PARP1 and chronic obstructive pulmonary disease: Furthermore, pre-incubation of PBMCs with UPF17 (4-methoxy-l-tyrosinyl-a-l-glutamyl-l-cysteinyl-glycine), a novel tetra peptide analog of glutathione (GSH), strongly reduced mRNA expression of PARP-1 in patients with COPD as compared to non-obstructive individuals.