A splice acceptor variant in RGS6 associated with intellectual disability, microcephaly, and cataracts disproportionately promotes expression of a subset of RGS6 isoforms.

Intellectual disability (ID) is associated with an increased risk of developing psychiatric disorders, suggesting a common underlying genetic factor. Importantly, altered signaling and/or expression of regulator of G protein signaling 6 (RGS6) is associated with ID and numerous psychiatric disorders. RGS6 is highly conserved and undergoes complex alternative mRNA splicing producing ~36 protein isoforms with high sequence similarity historically necessitating a global approach in functional studies. However, our recent analysis in mice revealed RGS6 is most highly expressed in CNS with RGS6L(+GGL) isoforms predominating. A previously reported genetic variant in intron 17 of RGS6 (c.1369-1G>C), associated with ID, may provide further clues into RGS6L(+GGL) isoform functional delineation. This variant was predicted to alter a highly conserved canonical 3' acceptor site creating an alternative branch point within exon 18 (included in a subset of RGS6L(+GGL) transcripts) and a frameshift forming an early stop codon. We previously identified this alternative splice site and demonstrated its use generates RGS6Lζ(+GGL) isoforms. Here, we show that the c.1369-1G>C variant disrupts the canonical, preferred (>90%) intron 17 splice site and leads to the exclusive use of the alternate exon 18 splice site, inducing disproportionate expression of a subset of isoforms, particularly RGS6Lζ(+GGL). Furthermore, RGS6 global knockout mice do not exhibit ID. Thus, ID caused by the c.1369-1G>C variant likely results from altered RGS6 isoform expression, rather than RGS6 isoform loss. In summary, these studies highlight the importance of proper RGS6 splicing and identify a previously unrecognized role of G protein signaling in ID.

The International Consortium on Primary Graft Dysfunction: Redefining Clinical Risk Factors in the Contemporary Era of Heart Transplantation.

BACKGROUND: Primary graft dysfunction (PGD) is the leading cause of morbidity and mortality early after heart transplantation (HT). The International Consortium on PGD is a multicenter collaboration dedicated to identifying the clinical risk factors for PGD in the contemporary era of HT. The objectives of the current report were (1) to assess the incidence of severe PGD in an international cohort; (2) to evaluate the performance of the most strongly validated PGD risk tool, the RADIAL score, in a contemporary cohort; and (3) to redefine clinical risk factors for severe PGD in the current era of HT. METHODS: This is a retrospective, observational study of consecutive adult HT recipients between 2010 and 2020 in 10 centers in the United States, Canada and Europe. Patients with severe PGD were compared to those without severe PGD (comprising those with no, mild and moderate PGD). The RADIAL score was calculated for each transplant recipient. The discriminatory power of the RADIAL score was evaluated using receiver operating characteristic (ROC) analysis, and its calibration was assessed by plotting the percentage of PGD predicted vs that which was observed. To identify clinical risk factors associated with severe PGD, we performed multivariable mixed-effects logistic regression modeling to account for among-center variability. RESULTS: A total of 2746 patients have been enrolled in the registry to date, including 2015 (73.4%) from North America, and 731 (26.6%) from Europe; 215 participants (7.8%) met the criteria for severe PGD. There was an increase in the incidence of severe PGD over the study period (P value for trend by difference sign test = 0.004). The Kaplan-Meier estimate for 1-year survival was 75.7% (95% CI 69.4-80.9%) in patients with severe PGD as compared to 94.4% (95% CI 93.5-95.2%) in those without severe PGD (log-rank P value < 0.001). The RADIAL score performed poorly in our contemporary cohort and was not associated with severe PGD; it had an AUC of 0.53 (95% CI 0.48-0.58). In the multivariable regression model, acute preoperative dialysis (OR 2.41, 95% CI 1.31-4.43), durable left ventricular assist device support (OR 1.77, 95% CI 1.13-2.77), and total ischemic time (OR 1.20 for each additional hour, 95% CI 1.02-1.41) were associated with an increased risk of severe PGD. CONCLUSIONS: Our consortium has identified an increasing incidence of PGD in the modern transplant era. We identified contemporary risk factors for this early post-transplant complication, which confers a high mortality risk. These results may enable the identification of patients at high risk for developing severe PGD in order to inform peri-transplant donor and recipient management practices.

Effects of N-carbamylglutamate and arginine on steroidogenesis and proliferation of pig granulosa cells in vitro.

Results of in vivo studies indicate dietary N-carbamylglutamate (NCG) and arginine (ARG) can enhance reproductive performance in gilts. It was hypothesized that both NCG and ARG will alter hormone-induced estradiol (E2) production by granulosa cells (GC), explaining why these compounds could improve reproductive performance in pigs. The objective of these studies, therefore, was to evaluate the direct effects of NCG and ARG on porcine GC proliferation and steroidogenesis, using an in vitro cell culture system. The GC from small (SM; 1-5 mm) and large (LG; >5 mm) pig follicles were cultured for 2 days in 5% fetal bovine serum and 5% porcine serum-containing medium followed by 2 days in serum-free medium containing 500 ng/mL of testosterone (as an E2 precursor), and NCG or ARG at various doses in the presence of either follicle-stimulating hormone (FSH; 30 ng/mL), insulin-like growth factor-1 (IGF1; 30 ng/mL), or both. Numbers of GC were determined at the end of the experiment and concentrations of progesterone (P4) and E2 in culture medium were determined. Results indicated that LG-follicle GC were more responsive to NCG and ARG than SM-follicle GC. Specifically, in LG-follicle GC, NCG inhibited (P <  0.05) basal and FSH-induced P4 and E2 production but stimulated cell numbers; whereas ARG inhibited FSH-induced E2 production and cell numbers. In SM-follicle GC, treatment with NCG and ARG decreased IGF1 plus FSH induced P4 production, but E2 production and cell proliferation were not affected. These studies indicate that NCG and ARG may directly affect follicular function in pigs.

Anetodermic mycosis fungoides: a new clinicopathological variant of mycosis fungoides.

Mycosis fungoides is the most common type of primary cutaneous T-cell lymphoma. Several rare clinicopathological variants of mycosis fungoides have been described. Patients with these variants often also have classic mycosis fungoides at other sites of the body. Anetoderma is a cutaneous disorder in which multiple, oval lesions or atrophic plaques with wrinkled surface develop progressively due to loss of the dermal elastic tissue. Primary anetoderma occurs when there is no underlying associated disease and it arises on clinically normal skin, whereas secondary anetoderma appears in the same site as a previous specific skin lesion. There is a large list of heterogeneous dermatoses associated with secondary anetoderma. Two patients developed areas of secondary anetoderma on plaque stage lesions of mycosis fungoides. The lesions consisted of exophytic nodular lesions, with very soft consistency on palpation, scattered over the hyperpigmented plaques in one patient and violaceous indurated plaques with overlying epidermal atrophy and mild scale in the other. Histopathological study demonstrated that the cells involving the dermis were mainly T-helper lymphocytes, with few histiocytes and some multinucleate giant cells engulfing distorted elastic fibres. Elastic tissue stain demonstrated that elastic fibres were almost completely absent in the dermis of the anetodermic lesions. Anetodermic mycosis fungoides should be added to the list of clinicopathological variants of mycosis fungoides and mycosis fungoides should also be considered as a possible disease causing secondary anetoderma. Anetodermic mycosis fungoides shows clinical and histopathological features different from those of granulomatous slack skin.