suggested that PEDF inhibits vascular leakage in acute myocardial infarction and confirmed the critical role of key amino acids in the regulation of endothelial cell permeability. This observation is also supported by echocardiography studies showing that the 34mer peptide sustained cardiac function during acute myocardial infarction. Besides, PEDF and 34mer could inhibit the aggregation of myofiber in the heart and promoted the formation of a dense cell layer in cardiomyocytes, which suggested that PEDF and 34mer peptide protect against AMI-induced cardiac dysfunction. These results suggest that PEDF inhibits the phosphorylation of downstream proteins, thereby preventing vascular leakage, which provides a new therapeutic direction for the treatment of acute myocardial infarction.

Integrin αvβ1 facilitates ACE2-mediated entry of SARS-CoV-2

Integrins have been suggested to be involved in SARS-CoV-2 infection, but the underlying mechanisms remain largely unclear. This study aimed to investigate how integrins facilitate the ACE2-mediated cellular entry of SARS-CoV-2. We first tested the susceptibility of a panel of human cell lines to SARS-CoV-2 infection using the spike protein pseudotyped virus assay and examined the expression levels of integrins in these cell lines by qPCR, western blot and flow cytometry. We found that integrin αvβ1 was highly enriched in the SARS-CoV-2 susceptible cell lines. Additional studies demonstrated that RGD (403-405)→AAA mutant was defective in binding to integrin αvβ1 compared to its wild type counterpart, and anti-αvβ1 integrin antibodies significantly inhibited the entry of SARS-CoV-2 into the cells. Further studies using mouse NIH3T3 cells expressing human ACE2, integrin αv, integrin β1, and/or integrin αvβ1 suggest that integrin αvβ1 was unable to function as an independent receptor but could significantly facilitate the cellular entry of SASR-CoV-2. Finally, we observed that the Omicron exhibited a significant increase in the ACE2-mediated viral entry. Our findings may enhance our understanding of the pathogenesis of SARS-CoV-2 infection and offer potential therapeutic target for COVID-19.

Establishment of a 6-OHDA Induced Unilaterally Lesioned Male Wistar Rat Model of Parkinson's Disease

Robust preclinical models of Parkinson's disease (PD) are valuable tools for understanding the biology and treatment of this complex disease. 6-Hydroxydopamine (6-OHDA) is a selective catecholaminergic drug injected into the substantia nigra pars compacta (SNc), medial forebrain bundle (MFB), or striatum, which is then metabolized to induce parkinsonism. Unilateral injection of 6-OHDA produces loss of dopaminergic (DAergic) neurons on the injected side with a marked motor asymmetry known as hemiparkinsonism, typically characterized by a rotational behavior to the impaired side. The present work describes a stable unilateral 6-OHDA-lesioned rat model of PD. 6-OHDA was administered into the MFB, leading to the consistent loss of striatal dopamine (DA) and behavioral imbalance in unilateral 6-OHDA-lesioned rats to establish the model of PD. This model of PD is a valuable tool for understanding the mechanisms underlying the generation of parkinsonian symptoms.

Methods of miRNA delivery and possibilities of their application in neuro-oncology

In the current phase of medical progress, practical neuro-oncology faces critical challenges. These include the quest for and development of innovative methodological approaches, as well as the enhancement of conventional therapies to boost their efficacy in treating brain tumors, especially the malignant varieties. Recent strides in molecular and cellular biology, molecular genetics, and immunology have charted the primary research pathways in the development of new anti-cancer medications, with a particular focus on microRNA (miRNA)-based therapy. MiRNAs possess the ability to function as suppressors of tumor growth while also having the potential to act as oncogenes. MiRNAs wield control over numerous processes within the human body, encompassing tumor growth, proliferation, invasion, metastasis, apoptosis, angiogenesis, and immune responses. A significant impediment to enhancing the efficacy of brain tumor treatment lies in the unresolved challenge of traversing the blood-brain barrier (BBB) and blood-tumor barrier (BTB) to deliver therapeutic agents directly to the tumor tissue. Presently, there is a worldwide effort to conduct intricate research and design endeavors aimed at creating miRNA-based dosage forms and delivery systems that can effectively target various structures within the central nervous system (CNS). MiRNA-based therapy stands out as one of the most promising domains in neuro-oncology. Hence, the development of efficient and safe methods for delivering miRNA agents to the specific target cells within brain tumors is of paramount importance. In this study, we will delve into recent findings regarding various methods for delivering miRNA agents to brain tumor cells. We will explore the advantages and disadvantages of different delivery systems and consider some clinical aspects of miRNA-based therapy for brain tumors.

Annihilation of Non-small Cell Lung Cancer by NKG2D CAR-T Cells Produced from T Cells from Peripheral Blood of Healthy Donors

Some progress has been made in immunotherapy with chimeric antigen receptor (CAR)-T cells targeting NKG2D-NKG2DL with the purpose of eradicating solid tumors. Non-small cell lung cancer (NSCLC) has been shown to express NKG2DL. This study hence evaluated the therapeutic effect of NKG2D CAR-T cells on NSCLC. Accordingly, NKG2D CAR-T cells were obtained from diverse human autologous T cell sources. T cells from peripheral blood T lymphocytes of healthy volunteers (without NKG2D CAR insertion) were used as NT-T cells. Coculture of effector cells (CAR-T cells or NT-T cells) with target cells (NSCLC cells such as PC-9 or NCL-H460 cells) was performed at different ratios. The cytotoxicity of CAR-T cells was examined using lactate dehydrogenase assay kits. Murine xenograft assay was conducted to investigate the in vivo antitumor effect of CAR-T cells. Cytokines secreted from CAR-T cells were assessed by enzyme-linked immunosorbent assay. CAR-T cell infiltration into xenografts was observed through immunochemical assay. Based on the results, NKG2DL was highly expressed in NSCLC cells. Compared with NT-T cells, NKG2D CAR-T cells from different sources of T cells delivered stronger toxicity, and secreted more effector and memory function-related cytokines to NSCLC cells, and those from the peripheral blood of healthy donors (H-T cells) exhibited the strongest effect. Furthermore, compared with NT-T cells, H-T cells and NKG2D CAR-T cells from NSCLC patients' peripheral blood diminished tumor, improved survival, increased body weight and tumor-infiltrating capacity, and upregulated serum IFN-γ level in NOG mice. Collectively speaking, NKG2D CAR-T cells exhibit a robust effect on eradicating NSCLC in a NKG2DL-dependent manner, thus making themselves a promising therapeutic candidate for NSCLC patients.

An ex vivo Model of Paired Cultured Hippocampal Neurons for Bi-directionally Studying Synaptic Transmission and Plasticity

Synapses provide the main route of signal transduction within neuronal networks. Many factors regulate critical synaptic functions. These include presynaptic calcium channels, triggering neurotransmitter release, and postsynaptic ionotropic receptors, mediating excitatory and inhibitory postsynaptic potentials. The key features of synaptic transmission and plasticity can be studied in primary cultured hippocampal neurons. Here, we describe a protocol for the preparation and electrophysiological analysis of paired hippocampal neurons. This model system allows the selective genetic manipulation of one neuron in a simple neuronal network formed by only two hippocampal neurons. Bi-directionally analyzing synaptic transmission and short-term synaptic plasticity allows the analysis of both pre- and postsynaptic effects on synaptic transmission. For example, with one single paired network synaptic responses induced by both, a wild-type neuron and a genetically modified neuron can be directly compared. Ultimately, this protocol allows experimental modulation and hence investigation of synaptic mechanisms and thereby improves previously developed methods of studying synaptic transmission and plasticity in ex vivo cultured neurons. Key features Preparation of ex vivo paired cultured hippocampal neurons. Bi-directional electrophysiological recordings of synaptic transmission and plasticity. Genetic modulation of synaptic network formation (demonstrated by presynaptic viral overexpression of the auxiliary calcium channel α2δ-2 subunit). Graphical overview.

OPTO-BLUE: An Integrated Bidirectional Optogenetic Lentiviral Platform for Controlled Light-Induced Gene Expression

Regulated systems for transgene expression are useful tools in basic research and a promising platform in biomedicine due to their regulated transgene expression by an inducer. The emergence of optogenetics expression systems enabled the construction of light-switchable systems, enhancing the spatial and temporal resolution of a transgene. The LightOn system is an optogenetic tool that regulates the expression of a gene of interest using blue light as an inducer. This system is based on a photosensitive protein (GAVPO), which dimerizes and binds to the UASG sequence in response to blue light, triggering the expression of a downstream transgene. Previously, we adapted the LightOn system to a dual lentiviral vector system for neurons. Here, we continue the optimization and assemble all components of the LightOn system into a single lentiviral plasmid, the OPTO-BLUE system. For functional validation, we used enhanced green fluorescent protein (EGFP) as an expression reporter (OPTO-BLUE-EGFP) and evaluated the efficiency of EGFP expression by transfection and transduction in HEK293-T cells exposed to continuous blue-light illumination. Altogether, these results prove that the optimized OPTO-BLUE system allows the light-controlled expression of a reporter protein according to a specific time and light intensity. Likewise, this system should provide an important molecular tool to modulate gene expression of any protein by blue light.

Role of circular RNA cdr1as in modulation of macrophage phenotype

AIMS

Macrophages are crucial for the initiation and resolution of an inflammatory response. Non-coding circular RNAs are ubiquitously expressed in mammalian tissue, highly conserved among species, and recently implicated in the regulation of macrophage activation. We sought to determine whether circRNAs modulate monocyte/macrophage biology and function.

MATERIALS AND METHODS

We performed circRNA microarray analyses to assess transcriptome changes using RNA isolated from bone marrow derived macrophages polarized to a pro-inflammatory phenotype (INFγ + TNFα) or an anti-inflammatory phenotype (IL-10, IL-4, and TGF-β). Among differentially expressed circRNAs, circ-Cdr1as was chosen for further investigation. Additionally, we performed loss or gain of function studies to investigate if circ-Cdr1as is involved in phenotypic switching. For gain of function, we overexpressed circ-Cdr1as using pc3.1 plasmid with laccase2 flanking regions to promote circularization. For loss of function, we used a lentiviral short hairpin RNA targeting the circ-Cdr1as splicing junction.

KEY FINDINGS

Among circRNAs that are highly conserved and differentially expressed in pro- and anti-inflammatory lineages, circ-Cdr1as was one of the most downregulated in pro-inflammatory macrophages and significantly upregulated in anti-inflammatory macrophages in vitro. Overexpression of circ-Cdr1as increased transcription of anti-inflammatory markers and percentage of CD206+ cells in naïve and pro-inflammatory macrophages in vitro. Meanwhile, knockdown decreased transcription of anti-inflammatory markers and increased the percentage of CD86+ cells in naïve and anti-inflammatory macrophages in vitro.

SIGNIFICANCE

This study suggests that circ-Cdr1as plays a key role in regulating anti-inflammatory phenotype of macrophages and may potentially be developed as an anti-inflammatory regulator in tissue inflammation.

The BRCT Domain from the Homologue of the Oncogene PES1 in Leishmania major (LmjPES) Promotes Malignancy and Drug Resistance in Mammalian Cells

Around 15% of cancer cases are attributable to infectious agents. Epidemiological studies suggest that an association between leishmaniasis and cancer does exist. Recently, the homologue of PES1 in Leishmania major (LmjPES) was described to be involved in parasite infectivity. Mammalian PES1 protein has been implicated in cellular processes like cell cycle regulation. Its BRCT domain has been identified as a key factor in DNA damage-responsive checkpoints. This work aimed to elucidate the hypothetical oncogenic implication of BRCT domain from LmjPES in host cells. We generated a lentivirus carrying this BRCT domain sequence (lentiBRCT) and a lentivirus expressing the luciferase protein (lentiLuc), as control. Then, HEK293T and NIH/3T3 mammalian cells were infected with these lentiviruses. We observed that the expression of BRCT domain from LmjPES conferred to mammal cells in vitro a greater replication rate and higher survival. In in vivo experiments, we observed faster tumor growth in mice inoculated with lentiBRCT respect to lentiLuc HEK293T infected cells. Moreover, the lentiBRCT infected cells were less sensitive to the genotoxic drugs. Accordingly, gene expression profiling analysis revealed that BRCT domain from LmjPES protein altered the expression of proliferation- (DTX3L, CPA4, BHLHE41, BMP2, DHRS2, S100A1 and PARP9), survival- (BMP2 and CARD9) and chemoresistance-related genes (DPYD, Dok3, DTX3L, PARP9 and DHRS2). Altogether, our results reinforced the idea that in eukaryotes, horizontal gene transfer might be also achieved by parasitism like Leishmania infection driving therefore to some crucial biological changes such as proliferation and drug resistance.

Virucidal N95 Respirator Face Masks via Ultrathin Surface-Grafted Quaternary Ammonium Polymer Coatings

N95 respirator face masks serve as effective physical barriers against airborne virus transmission, especially in a hospital setting. However, conventional filtration materials, such as nonwoven polypropylene fibers, have no inherent virucidal activity, and thus, the risk of surface contamination increases with wear time. The ability of face masks to protect against infection can be likely improved by incorporating components that deactivate viruses on contact. We present a facile method for covalently attaching antiviral quaternary ammonium polymers to the fiber surfaces of nonwoven polypropylene fabrics that are commonly used as filtration materials in N95 respirators via ultraviolet (UV)-initiated grafting of biocidal agents. Here, C₁₂-quaternized benzophenone is simultaneously polymerized and grafted onto melt-blown or spunbond polypropylene fabric using 254 nm UV light. This grafting method generated ultrathin polymer coatings which imparted a permanent cationic charge without grossly changing fiber morphology or air resistance across the filter. For melt-blown polypropylene, which comprises the active filtration layer of N95 respirator masks, filtration efficiency was negatively impacted from 72.5 to 51.3% for uncoated and coated single-ply samples, respectively. Similarly, directly applying the antiviral polymer to full N95 masks decreased the filtration efficiency from 90.4 to 79.8%. This effect was due to the exposure of melt-blown polypropylene to organic solvents used in the coating process. However, N95-level filtration efficiency could be achieved by wearing coated spunbond polypropylene over an N95 mask or by fabricating N95 masks with coated spunbond as the exterior layer. Coated materials demonstrated broad-spectrum antimicrobial activity against several lipid-enveloped viruses, as well as Staphylococcus aureus and Escherichia coli bacteria. For example, a 4.3-log reduction in infectious MHV-A59 virus and a 3.3-log reduction in infectious SuHV-1 virus after contact with coated filters were observed, although the level of viral deactivation varied significantly depending on the virus strain and protocol for assaying infectivity.

Detecting Intact Virus Using Exogenous Oligonucleotide Labels

The COVID-19 pandemic has revealed how an emerging pathogen can cause a sudden and dramatic increase in demand for viral testing. Testing pooled samples could meet this demand; however, the sensitivity of reverse transcription quantitative polymerase chain reaction (RT-qPCR), the gold standard, significantly decreases with an increasing number of samples pooled. Here, we introduce detection of intact virus by exogenous-nucleotide reaction (DIVER), a method that quantifies intact virus and is robust to sample dilution. As demonstrated using two models of severe acute respiratory syndrome coronavirus 2, DIVER first tags membraned particles with exogenous oligonucleotides, then captures the tagged particles on beads functionalized with a virus-specific capture agent (in this instance, angiotensin-converting enzyme 2), and finally quantifies the oligonucleotide tags using qPCR. Using spike-presenting liposomes and spike-pseudotyped lentivirus, we show that DIVER can detect 1 × 10⁵ liposomes and 100 plaque-forming units of lentivirus and can successfully identify positive samples in pooling experiments. Overall, DIVER is well positioned for efficient sample pooling and clinical validation.

Studying Cell Polarity Dynamics During Cancer Initiation Using Inducible 3D Organotypic Cultures

Epithelial tissues are highly organized structures that are structured at both the cellular and tissue levels. Individual cells are characterized by an apical membrane facing a central lumen, and a basolateral membrane that contacts adjacent cells and the basement membrane. The maintenance of apical-basal polarity is crucial for maintaining epithelial homeostasis and is considered a barrier to carcinogenesis. Apical-basal cell polarity is compromised in many epithelial cancers, such as breast, lung, and prostate, and has been associated with disease progression. Three-dimensional (3D) organotypic cultures recapitulate the 3D tissue architecture and mechanical properties found in vivo. This chapter describes methods to establish 3D organoids from human cell lines or mouse primary cells with inducible oncogene expression in polarized epithelial structures to investigate mechanisms of tumor initiation, luminal filling, and growth. The method is versatile, and simple modifications can be made to study diverse cell/tissue types and oncogenes.

Activation of Paraventricular Melatonin Receptor 2 Mediates Melatonin-Conferred Cardioprotection Against Myocardial Ischemia/Reperfusion Injury

Previous studies have shown that melatonin (Mel) can effectively ameliorate myocardial ischemia/reperfusion (MI/R) injury, but the mechanism is yet to be fully elucidated. Mel receptors are expressed in the paraventricular nucleus (PVN), which is also involved in regulating cardiac sympathetic nerve activity. The aim of this study was to examine whether Mel receptors in the PVN are involved in the protective effects of Mel against MI/R injury. The results of quantitative polymerase chain reaction, western blot, and immunofluorescence assays indicated that Mel receptor 2 (MT2) expression in the PVN was upregulated after MI/R. Intraperitoneal administration of Mel significantly improved post-MI/R cardiac function and reduced the infarct size, whereas shRNA silencing of MT2 in the PVN partially blocked this effect. Intraperitoneal administration of Mel reduced sympathetic nerve overexcitation caused by MI/R, whereas shRNA silencing of MT2 in the PVN partially diminished this effect. Furthermore, enzyme-linked immunosorbent assay and western blot results indicated that intraperitoneal administration of Mel lowered the levels of inflammatory cytokines in the PVN after MI/R injury, whereas the application of sh-MT2 in the PVN reduced this effect of Mel. Mel significantly reduced the levels of NF-κB after astrocyte oxygen and glucose deprivation/reoxygenation injury, and this effect was offset when MT2 was silenced. The above experimental results suggest that MT2 in the PVN partially mediated the protective effects of Mel against MI/R injury, and its underlying mechanisms may be related to postactivation amelioration of PVN inflammation and reduction of cardiac sympathetic nerve overexcitation.

Toward Community Surveillance: Detecting Intact SARS-CoV-2 Using Exogeneous Oligonucleotide Labels

The persistence of the COVID-19 pandemic demands a dramatic increase in testing efficiency. Testing pooled samples for SARS-CoV-2 could meet this need; however, the sensitivity of RT-qPCR, the gold standard, significantly decreases with an increasing number of samples pooled. Here, we introduce DIVER, a method that quantifies intact virus and is robust to sample dilution. DIVER first tags viral particles with exogeneous oligonucleotides, then captures the tagged particles on ACE2-functionalized beads, and finally quantifies the oligonucleotide tags using qPCR. Using spike-presenting liposomes and Spike-pseudotyped lentivirus as SARS-CoV-2 models, we show that DIVER can detect 1×10 ⁵ liposomes and 100 pfu lentivirus and can successfully identify positive samples in pooling experiments. Overall, DIVER is well-positioned for efficient sample pooling and expanded community surveillance.

Myostatin Promotes Osteoclastogenesis by Regulating Ccdc50 Gene Expression and RANKL-Induced NF-κB and MAPK Pathways

Myostatin is a crucial cytokine that is widely present in skeletal muscle and that negatively regulates the growth and development of muscle cells. Recent research has shown that myostatin might play an essential role in bone metabolism. In RAW264.7 cells and bone marrow monocytes (BMMCs), myostatin activates the expression of the II type receptor ActR II B. Here, we report that myostatin significantly promoted RANKL/M-CSF-induced osteoclastogenesis and activated NF-κB and MAPK pathways in vitro via the Ccdc50 gene. Overexpression of myostatin promoted osteoclastogenesis and osteoclastogenesis-related markers including c-Src, MMP9, CTR, CK, and NFATc1. Specifically, myostatin increased the phosphorylation of Smad2, which led to the activation of NF-κB and MAPK pathways to activate osteoclastogenesis. Ccdc50 was identified as a gene whose expression was highly decreased in osteoclastogenesis upon myostatin treatment, and it could inhibit the function of myostatin in osteoclastogenesis by blocking NF-κB and MAPKs pathways. Our study indicates that myostatin is a promising candidate target for inhibiting RANKL-mediated osteoclastogenesis and might participate in therapy for osteoporosis, and that the Ccdc50 gene plays a significant role in the regulatory process.

A Single-Cell Transcriptomic Atlas of Human Skin Aging

Skin undergoes constant self-renewal, and its functional decline is a visible consequence of aging. Understanding human skin aging requires in-depth knowledge of the molecular and functional properties of various skin cell types. We performed single-cell RNA sequencing of human eyelid skin from healthy individuals across different ages and identified eleven canonical cell types, as well as six subpopulations of basal cells. Further analysis revealed progressive accumulation of photoaging-related changes and increased chronic inflammation with age. Transcriptional factors involved in the developmental process underwent early-onset decline during aging. Furthermore, inhibition of key transcription factors HES1 in fibroblasts and KLF6 in keratinocytes not only compromised cell proliferation, but also increased inflammation and cellular senescence during aging. Lastly, we found that genetic activation of HES1 or pharmacological treatment with quercetin alleviated cellular senescence of dermal fibroblasts. These findings provide a single-cell molecular framework of human skin aging, providing a rich resource for developing therapeutic strategies against aging-related skin disorders.

An Efficient Method for Isolation of Plasmid DNA for Transfection of Mammalian Cell Cultures

In this article, we present several protocols that describe the steps from cloning and obtaining a large amount of pure plasmid DNA to generation of lentiviruses based on these constructs. The protocols have been worked out on human cell culture HEK293T but can be adapted for other cell cultures. This protocol was designed to be simple to execute and cheap since it requires only materials and consumables widely available in molecular laboratories, such as salts, alcohols, etc., and no complicated laboratory equipment. These protocols are highly effective and can be performed in any standard molecular biology laboratory.

Novel cellular immunotherapy using NKG2D CAR-T for the treatment of cervical cancer

Cellular immunotherapy, including chimeric antigen receptor (CAR) modified T cell therapy, has been regarded as one of the most potential antineoplastic drugs for hematological malignancies and solid tumor. However, due to lacking the suitable target, there is no CAR-T drug had been appoved by FDA for the treatment of cervical cancer, one of the most malignant cancers for women. In current study, we designed a NKG2D CAR-T targeting NKG2DL. The NKG2D CAR-T exhibited high-efficient anti-tumor capacity for NKG2DL positive cervical cancer cell line in vitro. In addition, the amount of cytokines secreted from CAR-T cells have had significantly enhanced after co-cultured with NKG2DL positive tumor cell in vitro. In vivo, NKG2D CAR-T cells presented a robust capacity of significantly suppressing tumor growth. Moreover, there was no obvious off-target toxicity after NKG2D CAR-T infusion. Taken together, NKG2D CAR-T showed excellent therapy effect for cervical cancer and might be used as a novel cellular therapeutic agent for treating cervical cancer.

Identification of DNMT3B2 as the Predominant Isoform of DNMT3B in Porcine Alveolar Macrophages and Its Involvement in LPS-Stimulated TNF-α Expression

DNA methyltransferase 3B (DNMT3B) as one member of the DNMT family functions as a de novo methyltransferase, characterized as more than 30 splice variants in humans and mice. However, the expression patterns of DNMT3B in pig as well as the biological function of porcine DNMT3B remain to be determined. In this study, we first examined the expression patterns of DNMT3B in porcine alveolar macrophages (PAM). We demonstrated that only DNMT3B2 and DNMT3B3 were the detectable isoforms in PAM. Furthermore, we revealed that DNTM3B2 was the predominant isoform in PAM. Next, in the model of LPS (lipopolysaccharide)-activated PAM, we showed that in comparison to the unstimulated PAM, (1) expression of DNTM3B is reduced; (2) the methylation level of TNF-α gene promoter is decreased. We further establish that DNMT3B2-mediated methylation of TNF-α gene promoter restricts induction of TNF-α in the LPS-stimulated PAM. In summary, these findings reveal that DNMT3B2 is the predominant isoform in PAM and its downregulation contributes to expression of TNF-α via hypomethylation of TNF-α gene promoter in the LPS-stimulated PAM.

ERINA Is an Estrogen-Responsive LncRNA That Drives Breast Cancer through the E2F1/RB1 Pathway

Resistance to therapeutic drugs is a major challenge in the treatment of cancers, including breast cancer. Long noncoding RNAs (lncRNA) are known to have diverse physiologic and pathophysiologic functions, including in cancer. In searching for lncRNA responsible for cancer drug resistance, we identified an intergenic lncRNA ERINA (estrogen inducible lncRNA) as a novel lncRNA highly expressed in multiple cancer types, especially in estrogen receptor-positive (ER⁺) breast cancers. Expression of ERINA was inversely correlated with survival of patients with ER⁺ breast cancer and sensitivity to CDK inhibitor in breast cancer cell lines. Functional characterization established ERINA as an oncogenic lncRNA, as knockdown of ERINA in breast cancer cells inhibited cell-cycle progression and tumor cell proliferation in vitro and xenograft tumor growth in vivo. In contrast, overexpression of ERINA promoted cell growth and cell-cycle progression. ERINA promoted cell-cycle progression by interacting with the E2F transcription factor 1 (E2F1), which prevents the binding of E2F1 to the tumor suppressor retinoblastoma protein 1 (RB1). ERINA also functioned as an estrogen and ER-responsive gene, and an intronic ER-binding site was identified as an enhancer that mediates the transactivation of ERINA. In summary, ERINA is an estrogen-responsive oncogenic lncRNA that may serve as a novel biomarker and potential therapeutic target in breast cancer. SIGNIFICANCE: These findings identify ERINA as an estrogen-responsive, oncogenic lncRNA, whose elevated expression may contribute to drug resistance and poor survival of patients with ER⁺ breast cancer.

Small interfering RNA target for long noncoding RNA PCGEM1 increases the sensitivity of LNCaP cells to baicalein

The objective of this study is to investigate the inhibitory effect and mechanism of long noncoding RNA PCGEM1 siRNA combined with baicalein on prostate cancer LNCaP cells. LNCaP cells transfected with small hairpin RNA lentiviral vector targeting PCGEM1 were constructed and their expression in LNCaP cells was absent. The stable cell line of LNCaP cells infected with LV3-shRNA-PCGEM1 was successfully constructed. In addition, LV3-shRNA-PCGEM1 was able to increase the baicalein-induced inhibitory effects on LNCaP cells, and the susceptibility was 2.3 fold higher than that of baicalein alone. LV3-shRNA-PCGEM1 combined with baicalein also inhibited the colony formation, increased G2 and S phase cells, inhibited the expression of PCGEM1, and induced autophagy of LNCaP cells. In summary, LV3-shRNA-PCGEM1 may improve the sensitivity of LNCaP cells to baicalein, and the molecular mechanism may be associated with the decrease of PCGEM1 expression and the induction of autophagy. Our findings provided an experimental basis for the combined treatment of Chinese traditional and Western medicine on prostate cancer in a clinical setting.

The Effects of Heme Oxygenase Upregulation on Obesity and the Metabolic Syndrome

Significance: Obesity is a chronic condition that is characterized by inflammation and oxidative stress with consequent cardiovascular complications of hypertension, dyslipidemia, and vascular dysfunction. Obesity-induced metabolic syndrome remains an epidemic of global proportions. Recent Advances: Gene targeting of the endothelium with a retrovirus using an endothelium-specific promoter vascular endothelium cadherin (VECAD)-HO-1 offers a potential long-term solution to adiposity by targeting the endothelium. This has resulted in improvements of both vascular function and adiposity attenuation. Critical Issues: Heme oxygenase plays an ever-increasing role in the understanding of human biology in the complex conditions of obesity and the metabolic syndrome. The heme oxygenase 1 (HO-1) system creates biliverdin/bilirubin, which functions as an antioxidant, and carbon monoxide, which has antiapoptotic properties. Future Directions: Upregulation of HO-1 has been shown to improve adiposity as well as vascular function in both animal and human studies.

Different Serotypes of Adeno-Associated Virus Vector- and Lentivirus-Mediated Tropism in Choroid Plexus by Intracerebroventricular Delivery

Regulation of gene expression by viral vectors is an effective method for researchers to explore the function of gene products in a target tissue. The choroid plexus (CP) is an important target for gene therapy of neuropsychiatric diseases such as Alzheimer's disease and major depressive disorder. However, viral tropism in CP has not been well studied as a result of limited viral vector applications. To identify CP-specific viral vectors, we intracerebroventricularly administered six different serotypes of adeno-associated virus (AAV) vectors (AAV2/1, AAV2/5, AAV2/8, AAV2/9, AAV2-BR1, and AAV2-PHP.eB) and lentivirus in adult mice. Tropism in CP was compared among these viruses. We found that AAV2/5 and AAV2/8 displayed remarkable infections in CP, while AAV2/1 infected both ependymal cells and cells in the CP. Except for the low infection intensity of AAV2/9 and lentivirus in the CP, no infection intensity was found for CP tissues injected with AAV2-BR1 or AAV2-PHP.eB. Green fluorescence protein expression in the CP after AAV2/5 infection was confirmed by Western blotting. AAV2/5-mediated tropism in epithelial cells of the CP was verified by immunostaining with transthyretin. In this study, we identified for the first time that serotype-specific AAVs 5 and 8 may be robust research tools for intracerebroventricular gene delivery.

Suppression of IRE1α Attenuated the Fatty Degeneration in Parenteral Nutrition-Related Liver Disease (PNALD) Cell Model

Aims

To model the parenteral nutrition-associated liver disease (PNALD) in rat normal hepatocytes BRL and investigate the role of endoplasmic reticulum stress- (ERS-) related IRE1α signal in the process of PNALD.

Methods

The BRL cells were treated with different concentrations of soybean oil emulsion (SO) to induce hepatocyte fatty degeneration. The PNALD cell disease model was further confirmed by analysis of Oil Red O staining and biochemical parameters. Next, the IRE1α signal in the process of PNALD. α signal in the process of PNALD. α signal in the process of PNALD. α signal in the process of PNALD.

Results

The results of Oil Red O staining indicated that the PNALD was successfully established in BRL cells and the CCK-8 data indicated which 0.6% that SO was further applied to the experiment owing to its better induction of PNALD and less toxicity to the cells. Besides, the value of biochemical parameters (TBIL, DBIL, ALT, and AST) was also elevated in the SO group compared with the NG group. After knockdown of IRE1α signal in the process of PNALD. α signal in the process of PNALD.

Conclusion

IRE1α was induced in PNALD cell model and suppression of IRE1α resulted in reduced steatosis in this cell disease model. Taken together, our data suggested that the IRE1α pathway may be involved in the development of PNALD.α signal in the process of PNALD. α signal in the process of PNALD. α signal in the process of PNALD.

Creation of Cultures Containing Mutations Linked with Cardiovascular Diseases using Transfection and Genome Editing

OBJECTIVE

In this review article, we analyzed the literature on the creation of cultures containing mutations associated with cardiovascular diseases (CVD) using transfection, transduction and editing of the human genome.

METHODS

We described different methods of transfection, transduction and editing of the human genome, used in the literature.

RESULTS

We reviewed the researches in which the creation of сell cultures containing mutations was described. According to the literature, system CRISPR/Cas9 proved to be the most preferred method for editing the genome. We found rather promising and interesting a practically undeveloped direction of mitochondria transfection using a gene gun. Such a gun can direct a genetically-engineered construct containing human DNA mutations to the mitochondria using heavy metal particles. However, in human molecular genetics, the transfection method using a gene gun is unfairly forgotten and is almost never used. Ethical problems arising from editing the human genome were also discussed in our review. We came to a conclusion that it is impossible to stop scientific and technical progress. It is important that the editing of the genome takes place under the strict control of society and does not bear dangerous consequences for humanity. To achieve this, the constant interaction of science with society, culture and business is necessary.

CONCLUSION

The most promising methods for the creation of cell cultures containing mutations linked with cardiovascular diseases, were system CRISPR/Cas9 and the gene gun.

Discovering master regulators in hepatocellular carcinoma: one novel MR, SEC14L2 inhibits cancer cells

Identification of master regulator (MR) genes offers a relatively rapid and efficient way to characterize disease-specific molecular programs. Since strong consensus regarding commonly altered MRs in hepatocellular carcinoma (HCC) is lacking, we generated a compendium of HCC datasets from 21 studies and identified a comprehensive signature consisting of 483 genes commonly deregulated in HCC. We then used reverse engineering of transcriptional networks to identify the MRs that underpin the development and progression of HCC. After cross-validation in different HCC datasets, systematic assessment using patient-derived data confirmed prognostic predictive capacities for most HCC MRs and their corresponding regulons. Our HCC signature covered well-established liver cancer hallmarks, and network analyses revealed coordinated interaction between several MRs. One novel MR, SEC14L2, exerted an anti-proliferative effect in HCC cells and strongly suppressed tumor growth in a mouse model. This study advances our knowledge of transcriptional MRs potentially involved in HCC development and progression that may be targeted by specific interventions.

Development of an improved lentiviral based vector system for the stable expression of monoclonal antibody in CHO cells

Therapeutic monoclonal antibodies (mAbs) have become the dominant products in biopharmaceutical industry. Mammalian cell expression systems including Chinese hamster ovary (CHO) cells are the most commonly used hosts for the production of complex recombinant proteins. However, development of stable, high producing CHO cell lines suffers from the low expression level and instability of the transgene. The increasing efforts in the development of novel therapeutic antibodies and the advent of biosimilars have revealed the necessity for the development of improved platforms for rapid production of products for initial characterization and testing. In line with this premise, vector design and engineering has been applied to improve the expression level and stability of the transgene. This study reports the application of an improved lentiviral vector system containing the human interferon-β scaffold attachment region (IFN-SAR) for the development of antibody producing stable CHO cells. mAb expressing clones producing 1100 µg/L of IgG1 monoclonal antibody were isolated without extensive screening of a large number of clones. Our results here indicate the positive effects of IFN-SAR on stable mAb expression using lentiviral based expression vectors. We also observed that although IFN-SAR can improve light chain (LC) and heavy chain (HC) gene copy numbers in stable cell pools, mAb expression in single cell clones was not affected by the transgene copy number.

Basic Concepts in Viral Vector-Mediated Gene Therapy

Today any researcher with the desire can easily purchase a viral vector. However, despite the availability of viral vectors themselves, the requisite knowledge that is absolutely essential to conducting a gene therapy experiment remains somewhat obscure and esoteric. To utilize viral vectors to their full potential, a large number of decisions must be made, in some instances prior to even obtaining the vector itself. For example, critical decisions include selection of the proper virus, selection of the proper expression cassette, whether to produce or purchase a viral vector, proper viral handling and storage, the most appropriate delivery method, selecting the proper controls, how to ensure your virus is expressing properly, and many other complex decisions that are essential to performing a successful gene therapy experiment. The need to make so many important decisions can be overwhelming and potentially prohibitive, especially to the novice gene therapist. In order to aid in this challenging process, here we provide an overview of basic gene therapy modalities and a decision tree that can be used to make oneself aware of the options available to the beginning gene therapist. This information can be used as a road map to help navigate the complex and perhaps confusing process of designing a successful gene therapy experiment.

New Tools for Epilepsy Therapy

One third of the epilepsies are refractory to conventional antiepileptic drugs (AEDs) and, therefore, identification of new therapies is highly needed. Here, we briefly describe two approaches, direct cell grafting and gene therapy, that may represent alternatives to conventional drugs for the treatment of focal epilepsies. In addition, we discuss more in detail some new tools, cell based-biodelivery systems (encapsulated cell biodelivery (ECB) devices) and new generation gene therapy vectors, which may help in the progress toward clinical translation. The field is advancing rapidly, and there is optimism that cell and/or gene therapy strategies will soon be ready for testing in drug-resistant epileptic patients.

Silencing Alpha Synuclein in Mature Nigral Neurons Results in Rapid Neuroinflammation and Subsequent Toxicity

Human studies and preclinical models of Parkinson’s disease implicate the involvement of both the innate and adaptive immune systems in disease progression. Further, pro-inflammatory markers are highly enriched near neurons containing pathological forms of alpha synuclein (α-syn), and α-syn overexpression recapitulates neuroinflammatory changes in models of Parkinson’s disease. These data suggest that α-syn may initiate a pathological inflammatory response, however the mechanism by which α-syn initiates neuroinflammation is poorly understood. Silencing endogenous α-syn results in a similar pattern of nigral degeneration observed following α-syn overexpression. Here we aimed to test the hypothesis that loss of α-syn function within nigrostriatal neurons results in neuronal dysfunction, which subsequently stimulates neuroinflammation. Adeno-associated virus (AAV) expressing an short hairpin RNA (shRNA) targeting endogenous α-syn was unilaterally injected into the substantia nigra pars compacta (SNc) of adult rats, after which nigrostriatal pathology and indices of neuroinflammation were examined at 7, 10, 14 and 21 days post-surgery. Removing endogenous α-syn from nigrostriatal neurons resulted in a rapid up-regulation of the major histocompatibility complex class 1 (MHC-1) within transduced nigral neurons. Nigral MHC-1 expression occurred prior to any overt cell death and coincided with the recruitment of reactive microglia and T-cells to affected neurons. Following the induction of neuroinflammation, α-syn knockdown resulted in a 50% loss of nigrostriatal neurons in the SNc and a corresponding loss of nigrostriatal terminals and dopamine (DA) concentrations within the striatum. Expression of a control shRNA did not elicit any pathological changes. Silencing α-syn within glutamatergic neurons of the cerebellum did not elicit inflammation or cell death, suggesting that toxicity initiated by α-syn silencing is specific to DA neurons. These data provide evidence that loss of α-syn function within nigrostriatal neurons initiates a neuronal-mediated neuroinflammatory cascade, involving both the innate and adaptive immune systems, which ultimately results in the death of affected neurons.

Modified Roller Tube Method for Precisely Localized and Repetitive Intermittent Imaging During Long-term Culture of Brain Slices in an Enclosed System

Cultured rodent brain slices are useful for studying the cellular and molecular behavior of neurons and glia in an environment that maintains many of their normal in vivo interactions. Slices obtained from a variety of transgenic mouse lines or use of viral vectors for expression of fluorescently tagged proteins or reporters in wild type brain slices allow for high-resolution imaging by fluorescence microscopy. Although several methods have been developed for imaging brain slices, combining slice culture with the ability to perform repetitive high-resolution imaging of specific cells in live slices over long time periods has posed problems. This is especially true when viral vectors are used for expression of exogenous proteins since this is best done in a closed system to protect users and prevent cross contamination. Simple modifications made to the roller tube brain slice culture method that allow for repetitive high-resolution imaging of slices over many weeks in an enclosed system are reported. Culturing slices on photoetched coverslips permits the use of fiducial marks to rapidly and precisely reposition the stage to image the identical field over time before and after different treatments. Examples are shown for the use of this method combined with specific neuronal staining and expression to observe changes in hippocampal slice architecture, viral-mediated neuronal expression of fluorescent proteins, and the development of cofilin pathology, which was previously observed in the hippocampus of Alzheimer's disease (AD) in response to slice treatment with oligomers of amyloid-β (Aβ) peptide.

Delta-Secretase Phosphorylation by SRPK2 Enhances Its Enzymatic Activity, Provoking Pathogenesis in Alzheimer's Disease

Delta-secretase, a lysosomal asparagine endopeptidase (AEP), simultaneously cleaves both APP and tau, controlling the onset of pathogenesis of Alzheimer's disease (AD). However, how this protease is post-translationally regulated remains unclear. Here we report that serine-arginine protein kinase 2 (SRPK2) phosphorylates delta-secretase and enhances its enzymatic activity. SRPK2 phosphorylates serine 226 on delta-secretase and accelerates its autocatalytic cleavage, leading to its cytoplasmic translocation and escalated enzymatic activities. Delta-secretase is highly phosphorylated in human AD brains, tightly correlated with SRPK2 activity. Overexpression of a phosphorylation mimetic (S226D) in young 3xTg mice strongly promotes APP and tau fragmentation and facilitates amyloid plaque deposits and neurofibrillary tangle (NFT) formation, resulting in cognitive impairment. Conversely, viral injection of the non-phosphorylatable mutant (S226A) into 5XFAD mice decreases APP and tau proteolytic cleavage, attenuates AD pathologies, and reverses cognitive defects. Our findings support that delta-secretase phosphorylation by SRPK2 plays a critical role in aggravating AD pathogenesis.

Current Experimental Studies of Gene Therapy in Parkinson's Disease

Parkinson's disease (PD) was characterized by late-onset, progressive dopamine neuron loss and movement disorders. The progresses of PD affected the neural function and integrity. To date, most researches had largely addressed the dopamine replacement therapies, but the appearance of L-dopa-induced dyskinesia hampered the use of the drug. And the mechanism of PD is so complicated that it's hard to solve the problem by just add drugs. Researchers began to focus on the genetic underpinnings of Parkinson's disease, searching for new method that may affect the neurodegeneration processes in it. In this paper, we reviewed current delivery methods used in gene therapies for PD, we also summarized the primary target of the gene therapy in the treatment of PD, such like neurotrophic factor (for regeneration), the synthesis of neurotransmitter (for prolong the duration of L-dopa), and the potential proteins that might be a target to modulate via gene therapy. Finally, we discussed RNA interference therapies used in Parkinson's disease, it might act as a new class of drug. We mainly focus on the efficiency and tooling features of different gene therapies in the treatment of PD.

Impact of age and vector construct on striatal and nigral transgene expression

Therapeutic protein delivery using viral vectors has shown promise in preclinical models of Parkinson's disease (PD) but clinical trial success remains elusive. This may partially be due to a failure to include advanced age as a covariate despite aging being the primary risk factor for PD. We investigated transgene expression following intracerebral injections of recombinant adeno-associated virus pseudotypes 2/2 (rAAV2/2), 2/5 (rAAV2/5), 2/9 (rAAV2/9), and lentivirus (LV) expressing green fluorescent protein (GFP) in aged versus young adult rats. Both rAAV2/2 and rAAV2/5 yielded lower GFP expression following injection to either the aged substantia nigra or striatum. rAAV2/9-mediated GFP expression was deficient in the aged striatonigral system but displayed identical transgene expression between ages in the nigrostriatal system. Young and aged rats displayed equivalent GFP levels following LV injection to the striatonigral system but LV-delivered GFP was deficient in delivering GFP to the aged nigrostriatal system. Notably, age-related transgene expression deficiencies revealed by protein quantitation were poorly predicted by GFP-immunoreactive cell counts. Further, in situ hybridization for the viral CβA promoter revealed surprisingly limited tropism for astrocytes compared to neurons. Our results demonstrate that aging is a critical covariate to consider when designing gene therapy approaches for PD.