A Potential Role of NFIL3 in Atherosclerosis

Nuclear factor interleukin-3 (NFIL3), a proline- and acidic-residue-rich (PAR) bZIP transcription factor, is called the E4 binding protein 4 (E4BP4) as well, which is relevant to regulate the circadian rhythms and the viability of cells. More and more evidence has shown that NFIL3 is associated with different cardiovascular diseases. In recent years, it has been found that NFIL3 has significant functions in the progression of atherosclerosis (AS) via the regulation of inflammatory response, macrophage polarization, some immune cells and lipid metabolism. In this overview, we sum up the function of NFIL3 during the development of AS and offer meaningful views how to treat cardiovascular disease related to AS.

Apelin-13: A Protective Role in Vascular Diseases

Vascular disease is a common problem with high mortality all over the world. Apelin-13, a key subtype of apelin, takes part in many physiological and pathological responses via regulating many target genes and target molecules or participating in many signaling pathways. More and more studies have demonstrated that apelin-13 is implicated in the onset and progression of vascular disease in recent years. It has been shown that apelin-13 could ameliorate vascular disease by inhibiting inflammation, restraining apoptosis, suppressing oxidative stress, and facilitating autophagy. In this article, we sum up the progress of apelin-13 in the occurrence and development of vascular disease and offer some insightful views about the treatment and prevention strategies of vascular disease.

The Potential Relationship Between Cardiovascular Diseases and Monkeypox

Mpox, a novel epidemic disease, has broken out the period of coronavirus disease 2019 since May 2022, which was caused by the mpox virus. Up to 12 September 2023, there are more than 90,439 confirmed mpox cases in over 115 countries all over the world. Moreover, the outbreak of mpox in 2022 was verified to be Clade II rather than Clade I. Highlighting the significance of this finding, a growing body of literature suggests that mpox may lead to a series of cardiovascular complications, including myocarditis and pericarditis. It is indeed crucial to acquire more knowledge about mpox from a perspective from the clinical cardiologist. In this review, we would discuss the epidemiological characteristics and primary treatments of mpox to attempt to provide a framework for cardiovascular physicians.

Dual-polarity metamaterial circular polarizer based on giant extrinsic chirality

Chirality is ubiquitous in nature. The associated optical activity has received much attention due to important applications in spectroscopy, analytical chemistry, crystallography and optics, however, artificial chiral optical materials are complex and difficult to fabricate, especially in the optical range. Here, we propose an ultrathin dual-polarity metamaterial circular polarizer by exploiting the mechanism of giant extrinsic chirality. The polarity of the circular polarizer with large suppression of linear anisotropy can be switched by changing the sign of incident angle. The microwave experiments and optical simulations demonstrate that the large angle of incidence facilitates the high-efficiency circular polarizer, which can be realized in the whole spectra from microwave to visible frequencies. The ultrathin single-layer metamaterials with extrinsic chirality will be a promising candidate for circular polarization devices.

A novel serine protease of the mammalian HtrA family is up-regulated in mouse uterus coinciding with placentation

This paper characterizes a novel gene, previously identified as uniquely regulated at implantation in mouse uterus. We cloned its full mRNA sequence encoding a serine protease possessing an IGF-binding domain and named it pregnancy-related serine protease (PRSP). PRSP is structurally similar to mammalian HtrA1 (56% amino acid similarity). Northern analysis revealed that the expression of PRSP mRNA was low before pregnancy, but it was increased at implantation and markedly up-regulated post-implantation. In-situ hybridization localized low levels of mRNA expression to the epithelium and stroma during very early pregnancy, but high expression to the decidual cells on day 8.5, primarily at the mesometrial pole where the placenta was forming. By day 10.5, PRSP mRNA was detected in the placenta. We also cloned an alternatively spliced PRSP mRNA that is expressed at a very low level. We located PRSP gene on chromosome 5 and established its intron/exon structure, which unambiguously explains how the two mRNA variants are produced through alternative splicing. Based on PRSP protein domain structure and its unique expression during pregnancy, we propose that PRSP plays an important role in the formation/function of the placenta.

Identification and cloning of two isoforms of human high-temperature requirement factor A3 (HtrA3), characterization of its genomic structure and comparison of its tissue distribution with HtrA1 and HtrA2

In the present study, we identified an additional member of the human high-temperature requirement factor A (HtrA) protein family, called pregnancy-related serine protease or HtrA3, which was most highly expressed in the heart and placenta. We cloned the full-length sequences of two forms (long and short) of human HtrA3 mRNA, located the gene on chromosome 4p16.1, determined its genomic structure and revealed how the two mRNA variants are produced through alternative splicing. The alternative splicing was also verified by Northern blotting. Four distinct domains were found for the long form HtrA3 protein: (i) an insulin/insulin-like growth factor binding domain, (ii) a Kazal-type S protease-inhibitor domain, (iii) a trypsin protease domain and (iv) a PDZ domain. The short form is identical to the long form except it lacks the PDZ domain. Comparison of all members of human HtrA proteins, including their isoforms, suggests that both isoforms of HtrA3 represent active serine proteases, that they may have different substrate specificities and that HtrA3 may have similar functions to HtrA1. All three HtrA family members showed very different mRNA-expression patterns in 76 human tissues, indicating a specific function for each. Interestingly, both HtrA1 and HtrA3 are highly expressed in the placenta. Identification of the tissue-specific function of each HtrA family member is clearly of importance.

Specific and transient up-regulation of proprotein convertase 6 at the site of embryo implantation and identification of a unique transcript in mouse uterus during early pregnancy

The present investigation was conducted to identify and characterize an mRNA that was found by RNA differential display to be uniquely regulated at the sites of embryo implantation in mouse uterus. This mRNA was upregulated at the sites of blastocyst attachment at implantation and was identified as proprotein convertase 6 (PC6). PC6 mRNA level was low in the nonpregnant and early pregnant uterus before embryo implantation commenced (before Day 4.5, vaginal plug = Day 0). During the initiation and progression of blastocyst attachment (around Day 4.5), the mRNA was dramatically upregulated only at the implantation sites. The increased transcription was maintained on Day 5.5; the mRNA level declined slightly on Day 6.5 and then fell sharply to reach the nonpregnant level around Days 8.5-10.5. Thus, the upregulation is transient and coincides with the period of embryo attachment and implantation; it is also very specific to implantation sites. In situ hybridization analysis localized the mRNA expression predominantly in the decidual cells immediately surrounding the implanting embryo at the antimesometrial pole. Additionally, multiple mRNA species resulting from alternative splicing were observed in the uterus, as previously reported in the intestine and brain, and further analysis of these transcripts identified a uterine-specific PC6 mRNA. These data lead us to suggest that PC6 plays an important role in the processes of stromal cell decidualization and embryo implantation.

Direct modification of somatotrope function by long-term leptin treatment of primary cultured ovine pituitary cells

Leptin is produced primarily in adipocytes and regulates body energy balance. A close link between leptin and pituitary hormones, including GH, has been reported. The mechanisms employed by leptin to influence somatotropes are not clear, however. Here we report a direct action of recombinant ovine leptin on primary cultured ovine somatotropes by analyzing the levels of mRNA encoding for GH or the receptors for GHRH (GHRH-R) and GH-releasing peptides (GHRP). Treatment of ovine somatotropes with leptin (10(-7)-10(-9) M) for 1-3 d reduced the mRNA levels encoding GH and GHRH-R, but increased GHRP receptor mRNA levels in a time- and dose-dependent manner. Three-day treatment of cells with leptin decreased the GH response to GHRH stimulation, but the GH response to GHRP-2 stimulation was increased. The combined effect of GHRH and GHRP-2 on GH secretion was not altered by treatment of the cells with leptin. These results demonstrated a direct action of leptin on ovine pituitary cells, leading to a reduced sensitivity of somatotropes to GHRH. It is also suggested that GHRP may be useful to correct the decrease in GHRH-induced GH secretion by leptin.

The in vitro effect of leptin on growth hormone secretion from primary cultured ovine somatotrophs

Although existing data suggest an influence of leptin on circulating levels of growth hormone (GH), the action site and properties of leptin are still controversial. Using primary cultured ovine pituitary cells, we studied the direct effect of leptin on the secretion of GH. Pituitary cells were dissociated by collagenase and subjected to Percoll gradient centrifugation to enrich the somatotroph population to 60-80% of cells. Treatment of primary cultured ovine somatotrophs with leptin (10(-9)-10(-7) M) for 30 min did not affect basal, GH-releasing hormone (GHRH) (10(-7) M)- or GH-releasing peptide-2 (GHRP-2)(10(-7) M)-stimulated GH secretion. Following treatment of cells for 1-3 d with leptin, GHRH-stimulated GH secretion was reduced and GHRP-2-stimulated GH secretion increased. The combined effect of GHRH and GHRP-2 on GH secretion was not altered by the treatment of cells with leptin for 3 d. GHRH receptor mRNA levels in cultured somatotrophs were decreased but GHRP receptor mRNA levels were increased by 3-d leptin treatment. These results suggest that leptin has a long-term effect on somatotrophs to reduce GHRH receptor synthesis leading to a decrease in GHRH-stimulated GH secretion. Leptin appears, however, to have an opposite effect on GHRP receptor synthesis leading to an increase in GHRP-stimulated GH secretion.

Uterine expression of alternatively spliced mRNAs of mouse splicing factor SC35 during early pregnancy

RNA differential display was applied to identify genes critical for the establishment of pregnancy in the mouse. One of the gene fragments identified was homologous to human SC35 splicing factor; the mouse counterpart had not then been cloned. To obtain the full cDNA sequence of the mouse gene, a cDNA library was screened and four positive clones were fully analysed. Sequencing analysis indicated that we had cloned alternatively spliced mRNA species of mouse SC35 splicing factor. A map of splicing structure for this gene's pre-mRNA was then proposed and region-specific mRNA species were tested on Northern blots. This analysis indicated that the overall expression level of SC35 mRNA was much higher in implantation sites than in inter-implantation sites in the mouse uterus during early pregnancy. The expression of alternatively spliced mRNAs for SC35 was differently regulated both during early pregnancy and by steroid hormones. Embryo-derived factors were also implicated in the up-regulation of SC35 mRNA at implantation sites. These results demonstrate, for the first time, that an essential splicing factor is regulated in a complex manner during implantation in the mouse uterus. Hence, its correct regulation could be important for the success of pregnancy.

Identification of monoclonal nonspecific suppressor factor beta (mNSFbeta) as one of the genes differentially expressed at implantation sites compared to interimplantation sites in the mouse uterus

Successful implantation requires synchronous development of and active dialogue between the maternal endometrium and the implanting blastocyst. While it is well established that appropriate maternal steroid hormones are essential for endometrial preparation for implantation, the molecular events at the actual site of implantation are still little understood. The aims of our studies were to identify genes explicitly expressed or repressed at the sites of implantation by utilising RNA differential display (DDPCR), and to establish the roles of these genes in the implantation process in a mouse model. Ten bands unique in implantation sites compared to interimplantation sites were identified by DDPCR and subsequently confirmed by Northern blotting. One of these bands contained a cDNA fragment that was highly homologous to mouse monoclonal nonspecific suppressor factor beta (MNSFbeta) or Fau. The full cDNA sequence of this gene, obtained by screening a lambdagt11 cDNA library, was essentially the same as MNSFbeta, except that it had much longer 5' untranslated region. Interestingly, both Northern and immunohistochemical analysis showed that the expression of this gene was much lower in implantation sites compared to interimplantation sites on day 4.5 of pregnancy, when embryos first attach to the uterus and initiate implantation, and on day 5.5, when implantation has advanced. These results suggest a role for MNSF during implantation and early pregnancy, possibly through regulating the proliferation and/or differentiation of uterine stromal cells. It may also be involved in the selective production of TH2-type cytokines in implantation sites to regulate the immune system at the maternal-fetal interface.

Complex regulation of calcium-binding protein D9k (calbindin-D(9k)) in the mouse uterus during early pregnancy and at the site of embryo implantation

Establishment of receptive endometrium is essential for implantation. Our aim was to identify and characterize genes uniquely regulated at the sites of implantation in mouse uterus by RNA differential display polymerase chain reaction (DDPCR). One of the gene fragments identified was 86% homologous to rat calcium-binding protein D9k (calbindin-D(9k)); the mouse counterpart had not then been cloned, but subsequently an mRNA sequence of mouse calbindin-D(9k) became available in GenBank (accession number: AF028071). This sequence is 99% homologous to the DDPCR-derived gene tag but has a shorter 3' end. Reverse transcription-polymerase chain reaction (RT-PCR) was performed using the sequence of 3' end of the DDPCR product and the 5' end of AF028071, and a full cDNA was obtained. This gene was primarily up-regulated by progesterone, but not by estrogen. It was further increased by the combination of the two steroids. Expression of calbindin-D(9k) was overall increased in the uterus during early pregnancy, but the level was significantly lower in implantation compared to interimplantation sites on Days 4.5 and 5.5 of pregnancy, becoming barely detectable in both sites after Day 6.5. In situ hybridization localized this mRNA predominantly in the luminal epithelium of the pregnant uterus. The complex regulation of calbindin-D(9k) in mouse uterus suggests an important role for this protein during pregnancy.

Construction and application of a multispecific competitor to quantify mRNA of matrix metalloproteinases and their tissue inhibitors in small human biopsies

Accurate quantitation of mRNA levels of a number of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) in very small samples such as human biopsy material has not been generally possible. This paper describes the development, validation and application of a quantitative RT-PCR (Q-RT-PCR) assay that allows the detection and quantitation of mRNAs encoding genes of three MMPs (MMP-1, MMP-2, MMP-3), three TIMPs (TIMP-1, TIMP-2, TIMP-3) and GAPDH simultaneously from small amounts of RNA (< 4 microg). A multispecific competitor which shares the same primer-binding sequences as the cellular mRNA of all seven genes, but yields different sized PCR products, was constructed by adding primers specific for the MMPs and TIMPs to a core molecule (mutated GAPDH) by sequential PCR and cloning, and its multispecificity was experimentally validated. Application of the technique to measurement of transcriptional levels of MMPs and TIMPs in cultured human endometrial stromal cells provided support to the hypothesis that progesterone withdrawal alters the ratio of MMPs to TIMPs in favor of MMPs. This Q-RT-PCR method is a relatively simple, highly specific and nonradioactive procedure and is widely applicable.

Hormonal and non-hormonal agents at implantation as targets for contraception

The processes leading to implantation and the establishment of pregnancy involve hormonal and non-hormonal agents that offer opportunities as targets for contraception. Hormonal agents include progesterone, luteolytic factors (prostaglandin F2 alpha) and embryonic signals (chorionic gonadotrophin, oestradiol-17 beta, interferon-tau) responsible for maintaining the corpus luteum. Non-hormonal agents include surface antigens (attachment and adhesion molecules), vasoactive agents, tissue-remodelling enzymes (matrix metalloproteinases) and inhibitors (TIMPs), growth factors (epidermal growth factor and insulin-like growth factor families) and cytokines (such as leukaemia inhibitory factor, colony-stimulating factor-1, interleukin-1 (IL-1) and IL-6) associated with the pre-attachment period and the apposition, adhesion and invasion of the blastocyst. This review describes some of the hormonal and non-hormonal agents present at the time of implantation that may be exploited as targets for contraception in feral species. Particular attention is paid to the mouse as an experimental model and potential target species. The considerable species differences which exist in the models of implantation and placentation and the way in which the female 'recognizes' the presence of a viable conceptus offer a means of conferring species specificity on potential contraceptive targets for feral species.

Acclimation of photosynthetic proteins to rising atmospheric CO2

In this review we discuss how the photosynthetic apparatus, particularly Rubisco, acclimates to rising atmospheric CO2 concentrations (ca). Elevated ca alters the control exerted by different enzymes of the Calvin cycle on the overall rate of photosynthetic CO2 assimilation, so altering the requirement for different functional proteins. A decreased flux of carbon through the photorespiratory pathway will decrease requirements for these enzymes. From modeling of the response of CO2 uptake (A) to intracellular CO2 concentration (ci) it is shown that the requirement for Rubisco is decreased at elevated ca, whilst that for proteins limiting ribulose 1,5 bisphosphate regeneration may be increased. This balance may be altered by other interactions, in particular plasticity of sinks for photoassimilate and nitrogen supply; hypotheses on these interactions are presented. It is speculated that increased accumulation of carbohydrate in leaves developed at elevated ca may signal the 'down regulation' of Rubisco. The molecular basis of this 'down regulation' is discussed in terms of the repression of photosynthetic gene expression by the elevated carbohydrate concentrations. This molecular model is then used to predict patterns of acclimation of perennials to long term growth in elevated ca.

Modifications to Thylakoid Composition during Development of Maize Leaves at Low Growth Temperatures

The effects of reductions in growth temperature on the development of thylakoids of maize (Zea mays var LG11) leaves are examined. Thylakoids isolated from mesophyll cells of leaves grown at 17 degrees and 14 degrees C, compared with 25 degrees C, exhibited a decreased accumulation of many polypeptides, which was accompanied by a loss of activity of photosystems (PS) I and II. Probing the polypeptide profiles with a range of antibodies specific for thylakoid proteins demonstrated that a number of polypeptides encoded by the chloroplast genome failed to accumulate at low temperatures. Although thylakoid protein synthesis was reduced severely at 14 degrees C compared with 25 degrees C, major synthesis of both chloroplast and nuclear encoded polypeptides was detected. It is suggested that the lack of accumulation of some thylakoid proteins at low temperatures may be due to an inability to stabilize the proteins in the membranes. A number of thylakoid polypeptides were found to appear as the growth temperature was decreased. Analyses of pigments and polypeptides demonstrated that decreases in the photosystem reaction center core complexes occur relative to the light harvesting complex associated with PS II at reduced growth temperatures. Differential effects on the development of PSI and PSII were also observed, with PSII activity being preferentially reduced. Reductions in PSII content and activity occurred in parallel with decreases in the quantum yield and light-saturated rate of CO(2) assimilation. Fractionation of thylakoid pigment-protein complexes showed that the ratio of monomeric:oligomeric form of the light harvesting complex associated with PSII increased at low growth temperature, which is consistent with a chill-induced modification of thylakoid organization. Many, but not all, of the characteristic changes in thylakoid protein metabolism, which were observed when leaves were grown at low temperatures in controlled environments, were identified in leaves of a field maize crop during the early growing season when low temperatures were experienced by the crop. Chill-induced perturbations of thylakoid development can occur in the field in temperate regions and may have implications for the photosynthetic productivity of the crop.

The involvement of the photoinhibition of photosystem II and impaired membrane energization in the reduced quantum yield of carbon assimilation in chilled maize

In this study we investigated the basis for the reduction in the quantum yield of carbon assimilation in maize (Zea mays L. cv. LG11) caused by chilling in high light. After chilling attached maize leaves at 5° C for 6 h at high irradiance (1000 μmol photons·m(-2)·s(-1)) chlorophyll fluorescence measurements indicated a serious effect on the efficiency of photochemical conversion by photosystem II (PSII) and measurements of [(14)C]atrazine binding showed that the plastoquinone binding site was altered in more than half of the PSII reaction centres. Although there were no direct effects of the chilling treatment on coupling-factor activity, ATP-formation capacity was affected because the photoinhibition of PSII led to a reduced capacity to energize the thylakoid membranes. In contrast to chilling at high irradiance, no photoinhibition of PSII accompanied the 20% decrease in the quantum yield of carbon assimilation when attached maize leaves were chilled in low light (50 μmol photons·m(-2)·s(-1)). Thus it is clear that photoinhibition of PSII is not the sole cause of the light-dependent, chillinduced decrease in the quantum yield of carbon assimilation. During the recovery of photosynthesis from the chilling treatment it was observed that full [(14)C]atrazinebinding capacity and membrane-energization capacity recovered significantly more slowly than the quantum yield of carbon assimilation. Thus, not only is photoinhibition of PSII not the sole cause for the decreased quantum yield of carbon assimilation, apparently an appreciable population of photoinhibited PSII centres can be tolerated without any reduction in the quantum yield of carbon assimilation.