The small intestine is essential for digestion, nutrient absorption, immune regulation, and microbial balance. Its epithelial lining, containing specialized cells like Paneth cells and tuft cells, is crucial for maintaining intestinal homeostasis. Paneth cells produce antimicrobial peptides and growth factors that support microbial regulation and intestinal stem cells, while tuft cells act as chemosensors, detecting environmental changes and modulating immune responses. Along with immune cells such as intraepithelial lymphocytes, innate lymphoid cells, T cells, and macrophages, they form a strong defense system that protects the epithelial barrier. Disruptions in this balance contribute to chronic inflammation, microbial dysbiosis, and compromised barrier function-key features of inflammatory bowel disease, celiac disease, and metabolic syndromes. Furthermore, dysfunctions in the small intestine and immune cells are linked to systemic diseases like obesity, diabetes, and autoimmune disorders. Recent research highlights promising therapeutic strategies, including modulation of epithelial and immune cell functions, probiotics, and gene editing to restore gut health and address systemic effects. This review emphasizes the pivotal roles of small intestinal epithelia and immune cells in maintaining intestinal homeostasis, their involvement in disease development, and emerging treatments for intestinal and systemic disorders.
Humans ; Intestinal Mucosa/cytology* ; Intestine, Small/cytology* ; Animals ; Inflammatory Bowel Diseases/immunology* ; Celiac Disease/immunology* ; Paneth Cells/immunology*

OBJECTIVE: Data on homocysteine (Hcy) status and its determinants are limited among women during pregnancy and postpartum. This cross-sectional study aimed to investigate Hcy levels during pregnancy and postpartum, and to explore the determinants like geographic factor. METHODS: This study was conducted in women at mid-pregnancy, late-pregnancy and postpartum from southern, central and northern China. Approximately 132 women were included in each stratum by the three phases and regions. Plasma Hcy concentrations were assessed using high-performance liquid chromatography (HPLC), with hyperhomocysteinemia defined as > 10.0 µmol/L. Quantile regression was to estimate medians and interquartile ranges ( IQRs), and logistic regression to examine the determinants of hyperhomocysteinemia. RESULTS: For 1,190 women included, the median (IQR) Hcy concentration was 5.66 (4.62, 7.37) μmol/L. The adjusted median in mid-pregnancy, late-pregnancy and postpartum women was 4.75 (4.13, 5.54), 5.72 (4.81, 6.85) and 7.09 (5.65, 8.75) μmol/L, respectively, showing an increasing trend ( P < 0.001). This increasing trend persisted across the three regions. Higher Hcy concentrations were observed in women residing in northern region and those with younger age or lower economic status. A total of 106 (8.9%) women had hyperhomocysteinemia, with a higher prevalence in those residing in northern region (16.0%), or in postpartum women (16.5%). CONCLUSION Hcy levels, varying with geographic region, maternal age and economic status, are increased from mid-pregnancy to late-pregnancy and postpartum, indicating a need to monitor Hcy levels in pregnant and postpartum women to control potential risks related to elevated Hcy levels.
Humans ; Female ; Pregnancy ; Homocysteine/blood* ; China/epidemiology* ; Adult ; Postpartum Period/blood* ; Cross-Sectional Studies ; Hyperhomocysteinemia/blood* ; Young Adult ; Pregnancy Trimester, Third/blood* ; Pregnancy Trimester, Second ; East Asian People

In patients with chronic kidney disease(CKD),the incidence of cardiovascular events and the mortality rate are significantly higher than those in the general population.Approximately 85% of end-stage CKD patients develop hyperhomocysteinemia(HHcy)due to impaired renal function.It is not yet fully determined whether HHcy merely acts as a biomarker of CKD or plays a role in the pathogenesis.Although supplementation with folic acid and other B vitamins(B6 and B12)has been proven to lower the plasma level of total homocysteine,their effectiveness in slowing CKD progression or reducing cardiovascular complications remains uncertain.This article reviews the latest research progress in the relationship between HHcy and CKD,aiming to give new insights into the prevention and treatment of CKD and its complications.
Humans ; Hyperhomocysteinemia/complications* ; Renal Insufficiency, Chronic/complications*

Platelet-rich plasma (PRP) shows promise as a regenerative modality for mild-to-moderate erectile dysfunction (ED). However, its efficacy in treating severe ED remains unknown. Blood samples from 8-week-old male rats were used to prepare PRP through a two-step centrifugation procedure, followed by chitosan activation and freeze thaw cycle. A hyperhomocysteinemia (HHcy)-related ED model was established using a methionine-enriched diet, and an apomorphine (APO) test was conducted during the 4 th week. APO-negative rats were divided into two groups and were injected with PRP or saline every 2 weeks. Erectile function and histological analyses of the corpus cavernosum were performed during the 16 th week. The results revealed that erectile function was significantly impaired in rats with HHcy-related ED compared to that in age-matched rats but was improved by repeated PRP injections. Immunofluorescence staining revealed a reduction in reactive oxygen species and additional benefits on the recovery of structures within the corpus cavernosum in rats that received PRP treatment compared to those in the saline-injected control group. Therefore, PRP could enhance functional and structural recovery in a severe HHcy-related ED model. A notable strength of the present study lies in the use of a repeated intracavernous injection method, mirroring protocols used in human studies, which offers more reliable results for translating the findings to humans.
Animals ; Male ; Platelet-Rich Plasma ; Hyperhomocysteinemia/complications* ; Erectile Dysfunction/etiology* ; Rats ; Disease Models, Animal ; Penis ; Rats, Sprague-Dawley ; Reactive Oxygen Species/metabolism* ; Penile Erection/physiology* ; Apomorphine/administration & dosage*

Hyperhomocysteinemia (HHcy) is considered to be an independent risk factor for cardiovascular diseases, but the molecular mechanisms underlying its pathogenesis are not fully understood. Endothelial dysfunction is a key initiating factor in the pathogenesis of atherosclerosis, which is commonly observed in almost all HHcy-induced vascular diseases. HHcy promotes oxidative stress, inhibits nitric oxide production, suppresses hydrogen sulfide signaling pathway, promotes endothelial mesenchymal transition, activates coagulation pathways, and promotes protein N-homocysteination and cellular hypomethylation, all of which can cause endothelial dysfunction. This article reviews the specific links between HHcy and endothelial dysfunction, and highlights recent evidence that endothelial mesenchymal transition contributes to HHcy-induced vascular damage, with a hope to provide new ideas for the clinical treatment of HHcy-related vascular diseases.
Humans ; Atherosclerosis ; Cardiovascular Diseases ; Endothelium, Vascular ; Homocysteine/metabolism* ; Hyperhomocysteinemia/complications* ; Oxidative Stress ; Risk Factors

Objective To explore the association between plasma homocysteine (Hcy) level and hyper-uricemia (HUA) in the elderly patients with hypertension.Methods From March to August in 2018,9902 hypertensive patients ≥ 60 years were routinely tested for blood biochemical indicators in Wuyuan county,Jiangxi province.The patients were assigned into a HUA group and a normal uric acid group.Multivariate Logistic regression was adopted to analyze the relationship between Hcy level and the risk of HUA.Results Compared with the normal uric acid group,the HUA group showed increased incidence of hyperhomocysteinemia (99.9% vs.98.7%,P<0.001) and elevated Hcy level[16.8 (13.8-21.5) μmol/L vs.14.4 (12.3-17.7) μmol/L,P<0.001].The multivariate Logistic regression analysis showed that after adjusting for influencing factors,the risk of HUA in the patients with hyperhomocysteinemia was 2.92 times of that in the patients with a normal Hcy level.The threshold effect analysis showed that the Hcy level was positively correlated with the occurrence of HUA in the case of Hcy<20 μmol/L (OR=1.05,95%CI=1.04-1.07,P<0.001).In the case of Hcy ≥ 20 μmol/L,there was no correlation between Hcy level and HUA (OR=1.00,95%CI=0.99-1.00,P=0.055),and the likelihood ratio test showed statistically significant results (P<0.001).Conclusion The elderly with hypertension should pay attention to control the Hcy level,which will be helpful to prevent the occurrence of HUA.
Humans ; Aged ; Hyperuricemia/complications* ; Hyperhomocysteinemia/epidemiology* ; Uric Acid ; Hypertension ; Homocysteine ; Risk Factors

OBJECTIVES: Hyperhomocysteinaemia (Hcy) is an independent risk factor for cardiovascular and cerebrovascular diseases. MicroRNA (miR)-18a-5p is closely related to cardiovascular diseases. This study aims to investigate the effects of miR-18a-5p on homocysteine (Hcy)-induced myocardial cells injury. METHODS: H9c2 cells were transfected with miR-18a-5p mimic/miR-18a-5p mimic negative control (NC) or combined with Hcy for intervention, and untreated cells were set as a control group. The transfection efficiency was verified by real-time RT-PCR, and cell counting kit-8 (CCK-8) assay was used to determine cell viability. Flow cytometry was used to detect apoptosis and reactive oxygen species (ROS) levels. Western blotting was performed to measure the protein levels of microtubule-associated protein 1 light chain 3 (LC3)-I, LC3-II, Beclin1, p62, Bax, Bcl-2, and Notch2. Dual luciferase reporter assay was used to detect the interaction of miR-18a-5p with Notch2. RESULTS: Compared with the control, treatment with Hcy or transfection with miR-18a-5p mimic alone, or combined treatment with Hcy and miR-18a-5p mimic/miR-18a-5p mimic NC significantly reduced the H9c2 cell viability, promoted apoptosis and ROS production, up-regulated the expressions of Bax and Beclin, down-regulated the expressions of Bcl-2, p62, and Notch2, and increased the ratio of LC3-II/LC3-I (all P<0.05). Compared with the combined intervention of miR-18a-5p mimic NC and Hcy group, the above indexes were more significantly changed in the combined intervention of miR-18a-5p mimic and Hcy group, and the difference between the 2 groups was statistically significant (all P<0.05). There is a targeted binding between Notch2 and miR-18a-5p. CONCLUSIONS MiR-18a-5p could induce autophagy and apoptosis via increasing ROS production in cardiomyocytes, and aggravate Hcy-induced myocardial injury. Notch2 is a target of miR-18a-5p.
Apoptosis/genetics* ; Autophagy/genetics* ; bcl-2-Associated X Protein ; MicroRNAs/metabolism* ; Proto-Oncogene Proteins c-bcl-2/genetics* ; Reactive Oxygen Species ; Rats ; Animals ; Myocytes, Cardiac/drug effects* ; Homocysteine/adverse effects* ; Hyperhomocysteinemia

Chronic stress is generally accepted as the main risk factor in the development of cognitive decline; however, the underlying mechanisms remain unclear. Previous data have demonstrated that the levels of homocysteine (Hcy) are significantly elevated in the plasma of stressed animals, which suggests that Hcy is associated with stress and cognitive decline. To test this hypothesis, we analyzed the cognitive function, plasma concentrations of Hcy, and brain-derived neurotropic factor (BDNF) levels in rats undergoing chronic unpredicted mild stress (CUMS). The results showed that decreased cognitive behavioral performance and decreased BDNF transcription and protein expression were correlated with hyperhomocysteinemia (HHcy) levels in stressed rats. Diet-induced HHcy mimicked the cognitive decline and BDNF downregulation in the same manner as CUMS, while Hcy reduction (by means of vitamin B complex supplements) alleviated the cognitive deficits and BDNF reduction in CUMS rats. Furthermore, we also found that both stress and HHcy disturbed the DNA methylation process in the brain and induced DNA hypermethylation in the BDNF promoter. In contrast, control of Hcy blocked BDNF promoter methylation and upregulated BDNF levels in the brain. These results imply the possibility of a causal role of Hcy in stress-induced cognitive decline. We also used ten-eleven translocation (TET1), an enzyme that induces DNA demethylation, to verify the involvement of Hcy and DNA methylation in the regulation of BDNF expression and the development of stress-related cognitive decline. The data showed that TET1-expressing viral injection into the hippocampus inhibited BDNF promoter methylation and significantly mitigated the cognitive decline in HHcy rats. Taken together, novel evidence from the present study suggests that Hcy is likely involved in chronic stress-induced BDNF reduction and related cognitive deficits. In addition, the negative side-effects of HHcy may be associated with Hcy-induced DNA hypermethylation in the BDNF promoter. The results also suggest the possibility of Hcy as a target for therapy and the potential value of vitamin B intake in preventing stress-induced cognitive decline.
Animals ; Brain-Derived Neurotrophic Factor/metabolism* ; Cognitive Dysfunction/complications* ; DNA Methylation ; Homocysteine/metabolism* ; Hyperhomocysteinemia/metabolism* ; Rats ; Stress, Psychological/physiopathology*

Objective: To investigate the clinical phenotypes and genotypic spectrum of exocrine pancreatic insufficiency in children with cystic fibrosis. Methods: This was a retrospective analysis of 12 children with cystic fibrosis who presented to Children's Hospital of Fudan University from December 2017 to December 2021. Clinical features, fecal elastase-1 level, genotype, diagnosis and treatment were systematically reviewed. Results: A total of 12 children, 7 males and 5 females, diagnosis aged 5.4 (2.0, 10.6) years, were recruited. Common clinical features included chronic cough in 12 cases, malnutrition in 7 cases, steatorrhea in 7 cases, bronchiectasis in 5 cases and electrolyte disturbance in 4 cases. Exocrine pancreatic insufficiency were diagnosed in 8 cases,the main clinical manifestations were steatorrhea in 7 cases, of which 5 cases started in infancy; 6 cases were complicated with malnutrition, including mild in 1 case, moderate in 2 cases and severe in 3 cases; 3 cases had abdominal distension; 2 cases had intermittent abdominal pain; 4 cases showed fatty infiltration or atrophy of pancreas and 3 cases showed no obvious abnormality by pancreatic magnetic resonance imaging or B-ultrasound. All 8 children were given pancreatic enzyme replacement therapy, follow-up visit of 2.3 (1.2,3.2) years. Diarrhea significantly improved in 6 cases, and 1 case was added omeprazole due to poor efficacy. A total of 20 variations of CFTR were detected in this study, of which 7 were novel (c.1373G>A,c.1810A>C,c.270delA,c.2475_2478dupCGAA,c.2489_c.2490insA, c.884delT and exon 1 deletion). Conclusions: There is a high proportion of exocrine pancreatic insufficiency in Chinese patients with cystic fibrosis. The main clinical manifestations are steatorrhea and malnutrition. Steatorrhea has often started from infancy. Pancreatic enzyme replacement therapy can significantly improve the symptoms of diarrhea and malnutrition.
Cystic Fibrosis/genetics* ; Diarrhea/complications* ; Exocrine Pancreatic Insufficiency/genetics* ; Female ; Genotype ; Humans ; Male ; Malnutrition/complications* ; Pancreatic Diseases/genetics* ; Phenotype ; Retrospective Studies ; Steatorrhea/genetics*

Child ; Humans ; Malabsorption Syndromes ; Gastritis