Rationale-Recent advancements have brought to light the origins, complexity, and functions of tissue-resident macrophages. However, in the context of tissue injury or disease, large numbers of monocytes infiltrate the heart and are thought to contribute to adverse remodeling and heart failure pathogenesis. Little is understood about the diversity of monocytes and monocyte-derived macrophages recruited to the heart after myocardial injury, including the mechanisms that regulate monocyte recruitment and fate specification.Objective-We sought to test the hypothesis that distinct subsets of tissue-resident CCR2− (C-C chemokine receptor 2) and CCR2+ macrophages orchestrate monocyte recruitment and fate specification after myocardial injury.Methods and Results-We reveal that in numerous mouse models of cardiomyocyte cell death (permanent myocardial infarction, reperfused myocardial infarction, and diphtheria toxin cardiomyocyte ablation), there is a shift in macrophage ontogeny whereby tissue-resident macrophages are predominately replaced by infiltrating monocytes and monocyte-derived macrophages. Using syngeneic cardiac transplantation to model ischemia-reperfusion injury and distinguish tissue-resident from recruited cell populations in combination with intravital 2-photon microscopy, we demonstrate that monocyte recruitment is differentially orchestrated by distinct subsets of tissue-resident cardiac macrophages. Tissue-resident CCR2+ macrophages promote monocyte recruitment through an MYD88 (myeloid differentiation primary response 88)dependent mechanism that results in release of MCPs (monocyte chemoattractant proteins) and monocyte mobilization. In contrast, tissue-resident CCR2− macrophages inhibit monocyte recruitment. Using CD (cluster of differentiation) 169-DTR (diphtheria toxin receptor) and CCR2-DTR mice, we further show that selective depletion of either tissue-resident CCR2− or CCR2+ macrophages before myocardial infarction results in divergent effects on left ventricular function, Bajpai et al.

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Agents that increase intracellular cAMP are potent stimulators of sperm motility. Anchoring inhibitor peptides, designed to disrupt the interaction of the cAMP-dependent protein kinase A (PKA) with A kinase-anchoring proteins (AKAPs), are potent inhibitors of sperm motility. These data suggest that PKA anchoring is a key biochemical mechanism controlling motility. We now report the isolation, identification, cloning, and characterization of AKAP110, the predominant AKAP detected in sperm lysates. AKAP110 cDNA was isolated and sequenced from mouse, bovine, and human testis libraries. Using truncated mutants, the RII-binding domain was identified. Alignment of the RII-binding domain on AKAP110 to those from other AKAPs reveals that AKAPs contain eight functionally conserved positions within an amphipathic helix structure that are responsible for RII interaction. Northern analysis of eight different tissues detected AKAP110 only in the testis, and in situ hybridization analysis detected AKAP110 only in round spermatids, suggesting that AKAP110 is a protein found only in male germ cells. Sperm cells contain both RI, located primarily in the acrosomal region of the head, and RII, located exclusively in the tail, regulatory subunits of PKA. Immunocytochemical analysis detected AKAP110 in the acrosomal region of the sperm head and along the entire length of the principal piece. These data suggest that AKAP110 shares compartments with both RI and RII isoforms of PKA and may function as a regulator of both motility- and head-associated functions such as capacitation and the acrosome reaction.

The objectives of this study were to (a) estimate the prevalence of auditory dys-synchrony in Mysore, a city of one million population in Southern India and, (b) present the results of audiological testing of this clinical population as well as the relationship between these figures. A register-based study design was employed wherein the results of audiological tests of all patients who visited the Department of Audiology, All India Institute of Speech and Hearing between January 2000 and December 2003 were reviewed. Results showed that the prevalence of auditory dys-synchrony was around 1 in 183 in individuals with sensory neural hearing loss. Behavioural thresholds and speech identification scores were variable. Around 60% of the individuals had no measurable speech identification scores. There was no relation between the hearing thresholds and speech identification scores or between otoacoustic emissions and speech identification scores. These results indicate that auditory dys-synchrony is not an extremely rare disorder.

The long-term goal of our work is to understand biochemical mechanisms underlying sperm motility and fertility. In a recent study we showed that tyrosine phosphorylation of a 55-kDa protein varied in direct proportion to motility. Tyrosine phosphorylation of the protein was low in immotile compared to motile epididymal sperm. Inhibition or stimulation of motility by high calcium levels or cAMP, respectively, results in a corresponding decrease or increase in tyrosine phosphorylation of the 55-kDa protein. Here we report purification and identification of this motility-associated protein. Soluble extracts from bovine caudal epididymal sperm were subjected to DEAE-cellulose, Affi-Gel blue, and cellulose phosphate chromatography. Tyrosine phosphate immunoreactive fractions contained glycogen synthase kinase-3 (GSK-3) activity, suggesting a possible correspondence between these proteins. This suggestion was verified by Western blot analyses following one-dimensional and two-dimensional gel electrophoresis of the purified protein using monoclonal and affinity-purified polyclonal antibodies against the catalytic amino-terminus and carboxy-terminus regions of GSK-3. Further confirmation of the identity of these proteins came from Western blot analysis using antibodies specific to the tyrosine phosphorylated GSK-3. Using this antibody, we also showed that GSK-3 tyrosine phosphorylation was high in motile compared to immotile sperm. Immunocytochemistry revealed that GSK-3 is present in the flagellum and the anterior portion of the sperm head. These data suggest that GSK-3, regulated by phosphorylation, could be a key element underlying motility initiation in the epididymis and regulation of mature sperm function.

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Neuronal growth regulator 1 (NEGR1) belongs to the immunoglobulin (IgLON) superfamily of cell adhesion molecules involved in cortical layering. Recent functional and genomic studies implicate the role of NEGR1 in a wide spectrum of psychiatric disorders, such as major depression, schizophrenia and autism. Here, we investigated the impact of Negr1 deficiency on brain morphology, neuronal properties and social behavior of mice. In situ hybridization shows Negr1 expression in the brain nuclei which are central modulators of cortical-subcortical connectivity such as the island of Calleja and the reticular nucleus of thalamus. Brain morphological analysis revealed neuroanatomical abnormalities in Negr1 −/− mice, including enlargement of ventricles and decrease in the volume of the whole brain, corpus callosum, globus pallidus and hippocampus. Furthermore, decreased number of parvalbumin-positive inhibitory interneurons was evident in Negr1 −/− hippocampi. Behaviorally, Negr1 −/− mice displayed hyperactivity in social interactions and impairments in social hierarchy. Finally, Negr1 deficiency resulted in disrupted neurite sprouting during neuritogenesis. Our results provide evidence that NEGR1 is required for balancing the ratio of excitatory/inhibitory neurons and proper formation of brain structures, which is prerequisite for adaptive behavioral profiles. Therefore, Negr1 −/− mice have a high potential to provide new insights into the neural mechanisms of neuropsychiatric disorders.

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