Reviews & Analysis

2013 has revealed interesting mechanisms that explain how glucocorticoid signalling responses can be influenced by childhood trauma, activity of other signalling molecules, glucocorticoid circadian rhythms and the sequence of DNA regulatory regions. In particular, studies this year highlight how different signalling environments can determine the molecular and physiological responses of glucocorticoids themselves, and how glucocorticoids can affect other signalling systems.

In 2013, studies in rodents and humans have reaffirmed the essential role of the gut microbiota in host metabolism. More importantly, several converging results have increased our knowledge regarding the taxa and functions of the gut microbiota that contribute to the management of energy homeostasis, glucose metabolism and metabolic inflammation.

Metabolic surgery has been proven to be effective in inducing remission of type 2 diabetes mellitus prior to any significant weight reduction. Studies in 2013 have investigated the mechanisms of action of these procedures and have highlighted a central role of the small intestine in the effects on glucose homeostasis.

Studies published in 2013 have addressed the question of whether the rising incidence of differentiated thyroid cancer is actually the result of overdiagnosis. Advances have also been made in the treatment of differentiated thyroid cancer, including improvements in radioiodine therapy.

In 2013, considerable progress was made towards deciphering the molecular foundations of puberty. Loss of transcriptional repression was identified as a core mechanism underlying the onset of puberty, and this loss was found to be precipitated by epigenetic cues. It was also discovered that nutritional deprivation delays puberty by repressing reproductive neuroendocrine function.

In 2012, we learned that functional thyroid tissue can be generated in vitro, and that thyroid hormones stimulate autophagy. Patients with defects in TRα have been identified, and di-iodothyropropionic acid has been shown to ameliorate MCT8 deficiency. Finally, we found that gene expression profiling can identify benign thyroid nodules.

2012 has been a rewarding year for adipocyte research. A new type of brown-like adipocyte—the beige adipocyte—and irisin, a previously unknown hormone that stimulates the formation of such cells, have been discovered. A bipotential adipocyte progenitor giving rise to both brown and white adipocytes has also been identified.

Neuroendocrine tumours are a heterogeneous group of neoplasms with various clinical presentations, growth rates and responses to available therapies. Studies published in 2012 have provided insights into tumour-cell signalling that will increase our knowledge of tumour biology and molecular genetics, making it possible to personalize patient care.

Researchers are trying to develop more efficient and safer antifracture treatments. Besides the ongoing promising clinical trials involving antibodies to the Wnt antagonist sclerostin or inhibition of the osteoclast enzyme cathepsin K, the year 2012 has seen several novel osteoporosis targets identified by using different methodological approaches.

Systemic administration of anti-PCSK9 antibodies induces dramatic reductions in LDL-cholesterol levels, and the effect of this therapy on LDL-receptor activity seems to be additive to that of statin therapy. Inhibition of PCSK9 is potentially very important to the clinician, and should enable more patients to achieve their LDL-cholesterol-level goal.

Worldwide, >366 million people with type 2 diabetes mellitus remain at excess risk of cardiovascular disease and face a lifetime of treatment escalation for this progressive disorder. Studies in 2012 have re-affirmed the safety of early insulin treatment, metformin use in renal impairment, and shown β-cell function preservation over several years.