Engineered calprotectin-sensing probiotics for IBD surveillance in humans

Inflammatory bowel disease (IBD) is a spectrum of autoimmune diseases affecting the gastrointestinal tract characterized by a relapsing and remitting course of gut mucosal inflammation. Disease flares can be difficult to predict, and the current practice of IBD disease activity surveillance through endoscopy is invasive and requires medical expertise. Recent advancements in synthetic biology raise the possibility that symbiotic microbes can be engineered to selectively detect disease biomarkers used in current clinical practice. Here, we introduce an engineered probiotic capable of detecting the clinical gold standard IBD biomarker, calprotectin, with sensitivity and specificity in IBD patients. Specifically, we identified a bacterial promoter in the probiotic strain Escherichia coli Nissle 1917 (EcN) which exhibits a specific expression increase in the presence of calprotectin. Using murine models of colitis, we show that the reporter signal is activated in vivo during transit of the GI tract following oral delivery. Furthermore, our engineered probiotic can successfully discriminate human patients with active IBD from those in remission and without IBD using patient stool samples, where the intensity of reporter signal quantitatively tracks with clinical laboratory-measured levels of calprotectin. Our pilot study sets the stage for probiotics that can be engineered to detect fecal calprotectin for precise noninvasive disease activity monitoring in IBD patients.

Advances in screening and detection of gastric cancer

With an estimated one million new cases and 769 000 deaths in 2020, gastric cancer is the fifth most frequent cancer and fourth leading cause of cancer death globally. Incidence rates are highest in Asia and Eastern Europe. This manuscript will review the current modalities of diagnosis, staging, and screening of gastric cancer. We will also highlight development of novel diagnostics and advancements in endoscopic detection of early gastric cancer.

[Comparison of single infusion of anti-BCMA versus combined infusion of anti-CD19 chimeric antigen receptor T cells for immune reconstruction in relapsed/refractory multiple myeloma]

Objective: We observed and compared the differences in immune reconstruction between single-infusion anti-B-cell maturation antigen (BCMA) , chimeric antigen receptor T cells (CAR-T) , and combined infusion of anti-CD19 CAR-T cells in the treatment of recurrent/refractory multiple myeloma (RRMM) . Methods: Sixty-one patients with RRMM who underwent CAR-T cell therapy in our hospital from June 2017 to December 2020 were selected. Among them, 26 patients received anti-BCMA target, and 35 patients received anti-BCMA combined with anti-CD19 target. Using flow cytometry, we determined T cell subsets (CD3(+), CD4(+), CD8(+), CD4(+)/CD8(+)) , B cells (CD19(+)) , and NK cells (CD16(+) CD56(+)) at different time points before and after CAR-T treatment, and detected immunoglobulin IgG, IgA and IgM levels by immunoturbidimetry. We compared the reconstruction rules of lymphocyte subsets and immunoglobulins in the two groups. Results: CD8(+) T lymphocytes recovered most rapidly after the infusion of CAR-T cells, returning to pre-infusion levels at 3 months and 1 month after infusion, respectively[BCMA: 695 (357, 1264) /μl vs 424 (280, 646) /μl; BCMA+CD19: 546 (279, 1672) /μl vs 314 (214, 466) /μl]. NK cells returned to normal levels at 3 months after infusion in both groups[BCMA: 171 (120, 244) /μl, BCMA+CD19: 153 (101, 218) /μl (Normal reference range 150-1100/μl) ]; however, the NK cells were not maintained at stable levels in the BCMA CAR-T cells group. The recovery of CD4(+) T lymphocytes in both groups was slow and remained persistently low within 12 months after infusion, and no recovery was observed in most patients. The reversal of the ratio of CD4(+)/CD8(+) lasted for more than a year. The levels of CD19(+) B cells in both groups returned to baseline 3 months after infusion[BCMA: 62 (10, 72) /μl vs 57 (24, 78) /μl; BCMA+CD19: 40 (4, 94) /μl vs 29 (14, 46) /μl]. IgG returned to the pre-infusion level 12 months after infusion in the group with anti-BCMA cells alone, but not in the group with combined infusion of CD19 CAR T cells[7.82 (6.03, 9.64) g/L vs 6.92 (4.62, 12.76) g/L]. IgA returned to pre-infusion levels at 9 and 12 months after infusion, respectively[BCMA: 0.46 (0.07, 0.51) g/L vs 0.22 (0.12, 4.01) g/L; BCMA+CD19: 0.46 (0.22, 0.98) g/L vs 0.27 (0.10, 0.53) g/L]. IgM in both groups returned to pre-infusion levels 6 months after infusion[BCMA: 0.43 (0.06, 0.60) g/L vs 0.20 (0.13, 0.37) g/L; BCMA+CD19: 0.53 (0.10, 0.80) g/L vs 0.16 (0.11, 0.28) g/L]. There was no significant difference in the indexes of lymphocyte subpopulation reconstruction and immunoglobulin recovery between the two groups at each time point. Conclusion: This study showed that in patients with RRMM treated with CAR-T cells, the appropriate target antigen can be selected without considering the difference of immune reconstruction between anti-BCMA CAR-T and combined anti-CD19 CAR-T therapy.

Anti-cancer effects of baicalein on cervical carcinoma cells through down-regulation of the ERK/p38/MAPK pathway

The objective of this study was to investigate the effects of baicalein on apoptosis of HeLa human cervical cancer (CC) cells and to elucidate the underlying mechanism. HeLa cells were treated with 20, 50, 100, or 200 μmol/L baicalein for 24, 36, and 48 hours, and CCK-8 assays were used to detect cell viability, and flow cytometry was performed to assess apoptosis rate. Reverse-transcription quantitative PCR was used to measure ERK1/2, p38, and JNK mRNA levels in HeLa cells, and western blotting was performed to measure ERK1/2, p38, and JNK protein levels. The CCK-8 assay showed that the OD value of HeLa cells gradually decreased with increasing baicalein concentrations (P < 0.01) and treatment time (P < 0.01). These results indicated a negative time- and dose-dependent effect of baicalein on HeLa cells. Baicalein treatment of HeLa cells significantly increased apoptosis rate (P < 0.01). In HeLa cells treated with 50 or 200 μmol/L baicalein for 24 h, expression levels of ERK1/2 and p38 mRNA were significantly reduced, whereas that of JNK mRNA was increased (P < 0.01). The levels of phosphorylated ERK1/2 and p38 were significantly reduced, and the level of JNK protein was increased (P < 0.01). Taken together, baicalein appeared to exert anti-cancer effects on HeLa cells through induction of apoptosis and regulation of the ERK/p38/mitogen-activated protein kinase pathway.

A pilot screening study for low bone mass in Singaporean women using years since menopause and BMI

OBJECTIVE

Current risk assessment tools for osteoporosis have inconsistent performance across different cohorts, making them difficult for clinical practice. This study aimed to evaluate a simple screening index comprising years since menopause (YSM) and body mass index (BMI) that identifies postmenopausal Singaporean women with a greater likelihood of low bone mass.

METHODS

The study used data from 188 treatment-naïve postmenopausal women. The associations between low bone mass and different demographic variables, including age, YSM and BMI, were assessed using multivariable logistic regression. Diagnostic performance of the calculated screening index was compared to the Osteoporosis Self-Assessment Tool for Asians (OSTA) and the Fracture Risk Assessment Tool (FRAX^®).

RESULTS

YSM and BMI were significantly associated with low bone mass. The area under the receiver operating characteristic curves was 0.803 for the screening index, 0.759 for the OSTA, 0.683 for the FRAX^® (major osteoporotic fracture probability [MOFP]) and 0.647 for the FRAX^® (hip fracture probability [HFP]). Non-parametric Spearman's correlation between the screening index and the other models was 0.857 with the OSTA score, 0.694 with the FRAX^® (HFP) and 0.565 with the FRAX^® (MOFP) (p < 0.0005).

CONCLUSIONS

The diagnostic performance of the screening index comprising YSM and BMI was equivalent to the OSTA and the FRAX^®. A risk chart was developed for clinicians to identify and recommend subjects for a further dual-energy X-ray absorptiometry scan. Validation of this model in larger and more diverse cohorts is required.

[Advances in research of microRNA in the growth and development of mandibular condyle cartilage]

MicroRNA (miRNA) are a class of small non-coding single-stranded RNA that exert their biological effects by binding to target messenger RNA (mRNA). There is new evidence that miRNA may play an important role in regulating the growth and development of mandibular condylar cartilage. In this paper, the production and mechanism of miRNA are reviewed, and the progress of studies on the growth and development of mandibular condylar cartilage, which is helpful to further study the growth and development of mandibular condylar cartilage.

Association of body mass index with mortality in cardiovascular disease: New insights into the obesity paradox from multiple perspectives

Over the past 4 decades, prevalence of obesity has increased rapidly at both the national and global level and presents a major public health challenge. Obesity is associated with increased risk of morbidity from cardiovascular diseases. Data suggesting that the presence of obesity may be protective in individuals with clinically manifest cardiovascular disease have led to discussion of an "obesity paradox", stirring controversy and leading to unclear messaging regarding the true health risks of excess weight. This review explores the relationship between obesity and fatal and non-fatal outcomes in patients with prevalent cardiovascular disease and offers novel insights into the obesity paradox.

[The current status and applications of implantable bone-conduction devices]

Implantable bone-conduction devices are characterized by the fact that the vibration is transmitted through bone conduction. The technology and surgical techniques in the application of implantable bone-conduction devices have developed considerably in recent years, experiencing a transformation from percutaneous to transcutaneous implantation. This article reviewed current developments in the types, surgical indications, and complications, as well as compared between the various bone-conduction devices to provid references for clinical application.

Acute loss of adipose tissue-derived adiponectin triggers immediate metabolic deterioration in mice

AIM/HYPOTHESIS

Adiponectin (APN), a circulating hormone secreted by mature adipocytes, has been extensively studied because it has beneficial metabolic effects. While many studies have focused on the congenital loss of APN and its effects on systemic body glucose and lipid metabolism, little is known about the effects triggered by acute loss of APN in the adult mouse. We anticipated that genetically induced acute depletion of APN in adult mice would have a more profound effect on systemic metabolic health than congenital deletion of Adipoq, the gene encoding APN, with its associated potential for adaptive responses that may mask the phenotypes.

METHODS

Mice carrying loxP-flanked regions of Adipoq were generated and bred to the Adipoq (APN) promoter-driven reverse tetracycline-controlled transactivator (rtTA) (APN-rtTA) gene and a tet-responsive Cre line (TRE-Cre) to achieve acute depletion of APN. Upon acute removal of APN in adult mice, systemic glucose and lipid homeostasis were assessed under basal and insulinopenic conditions.

RESULTS

The acute depletion of APN results in more severe systemic insulin resistance and hyperlipidaemia than in mice with congenital loss of APN. Furthermore, the acute depletion of APN in adult mice results in a much more dramatic reduction in survival rate, with 50% of inducible knockouts dying in the first 5 days under insulinopenic conditions compared with 0% of congenital Adipoq knockout mice under similar conditions.

CONCLUSIONS/INTERPRETATION

Acute systemic removal of APN results in a much more negative metabolic phenotype compared with congenital knockout of Adipoq. Specifically, our data demonstrate that acute depletion of APN is especially detrimental to lipid homeostasis, both under basal and insulinopenic conditions. This suggests that compensatory mechanisms exist in congenital knockout mice that offset some of the metabolic actions covered by APN.

[Protective effect of Angelica sinensis polysaccharide against liver injury induced by D-galactose in aging mice and its mechanisms]

OBJECTIVE

To investigate the protective effect of Angelica sinensis polysaccharide (ASP) against liver injury induced by D-galactose in aging mice and its mechanisms.

METHODS

Male C57BL/6J were randomly divided into three groups with 10 mice in each group. In the D-galactose model group, the mice were subcutaneously injected with D-galactose (120 mg/kg) qd×42; in the ASP+D-galactose group, from the 8th day of the establishment of D-galactose model, the mice were subcutaneously injected with ASP (120 mg/kg) qd×35. In the normal control group, the mice were subcutaneously injected with isotonic saline of the same volume at the same time point. On the 2nd day after the injection was finished, the ocular blood was collected to prepare serum and measure the content of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total bilirubin (TBil). The liver tissue homogenate was prepared to measure the content of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), malondialdehyde (MDA), and advanced glycation end products (AGEs). A paraffin section of liver tissue was prepared; HE staining was performed to observe the pathomorphological changes of the liver, periodic acid-Schiff staining (PAS) was used to observe the changes in glycogen in the liver, and a transmission electron microscope was used to observe the hepatocyte ultrastructure.

RESULTS

The D-galactose model group had increased content of ALT, AST, and TBil, reduced activities of SOD and GSH-Px, an increased content of MDA, and severe liver injuries; the hepatocytes showed degenerative changes, the amount of glycogen in the liver decreased, and the accumulation of AGEs increased. The ASP+D-galactose group had reduced content of ALT, AST, and TBil, increased activities of SOD and GSH-Px, and reduced content of MDA and AGEs; the amount of glycogen in the liver increased, and liver injury and hepatocyte injury were alleviated.

CONCLUSION

ASP can antagonize the liver injury induced by D-galactose in aging mice, and its mechanism may be related to the inhibition of oxidative stress.

Directing visceral white adipocyte precursors to a thermogenic adipocyte fate improves insulin sensitivity in obese mice

Visceral adiposity confers significant risk for developing metabolic disease in obesity whereas preferential expansion of subcutaneous white adipose tissue (WAT) appears protective. Unlike subcutaneous WAT, visceral WAT is resistant to adopting a protective thermogenic phenotype characterized by the accumulation of Ucp1⁺ beige/BRITE adipocytes (termed ‘browning’). In this study, we investigated the physiological consequences of browning murine visceral WAT by selective genetic ablation of Zfp423, a transcriptional suppressor of the adipocyte thermogenic program. Zfp423 deletion in fetal visceral adipose precursors (Zfp423^loxP/loxP; Wt1-Cre), or adult visceral white adipose precursors (Pdgfrb^rtTA; TRE-Cre; Zfp423^loxP/loxP), results in the accumulation of beige-like thermogenic adipocytes within multiple visceral adipose depots. Thermogenic visceral WAT improves cold tolerance and prevents and reverses insulin resistance in obesity. These data indicate that beneficial visceral WAT browning can be engineered by directing visceral white adipocyte precursors to a thermogenic adipocyte fate, and suggest a novel strategy to combat insulin resistance in obesity.

DOI:http://dx.doi.org/10.7554/eLife.27669.001

Mammals have different types of fat cells in their bodies. White fat cells store energy for later use, and brown and beige fat cells burn energy to help keep the body warm. Individuals who are obese typically have too many white fat cells in and around their belly. This belly fat, also called visceral fat, accumulates around the organs and is believed to contribute to metabolic diseases, such as diabetes and heart disease. Individuals who are obese also have relatively few brown and beige energy-burning fat cells.

Boosting the amount of brown and beige fat in individuals who are obese has been proposed as a potential way to reduce their risk of metabolic disease. One way to do this would be to encourage white visceral fat cells to become more like energy-burning beige or brown fat cells.

Recent research has shown that white fat cells contain higher amounts of a protein called Zfp423 than brown or beige fat cells. This protein turns off the genes that fat cells use to burn energy and so keeps white fat cells in an energy-storing state. Now, Hepler et al. show that genetically modifying mice to turn off the gene that produces Zfp423 specifically in the precursor cells that become white fat cells causes more energy-burning beige cells to appear in their visceral fat.

The genetically modified mice were better able to tolerate cold than normal mice. When placed on a high-fat diet, the modified mice were also less likely to become resistant to the effects of the hormone insulin – a process that can lead to the development of type 2 diabetes and may be linked to heart disease. This suggests that treatments that prevent Zfp423 from working in fat cells could help to treat or prevent diabetes and heart disease in people who are obese. Before such treatments can be developed, further work is needed to investigate how Zfp423 works in more detail, and to confirm that it has the same effects in human fat cells as it does in mice.

DOI:http://dx.doi.org/10.7554/eLife.27669.002

Inducible overexpression of adiponectin receptors highlight the roles of adiponectin-induced ceramidase signaling in lipid and glucose homeostasis

Objective

Adiponectin and the signaling induced by its cognate receptors, AdipoR1 and AdipoR2, have garnered attention for their ability to promote insulin sensitivity and oppose steatosis. Activation of these receptors promotes the deacylation of ceramide, a lipid metabolite that appears to play a causal role in impairing insulin signaling.

Methods

Here, we have developed transgenic mice that overexpress AdipoR1 or AdipoR2 under the inducible control of a tetracycline response element. These represent the first inducible genetic models that acutely manipulate adiponectin receptor signaling in adult mouse tissues, which allows us to directly assess AdipoR signaling on glucose and lipid metabolism.

Results

Overexpression of either adiponectin receptor isoform in the adipocyte or hepatocyte is sufficient to enhance ceramidase activity, whole body glucose metabolism, and hepatic insulin sensitivity, while opposing hepatic steatosis. Importantly, metabolic improvements fail to occur in an adiponectin knockout background. When challenged with a leptin-deficient genetic model of type 2 diabetes, AdipoR2 expression in adipose or liver is sufficient to reverse hyperglycemia and glucose intolerance.

Conclusion

These observations reveal that adiponectin is critical for AdipoR-induced ceramidase activation which enhances hepatic glucose and lipid metabolism via rapidly acting “cross-talk” between liver and adipose tissue sphingolipids.

•

Adiponectin receptor signaling in adipose prompts beneficial effects on whole-body glucose and lipid metabolism.

•

The small molecule adiponectin receptor antagonist AdipoRon lowers hepatic ceramides.

•

Depletion of ceramides in adipocytes results in diminished hepatic ceramide accumulation.

•

Depletion of ceramides in hepatocytes results in diminished adipose sphingolipid accumulation.

•

Adiponectin is essential for the beneficial effects of adiponectin receptors on glucose, ceramide, and lipid metabolism.

Targeted Induction of Ceramide Degradation Leads to Improved Systemic Metabolism and Reduced Hepatic Steatosis

Sphingolipids have garnered attention for their role in insulin resistance and lipotoxic cell death. We have developed transgenic mice inducibly expressing acid ceramidase that display a reduction in ceramides in adult mouse tissues. Hepatic overexpression of acid ceramidase prevents hepatic steatosis and prompts improvements in insulin action in liver and adipose tissue upon exposure to high-fat diet. Conversely, overexpression of acid ceramidase within adipose tissue also prevents hepatic steatosis and systemic insulin resistance. Induction of ceramidase activity in either tissue promotes a lowering of hepatic ceramides and reduced activation of the ceramide-activated protein kinase C isoform PKCζ, though the induction of ceramidase activity in the adipocyte prompts more rapid resolution of hepatic steatosis than overexpression of the enzyme directly in the liver. Collectively, our observations suggest the existence of a rapidly acting "cross-talk" between liver and adipose tissue sphingolipids, critically regulating glucose metabolism and hepatic lipid uptake.

Differential transendothelial transport of adiponectin complexes

Background

Adiponectin’s effects on systemic physiology and cell-specific responses are well-defined, but little is known about how this insulin-sensitizing and anti-inflammatory adipokine reaches its target cells. All molecules face active and passive transport limitations, but adiponectin is particularly noteworthy due to the diverse size range and high molecular weights of its oligomers. Additionally, its metabolic target organs possess a range of endothelial permeability.

Methods

Full-length recombinant murine adiponectin was produced and oligomer fractions isolated by gel filtration. Adiponectin complex sizes were measured by dynamic light scattering to determine Stokes radii. Transendothelial transport of purified oligomers was quantitatively assessed under a number of different conditions in vitro using murine endothelial cells and in vivo using several mouse models of altered endothelial function.

Results

Adiponectin oligomers exhibit large transport radii that limit transendothelial transport. Oligomerization is a significant determinant of flux across endothelial monolayers in vitro; low molecular weight adiponectin is preferentially transported. In vivo sampled sera from the heart, liver, and tail vein demonstrated significantly different complex distribution of lower molecular weight oligomers. Pharmacological interventions, such as PPARγ agonist treatment, differentially affect adiponectin plasma clearance and tissue uptake. Exercise induces enhanced adiponectin uptake to oxidative skeletal muscles, wherein adiponectin potently lowers ceramide levels. In total, endothelial barriers control adiponectin transport in a cell- and tissue-specific manner.

Conclusions

Adiponectin oligomer efficacy in a given tissue may therefore be endothelial transport mediated. Targeting endothelial dysfunction in the metabolic syndrome through exercise and pharmaceuticals may afford an effective approach to increasing adiponectin’s beneficial effects.

The adipokine/ceramide axis: key aspects of insulin sensitization

Until recently, sphingolipid physiology was primarily the domain of oncologists and immunologists. However, mounting evidence implicates ceramides and their derivatives in various aspects of metabolism via directly impacting the insulin receptor as well as modulating cell survival and proliferation. More recent observations suggest a strong link between a number of adipokines and ceramide catabolism. Here, we aim to briefly review the available data on the established metabolic effects of sphingolipids in various cell types and will discuss how adipokines exert a critical influence on the steady state levels of these lipid mediators.

Human tumor antigens Tn and sialyl Tn arise from mutations in Cosmc

Neoplastic lesions typically express specific carbohydrate antigens on glycolipids, mucins, and other glycoproteins. Such antigens are often under epigenetic control and are subject to reversion and loss upon therapeutic selective pressure. We report here that two of the most common tumor-associated carbohydrate antigens, Tn and sialyl Tn (STn), result from somatic mutations in the gene Cosmc that encodes a molecular chaperone required for formation of the active T-synthase. Diverse neoplastic lesions, including colon cancer and melanoma-derived cells lines, expressed both Tn and STn antigen due to loss-of-function mutations in Cosmc. In addition, two human cervical cancer specimens that showed expression of the Tn/STn antigens were also found to have mutations in Cosmc and loss of heterozygosity for the cross-linked Cosmc locus. This is the first example of somatic mutations in multiple types of cancers that cause global alterations in cell surface carbohydrate antigen expression.