Maturational Aspects of Postnatal Lymphangiogenesis

In addition to highlighting the burgeoning interest in and insights into lymphatic developmental biology, Lymphatic Research and Biology, almost from its inception, has had a profound and recurring emphasis upon the processes that serve postnatal lymphangiogenesis, both in health and in disease.^1–12

In the current issue, Yuen et al. shed interesting new light upon this topic. Their manuscript sheds light upon the maturational aspects of the process, utilizing a well-studied model of lymphangiogenesis and hemangiogenesis in the cornea. ¹³ In their investigation, they incited corneal inflammatory responses in cohorts of murine subjects at varying ages. Remarkably, their observations support the conclusion that the infant cornea exhibits more intense lymphangiogenesis and hemangiogenesis; the lymphatic neovasculature displayed similar branching points, but demonstrated greater density, invasion area, and diameter than the vessels that were observed in the older mouse cohort.

These observations may be of particular clinical relevance, insofar as these same processes contribute to the pathological process of corneal transplant rejection. It is known that children experience higher rates of rejection of such transplants. The current investigation may begin to shed light on some of the mechanistic underpinning of this phenomenon.

Elsewhere within this issue, we continue to emphasize the diagnostic and therapeutic implications of human limb lymphedema.^14–16 . And, importantly, the journal continues its emphasis upon anomalies of the lymphatic vasculature ¹⁷ with an important contribution by Kirsh et al. that serves to consider the development of tertiary lymphoid organs in lymphatic malformations. ¹⁸