Clinical utility of mesenchymal stem/stromal cells in regenerative medicine and cellular therapy.

Mesenchymal stem/stromal cells (MSCs) have been carefully examined to have tremendous potential in regenerative medicine. With their immunomodulatory and regenerative properties, MSCs have numerous applications within the clinical sector. MSCs have the properties of multilineage differentiation, paracrine signaling, and can be isolated from various tissues, which makes them a key candidate for applications in numerous organ systems. To accentuate the importance of MSC therapy for a range of clinical indications, this review highlights MSC-specific studies on the musculoskeletal, nervous, cardiovascular, and immune systems where most trials are reported. Furthermore, an updated list of the different types of MSCs used in clinical trials, as well as the key characteristics of each type of MSCs are included. Many of the studies mentioned revolve around the properties of MSC, such as exosome usage and MSC co-cultures with other cell types. It is worth noting that MSC clinical usage is not limited to these four systems, and MSCs continue to be tested to repair, regenerate, or modulate other diseased or injured organ systems. This review provides an updated compilation of MSCs in clinical trials that paves the way for improvement in the field of MSC therapy.

TNX-1500, a crystallizable fragment-modified anti-CD154 antibody, prolongs nonhuman primate renal allograft survival.

The blockade of the CD154-CD40 pathway with anti-CD154 monoclonal antibody has been a promising immunomodulatory approach to prevent allograft rejection. However, clinical trials of immunoglobulin G1 antibodies targeting this pathway revealed thrombogenic properties, which were subsequently shown to be mediated by crystallizable fragment (Fc)-gamma receptor IIa-dependent platelet activation. To prevent thromboembolic complications, an immunoglobulin G4 anti-CD154 monoclonal antibody, TNX-1500, which retains the fragment antigen binding region of ruplizumab (humanized 5c8, BG9588), was modified by protein engineering to decrease Fc binding to Fc-gamma receptor IIa while retaining certain other effector functions and pharmacokinetics comparable with natural antibodies. Here, we report that TNX-1500 treatment is not associated with platelet activation in vitro and consistently inhibits kidney allograft rejection in vivo without clinical or histologic evidence of prothrombotic phenomena. We conclude that TNX-1500 retains efficacy similar to that of 5c8 to prevent kidney allograft rejection while avoiding previously identified pathway-associated thromboembolic complications.

An anti-HER2 biparatopic antibody that induces unique HER2 clustering and complement-dependent cytotoxicity.

Human epidermal growth factor receptor 2 (HER2) is a receptor tyrosine kinase that plays an oncogenic role in breast, gastric and other solid tumors. However, anti-HER2 therapies are only currently approved for the treatment of breast and gastric/gastric esophageal junction cancers and treatment resistance remains a problem. Here, we engineer an anti-HER2 IgG1 bispecific, biparatopic antibody (Ab), zanidatamab, with unique and enhanced functionalities compared to both trastuzumab and the combination of trastuzumab plus pertuzumab (tras + pert). Zanidatamab binds adjacent HER2 molecules in trans and initiates distinct HER2 reorganization, as shown by polarized cell surface HER2 caps and large HER2 clusters, not observed with trastuzumab or tras + pert. Moreover, zanidatamab, but not trastuzumab nor tras + pert, elicit potent complement-dependent cytotoxicity (CDC) against high HER2-expressing tumor cells in vitro. Zanidatamab also mediates HER2 internalization and downregulation, inhibition of both cell signaling and tumor growth, antibody-dependent cellular cytotoxicity (ADCC) and phagocytosis (ADCP), and also shows superior in vivo antitumor activity compared to tras + pert in a HER2-expressing xenograft model. Collectively, we show that zanidatamab has multiple and distinct mechanisms of action derived from the structural effects of biparatopic HER2 engagement.

Protocol for a mobile laboratory study of co-administration of cannabis concentrates with a standard alcohol dose in humans.

Cannabis is commonly used among people who drink alcohol, yet evidence on acute effects of co-use is conflicting. Two important variables that may influence the effects of cannabis and alcohol are cannabinoid content (i.e., the ratio of cannabidiol [CBD] and 9-tetrahydrocannabinol [THC]) as well as the order of use (i.e., cannabis before alcohol vs. alcohol before cannabis). Research is mixed regarding the acute imapct of cannabis on alcohol consumption and intoxication, with some studies suggesting additive effects of alcohol and cannabis, and others demonstrating negligible effects of combining these substances. Further complicating this, high-THC-content cannabis concentrates are increasingly popular on the legal-market, but to our knowledge, no studies have explored concentrate and alcohol co-use. In addition to cannabinoid content, order of use may influence intoxication and other acute effects, but is also understudied. Co-use studies typically administer a fixed dose of alcohol before cannabis, and there is a lack of data on the acute effects of cannabis before alcohol. Thus, there is a need for experimental co-use studies exploring the impact of cannabinoid content (particularly of highly potent cannabis concentrates) and order effects on intoxication. This study uses a federally-compliant mobile laboratory procedure to explore the effects of co-administration of legal-market cannabis concentrates with a moderate alcohol dose (.8g/kg) in a sample of community participants who regularly use alcohol and cannabis. The study will also explore alcohol and cannabis order effects (cannabis before alcohol vs. alcohol before cannabis). Outcomes are objective intoxication (measured using blood cannabinoid level, heart rate, psychomotor performance and breath alcohol level [BrAC]) and subjective intoxication (assessed via self-report measures). Overall, this study may influence harm-reduction recommendations for individuals who drink alcohol and use cannabis.

Does Accessibility of Cannabis Mediate the Relation Between Method of Acquisition and Cannabis Use Frequency among Adolescents?

Cannabis use frequency among adolescents is associated with negative outcomes. Two variables associated with cannabis use frequency are method of acquisition and accessibility of cannabis. Prior research on the relation between methods of acquisition and cannabis use frequency is sparse. Differences in cannabis use in states in which the sale of recreational cannabis is legal (recreational states) compared to states in which it is not warrants research on how adolescents acquire cannabis in recreational states, and how easy it is for them to do so. The primary way in which adolescents acquire cannabis and the ease by which they can acquire cannabis may be associated with cannabis use frequency via specific interactions. We hypothesized that primarily acquiring cannabis from a store would be positively associated with cannabis use frequency when compared to other primary methods of acquisition, and that accessibility would meditate relations between primary method of acquisition and cannabis use frequency. This study used data from high school students who completed the 2019 Healthy Kids Colorado Survey (HKCS) who reported using cannabis in the past 30 days. Results indicated that primary method of acquisition was significantly differentially associated with 30-day cannabis use frequency, with participants who reported buying cannabis at a store reporting significantly higher 30-day cannabis use frequency than any other method of acquisition. Ease of accessibility was not significantly associated with 30-day cannabis use frequency and did not significantly mediate the relation between primary method of acquisition and 30-day cannabis use frequency. Results of the current study indicate that the ways in which adolescents acquire cannabis are associated with how often they use it. Further, the positive relation between primarily acquiring cannabis at stores and frequency of use provide evidence that access to stores may be a risk factor for cannabis use frequency among adolescents.

Conserved amino acids in the region connecting membrane spanning domain 1 to nucleotide binding domain 1 are essential for expression of the MRP1 (ABCC1) transporter.

Multidrug resistance protein 1 (MRP1) (gene symbol ABCC1) is an ATP-binding cassette (ABC) transporter which effluxes xeno- and endobiotic organic anions including estradiol glucuronide and the pro-inflammatory leukotriene C4. MRP1 also confers multidrug resistance by reducing intracellular drug accumulation through active efflux. MRP1 has three membrane spanning domains (MSD), and two nucleotide binding domains (NBD). MSD1 and MSD2 are linked to NBD1 and NBD2 by connecting regions (CR) 1 and CR2, respectively. Here we targeted four residues in CR1 (Ser612, Arg615, His622, Glu624) for alanine substitution and unexpectedly, found that cellular levels of three mutants (S612A, R615A, E624A) in transfected HEK cells were substantially lower than wild-type MRP1. Whereas CR1-H622A properly trafficked to the plasma membrane and exhibited organic anion transport activity comparable to wild-type MRP1, the poorly expressing R615A and E624A (and to a lesser extent S612A) mutant proteins were retained intracellularly. Analyses of cryogenic electron microscopic and atomic homology models of MRP1 indicated that Arg615 and Glu624 might participate in bonding interactions with nearby residues to stabilize expression of the transporter. However, this was not supported by double exchange mutations E624K/K406E, R615D/D430R and R615F/F619R which failed to improve MRP1 levels. Nevertheless, these experiments revealed that the highly conserved CR1-Phe619 and distal Lys406 in the first cytoplasmic loop of MSD1 are also essential for expression of MRP1 protein. This study is the first to demonstrate that CR1 contains several highly conserved residues critical for plasma membrane expression of MRP1 but thus far, currently available structures and models do not provide any insights into the underlying mechanism(s). Additional structures with rigorous biochemical validation data are needed to fully understand the bonding interactions critical to stable expression of this clinically important ABC transporter.

Genetic counseling considerations with rapid genome-wide sequencing in a neonatal intensive care unit.

As genome-wide sequencing (GWS; exome sequencing [ES] and whole genome sequencing [WGS]) is implemented more frequently in the neonatal intensive care unit (NICU), it is important to understand parents' opinions regarding GWS, and views toward incidental findings (IFs) (also known as secondary findings). RAPIDOMICS was a pilot study of rapid trio-based (biological parents and neonate) ES for 25 neonates with a suspected genetic condition at the BC Women's Hospital NICU. As part of RAPIDOMICS, we explored parents' motivations and concerns regarding ES of their child, uptake of IFs for themselves, and rates of anxiety and depression at the time of pre-test genetic counseling via administration of the Generalized Anxiety Disorder Assessment 7 and Patient Health Questionnaire 8. These findings were compared to those from the Clinical Assessment of the Utility of Sequencing and Evaluation as a Service (CAUSES) study (outpatient trio-based GWS) that includes pediatric patients with suspected genetic disease (with an average age of 10 years). Parents in RAPIDOMICS were more likely to identify "diagnosis" as their primary motivation to pursue GWS (p = 0.011), less likely to identify "no concerns" (p = 0.003), and less likely to opt in to receive IFs (p = 0.003) than parents in CAUSES. Rates of depression and anxiety in both groups were higher relative to the general population. We present novel findings regarding the similarities and differences in parental opinions and decisions of these cohorts.

Preparation of potential cell-permeant nucleoside-2',3'-cyclic phosphate precursors.

Uridine-3'-phosphorothiolate triesters bearing lipophilic moieties were prepared via Michaelis-Arbuzov chemistry. Subsequent deprotection of the S-cholesteryl phosphorothiolate triester afforded the corresponding diester which underwent spontaneous Cyclization to cleanly afford uridine 2',3'-cyclic phosphate. This transesterification reaction could be expedited by treatment with iodine under mild, neutral conditions.