Colon mucus in colorectal neoplasia and beyond

The intervention of NLRP3 inflammasome inhibitor: oridonin against azoxymethane and dextran sulfate sodium-induced colitis-associated colorectal cancer in male BALB/c mice

Colorectal cancer (CRC) ranks third globally in cancer diagnoses. The dysregulation of the NLRP3 inflammasome is prominently linked to several types of cancers. Oridonin, a principal component of Rabdosia rubescens, exhibits inhibitory activity against NLRP3 and is well-recognized for its diverse pharmacological benefits. However, its role in an animal model of colitis-associated colorectal cancer (CACC) remains unexplored. In the present study, the effectiveness of oridonin was investigated against CACC, developed using azoxymethane (AOM), a tumour initiator, and dextran sulphate sodium (DSS), a tumour promoter, in male BALB/c mice. The two-stage murine model of inflammation-associated cancer was established by administering AOM (10 mg/kg b.w.; i.p., once) followed by DSS (2% w/v) in drinking water (3 cycles, 7 days/cycle). Over a span of 10 weeks, the dose-dependent (2.5, 5, and 10 mg/kg, b.w.; i.p.) effects of oridonin were investigated in BALB/c mice. Oridonin significantly alleviated CACC severity, as evidenced by reduced DAI scores and restored body weight. Moreover, it attenuated surrogate markers of inflammation, including myeloperoxidase, nitrite, plasma LPS, TNF-α, IL-1β, and DNA damage. Histopathological examination revealed diminished tumorigenesis and apoptotic cells, corroborated by reduced Ki-67 and TNF-α, along with increased p53 expression in the colon. Following oridonin treatment, IHC/immunofluorescence analyses demonstrated a significantly reduced expression of the components of NLRP3 inflammasome including NLRP3, ASC-1, and caspase-1. Notably, the high dose of oridonin (10 mg/kg) consistently exhibited significant protective effects against CACC by modulating various molecular targets. Present findings confirmed the potential of oridonin in the protection of colitis-associated colorectal cancer, providing valuable insights into its mechanism of action and clinical significance.

Association Between Genetically Proxied SLC12A2 Inhibition and Inflammatory Bowel Disease: A Mendelian Randomization Study

The global rise in hypertension prompts the use of medications to manage blood pressure. However, selecting first-line drugs remains challenging as their efficacy often stems from blood pressure reduction rather than specific pharmacological actions. Evaluating interactions between antihypertensive drugs and common diseases can aid tailored treatment. Here, we assess the potential link between antihypertensives and inflammatory bowel disease (IBD). Summary-level coronary heart disease (CHD) data (184,305 individuals), systolic BP (SBP) data (757,601 individuals), ulcerative ileocolitis data (361,188 individuals), ulcerative colitis data (364,454 individuals), other ulcerative colitis data (361,619 individuals), and ulcerative proctitis data (361,700 individuals) were all from genome-wide association studies (GWASs), FinnGen or eQTL studies publicly accessible. The DrugBank10 and ChEMBL11 databases function to identify genes encoding protein products targeted by active constituents of BP-lowering drugs. Summary-data-based MR (SMR) estimated the associations between expressions of drug target genes and symptoms of IBD. A multivariable MR study was further conducted to examine if the observed association was direct association. Subsequently, we collected blood samples from IBD patients in the Gastroenterology Department of Gastroenterology, the First Affiliated Hospital of Anhui Medical University and blood from healthy individuals at the physical examination center. Real-time quantitative PCR was employed to detect the expression changes of drug target genes in the peripheral blood of patients with IBD. Furthermore, we used Caco2 cells to construct an in vitro model of IBD, examined the expression of the target molecules, and verified the potential of Bumetanide to improve IBD. SMR analysis revealed that enhanced SLC12A2 gene expression in blood (equivalent to a one standard deviation increase) was a risk factor for ulcerative ileocolitis (beta = 0.5861, se = 0.2972, p = 0.0486) and enhanced gene expression of ACE was a protective factor. Additionally, SCNN1D and SLC16A1 played protective roles of IBD, while NR3C1 was identified as a risk factor. However, among these genes, only SLC12A2 was considered to influence the progress of inflammatory bowel disease through systolic blood pressure based on Mendelian randomization analysis results. Other genes may be associated with IBD depending on the expression of their own proteins, independent of changes in blood pressure. In the peripheral blood of IBD patients and in vitro experiments, SCL12A2 has been shown to be highly expressed in IBD. In vitro experiments have confirmed that Bumetanide can inhibit SCL12A2 to improve tight junctions, reduce inflammation levels, and ameliorate IBD symptoms. Therapeutic inhibition of SCL12A2 may benefit patients with IBD. In the future, this study may contribute to the selection of more personalized antihypertensive medications for different subgroups of hypertensive patients.

Age-related decline in goblet cell numbers and mucin content of the human colon: Implications for lower bowel functions in the elderly

BACKGROUND & AIMS

Older people experience a greater incidence of lower bowel disorders, including constipation. Causes can include factors associated with growing older, such as use of medications or disease, but compounded by degenerative changes within the bowel wall. It has been suggested that the latter is exacerbated by loss of an effective mucosal barrier to luminal contents. In human colon, little is known about the impact of ageing on key components of this barrier, namely the goblet cells and mucin content.

METHODS

Changes in the number of goblet cells and density of mucin content were investigated in macroscopically normal human ascending (AC; n = 13) and descending (DC; n = 14) colon from elderly (≥ 67 years) and younger adults (60 years and below). Samples were serially sectioned and stained for haematoxylin and eosin to assess tissue morphology, and alcian blue periodic acid Schiff (ABPAS) and MUC-2 antibody to identify goblet cells producing mucins. New procedures in visualization and identification of goblet cells and mucin contents were employed to ensure unbiased counting and densitometric analysis.

RESULTS

Compared with the younger adults, the numbers of goblet cells per crypt were significantly lower in the elderly AC (72 ± 1.2 vs 51 ± 0.5) and DC (75 ± 2.6 vs. 54 ± 1.9), although this reduction did not reach statistical significance when assessed per mucosal area (AC: P = 0.068; DC: P = 0.096). In both regions from the elderly, numerous empty vesicles (normally containing mucins) were observed, and some areas of epithelium were devoid of goblet cells. Thus, the density of mucin content per unit mucosal area were significantly reduced with age.

CONCLUSIONS

Ageing could result in a reduced number of goblet cells and development of degenerative changes in mucin production. Together, these have implications for the mucus barrier function in the colon of elderly individuals.

Microbiota-associated mechanisms in colorectal cancer

Colorectal cancer (CRC) is one of the most common cancers worldwide, ranking third in terms of incidence and second as a cause of cancer-related death. There is growing scientific evidence that the gut microbiota plays a key role in the initiation and development of CRC. Specific bacterial species and complex microbial communities contribute directly to CRC pathogenesis by promoting the neoplastic transformation of intestinal epithelial cells or indirectly through their interaction with the host immune system. As a result, a protumoural and immunosuppressive environment is created conducive to CRC development. On the other hand, certain bacteria in the gut microbiota contribute to protection against CRC. In this chapter, we analysed the relationship of the gut microbiota to CRC and the associations identified with specific bacteria. Microbiota plays a key role in CRC through various mechanisms, such as increased intestinal permeability, inflammation and immune system dysregulation, biofilm formation, genotoxin production, virulence factors and oxidative stress. Exploring the interaction between gut microbiota and tumourigenesis is essential for developing innovative therapeutic approaches in the fight against CRC.

Mucus Impaction Related to Postoperative Anastomosis Site Obstruction: A Rare Case

Anastomotic stricture has an incidence rate of 6-10% and typically manifests three to six months after colorectal surgery. Immediate postoperative stricture is exceedingly rare and underreported in the literature. The possible etiology includes poor circulation, leakage, local inflammation, or infection. We report a rare case of a patient with total obstruction by mucus on the anastomosis site on postoperation day two. We used a sigmoidoscope to remove mucus material, following which the patient recovered well.

Current Advances of Nanomaterial-Based Oral Drug Delivery for Colorectal Cancer Treatment

Colorectal cancer (CRC) is a common malignant tumor, and traditional treatments include surgical resection and radiotherapy. However, local recurrence, distal metastasis, and intestinal obstruction are significant problems. Oral nano-formulation is a promising treatment strategy for CRC. This study introduces physiological and environmental factors, the main challenges of CRC treatment, and the need for a novel oral colon-targeted drug delivery system (OCDDS). This study reviews the research progress of controlled-release, responsive, magnetic, targeted, and other oral nano-formulations in the direction of CRC treatment, in addition to the advantages of oral colon-targeted nano-formulations and concerns about the oral delivery of related therapeutic agents to inspire related research.

Autophagy and the Insulin-like Growth Factor (IGF) System in Colonic Cells: Implications for Colorectal Neoplasia

Colorectal cancer (CRC) is one of the most common human malignancies worldwide. Along with apoptosis and inflammation, autophagy is one of three important mechanisms in CRC. The presence of autophagy/mitophagy in most normal mature intestinal epithelial cells has been confirmed, where it has mainly protective functions against reactive oxygen species (ROS)-induced DNA and protein damage. Autophagy regulates cell proliferation, metabolism, differentiation, secretion of mucins and/or anti-microbial peptides. Abnormal autophagy in intestinal epithelial cells leads to dysbiosis, a decline in local immunity and a decrease in cell secretory function. The insulin-like growth factor (IGF) signaling pathway plays an important role in colorectal carcinogenesis. This is evidenced by the biological activities of IGFs (IGF-1 and IGF-2), IGF-1 receptor type 1 (IGF-1R) and IGF-binding proteins (IGF BPs), which have been reported to regulate cell survival, proliferation, differentiation and apoptosis. Defects in autophagy are found in patients with metabolic syndrome (MetS), inflammatory bowel diseases (IBD) and CRC. In neoplastic cells, the IGF system modulates the autophagy process bidirectionally. In the current era of improving CRC therapies, it seems important to investigate the exact mechanisms not only of apoptosis, but also of autophagy in different populations of tumor microenvironment (TME) cells. The role of the IGF system in autophagy in normal as well as transformed colorectal cells still seems poorly understood. Hence, the aim of the review was to summarize the latest knowledge on the role of the IGF system in the molecular mechanisms of autophagy in the normal colon mucosa and in CRC, taking into account the cellular heterogeneity of the colonic and rectal epithelium.