Longitudinal evolution and plasma biomarkers for excessive daytime sleepiness in Parkinson's disease.

BACKGROUND: Excessive daytime sleepiness (EDS) is one of the most frequent non-motor symptoms in Parkinson's disease (PD); however, the pathogenesis of EDS is unclear, and there is a lack of information on plasma biomarkers for EDS in PD. We aimed to investigate the plasma biomarkers of EDS in a large PD cohort. METHODS: A total of 159 PD patients were included in the prospective cohort study and followed up annually for three years. Plasma biomarkers including glial fibrillary acidic protein, amyloid-beta, p-tau181, and neurofilament light chain (NfL), were measured using an ultrasensitive single-molecule array (SimoaTM) technology at each visit. EDS was evaluated using the Epworth Sleepiness Scale (ESS). RESULTS: The frequency of EDS in PD increased from 15.1% at baseline to 25.0% after three years. The mean ESS scores increased from 5.1 [Standard Deviation (SD): 4.8] at baseline to 6.1 [SD: 5.5] at the third year of follow-up. At baseline, compared with patients with PD without EDS, those with EDS were more likely to be male, had poorer cognitive performance, and more severe motor and non-motor symptoms. The adjusted generalized estimating equations models showed that higher plasma NfL levels (OR 1.047 [1.002-1.094], p = 0.042) were associated with EDS during follow-ups. The adjusted linear mixed-effects model showed that higher plasma NfL levels (ß 0.097 [0.012-0.183], p = 0.026) were associated with ESS scores during follow-ups. CONCLUSIONS: Higher plasma NfL levels were associated with EDS in PD, indicating an association between neuro-axonal degeneration and EDS in PD.

Genome-wide DNA methylation analysis related to ALS patient progression and survival.

BACKGROUND: Epigenetics contributes to the pathogenesis of amyotrophic lateral sclerosis (ALS). We aimed to characterize the DNA methylation profiles associated with clinical heterogeneity in disease progression and survival among patients. METHODS: We included a cohort of 41 patients with sporadic ALS, with a median follow-up of 86.9 months, and 27 rigorously matched healthy controls. Blood-based genome-wide DNA methylation analysis was conducted. RESULTS: A total of 948 progression rate-associated differentially methylated positions, 298 progression rate-associated differentially methylated regions (R-DMRs), 590 survival time-associated DMPs, and 197 survival time-associated DMRs (S-DMRs) were identified, using complementary grouping strategies. Enrichment analysis of differentially methylated genes highlighted the involvement of synapses and axons in ALS progression and survival. Clinical analysis revealed a positive correlation between the average methylation levels of the R-DMR in PRDM8 and disease progression rate (r = 0.479, p = 0.002). Conversely, there was an inverse correlation between the average methylation levels of the R-DMR in ANKRD33 and disease progression rate (r = - 0.476, p = 0.002). In addition, patients with higher methylation levels within the S-DMR of ZNF696 experienced longer survival (p = 0.016), while those with elevated methylation levels in the S-DMR of RAI1 had shorter survival (p = 0.006). CONCLUSION: DNA methylation holds promise as a potential biomarker for tracking disease progression and predicting survival outcome and also offers targets for precision medicine.

The Long Non-Coding RNA NR3C2-8:1 Promotes p53-Mediated Apoptosis through the miR-129-5p/USP10 Axis in Amyotrophic Lateral Sclerosis.

Motor neuron degeneration in amyotrophic lateral sclerosis (ALS) is a form of apoptosis, but the mechanisms underlying this neuronal cell death remain unclear. Numerous studies demonstrate abnormally elevated and active p53 in the central nervous system of ALS patients. Activation of p53-regulated pro-apoptotic signaling pathways may trigger motor neuron death. We previously reported decreased expression of the long non-coding RNA NR3C2-8:1 (Lnc-NR3C) in leukocytes of ALS patients. Here, we show lnc-NR3C promotes p53-mediated cell death in ALS by upregulating USP10 and promoting lnc-NR3C-triggered p53 activation, resulting in cell death. Conversely, lnc-NR3C knockdown inhibited USP10-triggered p53 activation, thereby protecting cells against oxidative stress. As a competitive endogenous RNA, lnc-NR3C competitively binds miR-129-5p, regulating the usp10/p53 axis. Elucidating the link between Lnc-NR3C and the USP10/p53 axis in an ALS cell model reveals a role for long non-coding RNAs in activating apoptosis. This provides new therapeutic opportunities in ALS.

CVD phenotyping in oncologic disorders: cardio-miRNAs as a potential target to improve individual outcomes in revers cardio-oncology.

With the increase of aging population and prevalence of obesity, the incidence of cardiovascular disease (CVD) and cancer has also presented an increasing tendency. These two different diseases, which share some common risk factors. Relevant studies in the field of reversing Cardio-Oncology have shown that the phenotype of CVD has a significant adverse effect on tumor prognosis, which is mainly manifested by a positive correlation between CVD and malignant progression of concomitant tumors. This distal crosstalk and the link between different diseases makes us aware of the importance of diagnosis, prediction, management and personalized treatment of systemic diseases. The circulatory system bridges the interaction between CVD and cancer, which suggests that we need to fully consider the systemic and holistic characteristics of these two diseases in the process of clinical treatment. The circulating exosome-miRNAs has been intrinsically associated with CVD -related regulation, which has become one of the focuses on clinical and basic research (as biomarker). The changes in the expression profiles of cardiovascular disease-associated miRNAs (Cardio-miRNAs) may adversely affect concomitant tumors. In this article, we sorted and screened CVD and tumor-related miRNA data based on literature, then summarized their commonalities and characteristics (several important pathways), and further discussed the conclusions of Cardio-Oncology related experimental studies. We take a holistic approach to considering CVD as a risk factor for tumor malignancy, which provides an in-depth analysis of the various regulatory mechanisms or pathways involved in the dual attribute miRNAs (Cardio-/Onco-miRNAs). These mechanisms will be key to revealing the systemic effects of CVD on tumors and highlight the holistic nature of different diseases. Therefore, the Cardio-miRNAs should be given great attention from researchers in the field of CVD and tumors, which might become new targets for tumor treatment. Meanwhile, based on the principles of precision medicine (such as the predictive preventive personalized medicine, 3PM) and reverse Cardio-oncology to better improve individual outcomes, we should consider developing personalized medicine and systemic therapy for cancer from the perspective of protecting cardiovascular function.

Generation of induced pluripotent stem cell line LNDWCHi001-A from a patient with early-onset Parkinson's disease carrying the homozygous c.1898C > T (p. A633V) mutation in the PLA2G6 gene.

A variant of the phospholipase A2 group VI gene (PLA2G6, PARK14) has been found to cause early-onset Parkinson's disease (EOPD). In this study, we reprogrammed peripheral blood mononuclear cells from a 39-year-old patient with EOPD carrying a homozygous PLA2G6 mutation c.1898C > T (p. A633V) to generate the human induced pluripotent stem cell line LNDWCHi001-A. This cell line was identified based on pluripotent markers and displayed differentiation capacity, providing an essential model for studying the pathogenesis of EOPD and drug screening.

Lnc-HIBADH-4 Regulates Autophagy-Lysosome Pathway in Amyotrophic Lateral Sclerosis by Targeting Cathepsin D.

Amyotrophic lateral sclerosis (ALS) is the most prevalent and lethal class of severe motor neuron diseases (MND) with no efficacious treatment. The pathogenic mechanisms underlying ALS remain unclear. Nearly 90% of patients exhibit sporadic onset (sALS). Therefore, elucidating the pathophysiology of ALS is imperative. Long non-coding RNA (lncRNA) is a large class of non-coding RNAs that regulate transcription, translation, and post-translational processes. LncRNAs contribute to the pathogenesis of diverse neurodegenerative disorders and hold promise as targets for interference in the realm of neurodegeneration. However, the mechanisms of which lncRNAs are involved in ALS have not been thoroughly investigated. We identified and validated a downregulated lncRNA, lnc-HIBADH-4, in ALS which correlated with disease severity and overall survival. Lnc-HIBADH-4 acted as a "molecular sponge" regulating lysosomal function through the lnc-HIBADH-4/miR-326/CTSD pathway, thereby impacting autophagy-lysosome dynamics and the levels of cell proliferation and apoptosis. Therefore, this study discovered and revealed the role of lnc-HIBADH-4 in the pathogenesis of ALS. With further research, lnc-HIBADH-4 is expected to provide a new biomarker in the diagnosis and treatment of ALS.

Plasma glial fibrillary acidic protein as a biomarker of disease progression in Parkinson's disease: a prospective cohort study.

BACKGROUND: Reactive astrogliosis has been demonstrated to have a role in Parkinson's disease (PD); however, astrocyte-specific plasma glial fibrillary acidic protein (GFAP)'s correlation with PD progression remains unknown. We aimed to determine whether plasma GFAP can monitor and predict PD progression. METHODS: A total of 184 patients with PD and 95 healthy controls (HCs) were included in this prospective cohort study and followed-up for 5 years. Plasma GFAP, amyloid-beta (Aß), p-tau181, and neurofilament light chain (NfL) were measured at baseline and at 1- and 2-year follow-ups. Motor and non-motor symptoms, activities of daily living, global cognitive function, executive function, and disease stage were evaluated using the Unified Parkinson's Disease Rating Scale (UPDRS) part III, UPDRS-I, UPDRS-II, Montreal Cognitive Assessment (MoCA), Frontal Assessment Battery (FAB), and Hoehn and Yahr (H&Y) scales at each visit, respectively. RESULTS: Plasma GFAP levels were higher in patients with PD (mean [SD]: 69.80 [36.18], pg/mL) compared to HCs (mean [SD]: 57.89 [23.54], pg/mL). Higher levels of GFAP were observed in female and older PD patients. The adjusted linear mixed-effects models showed that plasma GFAP levels were significantly associated with UPDRS-I scores (ß: 0.006, 95% CI [0.001-0.011], p = 0.027). Higher baseline plasma GFAP correlated with faster increase in UPDRS-I (ß: 0.237, 95% CI [0.055-0.419], p = 0.011) and UPDRS-III (ß: 0.676, 95% CI [0.023-1.330], p = 0.043) scores and H&Y stage (ß: 0.098, 95% CI [0.047-0.149], p < 0.001) and faster decrease in MoCA (ß: - 0.501, 95% CI [- 0.768 to - 0.234], p < 0.001) and FAB scores (ß: - 0.358, 95% CI [- 0.587 to - 0.129], p = 0.002). Higher baseline plasma GFAP predicted a more rapid progression to postural instability (hazard ratio: 1.009, 95% CI [1.001-1.017], p = 0.033). CONCLUSIONS: Plasma GFAP might be a potential biomarker for monitoring and predicting disease progression in PD.

Evolution and Predictive Role of Plasma Alzheimer's Disease-related Pathological Biomarkers in Parkinson's Disease.

Plasma Alzheimer's disease-related pathological biomarkers' role in Parkinson's disease (PD) remains unknown. We aimed to determine whether plasma Alzheimer's disease-related biomarkers can predict PD progression. A total of 184 PD patients and 86 healthy controls were included and followed up for 5 years. Plasma phosphorylated tau181 (p-tau181), Aß40, and Aß42 were measured at baseline and the 1- and 2-year follow-ups using the Quanterix-single-molecule array. Global cognitive function and motor symptoms were assessed using the Montreal Cognitive Assessment and Unified Parkinson's Disease Rating Scale part III. Genetic analyses were conducted to identify APOE and MAPT genotypes. Plasma p-tau181 levels were higher in PD than healthy controls. APOE-ε4 carriers had lower plasma Aß42 levels and Aß42/Aß40 ratio. The linear mixed-effects models showed that Montreal Cognitive Assessment scores were associated with plasma p-tau181/Aß42 ratio (ß -1.719 [-3.398 to -0.040], p = .045). Higher baseline plasma p-tau181 correlated with faster cognitive decline and motor symptoms deterioration in total patients (ß -0.170 [-0.322 to -0.018], p = .029; ß 0.329 [0.032 to 0.626], p = .030) and APOE-ε4 carriers (ß -0.318 [-0.602 to -0.034], p = .030; ß 0.632 [0.017 to 1.246], p = .046), but not in the noncarriers. Higher baseline plasma Aß40 correlated with faster cognitive decline in total patients (ß -0.007 [-0.015 to -0.0001], p = .047) and faster motor symptoms deterioration in total patients (ß 0.026 [0.010 to 0.041], p = .001) and APOE-ε4 carriers (ß 0.044 [-0.026 to 0.049], p = .020), but not in the noncarriers. The plasma p-tau181/Aß2 ratio monitors the cognitive status of PD. Higher baseline plasma p-tau181 and Aß40 predict faster cognitive decline and motor symptoms deterioration in PD, especially in APOE-ε4 carriers.

Shared genetic links between frontotemporal dementia and psychiatric disorders.

BACKGROUND: Epidemiological and clinical studies have suggested comorbidity between frontotemporal dementia (FTD) and psychiatric disorders. FTD patients carrying specific mutations were at higher risk for some psychiatric disorders, and vice versa, implying potential shared genetic etiology, which is still less explored. METHODS: We examined the genetic correlation using summary statistics from genome-wide association studies and analyzed their genetic enrichment leveraging the conditional false discovery rate method. Furthermore, we explored the causal association between FTD and psychiatric disorders with Mendelian randomization (MR) analysis. RESULTS: We identified a significant genetic correlation between FTD and schizophrenia at both genetic and transcriptomic levels. Meanwhile, robust genetic enrichment was observed between FTD and schizophrenia and alcohol use disorder. Seven shared genetic loci were identified, which were mainly involved in interleukin-induced signaling, synaptic vesicle, and brain-derived neurotrophic factor signaling pathways. By integrating cis-expression quantitative trait loci analysis, we identified MAPT and CADM2 as shared risk genes. MR analysis showed mutual causation between FTD and schizophrenia with nominal association. CONCLUSIONS: Our findings provide evidence of shared etiology between FTD and schizophrenia and indicate potential common molecular mechanisms contributing to the overlapping pathophysiological and clinical characteristics. Our results also demonstrate the essential role of autoimmunity in these diseases. These findings provide a better understanding of the pleiotropy between FTD and psychiatric disorders and have implications for therapeutic trials.

Animal models of male subfertility targeted on LanCL1-regulated spermatogenic redox homeostasis.

Oxidative stress in spermatozoa is a major contributor to male subfertility, which makes it an informed choice to generate animal models of male subfertility with targeted modifications of the antioxidant systems. However, the critical male germ cell-specific antioxidant mechanisms have not been well defined yet. Here we identify LanCL1 as a major male germ cell-specific antioxidant gene, reduced expression of which is related to human male infertility. Mice deficient in LanCL1 display spermatozoal oxidative damage and impaired male fertility. Histopathological studies reveal that LanCL1-mediated antioxidant response is required for mouse testicular homeostasis, from the initiation of spermatogenesis to the maintenance of viability and functionality of male germ cells. Conversely, a mouse model expressing LanCL1 transgene is protected against high-fat-diet/obesity-induced oxidative damage and subfertility. We further show that germ cell-expressed LanCL1, in response to spermatogenic reactive oxygen species, is regulated by transcription factor specific protein 1 (SP1) during spermatogenesis. This study demonstrates a critical role for the SP1-LanCL1 axis in regulating testicular homeostasis and male fertility mediated by redox balance, and provides evidence that LanCL1 genetically modified mice have attractive applications as animal models of male subfertility.

The expression discrepancy and characteristics of long non-coding RNAs in peripheral blood leukocytes from amyotrophic lateral sclerosis patients.

Amyotrophic lateral sclerosis (ALS) is known to be a progressive neurodegenerative disease that affects upper and lower motor neurons. Less than 10% of ALS patients are defined as familial ALS, and more than 90% are sporadic ALS (SALS). According to the genomic information described in existing databases, up to 98% of the human genome consists of non-coding sequences. Nearly 40% of long non-coding RNAs (lncRNAs) are specifically expressed in the brain. We believe that the discrepancy of lncRNAs expression plays a key role in neurodegenerative diseases. We screened 30 lncRNAs with altered expression from peripheral blood leukocytes of SALS patients by microarray and validated 13 of them in leukocytes of SALS, Parkinson's disease (PD) patients, and healthy controls (HC). We followed the bioinformatics to perform a functional enrichment analysis of co-expressed mRNAs, transcription factors, and lncRNAs for functional prediction. We identified that lnc-DYRYK2-7:1, lnc-ABCA12-3:1, and lnc-POTEM-4:7 show decreased expression in SALS patients, whereas in PD patients, they show increased expression or no change. In addition, expression of lnc-CNTN4-2:1 and lnc-NR3C2-8:1 was decreased in both SALS and PD patients. We found that XIST was only reduced in male patients with SALS and PD, and not in female patients with SALS but was elevated in PD by gender grouping. We also performed GO term enrichment and KEGG pathway analysis for lncRNAs showing differential expression in microarray. We discovered that a significant proportion of differential expressed lncRNAs were associated with various signaling pathways and transcription factors which are consistent with other clinical findings.

Rheb Promotes Triglyceride Secretion and Ameliorates Diet-Induced Steatosis in the Liver.

Hepatosteatosis, characterized by excessive accumulation of lipids in the liver, is a major health issue in modern society. Understanding how altered hepatic lipid metabolism/homeostasis causes hepatosteatosis helps to develop therapeutic interventions. Previous studies identify mitochondrial dysfunction as a contributor to hepatosteatosis. But, the molecular mechanisms of mitochondrial dysfunction leading to altered lipid metabolism remain incompletely understood. Our previous work shows that Rheb, a Ras-like small GTPase, not only activates mTORC1 but also promotes mitochondrial ATP production through pyruvate dehydrogenase (PDH). In this study, we further demonstrate that Rheb controls hepatic triglyceride secretion and reduces diet-induced lipid accumulation in a mouse liver. Genetic deletion of Rheb causes rapid and spontaneous steatosis in the liver, which is unexpected from the role of mTORC1 that enhances lipid synthesis, whereas Rheb transgene remarkably reduces diet-induced hepatosteatosis. Results suggest that the hepatosteatosis in Rheb KO is an outcome of impaired lipid secretion, which is linked to mitochondrial ATP production of hepatocytes. Our findings highlight an under-appreciated role of Rheb in the regulation of hepatic lipid secretion through mitochondrial energy production, with therapeutic implication.

Pectic polysaccharide from Nelumbo nucifera leaves promotes intestinal antioxidant defense in vitro and in vivo.

In this study, the Nelumbo nucifera leaf polysaccharide (NNLP) was isolated by hot water extraction and ethanol precipitation. DEAE anion exchange chromatography and gel filtration were further performed to obtained the purified fraction NNLP-I-I, the molecular weight of which was 16.4 kDa. The monosaccharide composition analysis and linkage units determination showed that the fraction NNLP-I-I was a pectic polysaccharide. In addition, the NMR spectra analysis revealed that NNLP-I-I mainly consisted of a homogalacturonan backbone and rhamnogalacturonan I, containing a long HG region and short RG-I region, with AG-II and 1-3 linked rhamnose as side chains. The biological studies demonstrated that NNLP-I-I displayed antioxidant properties through mediating the Nrf2-regulated intestinal cellular antioxidant defense, which could protect cultured intestinal cells from oxidative stress and improve the intestinal function of aged mice.

Rheb mediates neuronal-activity-induced mitochondrial energetics through mTORC1-independent PDH activation.

Neuronal activity increases energy consumption and requires balanced production to maintain neuronal function. How activity is coupled to energy production remains incompletely understood. Here, we report that Rheb regulates mitochondrial tricarboxylic acid cycle flux of acetyl-CoA by activating pyruvate dehydrogenase (PDH) to increase ATP production. Rheb is induced by synaptic activity and lactate and dynamically trafficked to the mitochondrial matrix through its interaction with Tom20. Mitochondria-localized Rheb protein is required for activity-induced PDH activation and ATP production. Cell-type-specific gain- and loss-of-function genetic models for Rheb reveal reciprocal changes in PDH phosphorylation/activity, acetyl-CoA, and ATP that are not evident with genetic or pharmacological manipulations of mTORC1. Mechanistically, Rheb physically associates with PDH phosphatase (PDP), enhancing its activity and association with the catalytic E1α-subunit of PDH to reduce PDH phosphorylation and increase its activity. Findings identify Rheb as a nodal point that balances neuronal activity and neuroenergetics via Rheb-PDH axis.

Soy isoflavones improve the oxidative stress induced hypothalamic inflammation and apoptosis in high fat diet-induced obese male mice through PGC1-alpha pathway.

Obesity is a common metabolic disorder that increases the risk of many diseases, such as type II diabetes, hypertension, cardiovascular disease. Hypothalamus plays a very important role in the progression of obesity, and many studies reveal that hypothalamic injures are implicated in obesity processes. Here, we describe that the consumption of soy isoflavones, with a structural similarity to that of estradiol, could mitigate obesity through improving the hypothalamic inflammation and apoptosis, which are induced by oxidative stress. Also, our in vitro studies demonstrate that daidzein and genistein, common ingredients of soy isoflavones, could protect hypothalamic N42 cells against palmitic acid induced oxidative stress and apoptosis. Moreover, the transcriptional coactivator peroxisome proliferator-activated receptor γ coactivator 1 alpha (PGC1-alpha), which plays a role in oxidative defense, is increased after soy isoflavone treatment in vivo and in vitro, suggesting an improved effect of soy isoflavones on hypothalamic antioxidant defense is mediated by PGC-1α. Our study reveals a potential mechanism of soy isoflavones regulating oxidative stress induced hypothalamic inflammation and cellular apoptosis, which will be important for obesity treatment.

Polyphyllin II inhibits liver cancer cell proliferation, migration and invasion through downregulated cofilin activity and the AKT/NF-κB pathway.

The morbidity and mortality of primary liver cancer is one of the highest amongst all cancers. Deficiency of effective treatment and characteristics of cancer metastasis are believed to be responsible for this situation, thus a great demand is required for new agent development. Polyphyllin II (PP2), an important steroidal saponin extracted from Rhizoma Paris, has emerged as a potential anti-cancer agent, but the effects of PP2 in liver cancers and its underlying mechanisms remain unexplored. In our study, we found that PP2 could remarkably suppress the proliferation of two liver cancer cell lines, HepG2 and BEL7402, resulting in significant cell death. Besides, low doses of PP2 have displayed properties that inhibit cellular motility and invasion of liver cancer cells. In addition, we have found that PP2-mediated cofilin activity suppression was implicated in the inhibition of liver cancer cell motility. Decreased expression of two major hydrolytic enzymes (MMP2/MMP9), through the AKT/NF-κB signaling pathway may also be also responsible for this process. Rescue experiments done with either non-phosphorylatable mutant cofilin-1 (S3A) transfection or an activator of the AKT pathway significantly reversed the inhibition effects of PP2 on liver cancer cells. Taken together, we report a potential agent for liver cancer treatment and reveal its underlying mechanisms.

LanCL1 promotes motor neuron survival and extends the lifespan of amyotrophic lateral sclerosis mice.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive loss of motor neurons. Improving neuronal survival in ALS remains a significant challenge. Previously, we identified Lanthionine synthetase C-like protein 1 (LanCL1) as a neuronal antioxidant defense gene, the genetic deletion of which causes apoptotic neurodegeneration in the brain. Here, we report in vivo data using the transgenic SOD1G93A mouse model of ALS indicating that CNS-specific expression of LanCL1 transgene extends lifespan, delays disease onset, decelerates symptomatic progression, and improves motor performance of SOD1G93A mice. Conversely, CNS-specific deletion of LanCL1 leads to neurodegenerative phenotypes, including motor neuron loss, neuroinflammation, and oxidative damage. Analysis reveals that LanCL1 is a positive regulator of AKT activity, and LanCL1 overexpression restores the impaired AKT activity in ALS model mice. These findings indicate that LanCL1 regulates neuronal survival through an alternative mechanism, and suggest a new therapeutic target in ALS.

Polyphyllin VII Promotes Apoptosis and Autophagic Cell Death via ROS-Inhibited AKT Activity, and Sensitizes Glioma Cells to Temozolomide.

The high recurrence frequency of gliomas but deficiency of effective treatment and prevalent chemoresistance have elicited interests in exploring and developing new agents. Paris polyphyllins are monomers extracted from rhizome of Paris polyphylla var. yunnanensis. Here, we first reported that polyphyllin VII (PP7) exhibited cytotoxic effect on glioma cells. PP7 significantly suppressed the viability and induced cell death of U87-MG and U251 cells after 24 h, with the IC50 values 4.24 ± 0.87 µM and 2.17 ± 0.14 µM, respectively. Both apoptotic and autophagic processes were involved in the cytotoxic effect of PP7, as PP7 activated the Bcl2/Bax pathway and the inhibition of autophagy partly rescued the toxicity of PP7 in glioma cells. In addition, an inhibition of AKT/mTORC1 activity was found after PP7 administration, and it seemed that the overproduction of reactive oxygen species (ROS) was responsible for this effect. Namely, the removal of ROS by NAC treatment mitigated PP7-induced cell death, autophagy, and its effect on the AKT/mTORC1 signaling. Additionally, a combination assay of PP7 with temozolomide (TMZ), the most used chemotherapy for glioma patients, was performed resulting in synergism, while PP7 reduced TMZ resistance through inhibition of MGMT expression. Thus, our study reports PP7 as a potential agent for glioma treatment and reveals its underlying mechanisms of action.

Characterization of Inulin-Type Fructan from Platycodon grandiflorus and Study on Its Prebiotic and Immunomodulating Activity.

Platycodon grandiflorus is a plant widely used in traditional Chinese medicine, of which polysaccharides are reported to be the main components responsible for its bio-functions. In this work, the inulin-type fructan (PGF) was obtained by DEAE anion exchange chromatography from the water extracted from P. grandifloras. Characterization was performed with methanolysis, methylation, and NMR and the results showed that PGF is a ß-(2-1) linked fructan, with terminal glucose and with a degree of polymerization of 2⁻10. In order to study its biofunctions, the prebiotic and immunomodulation properties were assayed. We found that PGF exhibited good prebiotic activity, as shown by a promotion on six strains of lactobacillus proliferation. Additionally, the PGF also displayed direct immunomodulation on intestinal epithelial cells and stimulated the expressions of anti-inflammatory factors. These results indicated that the inulin from P. grandiflorus is a potential natural source of prebiotics as well as a potential intestinal immunomodulator, which will be valuable for further studies and new applications.