Macroprolactin in mothers and their babies: what is its origin?

OBJECTIVES: Macroprolactinemia is one of the major causes of hyperprolactinemia. The aim of this study was to clarify the origin of macroprolactin (macro-PRL). METHODS: We examined macro-PRL in the sera of 826 pregnant women and in those of their babies' umbilical cords at delivery. Macro-PRL was evaluated by precipitation with polyethylene glycol (PEG), gel filtration chromatography (GFC), and absorption with protein G (PG). RESULTS: We detected macro-PRL in 16 out of the 826 pregnant women (1.94 %) and in 14 of their babies, which may indicate the possibility of hereditary origin of macro-PRL. However, the macro-PRL ratios of the babies correlated positively with those of their mothers (r=0.72 for GFC, p<0.001 and r=0.77 for PG, p<0.001), suggesting that the immunoglobulin (Ig)G-type anti-PRL autoantibodies might be actively transferred to babies via the placenta and form macro-PRL by binding to their babies' PRL or PRL-IgG complexes may possibly pass through the placenta. There were two cases in which only mothers had macro-PRL, indicating that the mothers had autoantibodies that did not pass through the placenta, such as IgA, PRL bound to the other proteins or PRL aggregates. No cases were found in which only the babies had macro-PRL and their mothers did not, suggesting that macro-PRL might not arise by non-hereditary congenital causes. CONCLUSIONS: Macro-PRL in women of reproductive age might be mostly IgG-type anti-PRL autoantibody-bound PRL. The likely origin of macro-PRL in babies is the transplacental transfer of IgG-type anti-PRL autoantibodies or PRL-IgG complexes from the mothers to their babies.

Sulfamethoxazole-trimethoprim for pneumocystis pneumonia prophylaxis, causes of discontinuation and thrombocytopenia observed during administration: A single-center retrospective study.

INTRODUCTION: The development of pneumocystis pneumonia (PCP) has recently become a growing concern; thus, its prevention has become increasingly important. Sulfamethoxazole-trimethoprim (ST) is a cost-effective first-line and prophylactic treatment for PCP. However, ST administration criteria for PCP prophylaxis remain unclear and are often discontinued because of adverse events (AEs). In this study, we aimed to investigate the causes of ST discontinuation and the associated AEs using objective data. METHODS: We retrospectively analyzed the data of 162 patients admitted to Kansai Medical University Hospital between January 2018 and December 2020, who received ST for PCP prophylaxis. We compared clinical characteristics, laboratory data, and incidence of AEs between ST non-discontinuation and ST discontinuation groups. Additionally, we divided the patients into non-developing and developing thrombocytopenia (≥ Grade 1) groups based on the investigation results. RESULTS: No patients developed PCP while receiving ST. The most common causes of ST discontinuation were thrombocytopenia (37%), liver dysfunction (20%), and rash (18%). Multivariate analysis revealed thrombocytopenia (≥ Grade 1) as a factor significantly associated with ST discontinuation. Furthermore, we identified three factors correlated with thrombocytopenia (≥ Grade 1): age ≥50 years, lymphocyte count <1000/µL, and platelet count <180,000/µL. CONCLUSIONS: Patients with the aforementioned factors are at higher risk of developing thrombocytopenia (≥ Grade 1) during ST administration for PCP prophylaxis. Therefore, platelet count monitoring is essential to enhance safety and efficacy of ST treatment. Nonetheless, further research is warranted to explore additional implications and interventions.

[A Case of Thrombocytopenia Following Minocycline Administration].

Drug-induced thrombocytopenia is associated with bleeding tendency and suggests the need for the immediate suspected drug withdrawal. Patients with drug-induced thrombocytopenia usually experience an acute drop in platelet (PLT) levels a week or two after starting a new medication. Thrombocytopenia has both immune and non-immune mechanisms. Minocycline (MINO)-induced thrombocytopenia is rare; thus, there are few studies of this condition. In the present study, intravenous administration of MINO led to thrombocytopenia. The female patient was 80 years old. She was receiving radiation therapy for tongue cancer and medication for pain control. She had fever and aspiration pneumonia and was being treated with an antibacterial drug. Empiric therapy consisting of intravenous administration of tazobactam/piperacillin was performed; however, inflammation and fever did not improve. The bacterial drug was changed to vancomycin and cefmetazole. Sputum culture was positive for Enterobacter cloacae thus, we changed her treatment to MINO. Seven days after starting MINO, PLT levels were low; however, they recovered when treatment was stopped. Our findings suggest that MINO may rarely cause severe thrombocytopenia; thus, it is necessary to observe the patient's blood collection.

Telmisartan is the most effective ARB to increase adiponectin via PPARα in adipocytes.

Telmisartan and irbesartan are angiotensin II receptor blockers (ARBs) and reportedly stimulate adiponectin secretion from adipocytes via partial peroxisome proliferator-activated receptor γ (PPARγ) activation. However, quantitative evaluation among different ARBs has not been performed. Adiponectin exerts strong protection against a number of pathological events by suppressing cell death, inhibiting inflammation, and enhancing cell survival, while leptin promotes inflammation, oxidative stress, atherogenesis, and thrombosis. The aim of this study was to identify the most effective ARB enhancing adiponectin secretion without raising leptin secretion from human white adipocytes (HWAs). Among seven ARBs (azilsartan, candesartan, irbesartan, losartan, olmesartan, telmisartan, and valsartan), telmisartan was the most effective ARB for the increase of adiponectin secretion and irbesartan was the second, whereas the other ARBs at 1 µM had no effect on adiponectin secretion. GW9662, a PPARγ antagonist, completely blocked pioglitazone (PPARγ agonist)-induced adiponectin secretion and mRNA expression, whereas it unexpectedly blocked neither telmisartan- nor irbesartan-induced adiponectin secretion and mRNA expression but rather increased them. GW6471, PPARα antagonist, and siRNA for PPARα suppressed telmisartan- and irbesartan-induced adiponectin secretion, suggesting that PPARα is the main target of these ARBs to increase adiponectin secretion in HWAs. Leptin secretion was not affected by any ARBs at 1 µM and GW9662 significantly decreased the basal secretion of leptin, suggesting that basal leptin secretion is regulated in a PPARγ-dependent manner. We conclude that telmisartan is the most effective ARB to increase adiponectin secretion via PPARα without raising leptin secretion from HWAs.

Disruption of Gap Junction-Mediated Intercellular Communication in the Spiral Ligament Causes Hearing and Outer Hair Cell Loss in the Cochlea of Mice.

It is well-known that outer hair cell (OHC) loss occurs in the cochlea of animal models of permanent hearing loss induced by intense noise exposure. Our earlier studies demonstrated the production of hydroxynonenal and peroxynitrite, as well as the disruption of gap junction-mediated intercellular communication (GJIC), in the cochlear spiral ligament prior to noise-induced sudden hearing loss. The goal of the present study was to evaluate the mechanism underlying cochlear OHC loss after sudden hearing loss induced by intense noise exposure. In organ of Corti explant cultures from mice, no significant OHC loss was observed after in vitro exposure to 4-hydroxynonenal (a product of lipid peroxidation), H2O2, SIN-1 (peroxynitrite generator), and carbenoxolone (a gap junction inhibitor). Interestingly, in vivo intracochlear carbenoxolone injection through the posterior semicircular canal caused marked OHC and hearing loss, as well as the disruption of gap junction-mediated intercellular communication in the cochlear spiral ligament. However, no significant OHC loss was observed in vivo in animals treated with 4-hydroxynonenal and SIN-1. Taken together, our data suggest that disruption of GJIC in the cochlear lateral wall structures is an important cause of cochlear OHC loss in models of hearing loss, including those induced by noise.

In vivo depletion of endogenous glutathione facilitates trimethyltin-induced neuronal damage in the dentate gyrus of mice by enhancing oxidative stress.

Acute treatment with trimethyltin chloride (TMT) produces neuronal damage in the hippocampal dentate gyrus of mice. We investigated the in vivo role of glutathione in mechanisms associated with TMT-induced neural cell damage in the hippocampus by examining mice depleted of endogenous glutathione by prior treatment with 2-cyclohexen-1-one (CHO). In the hippocampus of animals treated with CHO 1h beforehand, a significant increase was seen in the number of single-stranded DNA-positive cells in the dentate gyrus when determined on day 2 after the injection of TMT at a dose of 2.0 mg/kg. Immunoblot analysis revealed that CHO treatment induced a significant increase in the phosphorylation of c-Jun N-terminal kinase in the cytosolic and nuclear fractions obtained from the dentate gyrus at 16 h after the TMT injection. There was also a concomitant increase in the level of phospho-c-Jun in the cytosol at 16 h after the injection. Expectedly, lipid peroxidation was increased by TMT in the hippocampus, and was enhanced by the CHO treatment. Moreover, CHO treatment facilitated behavioral changes induced by TMT. Taken together, our data indicate that TMT-induced neuronal damage is caused by activation of cell death signals induced at least in part by oxidative stress. We conclude that endogenous glutathione protectively regulates neuronal damage induced by TMT by attenuating oxidative stress.

Lack of trimethyltin (TMT)-induced elevation of plasma corticosterone in PACAP-deficient mice.

Accumulating evidence implicates pituitary adenylate cyclase-activating polypeptide (PACAP) in a number of stress responses. By using PACAP-deficient mice, PACAP has been shown to have an in vivo role in the regulation of the sympathoadrenal axis, but a role in regulating the hypothalamo-pituitary-adrenal (HPA) axis has not been fully addressed. To elucidate the role of endogenous PACAP in HPA axis regulation during pathological conditions, mice lacking the Adcyap1 gene encoding the neuropeptide PACAP (Adcyap1-/-) were injected with trimethyltin (TMT), a neurotoxin known to induce neuronal damage and several systemic responses including elevated plasma corticosterone levels. In wild-type controls, TMT induced transient decreases in water and food intake, with a concomitant decrease in body weight; however, no significant changes were observed in Adcyap1-/- mice. Basal corticosterone levels were not significantly different between the mutant and wild-type mice. TMT induced a marked elevation of plasma corticosterone above basal levels in wild-type mice but no significant increase was seen in Adcyap1-/- mice. The present article suggests that PACAP is involved in the corticosterone release in some pathological conditions but not in the basal state.

Expression of m-Golsyn/Syntabulin gene during mouse brain development.

We recently isolated the cDNA for the mouse Golsyn/Syntabulin (m-Golsyn/Syntabulin) gene and mapped it to mouse chromosome 15B3.2 syntenic with human chromosome 8q23, on which a locus responsible for primary open-angle glaucoma had been located. In the present study, we examined the expression of m-Golsyn/Syntabulin protein in various regions of mouse brain and its developmental changes by use of anti-GOLSYN antibody. m-Golsyn/Syntabulin protein was detected in various brain regions at embryonic day 14 and throughout the postnatal stages. Furthermore, as the histogenesis and maturation of brain proceeded, strong expression of the protein became detectable in cells of the choroid plexus, piriform cortex, pyramidal cell layer, and Purkinje cell layer. In situ hybridization analysis of the mouse brain revealed that localization of the m-Golsyn/Syntabulin transcript was very similar to that of m-Golsyn/Syntabulin protein, confirming the high-level expression of the m-Golsyn/Syntabulin gene in the specific brain regions. High-level expression of m-Golsyn/Syntabulin protein was also observed in the ocular tissues including the ciliary body, which is known as a site for the production of aqueous humor. These results may indicate a significant role for this protein in neuronal cells and other types of cells such as those of the choroid plexus and ciliary body.

Molecular cloning of the m-Golsyn gene and its expression in the mouse brain.

The mouse ortholog of the human GOLSYN gene, termed the m-Golsyn gene, was isolated and mapped to the region on mouse chromosome 15B3.2 syntenic with human chromosome 8q23. Three mRNA species (type la, 1b, and type 2) were produced by use of alternative transcription initiation points and alternative splicing events. The type 1 mRNAs were expressed only in the brain, whereas the type 2 was detected in various tissues. m-Golsyn protein was expressed in various tissues including the brain. Immunohistochemical study of m-Golsyn protein showed its prominent expression in the neuronal cells in various regions of the brain and strong expression in the choroid plexus ependymal cells lining the ventricles. m-Golsyn protein was found to be homologous to syntaphilin, a regulator of synaptic vesicle exocytosis. These results indicate that the m-Golsyn protein may play an important role in intracellular protein transport in neuronal cells of the brain.

Regeneration of granule neurons after lesioning of hippocampal dentate gyrus: evaluation using adult mice treated with trimethyltin chloride as a model.

The hippocampal dentate gyrus in adult animals is known to contain neural progenitors that proliferate and differentiate into neurons in response to brain injury. Little has been observed, however, on regeneration of the granule cell layer of the dentate gyrus that has been directly injured. Using trimethyltin (TMT)-treated mice as an in vivo model, we evaluated the ability of this layer to regenerate after injury. The administration of TMT induced neuronal death in the dentate gyrus selectively 2 days later, with recovery of granule neurons on day 14 and thereafter. At an early stage (days 2-5) after the damage by TMT treatment, 5-bromo-2'-deoxyuridine (BrdU) incorporation into at least two different types of cells was facilitated in the dentate gyrus: BrdU-positive/neuronal nuclear antigen (NeuN)-negative cells were found predominantly in the subgranular zone and granule cell layer, whereas BrdU-positive/NeuN-positive cells were numerous in the dentate molecular layer and hilus. In addition, expression of proliferating cell nuclear antigen, nestin, NeuroD3, and doublecortin, which are markers for proliferating cells and neural progenitors/neuronal precursors, was extremely enhanced in the dentate gyrus at the early stage after treatment. Double staining revealed that BrdU was colocalized with nestin and doublecortin in the subgranular zone. Behavioral analysis revealed that TMT-induced cognition impairment was ameliorated by day 14 after the treatment. Taken together, our data indicate that the hippocampal dentate gyrus itself is capable of regenerating the neuronal cell layer through rapid enhancement of neurogenesis after injury.

In vivo activation of c-Jun N-terminal kinase signaling cascade prior to granule cell death induced by trimethyltin in the dentate gyrus of mice.

The systemic administration of trimethyltin (TMT, 2.8 mg/kg, i.p.) induced granule cell death in the mouse dentate gyrus selectively 2 days later. The administration of TMT not only enhanced activator protein-1 DNA binding, along with an increase in expression of c-Jun and Fra-2, in the hippocampus 1 day later, but also facilitated phosphorylation of c-Jun N-terminal kinase (JNK) within the cytosol and nucleus. There was also a concomitant increase in the level of phosphorylated JNK kinase (MKK4/SEK1) in the cytosol 16-24 h after the administration. Moreover, TMT markedly elevated endogenous levels of both phosphorylated c-Jun and phosphorylated activating transcription factor-2 (ATF-2), in addition to activating JNK activity in the nuclear extracts obtained 16-24 h post-administration. Immunohistochemical analysis revealed that whereas Fra-2 and phosphorylated ATF-2 were expressed in the CA1 pyramidal cell layer predominantly, phosphorylated c-Jun was observed in both the CA1 pyramidal and dentate granule cell layers after TMT administration. Taken together, our data indicate that TMT activates the JNK pathway in the hippocampus prior to neuronal cell death. The prior activation of this pathway could be at least in part involved in the TMT-induced neural damage seen in the dentate granule cells of mice.

Enhanced binding activity of nuclear antioxidant-response element through possible formation of Nrf2/Fos-B complex after in vivo treatment with kainate in murine hippocampus.

To evaluate whether in vivo glutamate signals modulate signaling processes mediated by antioxidant-response element (ARE), we examined ARE binding in nuclear extracts from the hippocampus after in vivo treatment of mice with kainate. Enhancement of ARE binding was found at 2 h to 3 days after kainate treatment. Supershift analysis indicated possible involvement of Nrf2, Fos-B, and c-Fos in ARE binding in hippocampal nuclear extracts obtained from kainate-treated animals. On super-supershift analysis by combination of these antibodies, ARE probe/protein complex was shifted by the anti-Fos-B antibody alone, but not by the anti-c-Fos antibody alone, and further addition of the anti-Nrf2 antibody dramatically eliminated binding of the complex shifted by the anti-Fos-B antibody in hippocampal nuclear extracts from kainate-treated animals. Kainate treatment induced a profound increase in levels of c-Fos and Fos-B, without markedly affecting that of Nrf2 in nuclear extracts from the hippocampus. Co-localization of Nrf2 with both Fos-B and c-Fos was found in neuronal cell layers of the hippocampus in kainate-treated animals. RT-PCR analysis revealed that kainate treatment increases glutathione-S-transferase mRNA level in the hippocampus. Taken together, kainate signals may enhance nuclear ARE binding through an interaction between constitutive Nrf2 with inducible Fos-B expressed in murine hippocampus.

In vivo neuroprotective role of NMDA receptors against kainate-induced excitotoxicity in murine hippocampal pyramidal neurons.

Activation of NMDA receptors has been shown to induce either neuronal cell death or neuroprotection against excitotoxicity in cultured cerebellar granule neurons in vitro. We have investigated the effects of pretreatment with NMDA on kainate-induced neuronal cell death in mouse hippocampus in vivo. The systemic administration of kainate (30 mg/kg), but not NMDA (100 mg/kg), induced severe damage in pyramidal neurons of the hippocampal CA1 and CA3 subfields 3-7 days later, without affecting granule neurons in the dentate gyrus. An immunohistochemical study using an anti-single-stranded DNA antibody and TdT-mediated dUTP nick end labeling analysis both revealed that kainate, but not NMDA, induced DNA fragmentation in the CA1 and CA3 pyramidal neurons 1-3 days after administration. Kainate-induced neuronal loss was completely prevented by the systemic administration of NMDA (100 mg/kg) 1 h to 1 day previously. No pyramidal neuron was seen with fragmented DNA in the hippocampus of animals injected with kainate 1 day after NMDA treatment. The neuroprotection mediated by NMDA was prevented by the non-competitive NMDA receptor antagonist MK-801. Taken together these results indicate that in vivo activation of NMDA receptors is capable of protecting against kainate-induced neuronal damage through blockade of DNA fragmentation in murine hippocampus.