Berberine potentiates liver inflammation and fibrosis in the PI*Z hAAT transgenic murine model.

BACKGROUND: Alpha-1 antitrypsin deficiency (AATD) is an inherited disease, the common variant caused by a Pi*Z mutation in the SERPINA1 gene. Pi*Z AAT increases the risk of pulmonary emphysema and liver disease. Berberine (BBR) is a nature dietary supplement and herbal remedy. Emerging evidence revealed that BBR has remarkable liver-protective properties against various liver diseases. In the present study, we investigated the therapeutic effects and toxicities of BBR in Pi*Z hepatocytes and Pi*Z transgenic mice. METHODS: Huh7.5 and Huh7.5Z (which carries the Pi*Z mutation) cells were treated with different concentrations of BBR for 48 hours. MTT was performed for cell viability assay. Intracellular AAT levels were evaluated by western blot. In vivo studies were carried out in wild type, native phenotype AAT (Pi*M), and Pi*Z AAT transgenic mice. Mice were treated with 50 mg/kg/day of BBR or solvent only by oral administration for 30 days. Western blot and liver histopathological examinations were performed to evaluate therapeutic benefits and liver toxicity of BBR. RESULTS: BBR reduced intracellular AAT levels in Huh7.5Z cells, meanwhile, no Pi*Z-specific toxicity was observed. However, BBR did not reduce liver AAT load but significantly potentiated liver inflammation and fibrosis accompanying the activation of unfolded protein response and mTOR in Pi*Z mice, but not in wild type and Pi*M mice. CONCLUSIONS: BBR exacerbated liver inflammation and fibrosis specifically in Pi*Z mice. This adverse effect may be associated with the activation of unfolded protein response and mTOR. This study implicates that BBR should be avoided by AATD patients.

The unfolded protein response to PI*Z alpha-1 antitrypsin in human hepatocellular and murine models.

Alpha-1 antitrypsin (AAT) deficiency (AATD) is an inherited disease caused by mutations in the serpin family A member 1 (SERPINA1, also known as AAT) gene. The most common variant, PI*Z (Glu342Lys), causes accumulation of aberrantly folded AAT in the endoplasmic reticulum (ER) of hepatocytes that is associated with a toxic gain of function, hepatocellular injury, liver fibrosis, and hepatocellular carcinoma. The unfolded protein response (UPR) is a cellular response to improperly folded proteins meant to alleviate ER stress. It has been unclear whether PI*Z AAT elicits liver cell UPR, due in part to limitations of current cellular and animal models. This study investigates whether UPR is activated in a novel human PI*Z AAT cell line and a new PI*Z human AAT (hAAT) mouse model. A PI*Z AAT hepatocyte cell line (Huh7.5Z) was established using clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 gene editing of the normal ATT (PI*MM) gene in the Huh7.5 cell line. Additionally, novel full-length genomic DNA PI*Z hAAT and PI*M hAAT transgenic mouse models were established. Using these new models, UPR in Huh7.5Z cells and PI*Z mice were comprehensively determined. Robust activation of UPR was observed in Huh7.5Z cells compared to Huh7.5 cells. Activated caspase cascade and apoptosis markers, increased chaperones, and autophagy markers were also detected in Z hepatocytes. Selective attenuation of UPR signaling branches was observed in PI*Z hAAT mice in which the protein kinase R-like ER kinase and inositol-requiring enzyme1α branches were suppressed while the activating transcription factor 6α branch remained active. This study provides direct evidence that PI*Z AAT triggers canonical UPR and that hepatocytes survive pro-apoptotic UPR by selective suppression of UPR branches. Our data improve understanding of underlying pathological molecular mechanisms of PI*Z AATD liver disease.

Mild closed head traumatic brain injury-induced changes in monoamine neurotransmitters in the trigeminal subnuclei of a rat model: mechanisms underlying orofacial allodynias and headache.

Our recent findings have demonstrated that rodent models of closed head traumatic brain injury exhibit comprehensive evidence of progressive and enduring orofacial allodynias, a hypersensitive pain response induced by non-painful stimulation. These allodynias, tested using thermal hyperalgesia, correlated with changes in several known pain signaling receptors and molecules along the trigeminal pain pathway, especially in the trigeminal nucleus caudalis. This study focused to extend our previous work to investigate the changes in monoamine neurotransmitter immunoreactivity changes in spinal trigeminal nucleus oralis, pars interpolaris and nucleus tractus solitaries following mild to moderate closed head traumatic brain injury, which are related to tactile allodynia, touch-pressure sensitivity, and visceral pain. Our results exhibited significant alterations in the excitatory monoamine, serotonin, in spinal trigeminal nucleus oralis and pars interpolaris which usually modulate tactile and mechanical sensitivity in addition to the thermal sensitivity. Moreover, we also detected a robust alteration in the expression of serotonin, and inhibitory molecule norepinephrine in the nucleus tractus solitaries, which might indicate the possibility of an alteration in visceral pain, and existence of other morbidities related to solitary nucleus dysfunction in this rodent model of mild to moderate closed head traumatic brain injury. Collectively, widespread changes in monoamine neurotransmitter may be related to orofacial allodynhias and headache after traumatic brain injury.