Peroxidase from foxtail millet bran exerts anti-colorectal cancer activity via targeting cell-surface GRP78 to inactivate STAT3 pathway

Molecular targeted therapy has become an emerging promising strategy in cancer treatment, and screening the agents targeting at cancer cell specific targets is very desirable for cancer treatment. Our previous study firstly found that a secretory peroxidase of class III derived from foxtail millet bran (FMBP) exhibited excellent targeting anti-colorectal cancer (CRC) activity in vivo and in vitro, whereas its underlying target remains unclear. The highlight of present study focuses on the finding that cell surface glucose-regulated protein 78 (csGRP78) abnormally located on CRC is positively correlated with the anti-CRC effects of FMBP, indicating it serves as a potential target of FMBP against CRC. Further, we demonstrated that the combination of FMBP with the nucleotide binding domain (NBD) of csGRP78 interfered with the downstream activation of signal transducer and activator of transcription 3 (STAT3) in CRC cells, thus promoting the intracellular accumulation of reactive oxygen species (ROS) and cell grown inhibition. These phenomena were further confirmed in nude mice tumor model. Collectively, our study highlights csGRP78 acts as an underlying target of FMBP against CRC, uncovering the clinical potential of FMBP as a targeted agent for CRC in the future.

Fraxetin inhibits interleukin-1β-induced apoptosis, inflammation, and matrix degradation in chondrocytes and protects rat cartilage in vivo

Osteoarthritis (OA) is a disease characterized by degeneration of the joint complex due to cartilage destruction. Fraxetin, a widely used and studied coumarin compound extracted from a traditional Chinese herb (Qin Pi), has shown anti-inflammatory and antioxidant properties, but its effects on OA have not been studied. In the present study, western blotting, immunofluorescence, and terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling (TUNEL) were used to evaluate the effects of fraxetin on IL-1β-induced apoptotic activity, inflammatory responses, and catabolism in rat chondrocytes. The results showed that fraxetin prevented IL-1β-induced apoptosis of chondrocytes and inhibited inflammatory mediator release by regulating the Toll-like receptor 4 (TLR4)/myeloid differentiation primary response 88 (MyD88)/nuclear factor (NF)-κB pathway in chondrocytes. Additionally, fraxetin suppressed the upregulation of matrix metalloproteinase 13 (MMP13) and degradation of collagen II in the extracellular matrix (ECM). Moreover, the effects of fraxetin in vivo were assessed in a monosodium iodoacetate (MIA)-induced rat model of OA using hematoxylin and eosin (H&E) and Safranin O-fast green staining and magnetic resonance imaging (MRI). The results showed that fraxetin protected the cartilage against destruction. In conclusion, fraxetin could be a potential therapeutic for OA.

A 28-day oral toxicology study of an aqueous extract of Polypodium leucotomos (Fernblock®)

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The NOAEL study was 5000 mg/kg bw/d—the highest dose tested.

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No target organs or treatment-related toxicological effects were identified.

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Our results are relevant to the evaluation of the safety of human ingestion of Fernblock^®.

Fernblock^® is a standardized commercial aqueous extraction of the leaves of the tropical fern Polypodium leucotomos promoted as an orally active photoprotective substance. In a previous battery of toxicological tests on Fernblock^®, no genotoxicy was observed and no oral toxicity was observed up to 1200 mg/kg bw/day. The current study was conducted in Hsd.Han Wistar rats using doses of 0, 2000, 3500, and 5000 mg/kg bw/day Fernblock^® by gavage for 28 consecutive days. No mortality or toxic effects were observed and no target organs were identified. The no observed adverse effect level was determined to be 5000 mg/kg bw/day, the highest dose tested.

Dietary fat and gut microbiota interactions determine diet-induced obesity in mice

Objective

Gut microbiota may promote positive energy balance; however, germfree mice can be either resistant or susceptible to diet-induced obesity (DIO) depending on the type of dietary intervention. We here sought to identify the dietary constituents that determine the susceptibility to body fat accretion in germfree (GF) mice.

Methods

GF and specific pathogen free (SPF) male C57BL/6N mice were fed high-fat diets either based on lard or palm oil for 4 wks. Mice were metabolically characterized at the end of the feeding trial. FT-ICR-MS and UPLC-TOF-MS were used for cecal as well as hepatic metabolite profiling and cecal bile acids quantification, respectively. Hepatic gene expression was examined by qRT-PCR and cecal gut microbiota of SPF mice was analyzed by high-throughput 16S rRNA gene sequencing.

Results

GF mice, but not SPF mice, were completely DIO resistant when fed a cholesterol-rich lard-based high-fat diet, whereas on a cholesterol-free palm oil-based high-fat diet, DIO was independent of gut microbiota. In GF lard-fed mice, DIO resistance was conveyed by increased energy expenditure, preferential carbohydrate oxidation, and increased fecal fat and energy excretion. Cecal metabolite profiling revealed a shift in bile acid and steroid metabolites in these lean mice, with a significant rise in 17β-estradiol, which is known to stimulate energy expenditure and interfere with bile acid metabolism. Decreased cecal bile acid levels were associated with decreased hepatic expression of genes involved in bile acid synthesis. These metabolic adaptations were largely attenuated in GF mice fed the palm-oil based high-fat diet. We propose that an interaction of gut microbiota and cholesterol metabolism is essential for fat accretion in normal SPF mice fed cholesterol-rich lard as the main dietary fat source. This is supported by a positive correlation between bile acid levels and specific bacteria of the order Clostridiales (phylum Firmicutes) as a characteristic feature of normal SPF mice fed lard.

Conclusions

In conclusion, our study identified dietary cholesterol as a candidate ingredient affecting the crosstalk between gut microbiota and host metabolism.

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Cholesterol-based but not plant sterol-based high-fat diet protects germfree (GF) mice from diet-induced obesity (DIO).

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DIO resistant GF mice show preferential carbohydrate oxidation, higher energy expenditure and energy and fat excretion.

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DIO resistance in GF mice is accompanied by increased steroid hormone levels but decreased bile acid levels in the cecum.

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Substrate oxidation and fat excretion in DIO resistant GF mice is linked to decreased hepatic Cyp7a1 and Nr1h4 expression.

IL33 Is a Stomach Alarmin That Initiates a Skewed Th2 Response to Injury and Infection

BACKGROUND & AIMS

Interleukin (IL)33 is a recently described alarmin that is highly expressed in the gastric mucosa and potently activates Th2 immunity. It may play a pivotal role during Helicobacter pylori infection. Here, we delineate the role of IL33 in the normal gastric mucosa and in response to gastropathy.

METHODS

IL33 expression was evaluated in mice and human biopsy specimens infected with H pylori and in mice after dosing with aspirin. IL33 expression was localized in the gastric mucosa using immunofluorescence. Mice were given 1 or 7 daily doses of recombinant IL33 (1 μg/dose), and the stomach and the spleen responses were quantified morphologically, by flow cytometry and using quantitative reverse-transcription polymerase chain reaction and immunoblotting.

RESULTS

In mice, the IL33 protein was localized to the nucleus of a subpopulation of surface mucus cells, and co-localized with the surface mucus cell markers Ulex Europaeus 1 (UEA1), and Mucin 5AC (Muc5AC). A small proportion of IL33-positive epithelial cells also were Ki-67 positive. IL33 and its receptor Interleukin 1 receptor-like 1 (ST2) were increased 4-fold after acute (1-day) H pylori infection, however, this increase was not apparent after 7 days and IL33 expression was reduced 2-fold after 2 months. Similarly, human biopsy specimens positive for H pylori had a reduced IL33 expression. Chronic IL33 treatment in mice caused systemic activation of innate lymphoid cell 2 and polarization of macrophages to the M2 phenotype. In the stomach, IL33-treated mice developed transmural inflammation and mucous metaplasia that was mediated by Th2/signal transducer and activator of transcription 3 signaling. Rag-1^-/- mice, lacking mature lymphocytes, were protected from IL33-induced gastric pathology.

CONCLUSIONS

IL33 is highly expressed in the gastric mucosa and promotes the activation of T helper 2-cytokine-expressing cells. The loss of IL33 expression after prolonged H pylori infection may be permissive for the T helper 1-biased immune response observed during H pylori infection and subsequent precancerous progression.

Preclinical evaluation of a Haemophilus influenzae type b conjugate vaccine process intended for technology transfer

Introduction of Haemophilus influenzae type b (Hib) vaccine in low- and middle-income countries has been limited by cost and availability of Hib conjugate vaccines for a long time. It was previously recognized by the Institute for Translational Vaccinology (Intravacc, originating from the former Vaccinology Unit of the National Institute of Public Health [RIVM] and the Netherlands Vaccine Institute [NVI]) that local production of a Hib conjugate vaccine would increase the affordability and sustainability of the vaccine and thereby help to speed up Hib introduction in these countries. A new affordable and a non-infringing production process for a Hib conjugate vaccine was developed, including relevant quality control tests, and the technology was transferred to a number of vaccine manufacturers in India, Indonesia, and China. As part of the Hib technology transfer project managed by Intravacc, a preclinical toxicity study was conducted in the Netherlands to test the safety and immunogenicity of this new Hib conjugate vaccine. The data generated by this study were used by the technology transfer partners to accelerate the clinical development of the new Hib conjugate vaccine. A repeated dose toxicity and local tolerance study in rats was performed to assess the reactogenicity and immunogenicity of a new Hib conjugate vaccine compared to a licensed vaccine. The results showed that the vaccine was well tolerated and immunogenic in rats, no major differences in both safety and immunogenicity in rats were found between the vaccine produced according to the production process developed by Intravacc and the licensed one. Rats may be useful to verify the immunogenicity of Hib conjugate vaccines and for preclinical evaluation. In general, nonclinical evaluation of the new Hib conjugate vaccine, including this proof of concept (safety and immunogenicity study in rats), made it possible for technology transfer partners, having implemented the original process with no changes in the manufacturing process and vaccine formulation, to start directly with phase 1 clinical trials.