Novel Covalent Modifier-Induced Local Conformational Changes within the Intrinsically Disordered Region of the Androgen Receptor.

Intrinsically disordered regions (IDRs) of transcription factors play an important biological role in liquid condensate formation and gene regulation. It is thus desirable to investigate the druggability of IDRs and how small-molecule binders can alter their conformational stability. For the androgen receptor (AR), certain covalent ligands induce important changes, such as the neutralization of the condensate. To understand the specificity of ligand-IDR interaction and potential implications for the mechanism of neutralizing liquid-liquid phase separation (LLPS), we modeled and performed computer simulations of ligand-bound peptide segments obtained from the human AR. We analyzed how different covalent ligands affect local secondary structure, protein contact map, and protein-ligand contacts for these protein systems. We find that effective neutralizers make specific interactions (such as those between cyanopyrazole and tryptophan) that alter the helical propensity of the peptide segments. These findings on the mechanism of action can be useful for designing molecules that influence IDR structure and condensate of the AR in the future.

Enhanced mineralization potential of vascular cells from SM22α-Rankl (tg) mice.

Vascular calcification, prevalent in diabetes and chronic kidney disease, contributes to morbidity and mortality. To investigate the effect of receptor activator of NF-kB ligand (RANKL) on vascular calcification in vivo, transgenic mice, where RANKL expression was targeted to vascular smooth muscle cells using the SM22α promoter (SM22α-Rankl ( tg )), were created. Sixteen-month-old male SM22α-Rankl ( tg ) mice had higher body weight and higher serum calcium levels but lower lumbar bone mineral density (BMD) compared with age- and gender-matched wild-type (WT) littermates. BMD of long bones, body fat (percent of weight) of the leg, and serum levels of phosphate and RANKL were not significantly different. No significant differences in these parameters were observed in female mice. Histological analysis did not reveal calcium deposits in the aortic roots of SM22α-Rankl ( tg ) mice. To analyze the osteoblastic differentiation and mineralization potentials of vascular cells, aortic smooth muscle cells (SMCs) were isolated and cultured. Results showed that SM22α-Rankl ( tg ) SMCs had higher baseline alkaline phosphatase (ALP) activity but not baseline matrix calcification. When induced by the PKA agonist forskolin, ALP activity was greater in SM22α-Rankl ( tg ) than in WT SMCs. Real-time RT-qPCR revealed higher baseline expression of ALP and ankylosis genes but lower osteoprotegerin gene in SM22α-Rankl ( tg ) SMCs. Matrix mineralization induced by inorganic phosphate or forskolin was greater in SM22α-Rankl ( tg ) than in WT SMCs. Treatment of these cells with the ALP inhibitor levamisole abolished forskolin-induced matrix mineralization but not inorganic phosphate-induced matrix mineralization. These findings suggest that RANKL overexpression in the vasculature may promote mineralization potential.

N-terminal prohormone brain natriuretic peptide as a predictor of cardiovascular disease and mortality in blacks with hypertensive kidney disease: the African American Study of Kidney Disease and Hypertension (AASK).

BACKGROUND: Higher levels of N-terminal prohormone brain-type natriuretic peptide (NT-proBNP) predict cardiovascular disease (CVD) in several disease states, but few data are available in patients with chronic kidney disease or in blacks. METHODS AND RESULTS: The African American Study of Kidney Disease and Hypertension trial enrolled hypertensive blacks with a glomerular filtration rate of 20 to 65 mL x min(-1) x 1.73 m(-2) and no other identified cause of kidney disease. NT-proBNP was measured with a sandwich chemiluminescence immunoassay (coefficient of variation 2.9%) in 994 African American Study of Kidney Disease and Hypertension participants. NT-proBNP was categorized as undetectable, low, moderate, or high. Proteinuria was defined as 24-hour urinary protein-creatinine ratio >0.22. A total of 134 first CVD events (CVD death or hospitalization for coronary artery disease, heart failure, or stroke) occurred over a median of 4.3 years. Participants with high NT-proBNP were much more likely to have a CVD event than participants with undetectable NT-proBNP after adjustment (relative hazard 4.0 [95% confidence interval [CI] 2.1 to 7.6]). A doubling of NT-proBNP was associated with a relative hazard of 1.3 (95% CI 1.0 to 1.6) for coronary artery disease, 1.7 (95% CI 1.4 to 2.2) for heart failure, 1.1 (95% CI 0.9 to 1.4) for stroke, and 1.8 (95% CI 1.4 to 2.4) for CVD death. The association of NT-proBNP with CVD events was significantly stronger (P(interaction)=0.05) in participants with than in those without proteinuria. Higher NT-proBNP was not associated with renal disease progression. CONCLUSIONS: These results suggest that elevated NT-proBNP levels are associated with higher CVD risk among blacks with hypertensive kidney disease. This association may be stronger in individuals with significant proteinuria.

Short-term outcomes of chronic back pain patients on an airbed vs innerspring mattresses.

OBJECTIVE: To compare SF-36, pain Visual Analog Scale (VAS), and sleep VAS outcomes of an adjustable airbed with innerspring mattresses in a population of chronic back pain sufferers. STUDY DESIGN: A-B-A trial, in 3 phases: the patients on their own bed for 1 night, on an adjustable airbed for 28 nights, and on their bed for 14 nights. SETTING: Outpatient pain rehabilitation, physical therapy, and alternative medicine clinics. PATIENTS: Three centers recruited 30 patients each with severe chronic back pain and without sleep apnea or other sleep disorders. MAIN OUTCOME MEASURES: SF-36 health status survey and VAS pain and sleep quality scales. RESULTS: On VAS scales, 95% showed pain improvement, and 88% reported better sleep. The average improvements were a 32% pain decrease and a 73% increase in sleep quality, significant at P less than.001 (two-tail t test). Eighty percent improved on the SF-36 physical functioning dimension and 88% improved on the bodily pain dimension. The average score on each dimension improved (P less than.001). Eighty-five percent preferred the adjustable airbed. DISCUSSION AND CONCLUSION: SF-36 and VAS outcomes measures showed a highly significant benefit for the airbed design in this short-term comparison. The airbed appears to be a useful sleep aid and an adjunct to medical and physical therapies for chronic back pain sufferers.

Recombinant human follicle-stimulating hormone is capable of exerting a biological effect in the adult hypophysectomized rat by reducing the numbers of degenerating germ cells.

There is considerable controversy as to whether FSH can, under normal circumstances, exert an effect to promote spermatogenesis in the adult rat. Recombinant human FSH (rhFSH) was used to answer a more limited question relating to whether FSH is capable of exerting a biological effect in promoting adult spermatogenesis. Can a pure preparation of FSH prevent the regressive changes seen after hypophysectomy (Hx) in a short term experiment? To answer this question, five groups of adult rats were used as follows: pituitary-intact animals, 3-day hypophysectomized (Hx), 3-day Hx given 3 mg testosterone propionate (T)/day for 7 days, 3-day Hx given 22 IU rhFSH for 7 days, and 3-day Hx given saline vehicle for 7 days. Testis weight, seminiferous tubule diameter, analysis of four degenerating germ cell types, the relative amount of lipid, and the levels of FSH receptors showed that FSH could, in a significant manner, prevent the regressive changes accompanying Hx. FSH was not as effective as T in doing so, because the FSH values were always intermediate between T-maintained animals and those after long term Hx. The Leydig cell was eliminated as a possible source of FSH-stimulated T promotion of spermatogenesis, given that morphometry and tissue T assays indicated that no additional production of T was elicited by rhFSH. The assay system used to enumerate degenerating germ cells proved a very sensitive indicator of the ability of hormones to maintain cell viability in short term experiments. The data not only show that FSH can exert a biological effect, but that this effect is qualitatively similar to that seen after the administration of T in terms of the maintenance of viability of specific germ cell types. A hypothesis is presented whereby FSH and T, although the former acting by a second messenger system and the latter by binding to nuclear receptors, can stimulate the genome to exert similar qualitative effects promoting the viability of germ cells.

An analysis of feeding regimens after pyloromyotomy for hypertrophic pyloric stenosis.

We retrospectively reviewed 223 infants who underwent pyloromyotomy for hypertrophic pyloric stenosis (HPS) at our institution from January 1984 to May 1990. Each patient's postoperative feeding regimen was determined by the attending surgeon. The four distinct regimens used were as follows: A (n = 66): NPO overnight (> 10 h) with cautious feeding advancement every 4 hours x 2, then every 2 hours x 2, then every 1 1/2 hours x 8, then ad lib; B (n = 46): NPO until 6 to 8 hours postoperatively with the same cautious feeding advancement as in A; C (n = 42): NPO until 6 hours postoperatively with accelerated feeding advancement every 2 hours x 8, then ad lib; D (n = 69): NPO until 6 hours postoperatively with accelerated feeding advancement every 1 hour x 12, then ad lib. There were no significant differences in age at diagnosis or degree of dehydration among groups. From group A to group D, there was a progressive increase in amount and incidence of postoperative vomiting, both after the first three feedings and in the total postoperative period. However, patients in groups C and D had a shorter postoperative hospital stay and lower charges than did patients in groups A and B. Following discharge, no patient was readmitted for vomiting or dehydration. We conclude that feedings started 6 hours after pyloromyotomy for HPS with accelerated feeding advancement every 2 hours increases the incidence and frequency of postoperative vomiting, but not unacceptably, and results in a significantly shorter postoperative stay.

Structural changes in rat Leydig cells posthypophysectomy: a morphometric and endocrine study.

Short and long term responses of the rat Leydig cell were studied posthypophysectomy, at times when germ cell degeneration was first prominent (6 days) and after long term regression of the testis (28 days). In the short term, virtually all structural parameters relating to the volume and surface area of the Leydig cell and its subcellular organelles were significantly lowered compared with those in control animals. Exceptions were the volumes of the nucleolus, heterochromatin, and lysosomes and the surface areas of the nucleus. Structural decreases were generally on the order of 2- to 5-fold in the 6-day period. A statistical analysis of the percent decreases in the short term was performed to determine whether any particular structural features were more sensitive to hypophysectomy than any others. In most instances, no particular organelles were decreased compared to others. However, lipid, although not commonly seen in rat Leydig cells, showed significantly greater percent decreases compared with several other organelles, indicating that the small amount of lipid present is rapidly lost (used) in the short term. After long term hypophysectomy, all structural parameters of the Leydig cell were significantly lowered compared with those in pituitary-intact animals. Only a few parameters (mitochondrial volume, cell surface area, and the surface areas of inner and outer mitochondrial membranes and smooth endoplasmic reticulum) showed more significant decreases in the long term compared with the short term hypophysectomized animals. Most organelle volumes and surface areas correlated positively and significantly with serum and tissue testosterone levels; the exceptions were the volumes of the nucleolus, heterochromatin, lipid, and lysosomes. Compared with the pituitary-intact animal, the content of LH receptors expressed per testis and per Leydig cell was significantly lower in both hypophysectomized groups; however, the number of receptors per given area of individual Leydig cell plasma membrane remained unchanged. Overall, data show that the Leydig cell manifests marked structural changes during early spermatogenic dysfunction.