Lactobacillus rhamnosus GG ameliorates osteoporosis in ovariectomized rats by regulating the Th17/Treg balance and gut microbiota structure

BACKGROUND

With increasing knowledge about the gut - bone axis, more studies for treatments based on the regulation of postmenopausal osteoporosis by gut microbes are being conducted. Based on our previous work, this study was conducted to further investigate the therapeutic effects of Lactobacillus rhamnosus GG (LGG) on ovariectomized (OVX) model rats and the immunological and microecological mechanisms involved.

RESULTS

We found a protective effect of LGG treatment in OVX rats through changes in bone microarchitecture, bone biomechanics, and CTX-I, PINP, Ca, and RANKL expression levels. LGG was more advantageous in promoting osteogenesis, which may be responsible for the alleviation of osteoporosis. Th17 cells were imbalanced with Treg cells in mediastinal lymph nodes and bone marrow, with RORγt and FOXP3 expression following a similar trend. TNF-α and IL-17 expression in colon and bone marrow increased, while TGF-β and IL-10 expression decreased; however, LGG treatment modulated these changes and improved the Th17/Treg balance significantly. Regarding the intestinal barrier, we found that LGG treatment ameliorated estrogen deficiency-induced inflammation and mucosal damage and increased the expression of GLP-2 R and tight junction proteins. Importantly, 16S rRNA sequencing showed a significant increase in the Firmicutes/Bacteroidetes ratio during estrogen deficiency. Dominant intestinal flora showed significant differences in composition; LGG treatment regulated the various genera that were imbalanced in OVX, along with modifying those that did not change significantly in other groups with respect to the intestinal barrier, inflammation development, and bile acid metabolism.

CONCLUSIONS

Overall, LGG ameliorated estrogen deficiency-induced osteoporosis by regulating the gut microbiome and intestinal barrier and stimulating Th17/Treg balance in gut and bone.

Quantitative proteomic analysis of exosomes from umbilical cord mesenchymal stem cells and rat bone marrow stem cells

Exosomes derived from mesenchymal stem cells (MSCs) have been used for cancer treatment, however, an in-depth analysis of the exosomal proteomes is lacking. In this manuscript, we use the diaPASEF (parallel accumulation serial fragmentation combined with the data-independent acquisition) method to quantify exosomes derived from human umbilical cord mesenchymal stem cells (UCMSCs) and rat bone marrow stem cells (BMSCs), resulting in identification of 4200 human proteins and 5362 rat proteins. Comparison of human exosomal proteins and total cellular proteins reveals that some proteins exist in the exosomes exclusively that can be served as potential markers for exosomes. Quantitative proteomic analysis of exosomes from different passages of BMSCs shows that the proteins involved in TGF-β signaling pathway are regulated in abundance, which could be markers for the therapeutic ability of BMSC exosomes. Collectively, the data presented by this study can be a resource for further study of exosome research.

Retraction: Cell membrane based biomimetic nanocomposites for targeted therapy of drug resistant EGFR-mutated lung cancer

Retraction of 'Cell membrane based biomimetic nanocomposites for targeted therapy of drug resistant EGFR-mutated lung cancer' by Pengying Wu et al., Nanoscale, 2019, 11, 19520-19528, https://doi.org/10.1039/C9NR05791A.

Gut microbiota and metabonomics used to explore the mechanism of Qing'e Pills in alleviating osteoporosis

CONTEXT

The traditional Chinese medicine Qing'e Pills (QEP) has been used to treat postmenopausal osteoporosis (PMO).

OBJECTIVE

We evaluated the regulatory effects of QEP on gut microbiota in osteoporosis.

MATERIALS AND METHODS

Eighteen female SD rats were divided into three groups: sham surgery (SHAM), ovariectomized (OVX) and ovariectomized treated with QEP (OVX + QEP). Six weeks after ovariectomy, QEP was administered to OVX + QEP rats for eight weeks (4.5 g/kg/day, i.g.). After 14 weeks, the bone microstructure was evaluated. Differences in gut microbiota were analysed via 16S rRNA gene sequencing. Changes in endogenous metabolites were studied using UHPLC-Q-TOF/MS technology. GC-MS was used to detect short-chain fatty acids. Furthermore, we measured serum inflammatory factors, such as IL-6, TNF-α and IFN-γ, which may be related to gut microbiota.

RESULTS

OVX + QEP exhibited increased bone mineral density (0.11 ± 0.03 vs. 0.21 ± 0.02, p< 0.001) compared to that of OVX. QEP altered the composition of gut microbiota. We identified 19 potential biomarkers related to osteoporosis. QEP inhibited the elevation of TNF-α (38.86 ± 3.19 vs. 29.43 ± 3.65, p< 0.05) and IL-6 (83.38 ± 16.92 vs. 45.26 ± 3.94, p< 0.05) levels, while it increased the concentrations of acetic acid (271.95 ± 52.41 vs. 447.73 ± 46.54, p< 0.001), propionic acid (28.96 ± 5.73 vs. 53.41 ± 14.26, p< 0.01) and butyric acid (24.92 ± 18.97 vs. 67.78 ± 35.68, p< 0.05).

CONCLUSIONS

These results indicate that QEP has potential of regulating intestinal flora and improving osteoporosis. The combination of anti-osteoporosis drugs and intestinal flora could become a new treatment for osteoporosis.

Transcriptome analysis reveals hepatotoxicity in zebrafish induced by cyhalofop‑butyl

Cyhalofop‑butyl is a highly effective aryloxyphenoxypropionate herbicide and widely used for weed control in paddy fields. With the increasing residue of cyhalofop‑butyl, it poses a threat to the survival of aquatic organisms. Here, we investigated the effect of cyhalofop‑butyl on zebrafish to explore its potential hepatotoxic mechanism. The results showed that cyhalofop‑butyl induced hepatocyte degeneration, vacuolation and necrosis of larvae after embryonic exposure for 4 days and caused liver atrophy after 5 days. Meanwhile, the activities of enzymes related to liver function were significantly increased by 0.2 mg/L cyhalofop‑butyl and higher, such as alanine transaminase (ALT) and aspartate transaminase (AST). And the contents of triglyceride (TG) involved in lipid metabolism were significantly decreased by 0.4 mg/L cyhalofop-buty. The expression of genes related to liver development was also significantly down-regulated. Furthermore, transcriptome results showed that the pathways involved in metabolism, immune system and endocrine system were significantly impacted, which may be related to hepatoxicity. To sum up, the present study demonstrated the hepatoxicity caused by cyhalofop-buty and its underlying mechanism. The results may provide new insights for the risk of cyhalofop‑butyl to aquatic organisms and new horizons for the pathogenesis of hepatotoxicity.

Sub-lethal concentration of metamifop exposure impair gut health of zebrafish (Danio rerio)

Previous studies have demonstrated that sublethal metamifop exposures induce hepatic lipid metabolism disorder in zebrafish. Whether metamifop will cause adverse effects in zebrafish gut is unknown. In the present study, effects of metamifop on gut heath of zebrafish were investigated after sublethal concentration (0.025, 0.10 and 0.40 mg/L) exposure. Histopathology analysis showed that metamifop induced inflammation and reduction of goblet cells in the gut, indicating that gut health may be impaired. Metamifop exposure could reduce activities of digestive enzymes (lipase and alkaline phosphatase), indicating the capacity of lipid absorption were impaired. Meanwhile, the content of fatty acid-binding protein 2 (FABP2) and mRNA levels of related genes (apoa-1a, apoe-b, fatp4, lpl and fabp2) were reduced in zebrafish gut after exposure to metamifop, suggesting the lipid transportation were decreased. The transcripts of genes associated with inflammation (il-17c, tnf-α and nf-kb) were significantly increased in 0.40 mg/L metamifop treatment group, which were 1.90-, 1.53- and 2.77-fold of the control group, respectively, confirming that metamifop induced inflammatory response in zebrafish gut. Moreover, reduction of mRNA levels of cldn-15 and elevation of lipopolysaccharides (LPS) content were observed in metamifop-treated groups, which suggested that metamifop exposure increased the intestinal permeability. Furthermore, metamifop exposure decreased the relative abundance of beneficial bacteria (Psychrobacter and Aeromonas) and elevated the abundance of pathogenic bacteria (Rhodobacter and Ralstonia) in zebrafish intestine. These results indicated that metamifop exposure at sublethal concentrations would impair zebrafish gut health, via reduction of lipids absorption, inflammatory response, elevation of permeability and microbiota disorder.

Life Cycle Exposure to Cyhalofop-Butyl Induced Reproductive Toxicity in Zebrafish

Cyhalofop-butyl (CyB) is a herbicide widely used in paddy fields that may transfer to aquatic ecosystems and cause harm to aquatic organisms. In this study, zebrafish (Danio rerio) were exposed to CyB at environmental concentrations (0.1, 1 and 10 µg/L) throughout their adult life cycle, from embryo to sexual maturity. The effects of CyB on zebrafish growth and reproduction were studied. It was found that female spawning was inhibited, and adult male fertility decreased. In addition, we examined the expression of sex steroid hormones and genes related to the hypothalamus-pituitary-gonad-liver (HPGL) axis. After 150 days of exposure, the hormone balance in zebrafish was disturbed, and the concentrations of 17β-estradiol (E2) and vitellogenin (VTG) were decreased. Changes in sex hormone were regulated by the expression of genes related to the HPGL axis. These results confirmed that long-term exposure to CyB at environmental concentrations can damage the reproductive capacity of zebrafish by disrupting the transcription of genes related to the HPGL axis. Overall, these data may provide a new understanding of the reproductive toxicity of long-term exposure to CyB in zebrafish parents and offspring.

[Patient experience in the implementation of enhanced recovery after surgery strategy after radical gastric cancer surgery]

Objective: To investigate the experience of patients in the implementation of enhanced recovery after surgery (ERAS) strategy after radical gastrectomy and the factors affecting the treatment experience. Methods: A prospective cohort study was carried out. Patients who were diagnosed with gastric cancer by pathology and underwent radical gastrectomy at the Xijing Digestive Disease Hospital from December 2019 to December 2020 were consecutively enrolled. Those who received emergency surgery, residual gastric cancer surgery, preoperative neoadjuvant chemotherapy, non-curative tumor resection, intraperitoneal metastasis, or other malignant tumors were excluded. Patients' expectation and experience during implementation were investigated by questionnaires. The questionnaire included three main parts: patients' expectation for ERAS, patients' experience during the ERAS implementation, and patients' outcomes within 30 days after discharge. The items on the expectation and experience were ranked from 0 to 10 by patients, which indicated to be unsatisfied/unimportant and satisfied/important respectively. According to their attitudes towards the ERAS strategy, patients were divided into the support group and the reject group. Patients' expectation and experience of hospital stay, and the clinical outcomes within 30 days after discharge were compared between the two groups. Categorical data were reported as number with percentage and the quantitative data were reported as mean with standard deviation, or where appropriate, as the median with interquartile range (Q₁, Q₃). Categorical data were compared using the Chi-squared test or Fisher's exact test, where appropriate. For continuous data, Student's t test or Mann-Whitney U test were used. Complication was classified according to Clavien-Dindo classification. Results: Of the included 112 patients (88 males and 24 females), aged (57.8±10.0) years, 35 patients (31.3%) were in the support group and 77 (68.7%) in the reject group. Anxiety was detected in 56.2% (63/112) of the patients with score >8. The admission education during the ERAS implementation improved the patients' cognitions of the ERAS strategy [M(Q₁, Q₃) score: 8 (4, 10) vs. 2 (0, 5), Z=-7.130, P<0.001]. The expected hospital stay of patients was longer than the actual stay [7 (7, 10) days vs. 6 (6, 7) days, Z=-4.800, P<0.001]. During the ERAS implementation, patients had low score in early mobilization [3 (1, 6)] and early oral intake [5 (2.25, 8)]. Fifty-eight (51.8%) patients planned the ERAS implementation at home after discharge, while 32.1% (36/112) preferred to stay in hospital until they felt totally recovered. Compared with the reject group, the support group had shorter expected hospital stay [7 (6, 10) days vs. 10 (7, 15) days, Z=-2.607, P=0.009], and higher expected recovery-efficiency score [9 (8, 10) vs. 7(5, 9), Z=-3.078, P=0.002], lower expected less-pain score [8 (6, 10) vs. 6 (5, 9) days, Z=-1.996, P=0.046], expected faster recovery of physical strength score [8 (6, 10) vs. 6 (4, 9), Z=-2.200, P=0.028] and expected less drainage tube score [8 (8, 10) vs. 8 (5, 10), Z=-2.075, P=0.038]. Worrying about complications (49.1%) and self-recognition of not recovery (46.4%) were the major concerns when assessing the experience toward ERAS. During the follow-up, 105 patients received follow-up calls. There were 57.1% (60/105) of patients who experienced a variety of discomforts after discharge, including pain (28.6%), bloating (20.0%), nausea (12.4%), fatigue (7.6%), and fever (2.9%). Within 30 days after discharge, 6.7% (7/105) of patients developed Clavien-Dindo level I and II operation-associated complications, including poor wound healing, intestinal obstruction, intraperitoneal bleeding, and wound infection, all of which were cured by conservative treatment. There were no complications of level III or above in the whole group after surgery. Compared with the support group, more patients in the reject group reported that they had not yet achieved self-expected recovery when discharged [57.1% (44/77) vs. 22.9% (8/35), χ²=11.372, P<0.001], and expected to return to their daily lives [39.0% (30/77) vs. 8.6% (3/35), χ²=10.693, P<0.001], with statistically significant differences (all P<0.05). Only 52.4% (55/105) of patients returned home to continue rehabilitation, and the remaining patients chose to go to other hospitals to continue their hospitalization after discharge, with a median length of stay of 7 (7, 9) days. Compared with the reject group, the support group had a higher proportion of home rehabilitation [59.7% (12/33) vs. 36.4% (43/72), χ²=4.950, P=0.026], and shorter time of self-perceived postoperative full recovery [14 (10, 20) days vs. 15 (14, 20) days, Z=2.100, P=0.036], with statistically significant differences (all P<0.05). Conclusions: Although ERAS has promoted postoperative rehabilitation while ensuring surgical safety, it has not been unanimously recognized by patients. Adequate rehabilitation education, good analgesia, good physical recovery, and early removal of drainage tubes may improve the patient's experience of ERAS.

Reverse anti-breast cancer drug resistance effects by a novel two-step assembled nano-celastrol medicine

Multidrug resistance (MDR) has become one of the most intractable problems in clinics as it would cause failure in chemotherapy. In this study, we demonstrated that a nanoscale self-assembled nanomedicine, which almost consisted of a pure chemo-drug, could efficiently overcome MDR. Celastrol (CST) was directly assembled into a discrete nanomedicine by precipitation, and then CST nanoparticles (CNPs) inhibited drug efflux pumps by activating HSF-1 expression and promoting HSF-1 translocation into nucleus to suppress the Pgp expression. The more drug accumulated in cells could activate apoptosis signals simultaneously and realize drug resistance reversal. CNPs significantly increased the level of ROS to regulate ERK/JNK signaling, which would further induce resistant cell apoptosis. The tandem apoptosis strategy used the same concentration of CST but achieved a higher antitumor effect. Overall, our study provides a new translational and alternative strategy using conventional natural products to overcome MDR with high efficacy.

Effect of High Molecular Mass Tail in the Mol Mass Distribution of Polypropylene on Injection Molding

The effect of high molecular mass (MM) tail in the molecular mass distribution (MMD) of polypropylene (PP) on injection molding has been studied using injection molded tensile bars from a commercial PP resin and two samples of the above resin deprived of the high MM tail in different degrees by controlled degradation during extruder reaction with an added processing aid named Promax. The central portions of the tensile bars were studied by polarizing microscopy of microtomed sections parallel and perpendicular to the melt flow direction, and by density and birefringence profiles across the thickness of the bar. Mechanical properties and acoustic emission behavior in stretching of these injection molded tensile bars are also discussed. The experimental results show that by stripping off the high MM tail in the MMD the injection molded tensile bar has smaller degree of crystallization, less frozen orientation, improved uniformity across the thickness and the thickness of the skin part is greatly reduced. Better quality of the fabricated articles is to be expected by using Promax with PP for injection molding.

Causal roles of daytime sleepiness in cardiometabolic diseases and osteoporosis

OBJECTIVE

Daytime sleepiness has some association with cardiometabolic diseases and osteoporosis, but it is unknown whether their relationship is causal. This two-sample Mendelian randomization (MR) study aims to explore their causal relationship.

MATERIALS AND METHODS

We included the largest genome-wide association studies (GWASs) associated with daytime sleepiness, cardiometabolic diseases and osteoporosis. 34 single nucleotide polymorphisms (SNPs) were used as the instrumental variables of daytime sleepiness.

RESULTS

Genetic predisposition to excessive daytime sleepiness was strongly associated with increased risk of coronary artery disease (beta-estimate: 0.610, 95% confidence interval [CI]: 0.128 to 1.093, standard error [SE]: 0.246, p-value=0.013) and may increase the incidence of type 2 diabetes (beta-estimate: 0.614, 95% CI: 0.009 to 1.219, SE: 0.309, p-value=0.047). We found no causal influence of daytime sleepiness on heart failure, atrial fibrillation, cerebral ischemia, intracerebral hemorrhage, forearm bone mineral density (FA-BMD), femoral neck BMD (FN-BMD), and lumbar spine BMD (LS-BMD).

CONCLUSIONS

This study suggested that excessive daytime sleepiness was causally associated with increased risk of coronary artery disease, which may benefit to prevent this disease.

[The effect of Endocrine disrupting chemicals on myocardial fibrosis and related mechanism]

Endocrine-disrupting chemicals (EDCs) an exogenous agent that interferes with the synthesis, secretion, transport, binding, action, or can mimic the occurrence of natural hormones that damage for the balance of homeostasis. Exposure to EDCs results in damage to human health that may persist in the long term. In recent years, accumulative evidence has demonstrated that EDCs also play a pivotal role in the onset and development of myocardial fibrosis, including heart failure, hypertension and vascular stiffening. Studies indicate that EDCs plays the negative effects of the cardiovascular system, however, EDCs-induced toxicity on heart remains unclear. This review summarized EDCs-induced myocardial fibrosis, and discuss the possible mechanisms of myocardial fibrosis induced by EDCs. This paper could provide further understandings for prevention, diagnosis and treatment of myocardial fibrosis.

Bcl-2 hijacks the arsenic trioxide resistance in SH-SY5Y cells

Aresenic trioxide (ATO) is proven to be active against leukaemia cells by inducing apoptosis and differentiation. Even though ATO could effectively induce remissions of leukaemia cells, the drug resistance was observed occasionally. To further dissect the mechanism of ATO resistance, we selected the ATO-resistant SH-SY5Y cells and found that Bcl-2 controlled the sensitivity of ATO in SH-SY5Y cells. We report that necroptosis, autophagy, NF-ƘB and MAPK signalling pathway are not involved in ATO-induced apoptosis. Moreover, the ATO-resistant cells showed distinct mitochondrial morphology compared with that of ATO-sensitive cells. Intriguingly, nude mice-bearing ATO-sensitive cells derived xenograft tumours are more sensitive to ATO treatment compared with that of ATO-resistant cells. These data demonstrate that cancer cells can acquire the ATO-resistance ability by increasing the Bcl-2 expression.

Research Progress on Cell Membrane-Coated Biomimetic Delivery Systems

Cell membrane-coated biomimetic nanoplatforms have many inherent properties, such as bio-interfacing abilities, self-identification, and signal transduction, which enable the biomimetic delivery system to escape immune clearance and opsonization. This can also maximize the drug delivery efficiency of synthetic nanoparticles (NPs) and functional cell membranes. As a new type of delivery system, cell membrane-coated biomimetic delivery systems have broadened the prospects for biomedical applications. In this review, we summarize research progress on cell membrane biomimetic technology from three aspects, including sources of membrane, modifications, and applications, then analyze their limitations and propose future research directions.

Carbon Nanotubes Promote the Development of Intestinal Organoids through Regulating Extracellular Matrix Viscoelasticity and Intracellular Energy Metabolism

The biological effect of engineered carbon nanotubes (CNTs) as beneficial biomaterials on the intestine, especially on its development, remains unclear. Here, we investigated the profitable effect of CNTs with a different graphene layer and surface modification on the 3D model of intestinal organoids and demonstrated that CNTs (50 μg/mL) promoted the development of intestinal organoids over time (0-5 days). The mechanisms involve the modulation of extracellular matrix (ECM) viscoelasticity and intracellular energy metabolism. In particular, CNTs reduced the hardness of the extracellular matrix through decreasing the elasticity and increasing the viscosity as a result of elevated metalloproteinase and binding to a protein scaffold, which activated the mechanical membrane sensors of cells, Piezo, and downstream P-p38-yes-associated protein (YAP) pathway. Moreover, CNTs altered the metabolic profile of intestinal organoids and induced increased mitochondria activity, respiration, and nutrient absorption. These mechanisms cooperated with each other to promote the proliferation and differentiation of intestinal organoids. In addition, the promoted effect of CNTs is highly dependent on the number of graphene layers, manifested as multiwalled CNTs > single-walled CNTs. Our findings highlight the CNT-intestine interaction and imply the potential of CNTs as biomaterials for intestine-associated tissue engineering.

Graphdiyne: from Preparation to Biomedical Applications

Graphdiyne(GDY) is a kind of two-dimensional carbon nanomaterial with specific configurations of sp and sp 2 carbon atoms. The key progress in the preparation and application of GDY is bringing carbon materials to a brand-new level. Here, the various properties and structures of GDY are introduced, including the existing strategies for the preparation and modification of GDY. In particular, GDY has gradually emerged in the field of life sciences with its unique properties and performance, therefore, the development of biomedical applications of GDY is further summarized. Finally, the challenges of GDY toward future biomedical applications are discussed.