NF-κB Inducing Kinase Regulates Intestinal Immunity and Homeostasis

[Research advances on B-cell activating factor and its targeted agents in inflammatory bowel disease]

B-cell activating factor (BAFF), a critical regulator of B cells, is involved in various autoimmune diseases. Inflammatory bowel disease (IBD) is a group of chronic and recurrent intestinal inflammatory disorders with unclear etiology, and its global incidence has been increasing in recent years. Abnormal immune responses triggered by multiple factors are closely related to the pathogenesis of IBD. Previous studies have confirmed the association of B-cell abnormal activation and increased production of autoantibodies with the development of ulcerative colitis. However, the involvement of BAFF in the mechanisms of IBD remains unclear. This review summarizes the potential role of BAFF in the pathogenesis of IBD and provides an overview of targeted therapies on BAFF in IBD, aiming to contribute insights for targeted treatments of IBD.

Understanding very early onset inflammatory bowel disease (VEOIBD) in relation to inborn errors of immunity

Inflammatory bowel diseases (IBD) are multifactorial diseases which are caused by the combination of genetic predisposition, exposure factors (environmental and dietary), immune status, and dysbiosis. IBD is a disease which presents at any age, ranging from newborns to the elderly. The youngest of the pediatric IBD population have a more unique presentation and clinical course and may have a different etiology. Very early onset IBD (VEOIBD) patients, designated as those diagnosed prior the age of 6, have distinct features which are more frequent in this patient population including increased incidence of monogenetic causes for IBD (0%-33% depending on the study). This proportion is increased in the youngest subsets, which is diagnosed prior to the age of 2. To date, there are approximately 80 monogenic causes of VEOIBD that have been identified and published. Many of these monogenic causes are inborn errors of immunity yet the majority of VEOIBD patients do not have an identifiable genetic cause for their disease. In this review, we will focus on the clinical presentation, evaluation, and monogenic categories which have been associated with VEOIBD including (1) Epithelial cell defects (2) Adaptive immune defects, (3) Innate Immune/Bacterial Clearance and Recognition defects, and (4) Hyperinflammatory and autoinflammatory disorders. We will highlight differential diagnosis of VEOIBD presentations, as well as evaluation and treatment, which will be helpful for those who study and care for VEOIBD patients outside of the pediatric gastroenterology field. This is a fast-moving field of research which has grown significantly based on knowledge that we gain from our patients. These scientific findings have identified novel mucosal biology pathways and will continue to inform our understanding of gastrointestinal biology.

Poly-(ADP-ribose) polymerases inhibition by olaparib attenuates activities of the NLRP3 inflammasome and of NF-κB in THP-1 monocytes

Poly-(ADP-ribose) polymerases (PARPs) are a protein family that make ADP-ribose modifications on target genes and proteins. PARP family members contribute to the pathogenesis of chronic inflammatory diseases, including atherosclerosis, in which monocytes/macrophages play important roles. PARP inhibition is protective against atherosclerosis. However, the mechanisms by which PARP inhibition exerts this beneficial effect are not well understood. Here we show that in THP-1 monocytes, inhibition of PARP by olaparib attenuated oxidized low-density lipoprotein (oxLDL)-induced protein expressions of nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain-containing-3 (NLRP3) inflammasome components: NLRP3, apoptosis-associated speck-like protein containing a caspase activation and recruitment domain (ASC), and caspase-1. Consistent with this effect, olaparib decreased oxLDL-enhanced interleukin (IL)-1β and IL-18 protein expression. Olaparib also decreased the oxLDL-mediated increase in mitochondrial reactive oxygen species. Similar to the effects of the NLRP3 inhibitor, MCC950, olaparib attenuated oxLDL-induced adhesion of monocytes to cultured human umbilical vein endothelial cells and reduced foam cell formation. Furthermore, olaparib attenuated the oxLDL-mediated activation of nuclear factor (NF)-κB through the oxLDL-mediated increase in IκBα phosphorylation and assembly of NF-κB subunits, demonstrated by co-immunoprecipitation of IκBα with RelA/p50 and RelB/p52 subunits. Moreover, PARP inhibition decreased oxLDL-mediated protein expression of a NF-κB target gene, VCAM1, encoding vascular cell adhesion molecule-1. This finding indicates an important role for NF-κB activity in PARP-mediated activation of the NLRP3 inflammasome. Thus, PARP inhibition by olaparib attenuates NF-κB and NLRP3 inflammasome activities, lessening monocyte cell adhesion and macrophage foam cell formation. These inhibitory effects of olaparib on NLRP3 activity potentially protect against atherosclerosis.

Natural compounds target programmed cell death (PCD) signaling mechanism to treat ulcerative colitis: a review

Ulcerative colitis (UC) is a nonspecific inflammatory bowel disease characterized by abdominal pain, bloody diarrhea, weight loss, and colon shortening. However, UC is difficult to cure due to its high drug resistance rate and easy recurrence. Moreover, long-term inflammation and increased disease severity can lead to the development of colon cancer in some patients. Programmed cell death (PCD) is a gene-regulated cell death process that includes apoptosis, autophagy, necroptosis, ferroptosis, and pyroptosis. PCD plays a crucial role in maintaining body homeostasis and the development of organs and tissues. Abnormal PCD signaling is observed in the pathological process of UC, such as activating the apoptosis signaling pathway to promote the progression of UC. Targeting PCD may be a therapeutic strategy, and natural compounds have shown great potential in modulating key targets of PCD to treat UC. For instance, baicalin can regulate cell apoptosis to alleviate inflammatory infiltration and pathological damage. This review focuses on the specific expression of PCD and its interaction with multiple signaling pathways, such as NF-κB, Nrf2, MAPK, JAK/STAT, PI3K/AKT, NLRP3, GPX4, Bcl-2, etc., to elucidate the role of natural compounds in targeting PCD for the treatment of UC. This review used (ulcerative colitis) (programmed cell death) and (natural products) as keywords to search the related studies in PubMed and the Web of Science, and CNKI database of the past 10 years. This work retrieved 72 studies (65 from the past 5 years and 7 from the past 10 years), which aims to provide new treatment strategies for UC patients and serves as a foundation for the development of new drugs.

Silencing HE4 alleviates the renal fibrosis in lupus nephritis mice by regulating the C3/MMPs/prss axis

To explore the regulatory effect of human epididymis protein 4 (HE4) on renal fibrosis in mice with lupus nephritis (LN) and the underlying mechanism. Ten-week old MRL/LPR mice were injected with HE4 shRNA adenovirus vector through the renal pelvis for 5 days. Renal tissues were extracted for HE and Masson staining to evaluate pathological changes and fibrosis in lupus nephritis mice. The level of urine protein was measured using a biochemical analyzer, while the expression level of HE4 and p-NF-κB p65 in renal tissues was visualized using an immunofluorescence assay. The level of β2-microglobulin (β2-MG), neutrophil gelatinase-associated lipocalin (NGAL), and kidney injury molecule 1 (Kim-1) was determined by the immunohistochemical assay. Western blotting was used to determine the levels of C3, HE4, matrix metalloproteinase-2 (MMP2), MMP9, p-p65, prss23, and prss35 in renal tissues. Compared to wild-type C57BL/6 mice, MRL/LPR mice showed a marked increase in the number of glomeruli, hyperplasic basement membrane, severe infiltration of inflammatory cells in renal tubules and glomeruli, obvious necrosis in glomeruli, elevated fibrosis levels, and increased levels of urine protein, β2-MG, NGAL, Kim-1, C3, HE4, MMP2, MMP9, and p-p65; and decreased levels of prss23 and prss35 were observed in MRL/LPR mice. After the administration of the HE4 shRNA adenovirus vector, the repaired structure of renal tubules and glomeruli improved infiltration of inflammatory cells, reduced collagen fiber and urine protein, suppressed levels of C3, HE4, MMP2, MMP9, and p-P65, and facilitated the expression of prss23 and prss35 which were observed. Silencing HE4 improved renal fibrosis and inhibited inflammation in mice with lupus nephritis, which may play a role in inhibiting C3/MMPs and promoting prss-related protein expression.

CRISPR-Cas-Based Engineering of Probiotics

Probiotics are the treasure of the microbiology fields. They have been widely used in the food industry, clinical treatment, and other fields. The equivocal health-promoting effects and the unknown action mechanism were the largest obstacles for further probiotic's developed applications. In recent years, various genome editing techniques have been developed and applied to explore the mechanisms and functional modifications of probiotics. As important genome editing tools, CRISPR-Cas systems that have opened new improvements in genome editing dedicated to probiotics. The high efficiency, flexibility, and specificity are the advantages of using CRISPR-Cas systems. Here, we summarize the classification and distribution of CRISPR-Cas systems in probiotics, as well as the editing tools developed on the basis of them. Then, we discuss the genome editing of probiotics based on CRISPR-Cas systems and the applications of the engineered probiotics through CRISPR-Cas systems. Finally, we proposed a design route for CRISPR systems that related to the genetically engineered probiotics.

Research progress of NF-κB signaling pathway and thrombosis

Venous thromboembolism is a very common and costly health problem. Deep-vein thrombosis (DVT) can cause permanent damage to the venous system and lead to swelling, ulceration, gangrene, and other symptoms in the affected limb. In addition, more than half of the embolus of pulmonary embolism comes from venous thrombosis, which is the most serious cause of death, second only to ischemic heart disease and stroke patients. It can be seen that deep-vein thrombosis has become a serious disease affecting human health. In recent years, with the deepening of research, inflammatory response is considered to be an important pathway to trigger venous thromboembolism, in which the transcription factor NF-κB is the central medium of inflammation, and the NF-κB signaling pathway can regulate the pro-inflammatory and coagulation response. Thus, to explore the mechanism and make use of it may provide new solutions for the prevention and treatment of thrombosis.

Hericium erinaceus, a medicinal fungus with a centuries-old history: Evidence in gastrointestinal diseases

Hericium erinaceus is an edible and medicinal mushroom commonly used in traditional Chinese medicine for centuries. Several studies have highlighted its therapeutic potential for gastrointestinal disorders such as gastritis and inflammatory bowel diseases. In addition, some components of this mushroom appear to possess strong antineoplastic capabilities against gastric and colorectal cancer. This review aims to analyse all available evidence on the digestive therapeutic potential of this fungus as well as the possible underlying molecular mechanisms.

GLP-1 Receptor Agonists in Obese Patients with Inflammatory Bowel Disease: from Molecular Mechanisms to Clinical Considerations and Practical Recommendations for Safe and Effective Use

PURPOSE OF REVIEW

To discuss current literature and provide practical recommendations for the safe and effective use of glucagon-like peptide 1 receptor agonists (GLP-1 RA) in people with inflammatory bowel disease (IBD) and type 2 diabetes (T2D) and/or obesity. The molecular mechanisms that justify the potential benefits of GLP-1 RA in IBD and the links between IBD, obesity, and cardiovascular disease are also discussed.

RECENT FINDINGS

Preliminary data suggest that GLP-1 RA can modulate crucial pathways in the pathogenesis of IBD, such as chronic inflammation circuits, intestinal tight junctions, and gut microbiome dysbiosis, setting the stage for human trials to investigate the role of these agents in the treatment of IBD among people with or without diabetes and obesity. However, gastrointestinal side effects related to GLP-1 RA need appropriate clinical management to mitigate risks and maximize the benefits of therapy in people with IBD. GLP-1 RA originally emerged as drugs for the treatment of hyperglycemia and are currently licensed for the management of T2D and/or overweight/obesity. However, their wealth of pleiotropic actions soon raised expectations that they might confer benefits on non-metabolic disorders. Future studies are expected to clarify whether GLP-1 RA deserve an adjunct place in the arsenal of drugs against IBD.

An integrated transcriptome and microbial community analysis reveals potential mechanisms for increased immune responses when replacing silybum marianum meal with soybean meal in growing lambs

Silybum marianum meal is a by-product that remains silymarin complex and is perceived as a potential-protein source. The potential and its mechanism of silybum marianum meal as a protein supplement in ruminants were evaluated by testing the growth performance, biochemical parameters, cytokine levels, gut transcriptome and microbial community profiles. Forty-two male Hulunbeier growing lambs (aged about 3-month-old; averaged body weight of 21.55 kg) were randomly divided into the CON (with 10% soybean meal) and SIL groups (with 10% silybum marianum meal). There was no significant difference in growth performance, feed intakes, or serum biochemical parameters between CON and SIL. The serum levels of IL-1β, TNF-α, TGF-β, HGF, and VEGF were all increased (p < 0.05) in the SIL group as compared with the CON group. Transcriptome gene set enrichment analysis (GSEA) revealed that the core genes in the rumen from SIL group were enriched with fructose and mannose metabolism, while the core genes in the ileum were enriched for three biological process, including digestive tract development, positive regulation of MAPK cascade, and regulation of I-kappaB kinase/NF-kappaB signaling. The 16S rDNA results showed that the relative abundance of Bacteroidetes, Firmicutes, Synergistetes, and Verrucomicrobia in the rumen from SIL group was significantly higher than that in CON group (p < 0.05), whereas Proteobacteria was significantly lower than that in CON group (p < 0.05). The LEfSe analysis showed that the genera Pyramidobacter, Saccharofermentans, Anaerovibrio, Oscillibacter and Barnesiella were enriched in the rumen from SIL group, whereas Sharpea was enriched in the CON group (LDA > 2). In the ileum, there were no significant differences in the phylum-level classification of microbes observed. At the genus level, the relative abundances of Bifidobacterium and Ruminococcus in the ileum from SIL group were significantly higher than that in the CON group (p < 0.05), whereas the relative abundance of Clostridium_XI was lower (p < 0.05). Correlation analysis showed that Clostridium_XI was negatively correlated with VEGF, TGF-β, TNF-α and HGF (p < 0.05). Core genes BMP4 and CD4 were negatively correlated with Clostridium_XI (p < 0.05). Our results indicated that supplementing silybum marianum meal as a replacement for soybean meal resulted in increased cytokines production without affecting growth performance in growing lambs, and the enrichment of immune-related genes and altered microbial community in the ileum were contributed to the increased immune responses.