Listening to Black Pregnant and Postpartum People: Using Technology to Enhance Equity in Screening and Treatment of Perinatal Mental Health and Substance Use Disorders.

Perinatal mood and anxiety disorders (PMADs), perinatal substance use disorders (PSUDs), and intimate partner violence (IPV) are leading causes of pregnancy-related deaths in the United States. Screening and referral for PMADs, PSUDs and IPV is recommended, however, racial disparities are prominent: Black pregnant and postpartum people (PPP) are less likely to be screened and attend treatment compared to White PPP. We conducted qualitative interviews to better understand the experience of Black PPP who used a text/phone-based screening and referral program for PMADs/PSUDs and IPV-Listening to Women and Pregnant and Postpartum People (LTWP). We previously demonstrated that LTWP led to a significant reduction in racial disparities compared to in-person screening and referral, and through the current study, sought to identify facilitators of PMAD/PSUD symptom endorsement and treatment attendance. Semi-structured interviews were conducted with 68 Black PPP who were or had been pregnant within the last 24 months, and who either had or did not have a PMAD or PSUD. Participants were enrolled in LTWP and provided feedback on their experience. Using a grounded theory approach, four themes emerged: usability, comfort, necessity, and recommendations. Ease of use, brevity, convenience, and comfort in discussing mental health and substance use via text were highlighted. Need for a program like LTWP in Black communities was discussed, given the reduction in perceived judgement and access to trusted information and resources for PMADs/PSUDs, which may lessen stigma. These qualitative findings illuminate how technology-based adaptations to behavioral health screening and referral can reduce perceived negative judgment and facilitate identification and referral to treatment, thereby more adequately meeting needs of Black PPP.

Exploration Into Patterns of Cannabis Use Across Pregnancy and Postpartum.

OBJECTIVES: Peripartum cannabis use can be harmful to pregnant individual's and children's health, yet it is the most used illicit substance during the peripartum period. Despite the ability of some people to reduce and abstain from cannabis use during pregnancy, the first year postpartum is a high-risk time for returning to cannabis. However, characterization of cannabis use patterns in the peripartum period and risk factors for return to use postpartum are not well established. The aims of this exploratory study were to describe patterns of peripartum cannabis use and identify factors associated with increased frequency of postpartum cannabis use among individuals who reported reduced use during pregnancy. METHODS: An online survey identified 47 individuals who used cannabis during the peripartum period. Descriptive statistics characterized the sample and among those who reduced use during pregnancy, χ 2 determined the frequency of postpartum cannabis use per preconception reasons for use. RESULTS: During preconception, 95.7% of individuals used cannabis, and of those who were presently postpartum, 65% resumed use after delivery. Anxiety and stress were the most common motivations for cannabis use throughout the peripartum period, but social motivations (ie, fun, relaxation) were the only preconception factors that increased frequency of return to cannabis use postpartum. CONCLUSIONS: Our exploratory study describes the characteristics of individuals using cannabis in the peripartum period and provides insight into correlates of resumption of cannabis use postpartum. These findings may inform future work to further determine temporal associations, confounding risk factors, and intervention techniques to prevent the return to cannabis use postpartum.

Hydration-mediated G-protein-coupled receptor activation.

The Rhodopsin family of G-protein­coupled receptors (GPCRs) comprises the targets of nearly a third of all pharmaceuticals. Despite structural water present in GPCR X-ray structures, the physiological relevance of these solvent molecules to rhodopsin signaling remains unknown. Here, we show experimental results consistent with the idea that rhodopsin activation in lipid membranes is coupled to bulk water movements into the protein. To quantify hydration changes, we measured reversible shifting of the metarhodopsin equilibrium due to osmotic stress using an extensive series of polyethylene glycol (PEG) osmolytes. We discovered clear evidence that light activation entails a large influx of bulk water (∼80­100 molecules) into the protein, giving insight into GPCR activation mechanisms. Various size polymer osmolytes directly control rhodopsin activation, in which large solutes are excluded from rhodopsin and dehydrate the protein, favoring the inactive state. In contrast, small osmolytes initially forward shift the activation equilibrium until a quantifiable saturation point is reached, similar to gain-of-function protein mutations. For the limit of increasing osmolyte size, a universal response of rhodopsin to osmotic stress is observed, suggesting it adopts a dynamic, hydrated sponge-like state upon photoactivation. Our results demand a rethinking of the role of water dynamics in modulating various intermediates in the GPCR energy landscape. We propose that besides bound water, an influx of bulk water plays a necessary role in establishing the active GPCR conformation that mediates signaling.

Specificity of Loxosceles α clade phospholipase D enzymes for choline-containing lipids: Role of a conserved aromatic cage.

Spider venom GDPD-like phospholipases D (SicTox) have been identified to be one of the major toxins in recluse spider venom. They are divided into two major clades: the α clade and the ß clade. Most α clade toxins present high activity against lipids with choline head groups such as sphingomyelin, while activities in ß clade toxins vary and include preference for substrates containing ethanolamine headgroups (Sicarius terrosus, St_ßIB1). A structural comparison of available structures of phospholipases D (PLDs) reveals a conserved aromatic cage in the α clade. To test the potential influence of the aromatic cage on membrane-lipid specificity we performed molecular dynamics (MD) simulations of the binding of several PLDs onto lipid bilayers containing choline headgroups; two SicTox from the α clade, Loxosceles intermedia αIA1 (Li_αIA) and Loxosceles laeta αIII1 (Ll_αIII1), and one from the ß clade, St_ßIB1. The simulation results reveal that the aromatic cage captures a choline-headgroup and suggest that the cage plays a major role in lipid specificity. We also simulated an engineered St_ßIB1, where we introduced the aromatic cage, and this led to binding with choline-containing lipids. Moreover, a multiple sequence alignment revealed the conservation of the aromatic cage among the α clade PLDs. Here, we confirmed that the i-face of α and ß clade PLDs is involved in their binding to choline and ethanolamine-containing bilayers, respectively. Furthermore, our results suggest a major role in choline lipid recognition of the aromatic cage of the α clade PLDs. The MD simulation results are supported by in vitro liposome binding assay experiments.

Activation of the G-Protein-Coupled Receptor Rhodopsin by Water.

Visual rhodopsin is an important archetype for G-protein-coupled receptors, which are membrane proteins implicated in cellular signal transduction. Herein, we show experimentally that approximately 80 water molecules flood rhodopsin upon light absorption to form a solvent-swollen active state. An influx of mobile water is necessary for activating the photoreceptor, and this finding is supported by molecular dynamics (MD) simulations. Combined force-based measurements involving osmotic and hydrostatic pressure indicate the expansion occurs by changes in cavity volumes, together with greater hydration in the active metarhodopsin-II state. Moreover, we discovered that binding and release of the C-terminal helix of transducin is coupled to hydration changes as may occur in visual signal amplification. Hydration-dehydration explains signaling by a dynamic allosteric mechanism, in which the soft membrane matter (lipids and water) has a pivotal role in the catalytic G-protein cycle.

D-Amino Acid Analogues of the Antimicrobial Peptide CDT Exhibit Anti- Cancer Properties in A549, a Human Lung Adenocarcinoma Cell Line.

INTRODUCTION: The importance of the antitumor activity of some antimicrobial peptides (AMPs) is being increasingly recognized. The antimicrobial peptide, tachyplesin, has been shown to exhibit anticancer properties and a linear, cysteine deleted analogue (CDT), was found to retain its antibacterial function. OBJECTIVES: The objective was to test CDT and related analogues against normal mammalian, bacterial, and cancer cells to determine their effectiveness and then utilize specific assays to determine a possible mechanism of action. METHODS: We used sequence reversal and D-amino acids to synthesize four CDT analogues by solid phase peptide synthesis. A number of assays were used including liposome dye-leakage, antibacterial activity against both Gram-positive and Gram-negative bacterial strains, hemolytic assays, methyl thiazolyl tetrazolium (MTT), and apoptosis to examine their effectiveness as both AMPs and anti-cancer peptides (ACPs). We then tested the analogues for their ability to inhibit proliferation of the human lung cancer cell line, A549. RESULTS: We found that D-CDT exhibited the best bactericidal properties of those tested and was not damaging to red blood cells. Both D-CDT and reverse D-CDT showed a dose-dependent reduction of cell viability. However, D-CDT was most effective with an IC50 of 9.814 µM, a value 9-fold lower than that calculated for reverse D-CDT (90.16 µM). Apoptosis does not appear to be a mechanism by which D-CDT exerts its anticancer properties since > 100 µM was required to increase activation of caspase 3. Moreover, the ERK1/2 pathway is also unlikely since only a modest (20%) decrease of activity was observed with > 100 µM D-CDT. However, D-CDT was found to operate via a hyaluronan (HA)-dependent mechanism as pretreatment of the cells with hyaluronidase decreased the cytotoxic effects of D-CDT on A549 cells and increased its IC50 29-fold to 283.9 µM. CONCLUSION: D-CDT is both an effective AMP and ACP, and likely exerts its anticancer effects through both membranolytic as well as an HA-mediated mechanism.