Review series

The mammalian eye is a markedly complex organ, and disruption of normal cell physiology at any of a number of levels may result in a devastating loss of vision. In recent years, ophthalmology research has advanced our understanding of fields as diverse as development, aging, immunology, and cancer. The articles in this series review this progress and highlight how the unique biology of the eye has allowed rapid advances in the areas of gene therapy and stem cell research.

In placental mammals, sexual reproduction is a highly complex and tightly controlled process that begins with germ cell development and ends with the birth of live young. The articles in this series comprise an overview of our current understanding of many of the events crucial to sexual reproduction in placental mammals and point to some of the ways forward to moving from “bench-to-bedside” to enhance pregnancy success rates in fertility clinics.

Stem cell biology is the study of how tissues and organs are formed and maintained throughout life. Recent efforts seek to translate scientific insights to the clinic. Such efforts are gaining momentum, but it is important to separate myth and hype from reality. The articles in this Review series aim to do just that, providing a balanced perspective on what the field has achieved, where it is headed, and what challenges must be overcome if effective stem cell–based therapies are to be developed.

Research into the pathogenesis, prevention, and control of infectious and parasitic diseases remains a global priority as these scourges continue to be a substantial cause of mortality and morbidity. As highlighted in this Review Series, genome-wide approaches have provided great insight into a range of human pathogens, leading to greater understanding of the human diseases that they cause. Challenges that must be overcome in order to maximize our ability to use this wealth of genomic information are also discussed.

Intermediate filaments (IFs) are one of the three major fibrillar cytoplasmic elements that make up the cytoskeleton. Cytoskeletal IFs in distinct cell types are formed from different members of a large family of proteins, the IF protein family, which also includes proteins that are present in the nucleus, where they are the main component of the nucleoskeleton. As discussed in this Review series, roles have been revealed for IFs in more than 80 human tissue-specific diseases.

Epithelial-mesenchymal transition (EMT) describes the series of events by which adherent, polarized epithelial cells convert to a mesenchymal cell phenotype, which includes an ability to both migrate and invade the extracellular matrix. As discussed in the articles in this Review series, EMT is now a recognized mechanism for dispersing cells in embryos, forming fibroblasts/mesenchymal cells in injured tissues, and initiating invasive and metastic behavior in epithelial cancer cells.

Mental disorders such as schizophrenia, bipolar illness, depression, and autism are the number one source of medical disability for people 15–44 years of age in the U.S. and Canada. In the past, these disorders have been considered psychological conflicts or chemical imbalances, but, as highlighted in this Review series, recent research indicates they are brain disorders, developmental disorders, and complex genetic disorders.

Cytokines are small protein mediators involved in essentially all biological processes. As such, abnormalities in cytokines, their receptors, and the signaling pathways that they initiate are involved in a wide variety of diseases. This Review Series discusses the important role of cytokines and their receptors in just a few of these diseases, specifically three chronic inflammatory disease areas and two forms of cancer, highlighting their potential as therapeutic targets.

Although advances in science and technology have resulted in substantial improvements in the health of individuals in the developed world, similar progress has not been observed for those living in the developing world. This Review Series focuses on the health conditions that affect people living in the developing world, and it highlights some of the areas that require attention if these conditions are either to be brought under control or eradicated.

When the homeostasis of a physiological system is markedly perturbed it is said to be stressed. It is hoped that understanding the response of physiological systems to stress stimuli, both physiologic and pathologic, will lead to the development of approaches to reduce the limitations these stimuli place on individuals. In this context, this Review Series focuses on the molecular response of several physiological systems to various stress stimuli.