Changes in the Expression of Insulin Pathway, Neutrophil Elastase and Alpha 1 Antitrypsin Genes from Leukocytes of Young Individuals with Insulin Resistance

BACKGROUND

Chronic hyperinsulinemia is a hallmark of insulin resistance that affects a diversity of cells, including leukocytes modifying the expression of some genes involved in insulin signaling.

PURPOSE

The aim of this study was to evaluate how hyperinsulinemia affects the expression of genes involved in the proximal insulin signaling pathway in leukocytes from 45 young individuals grouped: normal weight with not insulin resistance (NIR), with insulin resistance (IR) and with obesity (OB-IR).

METHODS

qPCR was performed to analyze the expression of insulin receptor (INSR), insulin receptor substrate 1 and 2 (IRS-1 and IRS-2), neutrophil elastase (NE), alpha 1 antitrypsin (A1AT), glucose transporters 1, 3 and 4 (GLUT-1, GLUT-3 and GLUT-4) by the 2^-ΔCt method, and the correlation between the genes was determined by Spearman's test.

RESULTS

The mRNA expression analysis of all genes between NIR and IR individuals revealed no differences. However, when comparing NIR and IR individuals with OB-IR, an increase in NE and A1AT expression and a clear trend towards a decrease in IRS-2 expression was observed, whereas the comparison of IR and OB-IR showed a decrease in GLUT-3 expression. Overall, the correlation analysis showed that in the IR group there was a positive correlation only between NE with IRS-1 (r = 0.72, p = 0.003), while in the OB-IR group, there was a positive correlation between the NE and A1AT with INSR (r = 0.62, p = 0.01 and r = 0.74, p = 0.002, respectively) and with IRS-2 (r = 0.74, p = 0.002 and r = 0.76, p = 0.001, respectively).

CONCLUSION

These results suggest that hyperinsulinemia and obesity are associated with changes in the expression of genes in leukocytes involved in the insulin pathway that are related to NE and A1AT.

Alpha 1 Antitrypsin is an Inhibitor of the SARS-CoV-2-Priming Protease TMPRSS2

BACKGROUND

Host proteases have been suggested to be crucial for dissemination of MERS, SARS-CoV, and SARS-CoV-2 coronaviruses, but the relative contribution of membrane versus intracellular proteases remains controversial. Transmembrane serine protease 2 (TMPRSS2) is regarded as one of the main proteases implicated in the coronavirus S protein priming, an important step for binding of the S protein to the angiotensin-converting enzyme 2 (ACE2) receptor before cell entry.

METHODS

We developed a cell-based assay to identify TMPRSS2 inhibitors. Inhibitory activity was established in SARS-CoV-2 viral load systems.

RESULTS

We identified the human extracellular serine protease inhibitor (serpin) alpha 1 anti-trypsin (A1AT) as a novel TMPRSS2 inhibitor. Structural modeling revealed that A1AT docked to an extracellular domain of TMPRSS2 in a conformation that is suitable for catalysis, resembling similar serine protease inhibitor complexes. Inhibitory activity of A1AT was established in a SARS-CoV-2 viral load system. Notably, plasma A1AT levels were associated with COVID-19 disease severity.

CONCLUSIONS

Our data support the key role of extracellular serine proteases in SARS CoV-2 infections and indicate that treatment with serpins, particularly the FDA-approved drug A1AT, may be effective in limiting SARS-CoV-2 dissemination by affecting the surface of the host cells.

Alpha 1 Antitrypsin is an Inhibitor of the SARS-CoV-2-Priming Protease TMPRSS2

Host proteases have been suggested to be crucial for dissemination of MERS, SARS-CoV, and SARS-CoV-2 coronaviruses, but the relative contribution of membrane versus intracellular proteases remains controversial. Transmembrane serine protease 2 (TMPRSS2) is regarded as one of the main proteases implicated in the coronavirus S protein priming, an important step for binding of the S protein to the angiotensin-converting enzyme 2 (ACE2) receptor before cell entry. The main cellular location where the SARS-CoV-2 S protein priming occurs remains debatable, therefore hampering the development of targeted treatments. Herein, we identified the human extracellular serine protease inhibitor (serpin) alpha 1 antitrypsin (A1AT) as a novel TMPRSS2 inhibitor. Structural modeling revealed that A1AT docked to an extracellular domain of TMPRSS2 in a conformation that is suitable for catalysis, resembling similar serine protease-inhibitor complexes. Inhibitory activity of A1AT was established in a SARS-CoV-2 viral load system. Notably, plasma A1AT levels were associated with COVID-19 disease severity. Our data support the key role of extracellular serine proteases in SARS-CoV-2 infections and indicate that treatment with serpins, particularly the FDA-approved drug A1AT, may be effective in limiting SARS-CoV-2 dissemination by affecting the surface of the host cells.

SUMMARY

Delivery of extracellular serine protease inhibitors (serpins) such as A1AT has the capacity to reduce SARS-CoV-2 dissemination by binding and inhibiting extracellular proteases on the host cells, thus, inhibiting the first step in SARS-CoV-2 cell cycle (i.e. cell entry).

Alpha 1 Antitrypsin Gene Therapy Extends the Lifespan of Lupus-Prone Mice

Systemic lupus erythematosus (SLE) is a heterogeneous autoimmune disease characterized by high levels of pathogenic autoantibodies and tissue damage. Multiple studies showed that dendritic cell (DC) activation plays a critical role in SLE pathogenesis. Human alpha 1 antitrypsin (hAAT) is a serine proteinase inhibitor with potent anti-inflammatory and cytoprotective properties. In this study, we first examined the effects of hAAT on the functions of DCs from lupus-prone mice, and we showed that hAAT treatment efficiently inhibited CpG- (TLR9 agonist) induced activation of bone marrow-derived conventional and plasmacytoid DCs as well as the production of pro-inflammatory cytokines. The hAAT treatment also attenuated DC help for B cell proliferation and immunoglobulin M (IgM) production. We next tested the protective effect of hAAT protein and gene therapy using recombinant adeno-associated virus 8 (rAAV8-CB-hAAT) in a spontaneous lupus mouse model, and we showed that both treatments decreased autoantibody levels. Importantly, rAAV8-CB-hAAT did not induce an immune response to its transgene product (hAAT), but it showed more pronounced therapeutic effects in reducing urine protein levels and extending the lifespan of these mice. These results indicate that AAT has therapeutic potential in the treatment of SLE in humans.

Massive ascites and the heterozygous alpha 1 antitrypsin (α1 AT) living related donor liver in the homozygous child

The following is a short report on the use of a heterozygous (PiMZ) alpha 1 antitrypsin (α1AT) living related donor liver in a homozygous (PiZ) child that was complicated by massive ascites early after transplant. This clinical report is then followed by a brief summary of present knowledge on the α₁ AT protein and management of massive ascites in the pediatric liver transplant recipient.

Intradermal alpha1-antitrypsin therapy avoids fatal anaphylaxis, prevents type 1 diabetes and reverses hyperglycaemia in the NOD mouse model of the disease

AIMS/HYPOTHESIS

Human alpha1-antitrypsin (hAAT) gene therapy prevents type 1 diabetes in a NOD mouse model of diabetes. However, repeated i.p. injections of hAAT into NOD mice leads to fatal anaphylaxis. The aim of the study was to determine if an alternative route of administration avoids anaphylaxis and allows evaluation of hAAT's potential for diabetes prevention and reversal. We also sought to determine if the addition of granulocyte colony-stimulating factor (G-CSF), augments hAAT's capacity to prevent or reverse disease in the NOD mice.

METHODS

To evaluate hAAT pharmacokinetics, serum hAAT levels were monitored in NOD mice receiving a single dose (2 mg) of hAAT by i.p., s.c. or i.d. injection. For studies of type 1 diabetes prevention and reversal, mice received i.d. hAAT (2 mg/mouse/3 days) for 8 or 10 weeks or hAAT and G-CSF (i.p., 6 microg/day) for 6 weeks. Blood glucose determinations, glucose tolerance testing and insulin tolerance tests were performed.

RESULTS

Both i.p. and s.c. injections resulted in fatal anaphylaxis. The i.d. injection avoided anaphylaxis and i.d. injection of hAAT into 11-week-old NOD mice prevented disease (p = 0.005, AAT vs PBS at 40 weeks of age). Treatment of diabetic NOD mice with hAAT or hAAT plus G-CSF provided long-term (at least 100 days) reversal of diabetes in 50% of treated animals. G-CSF did not enhance the reversal rates of hAAT. Glucose tolerance and insulin levels were normalised in mice with hAAT prevention and reversal.

CONCLUSIONS/INTERPRETATION

Intradermal hAAT prevents and reverses disease in a NOD mouse model of type 1 diabetes without inducing anaphylaxis.