Hydrogen sulfide regulates macrophage polarization and necroptosis to accelerate diabetic skin wound healing.

Hydrogen sulfide (H2S), recognized as the third gasotransmitter, plays a pivotal role in the pathophysiological processes of various diseases. Cystathionine γ-lyase (CSE) is the main enzyme for H2S production in the skin. However, effects and mechanisms of H2S in diabetic skin wound healing remain unclear. Our findings revealed a decrease in plasma H2S content in diabetic patients with skin wounds. CSE knockout (KO) diabetic mice resulted in delayed wound healing, reduced blood perfusion, and CD31 expression around the wounds. It also led to increased infiltration of inflammatory cells and M1-type macrophages, decreased collagen levels, α-smooth muscle actin (α-SMA), and proliferating cell nuclear antigen (PCNA) expression. Additionally, there were enhanced expressions of necroptosis related proteins, including receptor interacting protein kinase 1 (RIPK1), RIPK3 and mixed lineage kinase domain like protein (MLKL). In comparison, sodium hydrosulfide (NaHS), H2S donor, accelerated skin wound healing in leptin receptor deficiency (db/db) mice. This acceleration was accompanied by increased blood perfusion and CD31 expression, reduced infiltration of inflammatory cells and M1-type macrophages, elevated collagen levels, α-SMA, and PCNA expressions, and decreased necroptosis-related protein expressions together with nuclear factor-κB (NF-κB) p65 phosphorylation. In conclusion, H2S regulates macrophage polarization and necroptosis, contributing to the acceleration of diabetic skin wound healing. These findings offer a novel strategy for the treatment of diabetic skin wounds.

Chromosome-level genome assembly of the predatory stink bug Arma custos.

The stink bug Arma custos (Hemiptera: Pentatomidae) is a predatory enemy successfully used for biocontrol of lepidopteran and coleopteran pests in notorious invasive species. In this study, a high-quality chromosome-scale genome assembly of A. custos was achieved through a combination of Illumina sequencing, PacBio HiFi sequencing, and Hi-C scaffolding techniques. The final assembled genome was 969.02 Mb in size, with 935.94 Mb anchored to seven chromosomes, and a scaffold N50 length of 135.75 Mb. This genome comprised 52.78% repetitive elements. The detected complete BUSCO score was 99.34%, indicating its completeness. A total of 13,708 protein-coding genes were predicted in the genome, and 13219 of them were annotated. This genome provides an invaluable resource for further research on various aspects of predatory bugs, such as biology, genetics, and functional genomics.

Progress in the treatment of advanced hepatocellular carcinoma with immune combination therapy.

Advanced hepatocellular carcinoma (HCC) is a severe malignancy that poses a serious threat to human health. Owing to challenges in early diagnosis, most patients lose the opportunity for radical treatment when diagnosed. Nonetheless, recent advancements in cancer immunotherapy provide new directions for the treatment of HCC. For instance, monoclonal antibodies against immune checkpoint inhibitors (ICIs) such as programmed cell death protein 1/death ligand-1 inhibitors and cytotoxic t-lymphocyte associated antigen-4 significantly improved the prognosis of patients with HCC. However, tumor cells can evade the immune system through various mechanisms. With the rapid development of genetic engineering and molecular biology, various new immunotherapies have been used to treat HCC, including ICIs, chimeric antigen receptor T cells, engineered cytokines, and certain cancer vaccines. This review summarizes the current status, research progress, and future directions of different immunotherapy strategies in the treatment of HCC.

Comparing Safety and Efficacy of TACE + Apatinib in Combination with a PD-1 Inhibitor versus a Non-triple Therapy for Treating Advanced Primary Hepatocellular Carcinoma: A Systematic Review and Meta-analysis.

BACKGROUND AND AIMS: This meta-analysis was performed to compare the efficacy and safety of a triple therapy, involving transcatheter arterial chemoembolization (TACE) + apatinib combined with a programmed-cell death protein-1 (PD-1) inhibitor versus TACE + apatinib, a dual therapy with apatinib and PD-1 inhibitor, and TACE alone for the treatment of advanced primary hepatocellular carcinoma (HCC). METHODS: A computerized systematic search of databases, such as PubMed, Embase, the Cochrane Library, CNKI, Wanfang Data, and VIP e-Journals was performed to retrieve studies comparing TACE + apatinib combined with a PD-1 inhibitor versus a non-triple therapy for the treatment of advanced primary HCC. The literature search, quality assessment, and data extraction were performed independently by two researchers. Stata 16.0 software was employed to analyze the data. Heterogeneity was assessed utilizing the I2 statistic and p-value, followed by conducting sensitivity analysis. RESULTS: A total of 2,352 patients were enrolled from 8 studies, including 900 patients in the triple therapy group of TACE + apatinib combined with a PD-1 inhibitor, 877 patients in the TACE + apatinib group, 52 patients in the apatinib + a PD-1 inhibitor group, and 112 patients in the TACE group. The results revealed that the objective response rate (ORR) was significantly higher in the triple therapy group of TACE + apatinib combined with a PD-1 inhibitor than that in the non-triple therapy group [odds ratio (OR)=2.47, 95% confidence interval (95%CI): 1.61-3.78]. Besides, disease control rate (DCR) was greater in the triple therapy group of TACE + apatinib combined with a PD-1 inhibitor than that in the non-triple therapy group (OR=1.87, 95%CI: 1.44-2.44). Patients in the triple therapy group experienced a significant extension of overall survival (OS) (HR=0.42, 95%CI: 0.36-0.49). In addition, there was no significant difference in the overall rate of adverse events (AEs) between the two groups (OR=1.05, 95%CI: 0.89-1.22). CONCLUSIONS: Compared with the non-triple therapy group, the triple therapy group of TACE + apatinib combined with a PD-1 inhibitor outperformed in terms of tumor response and long-term survival with manageable AEs.

Research Progress of Plant-Derived Natural Products against Drug-Resistant Cancer.

As one of the malignant diseases globally, cancer seriously endangers human physical and mental health because of its high morbidity and mortality. Conventional cancer treatment strategies, such as surgical resection and chemoradiotherapy, are effective at the early stage of cancer but have limited efficacy for advanced cancer. Along with cancer progress and treatment, resistance develops gradually within the population of tumor cells. As a consequence, drug resistance become the major cause that leads to disease progression and poor clinical prognosis in some patients. The mechanisms of cancer drug resistance are quite complex and involve various molecular and cellular mechanisms. Therefore, exploring the mechanisms and finding specific targets are becoming imperative to overcome drug resistance. In recent years, plant-derived natural products have been evaluated as potential therapeutic candidates against cancer with drug resistance due to low side effects and high anticancer efficacy. A growing number of studies have shown that natural products can achieve superior antitumor effects through multiple signaling pathways. The mechanisms include regulation of multiple drug resistance (MDR)-related genes, inhibition of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway, induction of autophagy, and blockade of the cell cycle. This paper reviews the molecular and cellular mechanisms of cancer drug resistance, as well as the therapeutic effects and mechanisms of plant-derived natural products against cancer drug resistance. It provides references for developing therapeutic medication for drug-resistant cancer treatment with high efficacy and low side effects.

Nanopore analysis of salvianolic acids in herbal medicines.

Natural herbs, which contain pharmacologically active compounds, have been used historically as medicines. Conventionally, the analysis of chemical components in herbal medicines requires time-consuming sample separation and state-of-the-art analytical instruments. Nanopore, a versatile single molecule sensor, might be suitable to identify bioactive compounds in natural herbs. Here, a phenylboronic acid appended Mycobacterium smegmatis porin A (MspA) nanopore is used as a sensor for herbal medicines. A variety of bioactive compounds based on salvianolic acids, including caffeic acid, protocatechuic acid, protocatechualdehyde, salvianic acid A, rosmarinic acid, lithospermic acid, salvianolic acid A and salvianolic acid B are identified. Using a custom machine learning algorithm, analyte identification is performed with an accuracy of 99.0%. This sensing principle is further used with natural herbs such as Salvia miltiorrhiza, Rosemary and Prunella vulgaris. No complex sample separation or purification is required and the sensing device is highly portable.

Nanopore analysis of cis-diols in fruits.

Natural fruits contain a large variety of cis-diols. However, due to the lack of a high-resolution sensor that can simultaneously identify all cis-diols without a need of complex sample pretreatment, direct and rapid analysis of fruits in a hand-held device has never been previously reported. Nanopore, a versatile single molecule sensor, can be specially engineered to perform this task. A hetero-octameric Mycobacterium smegmatis porin A (MspA) nanopore modified with a sole phenylboronic acid (PBA) adapter is prepared. This engineered MspA accurately recognizes 1,2-diphenols, alditols, α-hydroxy acids and saccharides in prune, grape, lemon, different varieties of kiwifruits and commercial juice products. Assisted with a custom machine learning program, an accuracy of 99.3% is reported and the sample pretreatment is significantly simplified. Enantiomers such as DL-malic acids can also be directly identified, enabling sensing of synthetic food additives. Though demonstrated with fruits, these results suggest wide applications of nanopore in food and drug administration uses.

Nanopore Identification of N-Acetylation by Hydroxylamine Deacetylation (NINAHD).

N-Acetyl modification, a chemical modification commonly found on biomacromolecules, plays a crucial role in the regulation of cell activities and is related to a variety of diseases. However, due to the instability of N-acetyl modification, accurate and rapid identification of N-acetyl modification with a low measurement cost is still technically challenging. Here, based on hydroxylamine deacetylation and nanopore single molecule chemistry, a universal sensing strategy for N-acetyl modification has been developed. Acetohydroxamic acid (AHA), which is produced by the hydroxylamine deacetylation reaction and serves as a reporter for N-acetylation identification, is specifically sensed by a phenylboronic acid (PBA)-modified Mycobacterium smegmatis porin A (MspA). With this strategy, N-acetyl modifications on RNA, DNA, proteins, and glycans were identified, demonstrating its generality. Specifically, histones can be treated with hydroxylamine deacetylation, from which the generated AHA can represent the amount of N-acetyl modification detected by a nanopore sensor. The unique event features of AHA also demonstrate the robustness of sensing against other interfering analytes in the environment.

TRIM44 promotes autophagy through SQSTM1 oligomerization in the response to oxidative stress induced by Arsenic Trioxide in cancer cells.

Tripartite motif containing 44 (TRIM44), a deubiquitinase, plays a pivotal role in connecting proteotoxic stress response to autophagic degradation in cancer and neurological diseases. While numerous studies have reported the upregulation of TRIM44 as a prognostic maker in various cancers, the detailed molecular mechanisms through which TRIM44 promotes autophagic degradation remain unclear. Here, we reported that TRIM44 can promote autophagy in response to oxidative stress which results in decreased cytotoxicity in Arsenic Trioxide treated cancer cells. The study focuses on the posttranslational modification of sequestosome-1 (SQSTM1) and its role in enhancing sequestration function during autophagic degradation. We discovered that TRIM44 significantly promotes SQSTM1 oligomerization in PB1 domain-dependent and oxidation-dependent manners. Furthermore, TRIM44 enhances the interaction between protein kinase A (PKA) and oligomerized SQSTM1, leading to increased phosphorylation of SQSTM1 at S349 and subsequent activation of NFE2L2 in response to oxidative stress. Collectively, our data support the potential roles of TRIM44 in the sensitivity of SQSTM1-mediated autophagy in the context of cancer, ageing and ageing-associated diseases, as well as neurodegenerative diseases.

DNA-induced assembly of biocatalytic nanocompartments for sensitive and selective aptasensing of aflatoxin B1.

Enzyme cascade with high specificity and catalytic efficiency has significant applications for developing efficient bioanalysis methods. In this work, a sensitive and selective aptasensor was constructed based on the DNA-induced assembly of biocatalytic nanocompartments. Different from the conventional co-immobilization in one pot, the cascade enzymes of glucose oxidase (GOX) and horseradish peroxidase (HRP) were separately encapsulated in ZIF-90 nanoparticles. After conjugating complementary DNA or aptermer on enzyme@ZIF-90, DNA hybridization drove enzyme@ZIF-90 connected into clusters or linked on other DNA modified biocatalytic nanocompartment (such as invertase loaded Fe3O4@SiO2). Owing to the shortened distance between enzymes, the catalytic efficiency of connected clusters was significantly enhanced. However, the specifically interaction between the substrate molecule and aptermer sequence would lead to the disassembly of DNA duplexes, resulting in the gradual "switching-off" of cascade reactions. With aflatoxin B1 (AFB1) as the model substrate, the compartmentalized three-enzyme nanoreactors showed good analytical performance in the linear range from 0.01 ng mL-1 to 50 ng mL-1 with a low detection limit (3.3 pg mL-1). In addition, the proposed aptasensor was applied to detect AFB1 in corn oil and wheat powder samples with total recoveries ranging from 94 % to 109 %. As a result, this DNA-induced strategy for enzyme cascade nanoreactors opens new avenues for stimuli-responsive applications in biosensing.

Intricate Ionic Behaviors in High-Performance Self-Powered Hydrothermal Chemical Generator Using Water and Iron (III) Gate.

Utilizing the ionic flux to generate voltage output has been confirmed as an effective way to meet the requirements of clean energy sources. Different from ionic thermoelectric (i-TE) and hydrovoltaic devices, a new hydrothermal chemical generator is designed by amorphous FeCl3 particles dispersing in MWCNT and unique ferric chloride or water gate. In the presence of gate, the special ion behaviors enable the cell to present a constant voltage of 0.60 V lasting for over 96 h without temperature difference. Combining the differences of cation concentration, humidity and temperature between the right and left side of sample, the maximum short-circuit current and power output can be obtained to 168.46 µA and 28.11 µW, respectively. The generator also can utilize the low-grade heat to produce electricity wherein Seebeck coefficient is 6.79 mV K-1 . The emerged hydrothermal chemical generator offers a novel approach to utilize the low-grade heat, water and salt solution resources, which provides a simple, sustainable and low-cost strategy to realize energy supply.

Brain cholesterol and Alzheimer's disease: challenges and opportunities in probe and drug development.

Cholesterol homeostasis is impaired in Alzheimer's disease (AD), however, attempts to modulate brain cholesterol biology have not translated into tangible clinical benefits for patients to date. Several recent milestone developments have substantially improved our understanding of how excess neuronal cholesterol contributes to the pathophysiology of AD. Indeed, neuronal cholesterol was linked to the formation of amyloid-ß (Aß) formation and neurofibrillary tangles through molecular pathways that were recently delineated in mechanistic studies. Further, remarkable advances in translational molecular imaging have now made it possible to probe cholesterol metabolism in the living human brain with positron emission tomography, which is an important prerequisite for future clinical trials that target the brain cholesterol machinery in AD patients - with the ultimate aim to develop disease-modifying treatments. This work summarizes current concepts of how the biosynthesis, transport and clearance of brain cholesterol are affected in AD. Further, current strategies to reverse these alterations by pharmacotherapy are critically discussed in the wake of emerging translational research tools that support the assessment of brain cholesterol biology not only in animal models but also in AD patients.

The value of D-dimer to lymphocyte ratio in predicting clinical outcomes after percutaneous coronary intervention in ST-segment elevation myocardial infarction patients: A retrospective study.

BACKGROUND: D-dimer to lymphocyte ratio (DLR) is a novel composite metric. This study investigated the association between DLR and major adverse cardiovascular events (MACEs) in patients with ST-segment elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention. MATERIALS AND METHODS: This retrospective study included 683 STEMI cases treated between January 2018 and June 2021 at a single center. DLR was calculated for each patient. Receiver operating characteristic curves assessed the predictive value of in-hospital and long-term MACEs, with calculated AUC. Based on the optimal DLR cutoff value, the population was categorized into groups for clinical characteristic analysis. Multivariate logistic and COX regression analyses determined factors independently associated with MACEs. Kaplan-Meier estimation method and log-rank tests assessed event-free survival among different DLR groups. Spearman's test explored the correlation between DLR and Gensini score. RESULTS: DLR demonstrated an AUC of 0.792 for predicting in-hospital MACEs and 0.708 for long-term MACEs in patients with STEMI. Multivariate logistic regression analysis revealed that a high DLR (cutoff value, 0.47) independently increased the risk of MACEs during hospitalization in patients with STEMI (P = 0.003; odds ratio: 3.015; 95 % CI: 1.438-6.321). Multivariate COX regression showed that a high DLR (cutoff value, 0.34) independently predicted MACEs during long-term follow-up in patients with STEMI (P = 0.011; hazard ratio: 1.724; 95 % CI: 1.135-2.619). Furthermore, DLR exhibited a positive correlation with the Gensini score (P < 0.001). CONCLUSIONS: DLR is a valuable predictor for MACEs occurrence in patients with STEMI during hospitalization and long-term follow-up after PCI.

Biochemical pancreatic ß-cell lineage reprogramming: Various cell fate shifts.

The incidence of pancreatic diseases has been continuously rising in recent years. Thus, research on pancreatic regeneration is becoming more popular. Chronic hyperglycemia is detrimental to pancreatic ß-cells, leading to impairment of insulin secretion which is the main hallmark of pancreatic diseases. Obtaining plenty of functional pancreatic ß-cells is the most crucial aspect when studying pancreatic biology and treating diabetes. According to the International Diabetes Federation, diabetes has become a global epidemic, with about 3 million people suffering from diabetes worldwide. Hyperglycemia can lead to many dangerous diseases, including amputation, blindness, neuropathy, stroke, and cardiovascular and kidney diseases. Insulin is widely used in the treatment of diabetes; however, innovative approaches are needed in the academic and preclinical stages. A new approach aims at synthesizing patient-specific functional pancreatic ß-cells. The present article focuses on how cells from different tissues can be transformed into pancreatic ß-cells.

Identification of oleic acid as an endogenous ligand of GPR3.

Although GPR3 plays pivotal roles in both the nervous system and metabolic processes, such as cold-induced thermogenesis, its endogenous ligand remains elusive. Here, by combining structural approach (including cryo-electron microscopy), mass spectrometry analysis, and functional studies, we identify oleic acid (OA) as an endogenous ligand of GPR3. Our study reveals a hydrophobic tunnel within GPR3 that connects the extracellular side of the receptor to the middle of plasma membrane, enabling fatty acids to readily engage the receptor. Functional studies demonstrate that OA triggers downstream Gs signaling, whereas lysophospholipids fail to activate the receptor. Moreover, our research reveals that cold stimulation induces the secretion of OA in mice, subsequently activating Gs/cAMP/PKA signaling in brown adipose tissue. Notably, brown adipose tissues from Gpr3 knockout mice do not respond to OA during cold stimulation, reinforcing the significance of GPR3 in this process. Finally, we propose a "born to be activated and cold to enhance" model for GPR3 activation. Our study provides a starting framework for the understanding of GPR3 signaling in cold-stimulated thermogenesis.

CYP46A1-mediated cholesterol turnover induces sex-specific changes in cognition and counteracts memory loss in ovariectomized mice.

The brain-specific enzyme CYP46A1 controls cholesterol turnover by converting cholesterol into 24S-hydroxycholesterol (24OH). Dysregulation of brain cholesterol turnover and reduced CYP46A1 levels are observed in Alzheimer's disease (AD). In this study, we report that CYP46A1 overexpression in aged female mice leads to enhanced estrogen signaling in the hippocampus and improved cognitive functions. In contrast, age-matched CYP46A1 overexpressing males show anxiety-like behavior, worsened memory, and elevated levels of 5α-dihydrotestosterone in the hippocampus. We report that, in neurons, 24OH contributes to these divergent effects by activating sex hormone signaling, including estrogen receptors. CYP46A1 overexpression in female mice protects from memory impairments induced by ovariectomy while having no effects in gonadectomized males. Last, we measured cerebrospinal fluid levels of 24OH in a clinical cohort of patients with AD and found that 24OH negatively correlates with neurodegeneration markers only in women. We suggest that CYP46A1 activation is a valuable pharmacological target for enhancing estrogen signaling in women at risk of developing neurodegenerative diseases.

Effect of Codonopsis pilosula polysaccharide on the quality of sheep semen preservation at 4°C.

Objective: This study aimed to investigate the effect of Codonopsis pilosula polysaccharide (CPP) on the motility, mitochondrial integrity, acrosome integrity rate, and antioxidant ability of sheep sperm after preservation at 4 °C. Methods: Semen from healthy adult rams were collected and divided into four groups with separate addition of 0, 200, 400, and 1000 mg/L CPP. Sperm motility was analyzed using the Computer-Assisted Semen Analysis software after preservation at 4 °C for 24, 72, 120, and 168 h. Sperm acrosome integrity rate was analyzed by Giemsa staining at 24, 72, and 120 h, and mitochondrial membrane integrity was analyzed by Mito-Tracker Red CMXRos. The total antioxidant capacity (T-AOC) and malondialdehyde (MDA) content of spermatozoa were measured after 120 h of preservation. Results: The sperm viability and forward-moving sperm under 200 mg/L CPP were significantly higher than that in the control group at 72 h (61.28% ± 3.89% vs. 52.83% ± 0.70%,51.53% ±4.06% vs.42.84% ± 1.14%), and 168 h (47.21% ±0.85% vs.41.43% ± 0.37%, 38.68% ±0.87% vs. 31.68% ± 0.89%). The percentage of fast-moving sperm (15.03% ± 1.10% vs.11.39% ± 1.03%) and slow-moving sperm (23.63% ± 0.76% vs.20.29% ± 1.11%) in the 200 mg/L group was significantly higher than control group at 168 h. The mitochondrial membrane integrity of the sperm in the group with 200 mg/L CPP was significantly higher than those in the control group after storage at 4 °C for 120 h (74.76% ± 2.54% vs. 65.67% ± 4.51%, p < 0.05). The acrosome integrity rate in the group with 200 mg/L (87.66%±1.26%) and 400 mg/L （84.00%±2.95%）was significantly higher than those in the control group (80.65%±0.16%) after storage for 24 h (p < 0.05). CPP also increased T-AOC and decreased the MDA concentration after preservation at 4 °C (p< 0.05). Conclusion: Adding CPP could improve the T-AOC of sperm, inhibit lipid peroxidation, and facilitate semen preservation.

Unambiguous discrimination of all 20 proteinogenic amino acids and their modifications by nanopore.

Natural proteins are composed of 20 proteinogenic amino acids and their post-translational modifications (PTMs). However, due to the lack of a suitable nanopore sensor that can simultaneously discriminate between all 20 amino acids and their PTMs, direct sequencing of protein with nanopores has not yet been realized. Here, we present an engineered hetero-octameric Mycobacterium smegmatis porin A (MspA) nanopore containing a sole Ni2+ modification. It enables full discrimination of all 20 proteinogenic amino acids and 4 representative modified amino acids, Nω,N'ω-dimethyl-arginine (Me-R), O-acetyl-threonine (Ac-T), N4-(ß-N-acetyl-D-glucosaminyl)-asparagine (GlcNAc-N) and O-phosphoserine (P-S). Assisted by machine learning, an accuracy of 98.6% was achieved. Amino acid supplement tablets and peptidase-digested amino acids from peptides were also analyzed using this strategy. This capacity for simultaneous discrimination of all 20 proteinogenic amino acids and their PTMs suggests the potential to achieve protein sequencing using this nanopore-based strategy.

Regulatory mechanisms and cell membrane properties of Candida glycerinogenes differ under 2-phenylethanol addition or fermentation conditions.

The biosynthesis of 2-phenylethanol (2-PE) at high yields and titers is often limited by its toxicity. In this study, we describe the molecular mechanisms of 2-PE tolerance in the multi-stress tolerant industrial yeast, Candida glycerinogenes. They were different under 2-PE addition or fermentation conditions. After extracellular addition of 2-PE, C. glycerinogenes cells became rounder and bigger, which reduced specific surface area. However, during 2-PE fermentation C. glycerinogenes cells were smaller, which increased specific surface area. Other differences in the tolerance mechanisms were studied by analyzing the composition and molecular parameters of the cell membrane. Extracellular 2-PE stress resulted in down-regulation of transcriptional expression of unsaturated fatty acid synthesis genes. This raised the proportion of saturated fatty acids in the cell membrane, which increased rigidity of the cell membrane and reduced 2-PE entry to the cell. However, intracellular 2-PE stress resulted in up-regulation of transcriptional expression of unsaturated fatty acid synthesis genes, and increased the proportion of unsaturated fatty acids in the cell membrane; this in turn enhanced flexibility of the cell membrane which accelerated efflux of 2-PE. These contrasting mechanisms are mediated by transcriptional factors Hog1 and Swi5. Under 2-PE addition, C. glycerinogenes activated Hog1 and repressed Swi5 to upregulate erg5 and erg4 expression, which increased cell membrane rigidity and resisted 2-PE import. During 2-PE fermentation, C. glycerinogenes activated Hog1 and repressed Swi5 to upregulate 2-PE transporter proteins cdr1 and Acyl-CoA desaturase 1 ole1 to increase 2-PE export, thus reducing 2-PE intracellular toxicity. The results provide new insights into 2-PE tolerance mechanisms at the cell membrane level and suggest a novel strategy to improve 2-PE production by engineering anti-stress genes.

Inhibition of 7α,26-dihydroxycholesterol biosynthesis promotes midbrain dopaminergic neuron development.

Dysregulated cholesterol metabolism has been linked to neurodegeneration. We previously found that free, non-esterified, 7α,(25R)26-dihydroxycholesterol (7α,26-diHC), was significantly elevated in the cerebrospinal fluid of patients with Parkinson's disease (PD). In this study we investigated the role of 7α,26-diHC in midbrain dopamine (mDA) neuron development and survival. We report that 7α,26-diHC induces apoptosis and reduces the number of mDA neurons in hESC-derived cultures and in mouse progenitor cultures. Voriconazole, an oxysterol 7α-hydroxylase (CYP7B1) inhibitor, increases the number of mDA neurons and prevents the loss of mDA neurons induced by 7α,26-diHC. These effects are specific since neither 7α,26-diHC nor voriconazole alter the number of Islet1+ oculomotor neurons. Furthermore, our results suggest that elevated 24(S),25-epoxycholesterol, which has been shown to promote mDA neurogenesis, may be partially responsible for the effect of voriconazole on mDA neurons. These findings suggest that voriconazole, and/or other azole CYP7B1 inhibitors may have implications in PD therapy development.