Epigenetic clocks for mice were generated based on deep-sequencing analysis of the methylome. Here, we demonstrate that site-specific analysis of DNA methylation levels by pyrosequencing at only three CG dinucleotides (CpGs) in the genes Prima1, Hsf4, and Kcns1 facilitates precise estimation of chronological age in murine blood samples, too. DBA/2 mice revealed accelerated epigenetic aging as compared to C57BL6 mice, which is in line with their shorter life-expectancy. The three-CpG-predictor provides a simple and cost-effective biomarker to determine biological age in large intervention studies with mice.

Mutations in GDAP1, which encodes protein located in the mitochondrial outer membrane, cause axonal recessive (AR-CMT2), axonal dominant (CMT2K) and demyelinating recessive (CMT4A) forms of Charcot-Marie-Tooth (CMT) neuropathy. Loss of function recessive mutations in GDAP1 are associated with decreased mitochondrial fission activity, while dominant mutations result in impairment of mitochondrial fusion with increased production of reactive oxygen species and susceptibility to apoptotic stimuli. GDAP1 silencing in vitro reduces Ca2+ inflow through store-operated Ca2+ entry (SOCE) upon mobilization of endoplasmic reticulum (ER) Ca2+, likely in association with an abnormal distribution of the mitochondrial network. To investigate the functional consequences of lack of GDAP1 in vivo, we generated a Gdap1 knockout mouse. The affected animals presented abnormal motor behavior starting at the age of 3 months. Electrophysiological and biochemical studies confirmed the axonal nature of the neuropathy whereas histopathological studies over time showed progressive loss of motor neurons (MNs) in the anterior horn of the spinal cord and defects in neuromuscular junctions. Analyses of cultured embryonic MNs and adult dorsal root ganglia neurons from affected animals demonstrated large and defective mitochondria, changes in the ER cisternae, reduced acetylation of cytoskeletal α-tubulin and increased autophagy vesicles. Importantly, MNs showed reduced cytosolic calcium and SOCE response. The development and characterization of the GDAP1 neuropathy mice model thus revealed that some of the pathophysiological changes present in axonal recessive form of the GDAP1-related CMT might be the consequence of changes in the mitochondrial network biology and mitochondria–endoplasmic reticulum interaction leading to abnormalities in calcium homeostasis.

High-density polyethylene-hydroxyapatite (HDPE-HA) composites with different filler content (5-20 %) were synthesized by in situ ethylene polymerization. Good filler dispersion was observed without formation of agglomerates. Osteoblast cell behavior in HDPE-HA composites was evaluated in terms of adhesion, alkaline phosphatase activity and proliferation. Fluorescence and scanning electron microscopy results showed good cell adhesion and proliferation, and extensive filopodium-like protrusion connected to hydroxyapatite particles.

The eccrine sweat gland (ESG) is a cutaneous appendage of key importance for thermoregulation in humans, although not in other mammals.1 They are also involved in partial thickness wound-induced epidermal repair (s1, s2). Notwithstanding other putative functions, their almost ubiquitous abundance and involvement in these two processes already suggest the relevance of ESGs in skin physiology. 2 In spite of this, compared to other epidermal appendages, they remain the subject of relatively little investigation.It is well known that embryonic wound healing regenerates ESGs, a feat accomplished by superficial wounds in the adult as well.However, deeper wounds of adult human skin cannot regenerate the sweat glands that are lost at the site of injury. indicating that further refinement of these (so far rather complicated) protocols is at hand. Additional unresolved issues lay ahead, such as achieving differentiation of stem cells to ESG duct cells, which is more challenging to accomplish than reconstruction of the secretory portion of the gland. This seems to be true not only in vitro but also in vivo. (Fig. 1a).Shh is a key morphogen that acts through both canonical and non-canonical signalling pathways and which is involved in numerous developmental processes (s16, s17). In the skin and similar to other body parts (s18, s19), Shh is involved in epidermal appendage morphogenesis and in basal cell carcinomas (s20), and specifically acts downstream of EDA-EDAR signalling in ESG morphogenesis (Fig. 1b). It is therefore not surprising that Shh is required for ESG secretory-like cell induction in vitro. As for the duct portion, it must be taken into account that the reported system lacks signals trig-

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