Disease relevance of Lhb

• Using in situ hybridization histochemistry with a CG-beta transcript-specific oligonucleotide probe and a non-specific LH/CG-beta oligonucleotide and riboprobe, we have demonstrated specific CG-beta expression in two of 35 random pituitary adenomas; LH-beta expression occurred in a further eight adenomas [1].
• To localize the LH beta estrogen response element (ERE) by biological function, portions of the 5'-flanking region of the LH beta gene or synthetic oligonucleotides were inserted in expression vectors next to the herpes simplex virus thymidine kinase promoter fused to the chloramphenicol acetyltransferase gene [2].

Psychiatry related information on Lhb

• Cytotoxic lesions of the entire Lhb prevented the onset of all components of maternal behavior compared with controls [3].

High impact information on Lhb

• These results suggest that GnRHa differentially activates ERK and JNK, and a JNK cascade is necessary to elicit the rat LHbeta promoter activity in a c-Jun-dependent mechanism in LbetaT2 cells [4].
• GnRH activated the rat LHbeta promoter activity in a time-dependent manner [4].
• Identification of an estrogen-responsive element in the rat LH beta gene. DNA-estrogen receptor interactions and functional analysis [2].
• A construct containing a synthetic oligonucleotide of this putative LH beta ERE was stimulated 1.7-3-fold by E2, while a construct containing two copies of the sequence was stimulated to a slightly higher level (2.5-4.0-fold) [2].
• The 15-base pair LH beta gene palindrome was found to bind estrogen receptor (ER) complex directly by gel retardation experiments [2].

Chemical compound and disease context of Lhb

• Expression of glycoprotein hormone alpha-subunit and, less commonly, free luteinizing hormone beta (LH-beta) or follicle-stimulating hormone beta is characteristic of endocrinologically inactive adenomas, a subgroup thought to be derived predominantly from the gonadotroph line [1].

Biological context of Lhb

• Furthermore, we have shown that DNA sequences at -490/-352 confer GnRH responsiveness to the rat LHbeta gene [5].
• Then we explored further the possibility that ovarian steroids are involved in modulating LH-beta mRNA stability in cultured rat pituitary cells where transcription was inhibited by actinomycin D [6].
• However, since their expression is inverse during the rat estrous cycle, other unidentified regulatory factors with differential effects on their expression may intervene in the regulation of SgII and LH beta mRNA levels [7].
• Plasma testosterone surge and luteinizing hormone beta (LH-beta) following parturition: lack of association in the male rat [8].
• In the in vivo study gonadotropin-releasing hormone binding sites and rat luteinizing hormone beta-messenger ribonucleic acid in the pituitary decreased during gonadotropin-releasing hormone agonist treatment, but serum levels of rat luteinizing hormone did not decrease [9].

Anatomical context of Lhb

• In short, our data show that the majority of the cells in the cell line RC-4B/C contain FSH beta, LH beta and PRL and that among these cells many bihormonal cells are present [10].
• Progesterone together with estradiol promotes luteinizing hormone beta-subunit mRNA stability in rat pituitary cells cultured in vitro [6].
• On Day 12 of pregnancy, bilateral cytotoxic lesions were produced in the Lhb with kainic acid or, as a control, just dorsal in the medial hippocampus [3].
• Following kainic acid-induced lesions of Lhb neurons, the fluorescent retrograde tracer Fluoro-Gold was injected into the ventral midbrain where many medial habenula (Mhb) and Lhb neurons project [11].
• Receptor mediated activation of reporter constructs containing either the estrogen response element (ERE) from the vitellogenin (Vit) gene or from the luteinizing hormone beta (LH) gene were examined in transiently transfected Cos-1 cells [12].

Associations of Lhb with chemical compounds

• Gonadotropin-releasing hormone activation of c-jun, but not early growth response factor-1, stimulates transcription of a luteinizing hormone beta-subunit gene [13].
• LH beta mRNA was suppressed by all steroid treatments (p < 0.01), FSH beta was lower in only the E2 group, and alpha-subunit was reduced in both the E2 + P4 and DHT groups (p < 0.01) [14].
• The pituitary luteinizing hormone beta mRNA level of ethanol-treated rats was significantly higher (P less than .05) but the follicle-stimulating hormone beta mRNA level was lower (P less than .05) than those of the diet control group [15].
• During this period, either progesterone alone or progesterone + estradiol clearly blocked the degradation of LH-beta mRNA species [6].
• We examined the pattern of postnatal LH secretion in the newborn male rat, coincident with plasma testosterone levels, using a specific monoclonal antibody for LH-beta [8].

Physical interactions of Lhb

• Small nuclear RING finger protein stimulates the rat luteinizing hormone-beta promoter by interacting with Sp1 and steroidogenic factor-1 and protects from androgen suppression [16].

Regulatory relationships of Lhb

• Although it is known that GnRH induces luteinizing hormone beta (LHbeta) gene transcription, the mechanisms by which this occurs remain to be elucidated [5].

Other interactions of Lhb

• Increases in pituitary SgII mRNA and LH beta mRNA levels occurred after ovariectomy, and decreases occurred after estrogen treatment of such animals [7].
• The LH and FSH antigen content of the GHRH target cells from proestrous rats demonstrates that the LHbeta and FSHbeta mRNAs are indeed translated [17].
• This study suggests that activation of GABAB receptor with baclofen may play differential roles in regulating hypothalamic GnRH and pituitary LH beta gene expression depending on steroid milieu [18].
• Ovariectomy increased GnRH-R significantly (by 30% during 2 wk) in parallel with receptor mRNA and with pituitary LH and LH-beta, but induced an earlier increase in serum gonadotropins [19].

Analytical, diagnostic and therapeutic context of Lhb

• Detection of luteinizing hormone beta messenger ribonucleic acid (RNA) in individual gonadotropes after castration: use of a new in situ hybridization method with a photobiotinylated complementary RNA probe [20].
• Plasma from individual animals was measured subsequently for LH-beta and testosterone by radioimmunoassay [8].
• Additional studies in untreated males and females born by cesarean section or natural birth also failed to reveal a postnatal rise in plasma LH-beta during the first 3 h after birth [8].
• Likewise, pituitary SgII mRNA and LH beta mRNA levels decreased after treatment of ovariectomized animals with a GnRH antagonist [7].
• Alpha and luteinizing hormone beta messenger ribonucleic acid (RNA) of male and female rats after castration: quantitation using an optimized RNA dot blot hybridization assay [21].

References