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Background: Adjunctive pharmacological treatment may improve nerve regeneration. We investigated nerve regeneration processes of PXL01 – a lactoferrin-derived peptide – after repair of the sciatic nerve in healthy Wistar rats. Materials & methods: PXL01, sodium hyaluronate (carrier) or sodium chloride was administered around the repair. After 6 days axonal outgrowth, Schwann cell response, pan- (CD68) and pro-healing (CD206) macrophages in sciatic nerve, sensory neuronal response in dorsal root ganglia (DRG) and expression of heat shock protein 27 (HSP27) in sciatic nerves and DRGs were analyzed. Results: Despite a lower number of pan-macrophages, other investigated variables in sciatic nerves or DRGs did not differ between the treatment groups. Conclusion: PLX01 applied locally inhibits inflammation through pan-macrophages in repaired sciatic nerves without any impact on nerve regeneration or pro-healing macrophages. Graphical Abstract Author highlights Local application of PXL01 decreases inflammation in the injured and immediate repaired nerve without changing the polarization of the macrophages. Local application of PXL01 does not improve or have any negative effect on nerve regeneration. Local application of PXL01 does not alter Schwann cell activity or neuroprotective effect of HSP27 in the injured and repaired nerve or in the sensory neurons. Hyaluronate, the PXL01 vehicle, does not alter nerve regeneration and has no effect on inflammation. CD206, known as antimannose receptor antibody, also stains the paranodal region in the contralateral-uninjured nerve. Results imply that PXL01 treatment can be used to treat scarred and tethered nerves, one of the defined neuromas after surgery, without a negative effect on the regeneration processes. [ABSTRACT FROM AUTHOR]

Circadian clocks coordinate physiological, behavioral, and biochemical events with predictable daily environmental changes by a self-sustained transcriptional feedback loop. CLOCK and ARNTL are transcriptional activators that regulate Per and Cry gene expression. PER and CRY inhibit their own transcription, and their turnover allows this cycle to restart. The transcription factors BHLHB2 and BHLHB3 repress Per activation, whereas orphan nuclear receptors of the NR1D and ROR families control Arntl expression. Here we show the AMP-activated protein kinase (AMPK)[[gamma].sub.3] subunit is involved in the regulation of peripheral circadian clock function. AMPK[gamma]3 knockout ([Prkag3.sup.-/-]) mice or wild-type littermates were injected with saline or an AMPK activator, 5-amino-4-imidazole-carboxamide riboside (AICAR), and white glycolytic gastrocnemius muscle was removed for gene expression analysis. Genes involved in the regulation of circadian rhythms (Cry2, Nrldl, and Bhlhb2) were differentially regulated in response to AICAR in wild-type mice but remained unaltered in [Prkag3.sup.-/-] mice. Basal expression of Per1 was higher in [Prkag3.sup.-/-] mice compared with wild-type mice. Distinct diurnal changes in the respiratory exchange ratio (RER) between the light and dark phase of the day were observed in wild-type mice but not [Prkag3.sup.-/-] mice. In summary, the expression profile of clock-related genes in skeletal muscle in response to AICAR, as well as the diurnal shift in energy utilization, is impaired in AMPK[[gamma].sub.3] subunit knockout mice. Our results indicate AMPK heterotrimeric complexes containing the AMPK[[gamma].sub.3] subunit may play a specific role in linking circadian oscillators and energy metabolism in skeletal muscle. adenosine 5'-monophosphate-activated protein kinase; clock genes; circadian rhythm

Mice lacking melanin-concentrating hormone receptor 1 demonstrate increased heart rate associated with altered autonomic activity. Am J Physiol Regul Integr Comp Physiol 287 R749-R758, 2004. First published May 6, 2004; 10.115/ajpregu.00134.2004.--Melanin-concentrating hormone (MCH) plays an important role in energy balance. The current studies were carried out on a new line of mice lacking the rodent MCH receptor (MCHR[1.sup.-/-] mice). These mice confirmed the previously reported lean phenotype characterized by increased energy expenditure and modestly increased caloric intake. Because MCH is expressed in the lateral hypothalamic area, which also has an important role in the regulation of the autonomic nervous system, heart rate and blood pressure were measured by a telemetric method to investigate whether the increased energy expenditure in these mice might be due to altered autonomic nervous system activity. Male MCHR[1.sup.-/-] mice demonstrated a significantly increased heart rate [24-h period: wild type 495 [+ or -] 4 vs. MCHR[1.sup.-/-] 561 [+ or -] 8 beats/min (P < 0.001/; dark phase: wild type 506 [+ or -] 8 vs. MCHR[1.sup.-/-] 582 [1.sup.-/-] 9 beats/min (P < 0.001); light phase: wild type 484 [+ or -] 13 vs. MCHR[1.sup.-/-] 539 [+ or -] 9 beats/min (P < 0.005)] with no significant difference in mean arterial pressure [wild type 110 [+ or -] 0.3 vs. MCHR[1.sup.-/-] 113 [+ or -] 0.4 mmHg (P > 0.05)]. Locomotor activity and cure body temperature were higher in the MCHR[1.sup.-/-] mice during the dark phase only and thus temporally dissociated from heart rate differences. On fasting, wild-type animals rapidly downregulated body temperature and heart rate. MCHR[1.sup.-/-] mice displayed a distinct delay in the onset of this downregulation. To investigate the mechanism underlying these differences, autonomic blockade experiments were carried out. Administration of the adrenergic antagonist metoprolol completely reversed the tachycardia seen in MCHR[1.sup.-/-] mice, suggesting an increased sympathetic tone. melanin-concentrating hormone: sympathetic; fasting

Expression patterns of the three isoforms of the regulatory [gamma]-subunit of AMP-activated protein kinase (AMPK) were determined in various tissues from adult humans, mice, and rats, as well as in human primary muscle cells. Real-time PCR-based quantification of mRNA showed similar expression patterns in the three species and a good correlation with protein expression in mice and rats. The [gamma]3-isoform appeared highly specific to skeletal muscle, whereas [gamma]1 and [gamma]2 showed broad tissue distributions. Moreover, the proportion of white, type lib fibers in the mouse and rat muscle samples, as indicated by real-time PCR quantification of Atplb2 mRNA, showed a strong positive correlation with the expression of [gamma]3. In samples of white skeletal muscle, [gamma]3 clearly appeared to be the most abundant [gamma]-isoform. Differentiation of human primary muscle cells from myoblasts into multinucleated myotubes was accompanied by upregulation of [gamma]3 mRNA expression, whereas levels of [gamma]1 and [gamma]2 remained largely unchanged. However, even in these cultured myotubes, [gamma]2 was the most highly expressed isoform, indicating a considerable difference compared with adult skeletal muscle, lmmunoblot analysis of mouse gastrocnemius and quadriceps muscle extracts precipitated with a [gamma]3-specific antibody showed that [gamma]3 was exclusively associated with the [alpha]2- and [beta]2-subunit isoforms. The observation that the AMPK[gamma]3 isoform is expressed primarily in white skeletal muscle, in which it is the predominant [gamma]-isoform, strongly suggests that [gamma]3 has a key role in this tissue. adenosine monophosphate; real-time polymerase chain reaction; antibodies; mouse; rat; human

A forkhead gene, FoxE3, has been shown to be necessary for closure of the lens vesicle and lens epithelial proliferation in eye development. The cloning of this gene, expressed in the lens epithelium, has been carried out. It is mutated in a classic mouse model with ensuing defective lens development. In the mouse mutant dysgenetic lens (dyl) the lens vesicle does not separate from the ectoderm and fusion between lens and cornea results. With no proliferating anterior lens epithelium absence of secondary lens fibers and a dysplastic cataractic lens results.

The forkhead transcription factor FREAC-1 is a potent transcriptional activator. We have localized a transcriptional activation domain in the C-terminus of FREAC-1 and another one to a stretch of approximately 60 amino acids in the central part of the protein. While the C-terminal activation domain activates in all cell lines tested, the activation domain in the central part of the protein is functional only in cell lines derived from lung. This cell-type-specific activity is retained when the activation domain is fused to the heterologous DNA binding domain of Ga14. The human FREAC-1 gene was found to consist of two exons separated by an intron of 1.2 kb. Exon 1 encodes the forkhead DNA binding domain and the cell-type-specific activation domain. Exon 2 encodes the general activation domain. The distribution of FREAC-1 expression during embryogenesis was investigated by in situ hybridization. FREAC-1 mRNA was found in mesenchyme in immediate proximity to endodermal epithelia throughout the digestive, urinary, and respiratory tracts. Mesenchyme surrounding the notochord and adjacent to the ectodermal epithelia of the oral cavity and developing teeth also expresses FREAC-1. The pattern of FREAC-1 expression, with highest levels in the mesenchyme next to the epithelium and gradually diminishing as the distance from the epithelium increases, suggests that FREAC-1 expression is a response to epithelial paracrine signaling and that FREAC-1 may play a role in epitheliomesenchymal interactions.