Influence of an extract from kudzu symbiosomes containing leghemoglobin on in vitro cutaneous procollagen production.

Cytoglobin is a hexacoordinate globin protein that was recently discovered in mammals. Interestingly, of the four human globin proteins that are now known, hemoglobin, myoglobin, neuroglobin and cytoglobin, the latter appears to have the closest resemblance to strikingly similar proteins expressed in plants. In legumes, these proteins accumulate in symbiosomes (root nodules) of various legumes and are called leghemoglobin. The paper will discuss the ability of an aqueous extract from Pueraria lobata (kudzu) symbiosomes that contains leghemoglobin to stimulate procollagen production in human dermal fibroblasts. This effect may be partly due to the possibility that leghemoglobin may mimic the function of cytoglobin by shuttling oxygen to prolyl-4-hydroxylase, the enzyme responsible for oxidizing proline residues in procollagen bundles. This hypothesis is supported by DNA microarray sequencing data that demonstrate that treatment of normal human dermal fibroblasts (NHDF) with highly purified cytoglobin or leghemoglobin upregulates a number of key collagen-related genes including COL1A1 and COL1A2.