Actin-related protein ACTL7B ablation leads to OAT with multiple morphological abnormalities of the flagellum and male infertility in mice†.

The formation of fertilisation-competent sperm requires spermatid morphogenesis (spermiogenesis), a poorly understood program that involves complex coordinated restructuring and specialised cytoskeletal structures. A major class of cytoskeletal regulators are the actin-related proteins (ARPs), which include conventional actin variants, and related proteins that play essential roles in complexes regulating actin dynamics, intracellular transport, and chromatin remodeling. Multiple testis-specific ARPs are well conserved among mammals, but their functional roles are unknown.

Rhox13 is required for a quantitatively normal first wave of spermatogenesis in mice.

We previously described a novel germ cell-specific X-linked reproductive homeobox gene (Rhox13) that is upregulated at the level of translation in response to retinoic acid (RA) in differentiating spermatogonia and preleptotene spermatocytes. We hypothesize that RHOX13 plays an essential role in male germ cell differentiation, and have tested this by creating a Rhox13 gene knockout (KO) mouse. Rhox13 KO mice are born in expected Mendelian ratios, and adults have slightly reduced testis weights, yet a full complement of spermatogenic cell types.

Targeting the Gdnf Gene in peritubular myoid cells disrupts undifferentiated spermatogonial cell development.

Spermatogonial stem cells (SSCs) are a subpopulation of undifferentiated spermatogonia located in a niche at the base of the seminiferous epithelium delimited by Sertoli cells and peritubular myoid (PM) cells. SSCs self-renew or differentiate into spermatogonia that proliferate to give rise to spermatocytes and maintain spermatogenesis. Glial cell line-derived neurotrophic factor (GDNF) is essential for this process.

Disrupting Cyclin Dependent Kinase 1 in Spermatocytes Causes Late Meiotic Arrest and Infertility in Mice.

While cyclin dependent kinase 1 (CDK1) has a critical role in controlling resumption of meiosis in oocytes, its role has not been investigated directly in spermatocytes. Unique aspects of male meiosis led us to hypothesize that its role is different in male meiosis than in female meiosis. We generated a conditional knockout (cKO) of the Cdk1 gene in mouse spermatocytes to test this hypothesis.

Medical resource use, disturbance of daily life and burden of hypoglycemia in insulin-treated patients with diabetes: results from a European online survey.

Hypoglycemia is common in patients with diabetes, and any severe hypoglycemic event can increase the fear of future hypoglycemic events. To try to reduce hypoglycemic events, many patients with diabetes maintain their blood glucose levels with a 'safety margin' (i.e.

Heat shock protein 2 promoter drives Cre expression in spermatocytes of transgenic mice.

We generated transgenic mouse line C57BL/6-Tg(Hspa2-cre)1Eddy/J (Hspa2-cre), which expresses cre-recombinase under the control of a 907-bp fragment of the heat shock protein 2 (Hspa2) gene promoter. Transgene expression was determined using Gt(ROSA)26Sor(tm1Sor)/J (ROSA26) and Tg(CAG-Bgeo/GFP)21Lbe/J (Z/EG) reporter strains and RT-PCR and immunohistochemistry assays. Hspa2-cre expression mimicked the spermatogenic cell-specific expression of endogenous HSPA2 within the testis, being first observed in leptotene/zygotene spermatocytes.

Self-monitoring of blood glucose (SMBG) in patients with type 2 diabetes on oral anti-diabetes drugs: cost-effectiveness in France, Germany, Italy, and Spain.

Objective: Stakeholders in Europe remain interested in assessments of country-specific value of self-monitoring of blood glucose (SMBG) for patients with type 2 diabetes treated with oral anti-diabetes drugs (OADs). This study used the IMS-CORE Diabetes Model to project the long-term (40-year) cost-effectiveness of SMBG at once, twice, or three times per day (vs. no SMBG) for this population from national reimbursement system perspectives in France, Germany, Italy, and Spain.

Peripheral and central sensitization in remote spinal cord regions contribute to central neuropathic pain after spinal cord injury.

Central neuropathic pain (CNP) developing after spinal cord injury (SCI) is described by the region affected: above-level, at-level and below-level pain occurs in dermatomes rostral, at/near, or below the SCI level, respectively. People with SCI and rodent models of SCI develop above-level pain characterized by mechanical allodynia and thermal hyperalgesia. Mechanisms underlying this pain are unknown and the goals of this study were to elucidate components contributing to the generation of above-level CNP.

Phosphoglycerate kinase 2 (PGK2) is essential for sperm function and male fertility in mice.

Phosphoglycerate kinase 2 (PGK2), an isozyme that catalyzes the first ATP-generating step in the glycolytic pathway, is encoded by an autosomal retrogene that is expressed only during spermatogenesis. It replaces the ubiquitously expressed phosphoglycerate kinase 1 (PGK1) isozyme following repression of Pgk1 transcription by meiotic sex chromosome inactivation during meiotic prophase and by postmeiotic sex chromatin during spermiogenesis. The targeted disruption of Pgk2 by homologous recombination eliminates PGK activity in sperm and severely impairs male fertility, but does not block spermatogenesis.

The role of TRPV1 receptors in pain evoked by noxious thermal and chemical stimuli.

Transient receptor potential receptors (TRP) on primary afferent neurons respond to noxious and/or thermal stimuli. TRPV1 receptors can be activated by noxious heat, acid, capsaicin and resiniferatoxin, leading to burning pain or itch mediated by discharges in C polymodal and Adelta mechano-heat nociceptors and in central neurons, including spinothalamic tract (STT) cells. Central nociceptive transmission involves both non-NMDA and NMDA receptors, and inhibitory interneurons as well as projection neurons contribute to the neural interactions.

Impaired sperm fertilizing ability in mice lacking Cysteine-RIch Secretory Protein 1 (CRISP1).

Mammalian fertilization is a complex multi-step process mediated by different molecules present on both gametes. Epididymal protein CRISP1, a member of the Cysteine-RIch Secretory Protein (CRISP) family, was identified by our laboratory and postulated to participate in both sperm-zona pellucida (ZP) interaction and gamete fusion by binding to egg-complementary sites. To elucidate the functional role of CRISP1 in vivo, we disrupted the Crisp1 gene and evaluated the effect on animal fertility and several sperm parameters.

Expression of the gene for mouse lactate dehydrogenase C (Ldhc) is required for male fertility.

The lactate dehydrogenase (LDH) protein family members characteristically are distributed in tissue- and cell type-specific patterns and serve as the terminal enzyme of glycolysis, catalyzing reversible oxidation reduction between pyruvate and lactate. They are present as tetramers, and one family member, LDHC, is abundant in spermatocytes, spermatids, and sperm, but also is found in modest amounts in oocytes. We disrupted the Ldhc gene to determine whether LDHC is required for spermatogenesis, oogenesis, and/or sperm and egg function.

The somatosensory system, with emphasis on structures important for pain.

Santiago Ramón y Cajal described a number of somatosensory structures, including several associated with pain, in his major work on the Histology of the Nervous System of Man and Vertebrates. Our knowledge of such structures has been considerably expanded since Cajal because of the introduction of a number of experimental approaches that were not available in his time. For example, Cajal made several drawings of peripheral mechanoreceptors, as well as of bare nerve endings, but later work by others described additional somatosensory receptors and investigated the ultrastructure of bare nerve endings.

Spinal CGRP1 receptors contribute to supraspinally organized pain behavior and pain-related sensitization of amygdala neurons.

CGRP receptor activation has been implicated in peripheral and central sensitization. The role of spinal CGRP receptors in supraspinal pain processing and higher integrated pain behavior is not known. Here we studied the effect of spinal inhibition of CGRP1 receptors on supraspinally organized vocalizations and activity of amygdala neurons.

Intradermal injection of capsaicin induces acute substance P release from rat spinal cord dorsal horn.

Increased release of substance P (SP) from the dorsal horn following noxious stimuli, such as spinal administration of capsaicin, has been demonstrated in previous studies. However, changes in the release of SP in response to intradermal injection of capsaicin still remain unknown. This study was designed to demonstrate in vivo spinal SP release following intradermal injection of capsaicin (3%, 50 microl), using polyimide tubing with a single hole introduced into the rat dorsal horn.

Pain-related synaptic plasticity in spinal dorsal horn neurons: role of CGRP.

Background: The synaptic and cellular mechanisms of pain-related central sensitization in the spinal cord are not fully understood yet. Calcitonin gene-related peptide (CGRP) has been identified as an important molecule in spinal nociceptive processing and ensuing behavioral responses, but its contribution to synaptic plasticity, cellular mechanisms and site of action in the spinal cord remain to be determined. Here we address the role of CGRP in synaptic plasticity in the spinal dorsal horn in a model of arthritic pain.

The effects of protein phosphatase inhibitors on the duration of central sensitization of rat dorsal horn neurons following injection of capsaicin.

Protein kinases and phosphatases catalyze opposing reactions of phosphorylation and dephosphorylation, which may modulate the function of crucial signaling proteins in central nervous system. This is an important mechanism in the regulation of intracellular signal transduction pathways in nociceptive neurons. To explore the role of protein phosphatase in central sensitization of spinal nociceptive neurons following peripheral noxious stimulation, using electrophysiological recording techniques, we investigated the role of two inhibitors of protein phosphatase type 2A (PP2A), fostriecin and okadaic acid (OA), on the responses of dorsal horn neurons to mechanical stimuli in anesthetized rats following intradermal injection of capsaicin.

Role of the Na+-K+-2Cl- cotransporter in the development of capsaicin-induced neurogenic inflammation.

Recent behavioral and electrophysiological studies have attributed an important role to dorsal root reflexes (DRRs) in the initiation and development of neurogenic inflammation produced by intradermal capsaicin (CAP). The DRRs can occur in peptidergic fibers, resulting in peripheral release of neuromediators that produce vasodilation, plasma extravasation and subsequently hyperalgesia and allodynia. In this study, we have evaluated the effect of spinal administration of bumetanide (a blocker of the Na+-K+-2Cl- cotransporter, NKCC) on DRR activity, changes in cutaneous blood flow (vasodilation), hindpaw edema, mechanical allodynia, and hyperalgesia induced by intradermal injection of 1% CAP in Sprague-Dawley rats.

John Eccles' studies of spinal cord presynaptic inhibition.

Presynaptic inhibition is one of many areas of neurophysiology in which Sir John Eccles did pioneering work. Frank and Fuortes first described presynaptic inhibition in 1957. Subsequently, Eccles and his colleagues characterized the process more fully and showed its relationship to primary afferent depolarization.

Protein phosphatase 2A regulates central sensitization in the spinal cord of rats following intradermal injection of capsaicin.

Background: Intradermal injection of capsaicin into the hind paw of rats induces spinal cord central sensititzation, a process in which the responsiveness of central nociceptive neurons is amplified. In central sensitization, many signal transduction pathways composed of several cascades of intracellular enzymes are involved. As the phosphorylation state of neuronal proteins is strictly controlled and balanced by the opposing activities of protein kinases and phosphatases, the involvement of phosphatases in these events needs to be investigated.

Activation of protein kinase B/Akt signaling pathway contributes to mechanical hypersensitivity induced by capsaicin.

We investigated the involvement of the protein kinase B/Akt (PKB/Akt) signaling pathway in the mechanical hypersensitivity induced in rats by capsaicin. Intradermal injection of capsaicin results in activation of PKB/Akt in the lumbar spinal cord, most prominently in the dorsal horn, starting by 5 min after capsaicin injection and lasting at least 1h. The activated PKB/Akt in the spinal cord is in neurons, since phospho-PKB/Akt (p-PKB/Akt) colocalizes with the neuronal marker, neuronal-specific nuclear protein (NeuN).

Sperm tail abnormalities in mutant mice with neo(r) gene insertion into an intron of the keratin 9 gene.

Keratin 9 (K9) is one of the components of the perinuclear ring of the manchette found in developing spermatids but is predominantly expressed in the epidermis of the footpad (palm and sole in human epidermis). As an initial step to determine the function of K9 protein in sperm development, we have generated a mutant mouse by homologous recombination of the targeting vector containing the disrupted K9 gene in which the neo(r) gene was inserted into the intron 6. This insertion resulted in the expression of two K9 mRNAs: a wild-type K9 mRNA, in which intron 6 with the neo(r) gene was completely spliced out, and a mutated form in which only a portion of the intron 6 between neo(r) gene and exon 7 was spliced out.

Protein phosphatase modulates the phosphorylation of spinal cord NMDA receptors in rats following intradermal injection of capsaicin.

The present study investigates the role of serine/threonine protein phosphatase 2A (PP2A) in the modulation of the phosphorylation of the NR1 and NR2B subunits of NMDA receptors in the spinal cord of rats following intradermal injection of capsaicin. The effects of a specific inhibitor of PP2A, fostriecin, on the expression of NR1, phospho-NR1, NR2B, and phospho-NR2B subunits of the NMDA receptor in the spinal cord of rats following noxious stimulation were examined. After continually perfusing with ACSF or fostriecin (3 microM) through a previously implanted microdialysis fiber for 30 min, central sensitization was initiated by injection of capsaicin into the plantar surface of the left paw of rats.

Protein kinase A-dependent enhanced NMDA receptor function in pain-related synaptic plasticity in rat amygdala neurones.

Mechanisms of pain-related plasticity in the amygdala, a key player in emotionality, were studied at the cellular and molecular levels in a model of arthritic pain. The influence of the arthritis pain state induced in vivo on synaptic transmission and N-methyl-d-aspartate (NMDA) receptor function was examined in vitro using whole-cell voltage-clamp recordings of neurones in the latero-capsular part of the central nucleus of the amygdala (CeA), which is now defined as the 'nociceptive amygdala'. Synaptic transmission was evoked by electrical stimulation of afferents from the pontine parabrachial area (part of the spino-parabrachio-amygdaloid pain pathway) in brain slices from control rats and from arthritic rats.