A deficiency in SUMOylation activity disrupts multiple pathways leading to neural tube and heart defects in Xenopus embryos.

BACKGROUND: Adenovirus protein, Gam1, triggers the proteolytic destruction of the E1 SUMO-activating enzyme. Microinjection of an empirically determined amount of Gam1 mRNA into one-cell Xenopus embryos can reduce SUMOylation activity to undetectable, but nonlethal, levels, enabling an examination of the role of this post-translational modification during early vertebrate development. RESULTS: We find that SUMOylation-deficient embryos consistently exhibit defects in neural tube and heart development. We have measured differences in gene expression between control and embryos injected with Gam1 mRNA at three developmental stages: early gastrula (immediately following the initiation of zygotic transcription), late gastrula (completion of the formation of the three primary germ layers), and early neurula (appearance of the neural plate). Although changes in gene expression are widespread and can be linked to many biological processes, three pathways, non-canonical Wnt/PCP, snail/twist, and Ets-1, are especially sensitive to the loss of SUMOylation activity and can largely account for the predominant phenotypes of Gam1 embryos. SUMOylation appears to generate different pools of a given transcription factor having different specificities with this post-translational modification involved in the regulation of more complex, as opposed to housekeeping, processes. CONCLUSIONS: We have identified changes in gene expression that underlie the neural tube and heart phenotypes resulting from depressed SUMOylation activity. Notably, these developmental defects correspond to the two most frequently occurring congenital birth defects in humans, strongly suggesting that perturbation of SUMOylation, either globally or of a specific protein, may frequently be the origin of these pathologies.

Massive Burn Injuries: Characteristics and Outcomes From a Single Institution.

Massive burn injuries are a unique patient population with unique treatment paradigms. Data from 155 adult patients, admitted from 2009 to 2019, with >50% total body surface area burns (TBSA) were collected and analyzed. Average burn size was 70% TBSA and 63% had a concomitant inhalation injury. Approximately 30% of patients (46/155) transitioned to comfort care-only measures within 24 hours of admission. Standard treatment patients were younger (37 ± 13 vs 60 ± 19 years; p < .00001), male (94% vs 28%; p = .001) and had smaller TBSA (66 ± 13 vs 80 ± 16; p < .00001). Of the standard treatment group, 72 (66%) survived to discharge. Survivors had smaller TBSA (64 ± 13 vs 71 ± 13; p = .003), less third-degree TBSA (48 ± 25 vs 71 ± 13; p = .003) and lower incidence of renal failure requiring dialysis (22% vs 73%, p < .00001). Multivariate regression analysis showed that age (OR 1.05; p = .025), total TBSA (OR 1.07; p = .005), and renal failure (OR 10.2; p = .00005) were independently associated with mortality. Inhalation injury was not significantly associated with mortality. About 23% (35/155) of patients had a psychiatric condition on admission and 19% (30/155) of patients were burned attempting suicide. Patients with psychiatric conditions spent more time in the hospital (62 vs 30 days; p = .004), more time on ventilator (31 vs 12 days; p = .046), underwent more surgery (4 vs 2 operations, p = .03), and were less likely to die (34% vs 59%; p = .02). In summary, age, burn size, and renal failure were independently associated with mortality, with renal failure being the strongest factor. Psychiatric conditions are prevalent pre-injury and tend to require more inpatient care.

Immunogenicity and Serological Cross-Reactivity of Saliva Proteins among Different Tsetse Species.

Tsetse are vectors of pathogenic trypanosomes, agents of human and animal trypanosomiasis in Africa. Components of tsetse saliva (sialome) are introduced into the mammalian host bite site during the blood feeding process and are important for tsetse's ability to feed efficiently, but can also influence disease transmission and serve as biomarkers for host exposure. We compared the sialome components from four tsetse species in two subgenera: subgenus Morsitans: Glossina morsitans morsitans (Gmm) and Glossina pallidipes (Gpd), and subgenus Palpalis: Glossina palpalis gambiensis (Gpg) and Glossina fuscipes fuscipes (Gff), and evaluated their immunogenicity and serological cross reactivity by an immunoblot approach utilizing antibodies from experimental mice challenged with uninfected flies. The protein and immune profiles of sialome components varied with fly species in the same subgenus displaying greater similarity and cross reactivity. Sera obtained from cattle from disease endemic areas of Africa displayed an immunogenicity profile reflective of tsetse species distribution. We analyzed the sialome fractions of Gmm by LC-MS/MS, and identified TAg5, Tsal1/Tsal2, and Sgp3 as major immunogenic proteins, and the 5'-nucleotidase family as well as four members of the Adenosine Deaminase Growth Factor (ADGF) family as the major non-immunogenic proteins. Within the ADGF family, we identified four closely related proteins (TSGF-1, TSGF-2, ADGF-3 and ADGF-4), all of which are expressed in tsetse salivary glands. We describe the tsetse species-specific expression profiles and genomic localization of these proteins. Using a passive-immunity approach, we evaluated the effects of rec-TSGF (TSGF-1 and TSGF-2) polyclonal antibodies on tsetse fitness parameters. Limited exposure of tsetse to mice with circulating anti-TSGF antibodies resulted in a slight detriment to their blood feeding ability as reflected by compromised digestion, lower weight gain and less total lipid reserves although these results were not statistically significant. Long-term exposure studies of tsetse flies to antibodies corresponding to the ADGF family of proteins are warranted to evaluate the role of this conserved family in fly biology.

Bezafibrate and medroxyprogesterone acetate target resting and CD40L-stimulated primary marginal zone lymphoma and show promise in indolent B-cell non-Hodgkin lymphomas.

B cell non-Hodgkin lymphomas (B-NHLs) are the most common adult hematological cancers and many remain incurable. Development of chemotherapy regimens is confounded by the prevalence of B-NHL in older, frailer patients and the chemo-protective tumor microenvironment. Although biological therapies such as rituximab have significantly improved outcomes and selective kinase inhibitors are showing promise, the rate of new drug discovery remains disappointing, the treatments expensive and long-term benefits uncertain. An alternative strategy is redeployment of available, inexpensive and non-toxic drugs. Here, we demonstrate the antiproliferative and mitochondrial superoxide (MSO) driven pro-apoptotic activities of bezafibrate (BEZ) and medroxyprogesterone acetate (MPA) against B-NHL cells, with a bias toward MZL, in the presence and absence of the microenvironmental signal CD40L. Our study is the first to confirm the presence of CD40L within the lymph node of B-NHL and its capacity to drive B-NHL proliferation. These findings implicate BEZ + MPA as a potential therapeutic strategy in B-NHL.

T-cell number and subtype influence the disease course of primary chronic lymphocytic leukaemia xenografts in alymphoid mice.

Chronic lymphocytic leukaemia (CLL) cells require microenvironmental support for their proliferation. This can be recapitulated in highly immunocompromised hosts in the presence of T cells and other supporting cells. Current primary CLL xenograft models suffer from limited duration of tumour cell engraftment coupled with gradual T-cell outgrowth. Thus, a greater understanding of the interaction between CLL and T cells could improve their utility. In this study, using two distinct mouse xenograft models, we investigated whether xenografts recapitulate CLL biology, including natural environmental interactions with B-cell receptors and T cells, and whether manipulation of autologous T cells can expand the duration of CLL engraftment. We observed that primary CLL xenografts recapitulated both the tumour phenotype and T-cell repertoire observed in patients and that engraftment was significantly shorter for progressive tumours. A reduction in the number of patient T cells that were injected into the mice to 2-5% of the initial number or specific depletion of CD8(+) cells extended the limited xenograft duration of progressive cases to that characteristic of indolent disease. We conclude that manipulation of T cells can enhance current CLL xenograft models and thus expand their utility for investigation of tumour biology and pre-clinical drug assessment.