Lymphatics on Michael’s Domain

Do fish have lymphatics?

Sat, 27 Jan 2024 00:00:00 +0000

Read the whole back story in our preprint: https://doi.org/10.20944/preprints202312.2119.v1 . It isn’t easy to believe that the scientific community cannot agree on whether zebrafish have a lymphatic vascular system. Zebrafish is one of the most successful model organisms in biology, and one would assume that we know its overall vascular setup. However, starting with W. Vogel in 1981 ( https://doi.org/10.1515/znc-1981-5-627 ), many fish physiologists subscribe to the notion that there are no lymphatics in fish, and most contemporary fish physiology textbooks have appropriated this point of view. At the same time, solid publications from multiple labs show that lymphatic vessels exist in fish ( https://doi.org/10.1038/nm1427 , https://doi.org/10.1016/j.cub.2006.05.026 ). What is going on? When the Yaniv lab published in 2022 that embryonic lymphatics in zebrafish can transdifferentiate into blood vessels ( https://doi.org/10.1038/s41586-022-04766-2 ), it suddenly appeared possible to unite the two contradictory views. In a nutshell: In most fish, an embryonic lymphatic system transdifferentiates during development into blood vessels that form a specialized subcompartment of the cardiovascular system (the so-called secondary vascular system). The degree of transdifferentiation seems quite variable between fish species, and some vessels - notably the thoracic duct - might retain a hybrid phenotype.As so often is the case in top journals, the original article by Das et al. neither discussed the 100-year-old controversy nor the ramifications of its landmark findings. Even though Kari Alitalo and I did so in a short commentary ( https://rdcu.be/cOjJ0 ), more space is needed to do justice to the topic. Although the controversy about piscine lymphatics is far from settled, it appears important to record the current status of the discussion in the scientific literature. Moreover, we wanted to describe a high-likelihood consensus model against which to plan future experiments. The result is an extended review; we hope you’ll enjoy reading it. If you find something that you don’t like, by all means, let us know! Especially if you can back up your critique with data or sound arguments. We sent the manuscript for review and are happy to improve it based on your input.

Cutting-edge vascular biology continues at the Wihuri Research Institute

Wed, 10 May 2023 00:00:00 +0000

Taija Mäkinen has been appointed to become the Wihuri Research Institute (WRI) Director starting in 2024. Like the current director Kari Alitalo , Taija has outstanding expertise in lymphatic vascular biology. Taija is currently doing research in Sweden at Uppsala University . With her contributions, she has revolutionized our understanding of how lymphatic vessels form and grow ( 10.1016/j.celrep.2015.02.026 , 10.1161/CIRCRESAHA.116.306170 ).The Wihuri Research Institute , located at Biomedicum Helsinki, was founded and is funded by the Jenny and Antti Wihuri Foundation . It focuses on cardiovascular and vascular biology. This research is essential for the development of new treatments for heart disease. However, blood and lymphatic vessels penetrate nearly all body organs and play a role in almost all diseases, including inflammatory and infectious diseases, neurodegenerative diseases, cancer, and vascular malformations or hypoplasia. Therefore, the research done at the WRI opens avenues for treating many diseases beyond heart disease. The Board of Trustees of the Jenny and Antti Wihuri Foundation has made an excellent choice, even though I am biased for many reasons. I do similar research, and I worked in the same lab as Taija during our Ph.D. education. Unnecessary to mention that Taija graduated faster than I did …

Lymphatics as the origin of the fish secondary vascular system

Thu, 26 May 2022 00:00:00 +0000

In zebrafish, the blood vessels of the anal fin develop from lymphatics by transdifferentiation. Karina Yaniv presented unorthodox, but very compelling data supporting this conclusion last September at the Kloster Seeon Angiogenesis meeting .Now her paper has been published in Nature .

Review published in Duodecim: Lymphatics and the eye

Fri, 28 Aug 2020 00:00:00 +0000

English is overwhelmingly the number one language in science. Nevertheless, sometimes there is a need to target audiences different from academic researchers. In Finland, the bi-weekly Duodecim is arguably the medical journal with the biggest reach among domestic medical professionals. Hence, the idea for a Finnish language review was born. Viewed from three different angles (from the laboratories of Sirpa Loukovaara, Kaisa Lehti, and Michael Jeltsch), we are looking at proliferative diabetic retinopathy (PDR), which is an eye complication that develops slowly over decades in diabetic patients and which is still a major cause of blindness. The treatment of PDR is often less successful than it potentially could be. Importantly, we present also advances in PDR research, from which new ideas might emerge of how to improve current treatment regimens.The original Finnish language version of the review just went online: https://www.duodecimlehti.fi/lehti/2020/16/duo15739 . An English translation is available from Zenodo: https://doi.org/10.5281/zenodo.4005517 .

Lymphatics and the eye

Wed, 12 Feb 2020 00:00:00 +0000

Our shared review about the eye lymphatics has been accepted for publication by Duodecim . In addition to review our current understanding about the eye lymphatics, it focuses on proliferative diabetic retinopathy (PDR). PDR is the advanced stage of diabetic retinopathy, which is one of the slowly developing complications of diabetes and which can result in blindness.It has been known for a long time that damage to the blood vessels in the retina is a central event in the disease development. Antiangiogenic therapy, targeting the major angiogenic growth factor VEGF-A, is a cornerstone of the therapy. However, the recent discovery of lymphatic-type vessels in the disease indicates, that it might be helpful to target also the lymphatic growth factors VEGF-C and VEGF-D. This is my first contribution to an article that is written in Finnish. While I even wrote some of the sentences in Finnish myself, big thanks go to Ani and Timo for weeding out the mistakes. However, my take-home message for similar future endeavors (i.e. writing with a team where key members are not very proficient in the target language) is that one should write everything first in English and then have it translated into the target language. If common languages are concerned, the best tool for the automated translation of scientific articles is DeepL . However, DeepL does not know Finnish, and adding Finnish is certainly not high on the developer’s priority list…

Unlocking the drains

Mon, 01 Aug 2005 00:00:00 +0000

Nice article by Phyllida Brown in Nature describing the discovery of the VEGF-C/VEGFR-3 signalling axis, and how research on the lymphatic system turned into a hot topic: https://www.nature.com/articles/436456a .

Lymphatics in Different Vertebrate Classes

Fri, 25 Jan 2002 00:00:00 +0000