Deoxynivalenol leads to endoplasmic reticulum stress-mediated apoptosis via the IRE1/JNK/CHOP pathways in porcine embryos

The cytotoxic mycotoxin deoxynivalenol (DON) reportedly has adverse effects on oocyte maturation and embryonic development in pigs. Recently, the interplay between cell apoptosis and endoplasmic reticulum (ER) stress has garnered increasing attention in embryogenesis. However, the involvement of the inositol-requiring enzyme 1 (IRE1)/c-jun N-terminal kinase (JNK)/C/EBP homologous protein (CHOP) pathways of unfolded protein response (UPR) signaling in DON-induced apoptosis in porcine embryos remains unknown. In this study, we revealed that exposure to DON (0.25 μM) substantially decreased cell viability until the blastocyst stage in porcine embryos, concomitant with initiation of cell apoptosis through the IRE1/JNK/CHOP pathways in response to ER stress. Quantitative PCR confirmed that UPR signaling-related transcription factors were upregulated in DON-treated porcine blastocysts. Western blot analysis showed that IRE1/JNK/CHOP signaling was activated in DON-exposed porcine embryos, indicating that ER stress-associated apoptosis was instigated. The ER stress inhibitor tauroursodeoxycholic acid protected against DON-induced ER stress in porcine embryos, indicating that the toxic effects of DON on early developmental competence of porcine embryos can be prevented. In conclusion, DON exposure impairs the developmental ability of porcine embryos by inducing ER stress-mediated apoptosis via IRE1/JNK/CHOP signaling.

Tauroursodeoxycholic acid liposome alleviates DSS-induced ulcerative colitis through restoring intestinal barrier and gut microbiota

Ulcerative colitis (UC) is a chronic and progressive inflammatory disease that damages the colonic mucosa and disrupts the intestinal epithelial barrier. The current clinical treatment for UC is mainly chemotherapy, which has the limited effectiveness and severe side effects. It mainly focuses on the treatment of inflammation while neglecting the repair of the intestinal mucosa and the restoration of the microbiota balance. Here, we aimed to address these challenges by using an amphipathic bile acid -tauroursodeoxycholic acid (TUDCA) to replace cholesterol (CHL) in conventional liposomes. We prepared TUDCA/Emodin liposomes by incorporating the hydrophobic drug emodin. The experimental results indicated that TUDCA/Emodin Lip had uniform particle size distribution, good stability, low cytotoxicity, and exhibited good mucus permeability and anti-inflammatory activity in in vitro experiments, and was able to protect cells from oxidative stress. After oral administration, TUDCA/Emodin Lip significantly alleviated the severity of UC. This was evidenced by increased colon length, decreased inflammation and reduced colonic endoplasmic reticulum stress (ERS). Furthermore, TUDCA/Emodin Lip maintained the normal levels of the tight junction proteins Claudin-1 and ZO-1, thereby restoring the integrity of the intestinal barrier. Importantly, TUDCA/Emodin Lip also promoted the ecological restoration of the gut microbiota, increased overall abundance and diversity. Taken together, TUDCA/Emodin Lip can fundamentally restore intestinal homeostasis, this work provides a new, efficient and easily transformable treatment for UC.

Separation of bile acid isomer plays a pivotal role in bioequivalence evaluation of ursodeoxycholic acid

Based on our experiences in bile acid profiling, this work developed and validated a liquid chromatography electrospray ionization tandem mass spectrometry method to separate endogenous bile acid isomers and quantitatively determine ursodeoxycholic acid (UDCA), glycoursodeoxycholic acid (GUDCA) and tauroursodeoxycholic acid (TUDCA) in human plasma. The separation was performed on a CORTECS C18 column with the mobile phase consisting of 1.0 mM ammonium acetate and acetonitrile-methanol (80:20, v/v). UDCA, GUDCA and TUDCA were detected in the negative mode on a triple-quadrupole mass spectrometer at the ion transitions of m/z 391 > 391, m/z 448 > 74, m/z 498 > 80, respectively. Phosphate buffer was employed as the surrogate matrix to establish the isotope internal standard corrected calibration curves of analytes. The background-method with a linearity range of 10-200 ng/mL was partially validated to determine the endogenous levels of analytes in blank human plasma, which was incorporated into the validation of bioequivalence-method with a linearity range of 50-10000 ng/mL. The bioequivalence (BE)-method was fully validated with special focus on matrix effects, which have been critically evaluated using the precision and accuracy of quality control samples prepared from the blank human plasma of 12 individuals. It is disclosed for the first time that the BE results of UDCA formulation may yield false results when the method is insufficient to separate UDCA from isoursodeoxycholic acid, a microbial metabolite of both endogenous and exogenous UDCA. The present method has established a milestone for the evaluation of UDCA formulations and is expected to provide a valuable reference for the bioanalytical development of endogenous medicinal products.

ER stress modulated Klotho restoration: A prophylactic therapeutic strategy against acute kidney injury-diabetes comorbidity

Klotho is a renoprotective factor that is at the forefront of research as a potential therapeutic agent and biomarker of acute kidney injury (AKI). Endoplasmic reticulum (ER) stress and Klotho downregulation are the critical hallmarks of AKI progression. Importantly, the crosstalk between ER and Klotho is still elusive in AKI under diabetic condition. Therefore, this study aimed to elucidate the affiliation between ER stress and Klotho regulation by using the ischemia-reperfusion renal injury (IRI) model based on male Wistar rats and the hypoxia-reperfusion injury (HRI) using NRK52E cells. Study outcomes demonstrated that the expression of AKI biomarkers: plasma creatinine, neutrophil gelatinase-associated lipocalin, kidney-injury molecule 1, and ER stress markers such as binding immunoglobulin binding protein (BiP), R/PKR-like ER kinase (PERK), and eukaryotic initiation factor-2 (eIF2α), were observed during AKI. Increased ER stress was associated with apoptosis induction as depicted by increased levels of Poly (ADP-ribose) polymerase (PARP) and caspase-7 and decreased tubular Klotho expression. Under diabetic settings, ER stress and apoptosis were exacerbated by additional Klotho downregulation. Treatment with Tauroursodeoxycholic acid (TUDCA) inhibited the ER stress, apoptosis, restored endogenous Klotho levels and ameliorated AKI under diabetic and non-diabetic conditions. ER stress and Klotho appear to be shared factors involved in the pathogenesis of AKI-diabetes comorbidity and targeting them could prove a novel therapeutic approach.

Effect of tauroursodeoxycholic acid on survival and safety in amyotrophic lateral sclerosis: a retrospective population-based cohort study

Background

Oral tauroursodeoxycholic acid (TUDCA) is a commercial drug currently tested in patients with amyotrophic lateral sclerosis (ALS) both singly and combined with sodium phenylbutyrate. This retrospective study aimed to investigate, in a real-world setting, whether TUDCA had an impact on the overall survival of patients with ALS who were treated with this drug compared to those patients who received standard care only.

Methods

This propensity score-matched study was conducted in the Emilia Romagna Region (Italy), which has had an ALS regional registry since 2009. Out of 627 patients with ALS diagnosed from January 1st, 2015 to June 30th, 2021 and recorded in the registry with available information on death/tracheostomy, 86 patients took TUDCA and were matched in a 1:2 ratio with patients who received only usual care according to age at onset, sex, phenotype, diagnostic latency, ALS Functional Rating Scale-Revised (ALSFRS-R) at first visit, disease progression rate at first visit, and BMI at diagnosis. The primary outcome was survival difference (time from onset of symptoms to tracheostomy/death) between TUDCA exposed and unexposed patients.

Findings

A total of 86 patients treated with TUDCA were matched to 172 patients who did not receive treatment. TUDCA-exposed patients were stratified based on dosage (less than or equal to 1000 mg/day or greater) and duration (less than or equal to 12 months or longer) of treatment. The median overall survival was 49.6 months (95% CI 41.7-93.5) among those treated with TUDCA and 36.2 months (95% CI 32.7-41.6) in the control group, with a reduced risk of death observed in patients exposed to a higher dosage (defined as ≥ 1000 mg/day) of TUDCA (HR 0.56; 95% CI 0.38-0.83; p = 0.0042) compared to both the control group and those with lower TUDCA dosages (defined as < 1000 mg/day). TUDCA was generally well-tolerated, except for a minority of patients (n = 7, 8.1%) who discontinued treatment due to side effects, primarily gastrointestinal and mild in severity; only 2 adverse events required hospital access but resolved without sequelae.

Interpretation

In this population-based exploratory study, patients with ALS who were treated with TUDCA may have prolonged survival compared to patients receiving standard care only. Additional prospective randomized studies are needed to confirm the efficacy and safety of this drug.

Funding

Emilia-Romagna Region.

Neuroprotective Effect of Tauroursodeoxycholic Acid (TUDCA) on In Vitro and In Vivo Models of Retinal Disorders: A Systematic Review

BACKGROUND

Tauroursodeoxycholic acid (TUDCA) is a naturally produced hydrophilic bile acid that has been used for centuries in Chinese medicine. Numerous recent in vitro and in vivo studies have shown that TUDCA has neuroprotective action in various models of retinal disorders.

OBJECTIVE

To systematically review the scientific literature and provide a comprehensive summary on the neuroprotective action and the mechanisms involved in the cytoprotective effects of TUDCA.

METHODS

A systematic review was conducted in accordance with the PRISMA (The Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Systematic literature search of United States National Library of Medicine (PubMed), Web of Science, Embase, Scopus and Cochrane Library was performed, which covered all original articles published up to July 2022. The terms, "TUDCA" in combination with "retina", "retinal protection", "neuroprotection" were searched. Possible biases were identified with the adopted SYRCLE's tool.

RESULTS

Of the 423 initially gathered studies, 24 articles met inclusion/exclusion criteria for full-text review. Six of them were in vitro experiments, 17 studies reported in vivo data and one study described both in vitro and in vivo data. The results revealed the effect of TUDCA on different retinal diseases, such as retinitis pigmentosa (RP), diabetic retinopathy (DR), retinal degeneration (RD), retinal gangli on cell (RGC) damage, Leber's hereditary optic neuropathy (LHON), choroidal neovascularization (CNV), and retinal detachment (RDT). The quality scores of the in vivo studies were ranged from 5 to 7 points (total 10 points), according to SYRCLE's risk of bias tool. Both in vitro and in vivo data suggested that TUDCA could effectively delay degeneration and apoptosis of retinal neurons, preserve retinal structure and function, and its mechanism of actions might be related with inhibiting apoptosis, decreasing inflammation, attenuating oxidative stress, suppressing endoplasmic reticulum(ES) stress, and reducing angiogenesis.

CONCLUSION

This systematic review demonstrated that TUDCA has neuroprotective effect on in vivo and in vitro models of retinal disorders, reinforcing the currently available evidence that TUDCA could be a promising therapeutic agent in retinal diseases treatment. However, well designed clinical trials are necessary to appraise the efficacy of TUDCA in clinical setting.

Effects of Tauroursodeoxycholic Acid and 4-Phenylbutyric Acid on Selenium Distribution in Mice Model with Type 1 Diabetes

The effect of selenium on diabetes is significant. As pharmaceutical chaperones, tauroursodeoxycholic acid (TUDCA) and 4-phenylbutyric acid (4-PBA) can effectively improve the oxidative stress of the endoplasmic reticulum. This study established a mice model with type 1 diabetes (T1D) to evaluate the effects of pharmaceutical chaperones on selenium distribution. Streptozotocin was used to induce Friend virus B-type mice to establish a T1D mice model. Mice were administered with TUDCA or 4-PBA. Selenium levels in different tissues were measured by inductively coupled plasma-mass spectroscopy (ICP-MS). After treatment with TUDCA and 4-PBA, related laboratory findings such as glucose and glycated serum protein were significantly reduced and were closer to normal levels. At 2 weeks, 4-PBA normalized selenium levels in the heart, and 4-PBA and TUDCA maintained the selenium in the liver, kidney, and muscle at normal. At 2 months, 4-PBA and TUDCA maintained the selenium in the heart, liver, and kidney at normal levels. The serum selenium had a positive correlation with zinc and copper in the diabetes group and the control group, while the serum selenium had no significant association with magnesium and calcium at 2 weeks and 2 months. TUDCA and 4-PBA have crucial effects on selenium distribution in diabetic mice, and further research is needed to research their internal mechanisms.

Potential therapeutic action of Tauroursodeoxycholic acid against cholestatic liver injury via hepatic Fxr/Nrf2 and CHOP-DR5-caspase-8 pathway

Cholestasis is a pathophysiologic syndrome with limited therapeutic options. Tauroursodeoxycholic acid (TUDCA) has been employed to treat hepatobiliary disorders and is as effective as UDCA in alleviating cholestatic liver disease in clinical trials. Until now, TUDCA's mechanism of action towards cholestasis remains unclear. In this study, cholestasis was induced with a cholic acid (CA)-supplemented diet or alpha-naphthyl isothiocyanate (ANIT) gavage in wild-type and Farnesoid X Receptor (FXR) deficient mice, using obeticholic acid (OCA) as control. The effects of TUDCA on liver histological changes, transaminase level, bile acid composition, hepatocyte death, expression of Fxr and Nuclear factor erythroid 2-related factor 2 (Nrf2) and target genes, as well as apoptotic signaling pathways, were investigated. Treating CA-fed mice with TUDCA markedly alleviated liver injury, attenuated bile acids retention in liver and plasma, increased Fxr and Nrf2 nuclear levels and modulated the expression of targets regulating synthesis and transportation of bile acids, including BSEP, MRP2, NTCP and CYP7A1. TUDCA, but not OCA, activated Nrf2 signaling and exerted protective effects against cholestatic liver injury in Fxr-/- mice fed with CA. Furthermore, in both mice with CA- and ANIT-induced cholestasis, TUDCA decreased expression of GRP78 and CCAAT/enhancer-binding protein homologous protein (CHOP); reduced Death Receptor 5 (DR5) transcription, caspase-8 activation, and BID cleavage; and subsequently inhibited activation of executioner caspases and apoptosis in liver. We confirmed that TUDCA protected against cholestatic liver injury by alleviating BAs burden of dually activating hepatic Fxr and Nrf2. Moreover, inhibiting CHOP-DR5-caspase-8 pathway contributed to the anti-apoptotic effect of TUDCA in cholestasis.

Tauroursodeoxycholic acid functions as a critical effector mediating insulin sensitization of metformin in obese mice

Metformin is widely used to surmount insulin resistance (IR) and type 2 diabetes. Accumulating evidence suggests that metformin may improve IR through regulating gut microbiota and bile acids. However, the underlying mechanisms remain unclear. Our metabolomic analysis showed that metformin significantly increased the accumulation of tauroursodeoxycholic acid (TUDCA) in intestine and liver from high-fat diet (HFD)-induced IR mice. TUDCA also alleviated IR, and reduced oxidative stress and intestinal inflammation in ob/ob mice. TUDCA blocked KEAP1 to bind with Nrf2, resulting in Nrf2 translocation into nuclear and initiating the transcription of antioxidant genes, which eventually reduced intracellular ROS accumulation and improved insulin signaling. Analysis of gut microbiota further revealed that metformin reduced the relative abundance of Bifidobacterium, which produces bile salt hydrolase (BSH). The reduction in BSH was probably crucial for the accumulation of TUDCA. Metformin also increased the proportion of Akkermanisia muciniphlia in gut microbiota of ob/ob mice via TUDCA. These beneficial effects of metformin in remodeling gut microbiota, reducing oxidative stress and improving insulin sensitivity were partly due to the accumulation of TUDCA, suggesting that TUDCA may be a potential therapy for metabolic syndrome.

Tauroursodeoxycholic acid: a potential therapeutic tool in neurodegenerative diseases

Most neurodegenerative disorders are diseases of protein homeostasis, with misfolded aggregates accumulating. The neurodegenerative process is mediated by numerous metabolic pathways, most of which lead to apoptosis. In recent years, hydrophilic bile acids, particularly tauroursodeoxycholic acid (TUDCA), have shown important anti-apoptotic and neuroprotective activities, with numerous experimental and clinical evidence suggesting their possible therapeutic use as disease-modifiers in neurodegenerative diseases. Experimental evidence on the mechanisms underlying TUDCA's neuroprotective action derives from animal models of Alzheimer's disease, Parkinson's disease, Huntington's diseases, amyotrophic lateral sclerosis (ALS) and cerebral ischemia. Preclinical studies indicate that TUDCA exerts its effects not only by regulating and inhibiting the apoptotic cascade, but also by reducing oxidative stress, protecting the mitochondria, producing an anti-neuroinflammatory action, and acting as a chemical chaperone to maintain the stability and correct folding of proteins. Furthermore, data from phase II clinical trials have shown TUDCA to be safe and a potential disease-modifier in ALS. ALS is the first neurodegenerative disease being treated with hydrophilic bile acids. While further clinical evidence is being accumulated for the other diseases, TUDCA stands as a promising treatment for neurodegenerative diseases.

A green strategy to produce potential substitute resource for bear bile using engineered Saccharomyces cerevisiae

BACKGROUND

Bear bile powder is a precious natural material characterized by high content of tauroursodeoxycholic acid (TUDCA) at a ratio of 1.00-1.50 to taurochenodeoxycholic acid (TCDCA).

RESULTS

In this study, we use the crude enzymes from engineered Saccharomyces cerevisiae to directionally convert TCDCA from chicken bile powder to TUDCA at the committed ratio in vitro. This S. cerevisiae strain was modified with heterologous 7α-hydroxysteroid dehydrogenase (7α-HSDH) and 7β-hydroxysteroid dehydrogenase (7β-HSDH) genes. S. cerevisiae host and HSDH gene combinatorial optimization and response surface methodology was applied to get the best engineered strain and the optimal biotransformation condition, respectively, under which 10.99 ± 0.16 g/L of powder products containing 36.73 ± 6.68% of TUDCA and 28.22 ± 6.05% of TCDCA were obtained using 12.00 g/L of chicken bile powder as substrate.

CONCLUSION

This study provides a healthy and environmentally friendly way to produce potential alternative resource for bear bile powder from cheap and readily available chicken bile powder, and also gives a reference for the green manufacturing of other rare and endangered animal-derived valuable resource.

From dried bear bile to molecular investigation: A systematic review of the effect of bile acids on cell apoptosis, oxidative stress and inflammation in the brain, across pre-clinical models of neurological, neurodegenerative and neuropsychiatric disorders

Bile acids, mainly ursodeoxycholic acid (UDCA) and its conjugated species glycoursodeoxycholic acid (GUDCA) and tauroursodeoxycholic acid (TUDCA) have long been known to have anti-apoptotic, anti-oxidant and anti-inflammatory properties. Due to their beneficial actions, recent studies have started to investigate the effect of UDCA, GUDCA, TUDCA on the same mechanisms in pre-clinical models of neurological, neurodegenerative and neuropsychiatric disorders, where increased cell apoptosis, oxidative stress and inflammation in the brain are often observed. A total of thirty-five pre-clinical studies were identified through PubMed/Medline, Web of Science, Embase, PsychInfo, and CINAHL databases, investigating the role of the UDCA, GUDCA and TUDCA in the regulation of brain apoptosis, oxidative stress and inflammation, in pre-clinical models of neurological, neurodegenerative and neuropsychiatric disorders. Findings show that UDCA reduces apoptosis, reactive oxygen species (ROS) and tumour necrosis factor (TNF)-α production in neurodegenerative models, and reduces nitric oxide (NO) and interleukin (IL)-1β production in neuropsychiatric models; GUDCA decreases lactate dehydrogenase, TNF-α and IL-1β production in neurological models, and also reduces cytochrome c peroxidase production in neurodegenerative models; TUDCA decreases apoptosis in neurological models, reduces ROS and IL-1β production in neurodegenerative models, and decreases apoptosis and TNF-α production, and increases glutathione production in neuropsychiatric models. In addition, findings suggest that all the three bile acids would be equally beneficial in models of Huntington's disease, whereas UDCA and TUDCA would be more beneficial in models of Parkinson's disease and Alzheimer's disease, while GUDCA in models of bilirubin encephalopathy and TUDCA in models of depression. Overall, this review confirms the therapeutic potential of UDCA, GUDCA and TUDCA in neurological, neurodegenerative and neuropsychiatric disorders, proposing bile acids as potential alternative therapeutic approaches for patients suffering from these disorders.

Effects of tauroursodeoxycholic acid on glucose homeostasis: Potential binding of this bile acid with the insulin receptor

AIMS

The bile acid (BA), tauroursodeoxycholic acid (TUDCA) regulates glucose homeostasis; however, it is not clear whether its effects on insulin signaling are due to its direct interaction with the insulin receptor (IR) or through activation of the G-coupled BA receptor, TGR5. We, herein, investigated whether the actions of TUDCA on glucose homeostasis occur via IR or TGR5 activation.

MAIN METHODS

Glucose homeostasis was evaluated in high-fat diet (HFD)-obese or control (CTL) mice, after 30 days or one intraperitoneal (ip) injection of 300 mg/kg TUDCA, respectively. Molecular docking was performed to investigate the potential binding of TUDCA on the IR and TGR5.

KEY FINDINGS

After 30 days of TUDCA treatment, HFD mice exhibited improvements in glucose tolerance and insulin sensitivity, which were abolished when these rodents received the IR antagonist, S961. Molecular docking experiments showed that TUDCA demonstrates high binding affinity for TGR5 and IR and strongly interacts with the insulin binding sites 1 and 2 of the IR. Consistent with this potential agonist activity of TUDCA on IR, CTL mice displayed increased hepatic phosphorylation of AKT after an ip injection of TUDCA. This effect was not associated with altered glycemia in CTL mice and was dependent on IR activation, as S961 prevented hepatic AKT activation by TUDCA. Furthermore, TUDCA activated the hepatic protein kinase A (PKA) and cAMP response element-binding protein (CREB) pathway in CTL mice, even after the administration of S961.

SIGNIFICANCE

We provide novel evidence that TUDCA may be an agonist of the IR, in turn activating AKT and contributing, at least in part, to its beneficial effects upon glucose homeostasis.

Tauroursodeoxycholic acid alleviates secondary injury in spinal cord injury mice by reducing oxidative stress, apoptosis, and inflammatory response

Background

Tauroursodeoxycholic acid (TUDCA) is a hydrophilic bile acid derivative, which has been demonstrated to have neuroprotective effects in different neurological disease models. However, the effect and underlying mechanism of TUDCA on spinal cord injury (SCI) have not been fully elucidated. This study aims to investigate the protective effects of TUDCA in the SCI mouse model and the related mechanism involved.

Methods

The primary cortical neurons were isolated from E16.5 C57BL/6 mouse embryos. To evaluate the effect of TUDCA on axon degeneration induced by oxidative stress in vitro, the cortical neurons were treated with H₂O₂ with or without TUDCA added and immunostained with Tuj1. Mice were randomly divided into sham, SCI, and SCI+TUDCA groups. SCI model was induced using a pneumatic impact device at T9-T10 level of the vertebra. TUDCA (200 mg/kg) or an equal volume of saline was intragastrically administrated daily post-injury for 14 days.

Results

We found that TUDCA attenuated axon degeneration induced by H₂O₂ treatment and protected primary cortical neurons from oxidative stress in vitro. In vivo, TUDCA treatment significantly reduced tissue injury, oxidative stress, inflammatory response, and apoptosis and promoted axon regeneration and remyelination in the lesion site of the spinal cord of SCI mice. The functional recovery test revealed that TUDCA treatment significantly ameliorated the recovery of limb function.

Conclusions

TUDCA treatment can alleviate secondary injury and promote functional recovery by reducing oxidative stress, inflammatory response, and apoptosis induced by primary injury, and promote axon regeneration and remyelination, which could be used as a potential therapy for human SCI recovery.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-021-02248-2.

Administration of tauroursodeoxycholic acid attenuates dexamethasone-induced skeletal muscle atrophy

Glucocorticoids are known to induce skeletal muscle atrophy by suppressing protein synthesis and promoting protein degradation. Tauroursodeoxycholic acid (TUDCA) has beneficial effects in several diseases, such as hepatobiliary disorders, hindlimb ischemia and glucocorticoid-induced osteoporosis. However, the effects of TUDCA on glucocorticoid -induced skeletal muscle atrophy remains unknown. Therefore, in the present research, we explored the effects of TUDCA on dexamethasone (DEX)-induced loss and the potential mechanisms involved. We found TUDCA alleviated DEX-induced muscle wasting in C2C12 myotubes, identified by improved myotube differentiation index and expression of myogenin and MHC. And it showed that TUDCA activated the Akt/mTOR/S6K signaling pathway and inhibited FoxO3a transcriptional activity to decreased expression of MuRF1 and Atrogin-1, while blocking Akt by MK2206 blocked these effects of TUDCA on myotubes. Besides, TUDCA also attenuated DEX-induced apoptosis of myotubes. Furthermore, TUDCA was administrated to the mouse model of DEX-induced skeletal muscle atrophy. The results showed that TUDCA improved DEX-induced skeletal muscle atrophy and weakness (identified by increased grip strength and prolonged running exhaustive time) in mice by suppression of apoptosis, reduction of protein degradation and promotion of protein synthesis. Taken together, our research proved for the first time that TUDCA protected against DEX-induced skeletal muscle atrophy not only by improving myogenic differentiation and protein synthesis, but also through decreasing protein degradation and apoptosis of skeletal muscle.

Tauroursodeoxycholic acid alleviates pulmonary endoplasmic reticulum stress and epithelial-mesenchymal transition in bleomycin-induced lung fibrosis

Background

Several studies demonstrate that endoplasmic reticulum (ER) stress-mediated epithelial-mesenchymal transition (EMT) is involved in the process of bleomycin (BLM)-induced pulmonary fibrosis. Tauroursodeoxycholic acid (TUDCA), a bile acid with chaperone properties, is an inhibitor of ER stress. This study aimed to investigate the preventive effects of TUDCA on BLM-induced EMT and lung fibrosis.

Methods

The model of lung fibrosis was established by intratracheal injection with a single dose of BLM (3.0 mg/kg). In TUDCA + BLM group, mice were intraperitoneally injected with TUDCA (250 mg/kg) daily.

Results

BLM-induced alveolar septal destruction and inflammatory cell infiltration were alleviated by TUDCA. BLM-induced interstitial collagen deposition, as determined by Sirius Red staining, was attenuated by TUDCA. BLM-induced elevation of pulmonary α-smooth muscle actin (α-SMA) and reduction of pulmonary E-cadherin were attenuated by TUDCA. BLM-induced pulmonary Smad2/3 phosphorylation was suppressed by TUDCA. BLM-induced elevation of Ki67 and PCNA was inhibited by TUDCA in mice lungs. In addition, BLM-induced elevation of HO-1 (heme oxygenase-1) and 3-NT (3-nitrotyrosine) was alleviated by TUDCA. Finally, BLM-induced upregulation of pulmonary GRP78 and CHOP was attenuated by TUDCA.

Conclusions

These results provide evidence that TUDCA pretreatment inhibits Smad2/3-medited EMT and subsequent lung fibrosis partially through suppressing BLM-induced ER stress and oxidative stress.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01514-6.

Tauroursodeoxycholic acid prevents Burkholderia pseudomallei-induced endoplasmic reticulum stress and is protective during melioidosis in mice

Background

Burkholderia pseudomallei, a facultative intracellular bacterium, is the aetiological agent of melioidosis that is responsible for up to 40% sepsis-related mortality in epidemic areas. However, no effective vaccine is available currently, and the drug resistance is also a major problem in the treatment of melioidosis. Therefore, finding new clinical treatment strategies in melioidosis is extremely urgent.

Results

We demonstrated that tauroursodeoxycholic acid (TUDCA), a clinically available endoplasmic reticulum (ER) stress inhibitor, can promote B. pseudomallei clearance both in vivo and in vitro. In this study, we investigated the effects of TUDCA on the survival of melioidosis mice, and found that treatment with TUDCA significantly decreased intracellular survival of B. pseudomallei. Mechanistically, we found that B. pseudomallei induced apoptosis and activated IRE1 and PERK signaling ways of ER stress in RAW264.7 macrophages. TUDCA treatment could reduce B. pseudomallei-induced ER stress in vitro, and TUDCA is protective in vivo.

Conclusion

Taken together, our study has demonstrated that B. pseudomallei infection results in ER stress-induced apoptosis, and TUDCA enhances the clearance of B. pseudomallei by inhibiting ER stress-induced apoptosis both in vivo and in vitro, suggesting that TUDCA could be used as a potentially alternative treatment for melioidosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-021-02199-x.

Tauroursodeoxycholic acid attenuates cisplatin-induced ototoxicity by inhibiting the accumulation and aggregation of unfolded or misfolded proteins in the endoplasmic reticulum

Cisplatin-induced ototoxicity is one of the important reasons that limit the drug's clinical application, and its mechanism has not been fully elucidated so far. The aim of this study was to explore the attenuate effect of tauroursodeoxycholic acid (TUDCA), a proteostasis promoter, on cisplatin-induced ototoxicity in vivo and in vitro, and to explore its possible mechanism. Auditory brainstem response (ABR) was measured to identify the attenuate effects of TUDCA administered subcutaneously [500 mg/kg/d × 3d, cisplatin: 4.6 mg/kg/d × 3d, intraperitoneal injection (i.p.)] or trans-tympanically (0.5 mg/mL, cisplatin: 12 mg/kg, i.p. with a pump) in Sprague-Dawley (SD) rats subjected to cisplatin-induced hearing loss. The cochlear explants of neonatal rats and OC1 auditory hair cell-like cell lines cultured in vitro were used to observe the number of apoptotic cells and the endoplasmic reticulum (ER) stress in the control, cisplatin (5 μM for 48 h for cochlear explants, 10 μM for 24 h for OC1 cells), and cisplatin + TUDCA (1 mM for 24 h for cochlear explants, 1.6 mM for 24 h for OC1 cells) groups. Differences in the expression of key proteins in the ER protein quality control (ERQC) system were detected. The changes in the attenuate effect of TUDCA on cisplatin-induced ototoxicity after down-regulating calreticulin (CRT), UDP-glucose ceramide glucosyltransferase-like 1 (UGGT1), and OS9 ER lectin (OS9) were also measured. The effect of TUDCA (10 mM) on stabilizing unfolded or misfolded proteins (UFP/MFP) was analyzed in a cell-free 0.2 % bovine serum albumin (BSA) aggregation system in vitro. Both the subcutaneous and trans-tympanic TUDCA administration alleviated cisplatin-induced increase in ABR thresholds in rats. TUDCA was able to reduce cisplatin-induced apoptosis and alleviate ER stress in cochlear explants and OC1 cells. Under the cisplatin treatment, the expression levels of CRT, UGGT1, and OS9 in the auditory hair cell increased, and the expression of total ubiquitinated proteins decreased. TUDCA attenuated the effect of cisplatin on UGGT1 and OS9, and recovered the protein ubiquitination levels. After down-regulating CRT, UGGT1, or OS9, the protective effect of TUDCA decreased. In the cell-free experimental system, TUDCA inhibited the aggregation of denatured BSA molecules. In summary, TUDCA can attenuate cisplatin-induced ototoxicity, possibly by inhibiting the accumulation and aggregation of UFP/MFP and the associated ER stress.

Mechanism of tauroursodeoxycholic acid-mediated neuronal protection after acute spinal cord injury through AKT signaling pathway in rats

OBJECTIVE

To explore themechanism of tauroursodeoxycholic acid- (TUDCA) mediated neuronal protection after acute spinal cord injury (ASCI) in rats. Methods: ASCI rat model was established following modified Allen's weight-drop method and these rats were assigned to sham group (received sham operation), model group (ASCI rats), TUDCA group (ASCI rats received TUDCA treatment), MK2206 group (ASCI rats received AKT inhibitor MK2206 orally) and TUDCA + MK2206 group. Motor function of rats was evaluated using Basso Beattie Bresnahan (BBB) method. Hematoxylin-eosin (H&E) staining was used to detect histopathologic changes in the spinal cord and TUNEL fluorescence staining was used to check apoptosis. Real time fluorescence quantitative polymerase chain reaction (qRT-PCR) and western blot were employed to detect the production of AKT pathway related factors, apoptosis related factors (Bax, Bcl-2, caspase-3), autophagy related factor Beclin-1 and endoplasmic reticulum (ER) stress related factors (IRE1, Chop, ATF6) in spinal cord of rats.

RESULTS

Compared to the rats in the sham group, rats in ASCI group had decreased BBB scores (P<0.05), more significant tissue edema, structural cavity and apoptosis. Compared to rats in sham group, AKT pathway was inactivated in ASCI rats and was activated by TUDCA treatment (P<0.05). Compared to sham group, expressions of ER stress-related factors were increased, apoptosis was largely induced in other four groups, and expression of Beclin-1 was increased in the model group (P<0.05). TUDCA increased the expression of Beclin-1 and Bcl-2, and inhibited the expression of Bax, Caspase-3, and ER stress-related factors, thus suppressing apoptosis (P<0.05). Treatment by MK2206 had contrary effects and protective effects of TUDCA on ASCI rats could be counteracted by MK2206.

CONCLUSION

TUDCA can significantly improve the neural damage, enhance neuron autophagy, alleviate ER stress, and inhibit apoptosis in ASCI rats, by activating the AKT signaling pathway.

Injectable Hydrogel Containing Tauroursodeoxycholic Acid for Anti-neuroinflammatory Therapy After Spinal Cord Injury in Rats

We investigate the anti-inflammatory effects of injectable hydrogel containing tauroursodeoxycholic acid (TUDCA) in a spinal cord injury (SCI) model. To this end, TUDCA-hydrogel (TC gel) is created by immersing the synthesized hydrogel in a TUDCA solution for 1 h. A mechanical SCI was imposed on rats, after which we injected the TC gel. After the SCI and injections, motor functions and lesions were significantly improved in the TC gel group compared with those in the saline group. The TC gel significantly decreased pro-inflammatory cytokine levels compared with the saline; TUDCA and glycol chitosan-oxidized hyaluronate were mixed at a ratio of 9:1 (CHA) gel independently. In addition, the TC gel significantly suppressed the phosphorylation of extracellular signal-regulated kinase (p-ERK) and c-Jun N-terminal kinase (p-JNK) in the mitogen-activated protein kinase (MAPK) pathway compared with the saline, TUDCA, and CHA gel independently. It also decreased tumor necrosis factor-α (TNF-α) and glial fibrillary acidic protein (GFAP), inflammatory marker, at the injured sites more than those in the saline, TUDCA, and CHA gel groups. In conclusion, the results of this study demonstrate the neuroinflammatory inhibition effects of TC gel in SCI and suggest that TC gel can be an alternative drug system for SCI cases.

Tauroursodeoxycholic acid attenuates cisplatin-induced hearing loss in rats

Tauroursodeoxycholic acid (TUDCA) has been reported to be protective against apoptosis and oxidative stress in various cell types. A few studies have demonstrated otoprotective effects of TUDCA in mouse models. This study investigated the otoprotective effects of TUDCA in cisplatin (CXP)-induced hearing-loss rats. Eight-week-old female Sprague-Dawley rats were used. The CXP group received intraperitoneal injection of CXP at a dose of 5 mg/kg from day 1 to day 3. The CXP + TUDCA group received an intraperitoneal injection of 5 mg/kg CXP and 100 mg/kg TUDCA from day 1 to day 3. The mRNA expression levels of heme oxygenase 1 (HO1) and superoxide dismutase 2 (SOD2) were measured, and the protein levels of caspase 3, cleaved caspase 3, and aryl hydrocarbon receptor (AhR) were evaluated. The CXP group demonstrated higher mean auditory brainstem responses (ABR) thresholds than the control group. The mean ABR threshold shifts were lower in the CXP + TUDCA group than in the CXP group. The CXP group showed elevated HO1 and SOD2 mRNA expression levels compared to the control group, but these changes were reversed in the CXP + TUDCA group. Compared to the levels in the control group, caspase 3, cleaved caspase 3, and AhR levels were higher in the CXP group, but the increase in cleaved caspase-3 was attenuated in the CXP + TUDCA group. The cochlea showed a higher number of spiral ganglion cells and outer hair cells in the CXP + TUDCA group than in the CXP group. TUDCA reduced CXP-induced hearing loss in adult rats. The HO1-mediated antioxidative effects attenuated apoptosis in the cochlea, but AhR activation was not reversed.

Tauroursodeoxycholic acid induces angiogenic activity in endothelial cells and accelerates bone regeneration

Angiogenesis is a crucial process during bone tissue regeneration. The aim of this study was to investigate the angiogenic activity and the potentiation of bone regeneration via angiogenesis using tauroursodeoxycholic acid (TUDCA) in vitro and in vivo. We investigated the effect of TUDCA on proliferation and angiogenic differentiation in human umbilical vein endothelial cells (HUVECs) and the associated signaling pathway. Proliferation was determined using crystal violet assay. Angiogenic effects were evaluated based on cell migration and tube formation. In order to explore TUDCA-signaling pathways, phosphorylation of mitogen activated protein kinase, protein kinase B (AKT), and endothelial nitric oxide synthase (eNOS) was determined using western blot. Furthermore, in vivo bone formation and angiogenesis were determined using a New Zealand outbred albino rabbit calvarial defect model, while angiogenesis and bone formation were evaluated using micro-CT and histological analysis. Our results show that TUDCA significantly increased cell proliferation. Moreover, TUDCA enhanced cell migration and tube formation in HUVECs. TUDCA increased the phosphorylation of AKT, ERK1/2, c-Jun N-terminal kinase, and eNOS. Specific inhibitors of ERK1/2 (PD98059), JNK (SP600125), and AKT (AKT1/2) inhibited the TUDCA-induced migration and tube formation, while the p38 inhibitor (SB203580) did not. The in vivo study used TUDCA to accelerate new blood vessel formation and promoted bone formation in rabbit calvarial defect model. These results indicate that TUDCA plays a critical role in enhancing the angiogenesis of endothelial cells and in vivo new bone regeneration. The use of TUDCA may contribute to the regeneration of bone tissue by improving angiogenesis.

Tauroursodeoxycholic acid (TUDCA) enhanced intracytoplasmic sperm injection (ICSI) embryo developmental competence by ameliorating endoplasmic reticulum (ER) stress and inhibiting apoptosis

PURPOSE

The objective of this study was to examine the effect of tauroursodeoxycholic acid (TUDCA) on intracytoplasmic sperm injection (ICSI) embryos by evaluating endoplasmic reticulum (ER) stress, apoptosis, and embryo developmental competence in vitro and in vivo.

METHODS

ER stress-associated genes and apoptosis-associated genes were measured and apoptosis index was analyzed. Embryo developmental competence was assessed in vitro and in vivo via the inner cell mass (ICM)/trophectoderm (TE) index, pregnancy and implantation rates, and birth rate.

RESULTS

The relative mRNA and protein expression of binding immunoglobulin protein (BIP) was significantly higher in the ICSI embryo group without TUDCA treatment (ICSI-C) than in the in vitro fertilization (IVF) group and in the ICSI embryo group with TUDCA treatment (200 μM) (ICSI-T), while TUDCA ameliorated ER stress in ICSI embryos. Embryos in the ICSI-C group showed a higher apoptosis index than those in the IVF group and ICSI-T group, and there was no significant difference between the IVF group and ICSI-T group. TUDCA can significantly improve ICSI embryo developmental competence in vitro and in vivo based on the ICM/TE index, pregnancy and implantation rates, and birth rate.

CONCLUSION

ICSI embryos manifested high ER stress and high apoptosis, while TUDCA ameliorated ER stress and reduced apoptosis in ICSI embryos. TUDCA can significantly improve the developmental competence of ICSI embryos in vitro and in vivo. This study provides a new idea for improving the efficiency of ICSI, and it will also have a positive effect on the development of assisted reproduction technologies for humans and other animals.

Effect of 4-Phenylbutyric Acid and Tauroursodeoxycholic Acid on Magnesium and Calcium Metabolism in Streptozocin-Induced Type 1 Diabetic Mice

Recent evidence has identified a role of micronutrients, such as magnesium (Mg²⁺) and calcium (Ca²⁺), in glycemic control. 4-Phenylbutyric acid (PBA) and tauroursodeoxycholic acid (TUDCA) are molecular chaperones that can improve protein folding and alleviate endoplasmic reticulum (ER) stress. Increasingly, research is focusing on the association between molecular chaperones and micronutrients. This study established and characterized a mouse model of type 1 diabetes (T1D) and investigated the effect of PBA and TUDCA on Mg²⁺ and Ca²⁺ metabolism in these mice. T1D was established in Friend virus B-type mice using multiple low doses of streptozotocin. Mice were administered chaperones. Mg²⁺and Ca²⁺ levels in tissues and serum were detected using acid digestion and ICP-MS. At 2 weeks and 2 months after chaperone administration was initiated, Mg²⁺ levels in the heart, liver, kidney, and serum and Ca²⁺ levels in spleen and serum of T1D mice were significantly decreased compared with controls; Ca²⁺ levels in the kidney and muscle of T1D mice were significantly increased; Mg²⁺ and Ca²⁺ levels in the heart, liver, kidney, muscle, spleen, and serum were positively correlated in control and T1D mice; and PBA restored renal Mg²⁺ levels to normal values and TUDCA restored hepatic, renal, and serum Mg²⁺ levels and renal and serum Ca²⁺ levels to normal values in T1D mice. PBA restored muscular Ca²⁺ levels to normal values in T1D mice at 2 months after chaperone or vehicle administration was initiated. Further research is required to investigate the underlying mechanisms by which chaperones regulate micronutrients in diabetes.

Protective effects of tauroursodeoxycholic acid on lipopolysaccharide-induced cognitive impairment and neurotoxicity in mice

Accumulating evidence has shown that tauroursodeoxycholic acid (TUDCA) is neuroprotective in different animal models of neurological diseases. However, whether TGR5 agonist TUDCA can improve lipopolysaccharide (LPS)-induced cognitive impairment in mice is less clear. Using a model of cognitive impairment with LPS (2.0 μg) we investigated the effects of TUDCA (200 or 400 μg) on cognitive dysfunction and neurotoxicity in mice. Both Morris water maze and Y-maze avoidance tests showed that TUDCA treatment significantly alleviated LPS-induced behavioral impairments. More importantly, we found that TUDCA treatment reversed TGR5 down-regulation, prevented neuroinflammation via inhibiting NF-κB signaling in the hippocampus of LPS-treated mice. Additionally, TUDCA treatment decreased LPS-induced apoptosis through decreasing TUNEL-positive cells and the overexpression of caspase-3, increasing the ratio of Bcl-2/Bax. TUDCA treatment also ameliorated synaptic plasticity impairments by increasing the ratio of mBDNF/proBDNF, the number of dendritic spines and the expression of synapse-associated proteins in the hippocampus. Our results indicated that TUDCA can improve cognitive impairment and neurotoxicity induced by LPS in mice, which is involved in TGR5-mediated NF-κB signaling.

TUDCA-treated chronic kidney disease-derived hMSCs improve therapeutic efficacy in ischemic disease via PrPC

Although autologous human mesenchymal stem cells (hMSCs) are a promising source for regenerative stem cell therapy in chronic kidney disease (CKD), the barriers associated with pathophysiological conditions limit therapeutic applicability to patients. We confirmed that level of cellular prion protein (PrP^C) in serum was decreased and mitochondria function of CKD-derived hMSCs (CKD-hMSCs) was impaired in patients with CKD. We proved that treatment of CKD-hMSCs with tauroursodeoxycholic acid (TUDCA), a bile acid, enhanced the mitochondrial function of these cells through regulation of PINK1-PrP^C-dependent pathway. In a murine hindlimb ischemia model with CKD, tail vein injection of TUDCA-treated CKD-hMSCs improved the functional recovery, including kidney recovery, limb salvage, blood perfusion ratio, and vessel formation along with restored expression of PrP^C in the blood serum of the mice. These data suggest that TUDCA-treated CKD-hMSCs are a promising new autologous stem cell therapeutic intervention that dually treats cardiovascular problems and CKD in patients.

Tauroursodeoxycholic Acid Ameliorates Lipopolysaccharide-Induced Depression Like Behavior in Mice via the Inhibition of Neuroinflammation and Oxido-Nitrosative Stress

Depression is a mental disease that causes severe economic and social burdens. The mechanism for the onset of depression remains largely unknown. Recently, more and more attention is being given to the role of neuroinflammation and oxidative stress in depression. Tauroursodeoxycholic acid (TUDCA), a clinically available agent used to treat cholesterol gallstone and protect neurons against neurodegeneration, has been reported to prevent neuroinflammation and oxidative stress. In this study, we investigated the effect of TUDCA on lipopolysaccharide (LPS)-induced depression-like behavior, neuroinflammation, and oxido-nitrosative stress in mice. Results showed that TUDCA pretreatment (once daily for 7 consecutive days) at the dosage of 200 and 400 mg/kg, but not 100 mg/kg, markedly attenuated LPS (0.83 mg/kg)-induced behavioral abnormalities in the tail suspension test, forced swim test, and sucrose preference test. Further analysis showed that the TUDCA pretreatment (200, 400 mg/kg) not only inhibited the production of proinflammatory cytokines induced by LPS stimulation, such as interleukin-6 and tumor necrosis factor-α, but attenuated LPS-triggered oxido-nitrosative stress in the hippocampus and prefrontal cortex. Taken together, our results provide evidence to show that the TUDCA could be a potential antidepressant, and its antidepressive mechanism may be associated with the inhibition of the neuroinflammatory response and oxido-nitrosative stress in the brain.

Alleviation of endoplasmic reticulum stress by tauroursodeoxycholic acid delays senescence of mouse ovarian surface epithelium

Ovarian surface epithelium (OSE) forms a single layer of mostly cuboidal cells on surface of mammalian ovaries that is inherently exposed to cell stress evoked by tissue damage every ovulation and declines morphologically after menopause. Endoplasmic reticulum (ER) is a principal cell organelle involved in proteosynthesis, but also integrating various stress signals. ER stress evokes a conserved signaling pathway, the unfolded protein response (UPR), leading to cell death or adaptation to stress conditions. In this work, we document that mouse OSE suffers from ER stress during replicative senescence in vitro, develops abnormalities in ER and initiates UPR. Attenuation of ER stress in senescent OSE by tauroursodeoxycholic acid (TUDCA) reconditions ER architecture and leads to delayed onset of senescence. In summary, we show for the first time a mutual molecular link between ER stress response and replicative senescence leading to phenotypic changes of non-malignant ovarian surface epithelium.

Tauroursodeoxycholic acid alleviates secondary injury in the spinal cord via up-regulation of CIBZ gene

Spinal cord injury (SCI) is generally divided into primary and secondary injuries, and apoptosis is an important event of the secondary injury. As an endogenous bile acid and recognized endoplasmic reticulum (ER) stress inhibitor, tauroursodeoxycholic acid (TUDCA) administration has been reported to have a potentially therapeutic effect on neurodegenerative diseases, but its real mechanism is still unclear. In this study, we evaluated whether TUDCA could alleviate traumatic damage of the spinal cord and improve locomotion function in a mouse model of SCI. Traumatic SCI mice were intraperitoneally injected with TUDCA, and the effects were evaluated based on motor function assessment, histopathology, apoptosis detection, qRT-PCR, and western blot at different time periods. TUDCA administration can improve motor function and reduce secondary injury and lesion area after SCI. Furthermore, the apoptotic ratios were significantly reduced; Grp78, Erdj4, and CHOP were attenuated by the treatment. Unexpectedly, the levels of CIBZ, a novel therapeutic target for SCI, were specifically up-regulated. Taken together, it is suggested that TUDCA effectively suppressed ER stress through targeted up-regulation of CIBZ. This study also provides a new strategy for relieving secondary damage by inhibiting apoptosis in the early treatment of spinal cord injury.

Tauroursodeoxycholic acid attenuates gentamicin-induced cochlear hair cell death in vitro

Gentamycin is one of the most clinically used aminoglycoside antibiotics which induce intrinsic apoptosis of hair cells. Tauroursodeoxycholic acid (TUDCA) is known as safe cell-protective agent in disorders associated with apoptosis. We aimed to investigate the protective effects of TUDCA against gentamicin-induced ototoxicity. House Ear Institute-Organ of Corti 1(HEI-OC1) cells and explanted cochlear tissue were treated with gentamicin and TUDCA, followed by serial analyses including cell viability assay, hair cell staining, qPCR, ELISA and western blotting to determine the cell damage by the parameters relevant to cell apoptosis and endoplasmic reticulum stress. TUDCA significantly attenuated gentamicin-induced cell damage in cultured HEI-OC1 cells and explanted cochlear hair cells. TUDCA alleviated gentamicin-induced cell apoptosis, supported by the decreased Bax/Bcl2 ratio compared with that of gentamicin treated alone. TUDCA decreased gentamicin-induced nitric oxide production and protein nitration in both models. In addition, TUDCA suppressed gentamicin-induced endoplasmic reticulum stress as reflected by inversing the expression levels of Binding immunoglobulin protein (Bip), CCAAT/-enhancer-binding protein homologous protein (CHOP) and Caspase 3. TUDCA attenuated gentamicin-induced hair cell death by inhibiting protein nitration activation and ER stress, providing new insights into the new potential therapies for sensorineural deafness.

Clinical efficacy of tauroursodeoxycholic acid combined with S-adenosyl methionine in treatment of cholestasis in patients with compensated alcoholic cirrhosis

AIM

To observe the clinical effects of taursodeoxycholic acid combined with S-adenosyl methionine in the treatment of cholestasis in patients with compensated alcoholic cirrhosis.

METHODS

One hundred patients with compensated alcoholic cirrhosis treated at our hospital from January 2012 to January 2017 were randomly divided into an experimental group and a control group, with 50 cases in each group. Both groups of patients were given S-adenosyl methionine and hepatoprotective drugs, and the experimental group was additionally given tauroursodeoxycholic acid. After 12 wk of treatment, the changes of liver biochemical indicators [alkaline phosphatase (ALP), gamma glutamyl transaminase (GGT), and total bilirubin (TBIL)] and prothrombin activity (PTA) were detected to evaluate the therapeutic effect.

RESULTS

The total effective rate in the experimental group was significantly higher than that of the control group (92% vs 56%, P < 0.05). After treatment, ALP, GGT, and TBIL in both groups decreased significantly compared with pretreatment values (P < 0.05), and the thereapeutic effect in the experimental group was better than that in the control group (P < 0.05).

CONCLUSION

Tauroursodeoxycholic acid combined with S-adenosyl methionine is effective in treating cholestasis in patients with compensated alcoholic cirrhosis, and can effectively improve the clinical symptoms and biochemical indexes.

Targeting the enhanced ER stress response in Marinesco-Sjögren syndrome

BACKGROUND AND OBJECTIVE

Marinesco-Sjögren syndrome (MSS) is an autosomal recessive infantile-onset disorder characterized by cataracts, cerebellar ataxia, and progressive myopathy caused by mutation of SIL1. In mice, a defect in SIL1 causes endoplasmic reticulum (ER) chaperone dysfunction, leading to unfolded protein accumulation and increased ER stress. However, ER stress and the unfolded protein response (UPR) have not been investigated in MSS patient-derived cells.

METHODS

Lymphoblastoid cell lines (LCLs) were established from four MSS patients. Spontaneous and tunicamycin-induced ER stress and the UPR were investigated in MSS-LCLs. Expression of UPR markers was analyzed by western blotting. ER stress-induced apoptosis was analyzed by flow cytometry. The cytoprotective effects of ER stress modulators were also examined.

RESULTS

MSS-LCLs exhibited increased spontaneous ER stress and were highly susceptible to ER stress-induced apoptosis. The inositol-requiring protein 1α (IRE1α)-X-box-binding protein 1 (XBP1) pathway was mainly upregulated in MSS-LCLs. Tauroursodeoxycholic acid (TUDCA) attenuated ER stress-induced apoptosis.

CONCLUSION

MSS patient-derived cells exhibit increased ER stress, an activated UPR, and susceptibility to ER stress-induced death. TUDCA reduces ER stress-induced death of MSS patient-derived cells. The potential of TUDCA as a therapeutic agent for MSS could be explored further in preclinical studies.

Tauroursodeoxycholic Acid Improves the Survival and Function of Nigral Transplants in a Rat Model of Parkinson's Disease

There is accumulating evidence showing that the majority of cell death in neural grafts results from apoptosis when cells are implanted into the brain. Tauroursodeoxycholic acid (TUDCA), a taurine-conjugated hydrophilic bile acid, has been found to possess antiapoptotic properties. In the present study we have examined whether the supplementation of TUDCA to cell suspensions prior to transplantation can lead to enhanced survival of nigral grafts. We first conducted an in vitro study to examine the effects of TUDCA on the survival of dopamine neurons in serum-free conditions. The number of tyrosine hydroxylase (TH)-positive neurons in the TUDCA-treated cultures was significantly greater than that of control cultures 7 days in vitro. In addition, a terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labeling (TUNEL) assay showed that the number of apoptotic cells in the TUDCA-treated cultures was dramatically smaller than that in the control cultures. In the transplantation study, a 50 μM concentration of TUDCA was added to the media when nigral tissue from Sprague-Dawley (SD) rats was trypsinized and dissociated. Two microliters of cell suspension containing TUDCA was then stereotaxically injected into the striatum of adult SD rats subjected to an extensive unilateral 6-hydroxydopamine lesion of the nigrastriatal dopamine pathway. At 2 weeks after transplantation, the rats that received a cell suspension with TUDCA exhibited a significant reduction in amphetamine-induced rotation scores when compared with pretransplantation value. There was a significant increase (approximately threefold) in the number of TH-positive cells in the neural grafts for the TUDCA-treated group when compared with the controls 6 weeks postgrafting. The number of apoptotic cells was much smaller in the graft areas in the TUDCA-treated groups than in the control group 4 days after transplantation. These data demonstrate that pretreatment of the cell suspension with TUDCA can reduce apoptosis and increase the survival of grafted cells, resulting in an improvement of behavioral recovery.

Tauroursodeoxycholic Acid Attenuates Angiotensin II Induced Abdominal Aortic Aneurysm Formation in Apolipoprotein E-deficient Mice by Inhibiting Endoplasmic Reticulum Stress

OBJECTIVE/BACKGROUND

Abdominal aortic aneurysm (AAA) is characterised by the infiltration of smooth muscle cell (SMC) apoptosis, inflammatory cells, neovascularisation, and degradation of the extracellular matrix. Previous work has shown that endoplasmic reticulum (ER) stress and SMC apoptosis were increased both in a mouse model and human thoracic aortic aneurysm. However, whether the ER stress is activated in AAA formation and whether suppressing ER stress attenuates AAA is unknown.

METHODS

Human AAA and control aorta samples were collected. Expression of ER stress chaperones glucose-regulated protein (GRP)-78 and GRP-94 was detected by immunohistochemical staining. The effect of ER stress inhibitor tauroursodeoxycholic acid (TUDCA) on AAA formation in angiotensin (Ang) II induced apolipoprotein E^-/- mice was explored. Elastin staining was used to observe the rupture of elastic fragmentation. Immunohistochemistry and Western blot analysis were performed, to detect the protein expression of ER stress chaperones and apoptosis molecules.

RESULTS

There was significant upregulation of GRP-78 and GRP-94 in aneurysmal areas of human AAA and Ang II induced ApoE^-/- mice (p < .05). TUDCA significantly attenuated the maximum diameters of abdominal aortas in Ang II induced ApoE^-/- mice (p < .05). TUDCA significantly reduced expression of ER stress chaperones and the apoptotic cell numbers (p < .05). Furthermore, TUDCA significantly reduced expression of apoptosis molecules, such as caspase-3, caspase-12, C/EBP homologous protein, c-Jun N-terminal kinase activating transcription factor 4, X-box binding protein, and eukaryotic initiation factor 2α in Ang II induced ApoE^-/- mice (p < .05).

CONCLUSION

The results suggest that ER stress is involved in human and Ang II induced AAA formation in ApoE^-/- mice. TUDCA attenuates Ang II induced AAA formation in ApoE^-/- mice by inhibiting ER stress mediated apoptosis.

Data on the potential impact of food supplements on the growth of mouse embryonic stem cells

The use of new compounds as dietary supplements is increasing, but little is known in terms of possible consequences of their use. Pluripotent stem cells are a promising research tool for citotoxicological research for evaluation of proliferation, cell death, pluripotency and differentiation. Using the mouse embryonic stem cell (mESC) model, we present data on three different compounds that have been proposed as new potential supplements for co-adjuvant disease treatments: kaempferol, berberine and Tauroursodeoxycholic acid (TUDCA). Cell number and viability were monitored following treatment with increased concentrations of each drug in pluripotent culture conditions.

Protection of tauroursodeoxycholic acid on high glucose-induced human retinal microvascular endothelial cells dysfunction and streptozotocin-induced diabetic retinopathy rats

ETHNOPHARMACOLOGICAL RELEVANCE

Tauroursodeoxycholic acid (TUDCA), one of the main ingredients from bear gall which hold "Clearing heat and detoxification, Removing liver fire for improving eyesight" functions, is formed by the conjugation of ursodeoxycholic acid (UDCA) with taurine. However, the limited information of TUDCA on protecting diabetic retinopathy (DR) has been known. The present study was conducted to evaluate the protection of TUDCA on high glucose-induced human retinal microvascular endothelial cells (HRMECs) dysfunction and streptozotocin (STZ)-induced diabetic retinopathy (DR) rats and the possible mechanism underlying was also explored.

MATERIALS AND METHODS

The proliferation of high glucose-induced HRMECs was determined by MTT assay. DR rats' model was established by an administration of high-glucose-fat diet and an intraperitoneal injection of STZ (30mg/kg). The cell supernatant and rats' serum were collected for the assays of NO content by ELISA kits. Retinas were stained with hematoxylin and eosin (HE) to observe pathological changes. Immunohistochemical assay was applied to examine the protein expression of ICAM-1, NOS, NF-κB p65 and VEGF in rat retinas. Furthermore, western blot analysis was carried out to examine the protein expression of ICAM-1, NOS, NF-κB p65 and VEGF in high glucose-induced HRMECs.

RESULTS

After treating with TUDCA, high glucose-induced HRMECs proliferation could be significantly inhibited. TUDCA (5.0μM, 25.0μM and 125.0μM) could decrease NO content in high glucose-induced HRMECs. Furthermore, TUDCA (500mg/kg/d and 250mg/kg/d) also decrease NO content in serum of DR rats. Additionally, both immunocytochemistry analysis and western blot analysis showed that the over-expression of ICAM-1, NOS, NF-κB p65 and VEGF were significantly decreased by TUDCA.

CONCLUSION

The data indicated that TUDCA could ameliorate DR by decreasing NO content and down-regulating the protein expression of ICAM-1, NOS, NF-κB p65 and VEGF. Thus, our experimental results suggested that TUDCA might be a potential drug for the prevention and treatment of DR.

Effect of Tauroursodeoxycholic Acid and 4-Phenylbutyric Acid on Metabolism of Copper and Zinc in Type 1 Diabetic Mice Model

Alternations of copper (Cu) and zinc (Zn) status in diabetes have received a great attention. Tauroursodeoxycholic acid (TUDCA) and 4-phenylbutyric acid (PBA) could alleviate the increased endoplasmic reticulum (ER) stress and prevent insulin resistance. This study aimed to investigate the effect of TUDCA and PBA on metabolism of Cu and Zn in diabetic mice model. Diabetes was induced by streptozotocin in FVB mice treated with and without TUDCA and PBA. Determination of Cu and Zn in tissues and serum by acid digestion was followed by ICP-MS. The renal and serum Cu levels were significantly higher, while the hepatic Cu and Zn levels were significantly decreased in the diabetic mice at 2 weeks and 2 months after diabetes onset. The increase of cardiac Cu together with the decrease of muscular Zn was found in the diabetic mice only at 2 months. Cu levels were positively correlated with Zn in the heart, liver, kidney, muscle, spleen, and serum of diabetic and control mice at both 2 weeks and 2 months. Both PBA and TUDCA reduced serum Zn, and PBA reduced hepatic Cu to normal levels in the diabetic mice at two time points, while PBA normalized serum Cu in the diabetic mice only at 2 months. PBA increased hepatic Zn to normal levels in the diabetic mice at 2 weeks, while it partially increased hepatic Zn in the same group at 2 months. Therefore, maintaining homeostasis of Cu and Zn by TUDCA and PBA in diabetes needs to be received with special attention.

Administration of tauroursodeoxycholic acid enhances osteogenic differentiation of bone marrow-derived mesenchymal stem cells and bone regeneration

It is known that osteogenic differentiation of mesenchymal stem cells (MSCs) can be promoted by suppression of adipogenesis of MSCs. We have recently found that the chemical chaperone tauroursodeoxycholic acid (TUDCA) significantly reduces adipogenesis of MSCs. In the present study, we examined whether TUDCA can promote osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMMSCs) by regulating Integrin 5 (ITGA5) associated with activation of ERK1/2 signal pathway and thereby enhance bone tissue regeneration by reducing apoptosis and the inflammatory response. TUDCA treatment promoted in vitro osteogenic differentiation of BMMSCs and in vivo bone tissue regeneration in a calvarial defect model, as confirmed by micro-computed tomography, histological staining, and immunohistochemistry for osteocalcin. In addition, TUDCA treatment significantly decreased apoptosis and the inflammatory response in vivo and in vitro, which is important to enhance bone tissue regeneration. These results indicate that TUDCA plays a critical role in enhancing osteogenesis of BMMSCs, and is therefore a potential alternative drug for bone tissue regeneration.

Tauroursodeoxycholic acid, a bile acid, promotes blood vessel repair by recruiting vasculogenic progenitor cells

Although serum bile acid concentrations are approximately 10 µM in healthy subjects, the crosstalk between the biliary system and vascular repair has never been investigated. In this study, tauroursodeoxycholic acid (TUDCA) induced dissociation of CD34(+) hematopoietic stem cells (HSCs) from stromal cells by reducing adhesion molecule expression. TUDCA increased CD34(+) /Sca1(+) progenitors in mice peripheral blood (PB), and CD34(+) , CD31(+) , and c-kit(+) progenitors in human PB. In addition, TUDCA increased differentiation of CD34(+) HSCs into EPC lineage cells via Akt activation. EPC invasion was increased by TUDCA, which was mediated by fibroblast activating protein via Akt activation. Interestingly, TUDCA induced integration of EPCs into human aortic endothelial cells (HAECs) by increasing adhesion molecule expression. In the mouse hind limb ischemia model, TUDCA promoted blood perfusion by enhancing angiogenesis through recruitment of Flk-1(+) /CD34(+) and Sca-1(+) /c-kit(+) progenitors into damaged tissue. In GFP(+) bone marrow-transplanted hind limb ischemia, TUDCA induced recruitment of GFP(+) /c-kit(+) progenitors to the ischemic area, resulting in an increased blood perfusion ratio. Histological analysis suggested that GFP(+) progenitors mobilized from bone marrow, integrated into blood vessels, and differentiated into VEGFR(+) cells. In addition, TUDCA decreased cellular senescence by reducing levels of p53, p21, and reactive oxygen species and increased nitric oxide. Transplantation of TUDCA-primed senescent EPCs in hind limb ischemia significantly improved blood vessel regeneration, as compared with senescent EPCs. Our results suggested that TUDCA promoted neovascularization by enhancing the mobilization of stem/progenitor cells from bone marrow, their differentiation into EPCs, and their integration with preexisting endothelial cells.

The exacerbating roles of CCAAT/enhancer-binding protein homologous protein (CHOP) in the development of bleomycin-induced pulmonary fibrosis and the preventive effects of tauroursodeoxycholic acid (TUDCA) against pulmonary fibrosis in mice

The purpose of this study was to evaluate the role of CCAAT/enhancer-binding protein homologous protein (CHOP), an important transcription factor that regulates the inflammatory reaction during the endoplasmic reticulum (ER) stress response, in the development of pulmonary fibrosis induced by bleomycin (BLM) in mice. An intratracheal injection of BLM transiently increased the expression of CHOP mRNA and protein in an early phase (days 1 and 3) in mice lungs. BLM-induced pulmonary fibrosis was significantly attenuated in Chop gene deficient (Chop KO) mice, compared with wild-type (WT) mice. Furthermore, the inflammatory reactions evaluated by protein concentration, the total number of leucocytes and neutrophils in the bronchoalveolar lavage fluid (BALF), the mRNA expression of interleukin 1b and caspase 11, and the apoptotic cell death were suppressed in Chop KO mice compared with those in WT mice. In addition, administration of tauroursodeoxycholic acid (TUDCA), a pharmacological agent that can inhibit CHOP expression, inhibited the BLM-induced pulmonary fibrosis and inflammation, and the increase in Chop mRNA expression in WT mice in a dose-dependent manner. These results suggest that the ER stress-induced transcription factor, CHOP, at least in part, plays an important role in the development of BLM-induced pulmonary fibrosis in mice, and that the inhibition of CHOP expression by a pharmacological agent, such as TUDCA, may be a promising strategy for the prevention of pulmonary fibrosis.

Curative effect of cholecystolithotomy combined with tauroursodeoxycholic acid in treatment of patients with cholecystolithiasis

AIM: To evaluate the clinical effect of gallbladder preserving cholecystolithotomy combined with tauroursodeoxycholic acid in the treatment of cholecystolithiasis.

METHODS: Three hundred and forty-six patients with gallstones treated at our hospital from June 2008 to June 2010 were randomly divided them into either an experimental group or a control group, with 173 patients in each group. The experimental group received minimally invasive endoscopic lithotomy combined with tauroursodeoxycholic acid capsules, while the control group received minimally invasive endoscopic lithotomy combined with routine anti-inflammatory treatment. All patients were followed postoperatively (average, 2 years) to record patients' symptom relief, gallbladder function and gallbladder stone recurrence for the two groups.

RESULTS: The rates of improvement of biliary colic (89.83% vs 74.24%), right lower quadrant abdominal discomfort (85.99% vs 71.22%) and bloating (90.28% vs 74.03%) were significantly higher in the experimental group than in the control group (P < 0.05). Combination with tauroursodeoxycholic acid capsules could effectively improve the gallbladder emptying index (53.95 ± 10.61 vs 43.81 ± 12.39, P < 0.05), and reduce the recurrence rates at 1 and 2 years (1.16% vs 6.36%, 4.62% vs 16.18%, P < 0.05) compared with the control group.

CONCLUSION: Cholecystolithotomy combined with tauroursodeoxycholic acid can effectively eliminate gallbladder stone recurrence, relieve symptoms, and restore the gallbladder contraction function in patients with cholecystolithiasis.

Clinical effects of tauroursodeoxycholic acid vs ursodeoxycholic acid in treatment of liver cirrhosis

AIM: To evaluate the efficacy and safety of tauroursodeoxycholic acid (TUDCA) vs ursodeoxycholic acid (UDCA) in patients with liver cirrhosis.

METHODS: Forty-eight patients with cirrhosis treated at Wuhan Union Hospital and Hubei Province Xinhua Hospital were enrolled. The patients were randomly divided into either a TUDCA group or a UDCA group. The TUDCA group had four cases receiving liver biopsy and the UDCA group had two cases. Both drugs were administered at a daily dose of 15 mg/(kg·d) in a randomly assigned sequence for a 6 mo period. Clinical, biochemical and histological features were recorded before and after the treatments to assess the clinical effects of TUDCA.

RESULTS: Forty-three patients were included in the final analysis. The TUDCA group had 21 patients and the UDCA group had 22 patients. Before treatment, there were no significant differences in age, sex or blood chemistry parameters between the two groups. After three months of treatment, serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyl transferase (GGT) and alkaline phosphatase (ALP) levels in the TUDCA group while only AST level in the UDCA group significantly reduced from baseline (P < 0.05). Serum albumin levels significantly increased in both groups (P < 0.05), and serum AST levels decreased more significantly in the TUDCA group than in the UDCA group. After 6 mo of treatment, serum AST, GGT and ALP levels in the TUDCA group while ALT and GGT levels in the UDCA group significantly reduced from baseline (P < 0.05). Serum albumin levels significantly increased in both groups (P < 0.05). Moreover, serum AST and ALP levels in the TUDCA group decreased more significantly than those in the UDCA group. Two patients in the TUDCA group had significant histological relief. Both treatments were well tolerated, and there was no side effect associated with treatment.

CONCLUSION: TUDCA [15 mg/(kg·d)] therapy is safe and appears to be more effective than UDCA in the treatment of liver cirrhosis, particularly in the improvement of biochemical parameters. TUDCA may delay the progression of liver fibrosis.

The role of tauroursodeoxycholic acid on adipogenesis of human adipose-derived stem cells by modulation of ER stress

Obesity has become a serious public health problem in the developed world. Increased mass of adipose tissue in the obese is due to an increase in both the size (hypertrophy) and number (hyperplasia) of adipocytes. The chemical chaperone tauroursodeoxycholic acid (TUDCA) not only decreases endoplasmic reticulum (ER) stress, but also plays a role as a leptin-sensitizing agent for preadipocytes in mice and humans. In this study, we examine whether TUDCA has an effect on adipogenesis from human adipose-derived stem cells (hASCs). Therefore, the effect of TUDCA on ER stress, lipid accumulation, and adipogenic differentiation from hASCs was investigated using histological staining, reverse-transcriptase polymerase chain reaction (RT-PCR), and western blotting in vitro. It was found that TUDCA treatment of hASCs significantly decreases the representative ER stress marker (glucose-regulated protein 78 kDa (GRP78)), adipogenic markers (peroxisome proliferator-activated receptor gamma (PPARγ) and glycerol-3-phosphate dehydrogenase 1 (GPDH)), and lipid accumulation. Furthermore, we confirmed that TUDCA treatment of hASCs significantly decreased in vivo adipogenic tissue formation and ER stress comparing with PBS treatment of hASCs. The results indicate that TUDCA plays a critical role in adipogenesis from hASCs by modulating ER stress and, therefore, has potential pharmacologic and therapeutic applications as an anti-obesity agent.

Tauroursodeoxycholic acid inhibits carbon tetrachloride-induced liver fibrosis in rats

AIM: To determine the inhibitory effects of tauroursodeoxycholic acid (TUDCA) on carbon tetrachloride-induced liver fibrosis in rats.

METHODS: A total of 75 healthy Sprague-Dawley rats were randomly divided into five groups: normal control group, model group, low-dose TUDCA group, high-dose TUDCA group and pentoxifylline (PTX) group. Hepatic fibrosis was induced in rats by hypodermic injection of carbon tetrachloride (40%). The low- and high-dose TUDCA groups were orally administered TUDCA at doses of 50 and 100 mg/(kg•d), respectively. The PTX group was orally administered PTX at a dose of 16 mg/(kg•d). The treatment lasted 8 wk for all the groups. Hematoxylin and eosin staining and Masson's trichrome staining of liver tissue was performed for histopathological evaluation of liver fibrosis. Serum parameters of liver fibrosis were detected by enzyme-linked immunosorbent assay. The expression of transforming growth factor-β1 (TGF-β1) and α-smooth muscle actin (α-SMA) in liver tissue was detected by immunohistochemistry.

RESULTS: Compared with the model group, the levels of serum hyaluronic acid (HA), laminin (LN) and type IV collagen (IV-C) significantly decreased in the low- and high-dose TUDCA groups and the PTX group (HA: 146.33 ± 35.13, 162.2 ± 24.80 and 137.14 ± 22.24 vs 252.83 ± 51.94; LN: 77.20 ± 11.84, 66.80 ± 16.78 and 82.00 ± 10.74 vs 108.00 ± 30.00; IV-C: 14.14 ± 2.59, 12.60 ± 3.17 and 10.09 ± 2.22 vs 25.08 ± 5.93, all P < 0.05). Compared with the model group and normal control group, fibrous septa became thinner and even disappeared, and the number of diffuse cirrhotic nodules and the area of collagen fiber decreased in the TUDCA and PTX intervention groups (all P < 0.05). The expression intensity of TGF-β1 and α-SMA proteins was significantly lower in the TUDCA and PTX intervention groups than in the model group (all P < 0.05), but showed no significant difference between the TUDCA and PTX treatment groups.

CONCLUSION: TUDCA can prevent carbon tetrachloride-induced liver fibrosis in rats by reducing TGF-β1 synthesis, inhibiting hepatic stellate cell activation and decreasing extracellular matrix synthesis.

Ursodeoxycholic acid improves gastrointestinal motility defects in gallstone patients

AIM: To simultaneously evaluate the presence of defects in gallbladder and gastric emptying, as well as in intestinal transit in gallstone patients (GS) and the effect of chronic ursodeoxycholic acid (UDCA) administration on these parameters and on serum bile acids and clinical outcome in GS and controls (CTR).

METHODS: After a standard liquid test meal, gallbla-dder and gastric emptying (by ultrasound), oroileal transit time (OITT) (by an immunoenzymatic technique) and serum bile acids (by HPLC) were evaluated before and after 3 mo of UDCA (12 mg/kg bw/d) or placebo administration in 10 symptomatic GS and 10 matched healthy CTR.

RESULTS: OITT was longer in GS than in CTR (P < 0.0001); UDCA significantly reduced OITT in GS (P < 0.0001), but not in CTR. GS had longer gastric half-emptying time (t_1/2) than CTR (P < 0.0044) at baseline; after UDCA, t_1/2 significantly decreased (P < 0.006) in GS but not in CTR. Placebo administration had no effect on gastric emptying and intestinal transit in both GS and CTR.

CONCLUSION: The gallstone patient has simultaneous multiple impairments of gallbladder and gastric emptying, as well as of intestinal transit. UDCA administration restores these defects in GS, without any effect in CTR. These results confirm the pathogenetic role of gastrointestinal motility in gallstone disease and suggest an additional mechanism of action for UDCA in reducing bile cholesterol supersaturation.