Human Alpha 1 Antitrypsin Suppresses NF-κB Activity and Extends Lifespan in Adult Drosophila.

Human alpha 1 antitrypsin (hAAT) is a multifunctional protein that has been shown to have anti-inflammatory and cellular protective properties. While previous studies demonstrated the antiaging potential of hAAT, the mechanism(s) underlying the antiaging effect remain elusive. In this study, we performed a detailed analysis of transcriptomic data that indicated that NF-κB-targeted genes and NF-κB-regulated pathways were selectively inhibited by hAAT treatment. We further showed that the first detectable impact of hAAT treatment was the inhibition of the nuclear activity of NF-κB. Subsequently, hAAT treatment suppressed the mRNA levels of NF-κB-targeted genes, as well as NF-κB itself (P65 and P50), in human senescent cells. Using Drosophila models, we further examined the impact of hAAT on locomotor activity and endurance. Finally, using an adult-specific promotor, we demonstrated that overexpression of hAAT in the late stage of life significantly extended the lifespan of transgenic flies. These results extend the current understanding of the anti-inflammatory function of hAAT.

Mouse characteristics that affect establishing xenografts from hepatocellular carcinoma patient biopsies in the United States.

BACKGROUND: Hepatocellular carcinoma (HCC) patient-derived xenograft (PDX) models hold potential to advance knowledge in HCC biology to help improve systemic therapies. Beside hepatitis B virus-associated tumors, HCC is poorly established in PDX. METHODS: PDX formation from fresh HCC biopsies were obtained and implanted intrahepatically or in subrenal capsule (SRC). Mouse liver injury was induced in immunodeficient Fah-/-  mice through cycling off nitisinone after HCC biopsy implantation, versus continuous nitisinone as non-liver injury controls. Mice with macroscopically detectable PDX showed rising human alpha1-antitrypsin (hAAT) serum levels, and conversely, no PDX was observed in mice with undetectable hAAT. RESULTS: Using rising hAAT as a marker for PDX formation, 20 PDX were established out of 45 HCC biopsy specimens (44%) reflecting the four major HCC etiologies most commonly identified at Memorial SloanKettering similar to many other institutions in the United States. PDX was established only in severely immunodeficient mice lacking lymphocytes and NK cells. Implantation under the renal capsule improved PDX formation two-fold compared to intrahepatic implantation. Two out of 18 biopsies required murine liver injury to establish PDX, one associated with hepatitis C virus and one with alcoholic liver disease. PDX tumors were histologically comparable to biopsy specimens and 75% of PDX lines could be passaged. CONCLUSIONS: Using cycling off nitisinone-induced liver injury, HCC biopsies implanted under the renal capsule of severely immunodeficient mice formed PDX with 57% efficiency as determined by rising hAAT levels. These findings facilitate a more efficient make-up of PDX for research into subset-specific HCC.

Anti-inflammaging effects of human alpha-1 antitrypsin.

Inflammaging plays an important role in most age-related diseases. However, the mechanism of inflammaging is largely unknown, and therapeutic control of inflammaging is challenging. Human alpha-1 antitrypsin (hAAT) has immune-regulatory, anti-inflammatory, and cytoprotective properties as demonstrated in several disease models including type 1 diabetes, arthritis, lupus, osteoporosis, and stroke. To test the potential anti-inflammaging effect of hAAT, we generated transgenic Drosophila lines expressing hAAT. Surprisingly, the lifespan of hAAT-expressing lines was significantly longer than that of genetically matched controls. To understand the mechanism underlying the anti-aging effect of hAAT, we monitored the expression of aging-associated genes and found that aging-induced expressions of Relish (NF-ĸB orthologue) and Diptericin were significantly lower in hAAT lines than in control lines. RNA-seq analysis revealed that innate immunity genes regulated by NF-kB were significantly and specifically inhibited in hAAT transgenic Drosophila lines. To confirm this anti-inflammaging effect in human cells, we treated X-ray-induced senescence cells with hAAT and showed that hAAT treatment significantly decreased the expression and maturation of IL-6 and IL-8, two major factors of senescence-associated secretory phenotype. Consistent with results from Drosophila,RNA-seq analysis also showed that hAAT treatment significantly inhibited inflammation related genes and pathways. Together, our results demonstrated that hAAT significantly inhibited inflammaging in both Drosophila and human cell models. As hAAT is a FDA-approved drug with a confirmed safety profile, this novel therapeutic potential may make hAAT a promising candidate to combat aging and aging-related diseases.

Elevating the expression level of biologically active recombinant human alpha 1-antitrypsin in Pichia pastoris

Background: Human alpha 1-antitrypsin (AAT) is a potent inhibitor of multiple serine proteases, and protects tissues against their harmful effects. Individuals with reduced or abnormal production of this inhibitor need intravenous administration of exogenous protein. In this study, we employed the methylotrophic (methanol utilizing) yeast Pichia pastoris (P. pastoris) as a preferential host for efficient production and secretion of recombinant AAT. Furthermore, we examined different strategies to maximize the yield of the secreted protein. Results: Our findings revealed that optimizing the codon usage of AAT gene for P. pastoris had positive effects on the level of secreted AAT under the control of inducible alcohol oxidase 1 (AOX1) and constitutive glycerol aldehyde phosphate dehydrogenase (GAP) promoters. Compared to AOX1, the GAP promoter increased the yield of AAT by more than two fold. It was also demonstrated that the human AAT native signal sequence was more effective than the well-known yeast signal sequence, alpha mating factor (α-MF). Doubling gene dosage nearly doubled the production of AAT, though dosages exceeding this limit had negative effects on the yield. Conclusion: P. pastoris is shown to be an efficient expression system for production of recombinant and biologically active AAT. Also different strategies could be used to elevate the amount of this secretable protein.