Optimization of human mesenchymal stem cell manufacturing: the effects of animal/xeno-free media.

Due to their immunosuppressive properties, mesenchymal stem cells (MSC) have been evaluated for the treatment of immunological diseases. However, the animal-derived growth supplements utilized for MSC manufacturing may lead to clinical complications. Characterization of alternative media formulations is imperative for MSC therapeutic application. Human BMMSC and AdMSC were expanded in media supplemented with either human platelet lysates (HPL), serum-free media/xeno-free FDA-approved culture medium (SFM/XF), or fetal bovine serum (FBS) and the effects on their properties were investigated. The immunophenotype of resting and IFN-γ primed BMMSC and AdMSC remained unaltered in all media. Both HPL and SFM/XF increased the proliferation of BMMSC and AdMSC. Expansion of BMMSC and AdMSC in HPL increased their differentiation, compared to SFM/XF and FBS. Resting BMMSC and AdMSC, expanded in FBS or SFM/XF, demonstrated potent immunosuppressive properties in both non-primed and IFN-γ primed conditions, whereas HPL-expanded MSC exhibited diminished immunosuppressive properties. Finally, IFN-γ primed BMMSC and AdMSC expanded in SFM/XF and HPL expressed attenuated levels of IDO-1 compared to FBS. Herein, we provide strong evidence supporting the use of the FDA-approved SFM/XF medium, in contrast to the HPL medium, for the expansion of MSC towards therapeutic applications

Assessment of Circulating MicroRNAs for the Diagnosis and Disease Activity Evaluation in Patients with Ulcerative Colitis by Using the Nanostring Technology

Background: Clinical decision and patient care management in inflammatory bowel diseases is largely based on the assessment of clinical symptoms, while the biomarkers currently in use poorly reflect the actual disease activity. Therefore, the identification of novel biomarkers will serve an unmet clinical need for IBD screening and patient management. We examined the utility of circulating microRNAs for diagnosis and disease activity monitoring in ulcerative colitis (UC) patients. Methods: Blood serum microRNAs were isolated from UC patients with active and inactive disease and healthy donors. High-throughput microRNA profiling was performed using the Nanostring technology platform. Clinical disease activity was captured by calculating the partial Mayo score. C-reactive protein (CRP) was measured in UC patients as part of their clinical monitoring. The profiles of circulating microRNAs and CRP were correlated with clinical disease indices. Results: We have identified a signature of 12 circulating microRNAs that differentiate UC patients from control subjects. Moreover, six of these microRNAs significantly correlated with UC disease activity. Importantly, a set of four microRNAs (hsa-miR-4454, hsa-miR-223-3p, hsa-miR-23a-3p, and hsa-miR-320e) which correlated with UC disease activity, were found to have higher sensitivity and specificity values than CRP. Conclusions: Circulating microRNAs provide a novel diagnostic and prognostic marker for UC patients. The use of an FDA approved platform could accelerate the application of microRNA screening in a GI clinical setting. When used in combination with current diagnostic and disease activity assessment modalities, microRNAs could improve both IBD screening and care management

Wnt signaling exerts an antiproliferative effect on adult cardiac progenitor cells through IGFBP3.

RATIONALE: Recent work in animal models and humans has demonstrated the presence of organ-specific progenitor cells required for the regenerative capacity of the adult heart. In response to tissue injury, progenitor cells differentiate into specialized cells, while their numbers are maintained through mechanisms of self-renewal. The molecular cues that dictate the self-renewal of adult progenitor cells in the heart, however, remain unclear. OBJECTIVE: We investigate the role of canonical Wnt signaling on adult cardiac side population (CSP) cells under physiological and disease conditions. METHODS AND RESULTS: CSP cells isolated from C57BL/6J mice were used to study the effects of canonical Wnt signaling on their proliferative capacity. The proliferative capacity of CSP cells was also tested after injection of recombinant Wnt3a protein (r-Wnt3a) in the left ventricular free wall. Wnt signaling was found to decrease the proliferation of adult CSP cells, both in vitro and in vivo, through suppression of cell cycle progression. Wnt stimulation exerted its antiproliferative effects through a previously unappreciated activation of insulin-like growth factor binding protein 3 (IGFBP3), which requires intact IGF binding site for its action. Moreover, injection of r-Wnt3a after myocardial infarction in mice showed that Wnt signaling limits CSP cell renewal, blocks endogenous cardiac regeneration and impairs cardiac performance, highlighting the importance of progenitor cells in maintaining tissue function after injury. CONCLUSIONS: Our study identifies canonical Wnt signaling and the novel downstream mediator, IGFBP3, as key regulators of adult cardiac progenitor self-renewal in physiological and pathological states

VPS: Excavating high-level C++ constructs from low-level binaries to protect dynamic dispatching

Polymorphism and inheritance make C++ suitable for writing complex software, but significantly increase the attack surface because the implementation relies on virtual function tables (vtables). These vtables contain function pointers that attackers can potentially hijack and in practice, vtable hijacking is one of the most important attack vector for C++ binaries. In this paper, we present VTable Pointer Separation (vps), a practical binary-level defense against vtable hijacking in C++ applications. Unlike previous binary-level defenses, which rely on unsound static analyses to match classes to virtual callsites, vps achieves a more accurate protection by restricting virtual callsites to validly created objects. More specifically, vps ensures that virtual callsites can only use objects created at valid object construction sites, and only if those objects can reach the callsite. Moreover, vps explicitly prevents false positives (falsely identified virtual callsites) from breaking the binary, an issue existing work does not handle correctly or at all. We evaluate the prototype implementation of vps on a diverse set of complex, real-world applications (MongoDB, MySQL server, Node.js, SPEC CPU2017/CPU2006), showing that our approach protects on average 97.8% of all virtual callsites in SPEC CPU2006 and 97.4% in SPEC CPU2017 (all C++ benchmarks), with a moderate performance overhead of 11% and 9% geomean, respectively. Furthermore, our evaluation reveals 86 false negatives in VTV, a popular source-based defense which is part of GCC

Poking Holes in Information Hiding

ASLR is no longer a strong defense in itself, but it still serves as a foundation for sophisticated defenses that use randomization for pseudo-isolation. Crucially, these defenses hide sensitive information (such as shadow stacks and safe regions) at a random position in a very large address space. Previous attacks on randomization-based information hiding rely on complicated side channels and/or probing of the mapped memory regions. Assuming no weaknesses exist in the implementation of hidden regions, the attacks typically lead to many crashes or other visible side-effects. For this reason, many researchers still consider the pseudo-isolation offered by ASLR sufficiently strong in practice. We introduce powerful new primitives to show that this faith in ASLR-based information hiding is misplaced, and that attackers can break ASLR and find hidden regions on 32 bit and 64 bit Linux systems quickly with very few malicious inputs. Rather than building on memory accesses that probe the allocated memory areas, we determine the sizes of the unallocated holes in the address space by repeatedly allocating large chunks of memory. Given the sizes, an attacker can infer the location of the hidden region with few or no side-effects. We show that allocation oracles are pervasive and evaluate our primitives on real-world server applications

On the effectiveness of code normalization for function identification

Information on the identity of functions is typically removed when translating source code to executable form. Yet being able to recognize specific functions opens up a number of applications. In this paper, we investigate normalization-based approaches for the purposes of aiding the reverse engineer and as an enabler for the rejuvenation of legacy binaries. We iteratively refine our methods and report on their effectiveness. Our results show that a naive approach can be surprisingly effective in both problem domains. Further, our evaluation looks into more advanced normalization techniques and finds that their practicality varies significantly with the problem domain

Isolation of resident cardiac progenitor cells by Hoechst 33342 staining

Cardiac resident stem/progenitor cells are critical to the cellular and functional integrity of the heart by maintaining myocardial cell homeostasis. Given their central role in myocardial biology, resident cardiac progenitor cells have become a major focus in cardiovascular research. Identification of putative cardiac progenitor cells within the myocardium is largely based on the presence or absence of specific cell surface markers. Additional purification strategies take advantage of the ability of stem cells to efficiently efflux vital dyes such as Hoechst 33342. During fluoresence activated cell sorting (FACS) such Hoechst-extruding cells appear to the side of Hoechst-dye retaining cells and have thus been termed side population (SP) cells. We have shown that cardiac SP cells that express stem cell antigen 1 (Sca-1) but not CD31 are cardiomyogenic, and thus represent a putative cardiac progenitor cell population. This chapter describes the methodology for the isolation of resident cardiac progenitor cells utilizing the SP phenotype combined with stem cell surface markers