Peering into the literature: A systematic review of the roles of people who inject drugs in harm reduction initiatives

BACKGROUND

People who inject drugs have been central to the development of harm reduction initiatives. Referred to as peer workers, peer helpers, or natural helpers, people with lived experience of drug use leverage their personal knowledge and skills to deliver harm reduction services. Addressing a gap in the literature, this systematic review focuses on the roles of people who inject drugs in harm reduction initiatives, how programs are organized, and obstacles and facilitators to engaging people with lived experience in harm reduction programs, in order to inform practice and future research.

METHODS

This systematic review included searches for both peer reviewed and gray literature. All titles and abstracts were screened by two reviewers. A structured data extraction tool was developed and utilized to systematically code information concerning peer roles and participation, program characteristics, obstacles, and facilitators.

RESULTS

On the basis of specific inclusion criteria 164 documents were selected, with 127 peer-reviewed and 37 gray literature references. Data extraction identified key harm reduction program characteristics and forms of participation including 36 peer roles grouped into five categories, as well as obstacles and facilitators at systemic, organizational, and individual levels.

CONCLUSIONS

Research on harm reduction programs that involve people with lived experience can help us better understand these approaches and demonstrate their value. Current evidence provides good descriptive content but the field lacks agreed-upon approaches to documenting the ways peer workers contribute to harm reduction initiatives. Implications and ten strategies to better support peer involvement in harm reduction programs are identified.

Feijoa sellowiana derived natural Flavone exerts anti-cancer action displaying HDAC inhibitory activities

Curative properties of some medicinal plants such as the Feijoa sellowiana Bert. (Myrtaceae), have been often claimed, although the corresponding molecular mechanism(s) remain elusive. We report here that the Feijoa acetonic extract exerts anti-cancer activities on solid and hematological cancer cells. Feijoa extract did not show toxic effects on normal myeloid progenitors thus displaying a tumor-selective activity. In the Feijoa acetonic extract, fractionation and subsequent purification and analyses identified Flavone as the active component. Flavone induces apoptosis which is accompanied by caspase activation and p16, p21 and TRAIL over-expression in human myeloid leukemia cells. Use of ex vivo myeloid leukemia patients blasts confirms that both the full acetonic Feijoa extract and its derived Flavone are able to induce apoptosis. In both cell lines and myeloid leukemia patients blasts the apoptotic activity of Feijoa extract and Flavone is accompanied by increase of histone and non-histone acetylation levels and by HDAC inhibition. Our findings show for the first time that the Feijoa apoptotic active principle is the Flavone and that this activity correlates with the induction of HDAC inhibition, supporting the hypothesis of its epigenetic pro-apoptotic regulation in cancer systems.

Bispyridinium Dienes: Histone Deacetylase Inhibitors with Selective Activities

A novel synthetic route to the cyclostellettamines 1 using as the key step a microwave-mediated macrocyclic ring-closing metathesis of precursors bispyridinium dienes 10 followed by catalytic hydrogenation has been developed. The open-chain bispyridinium dienes 10 showed uniformly higher histone deacetylase (HDAC) inhibitory potency than the natural products. Diene 10b inhibited HDAC1 and was inactive on HDAC4, whereas 10a showed a weak inhibition of HDAC1 and a higher activity on HDAC4. Neither 10b nor 10a inhibited isoforms HDAC2 and HDAC3. Cell cycle analysis, cell differentiation, and apoptosis as well as evaluation of the acetylation status of H3 lysine tails, up-regulation of p21WAF1/CIP1, and alpha-tubulin acetylation induced by the dienes 10 and cyclostellettamines 1 were also carried out on the human leukemia U937 cell line. These enzymatic and functional assays suggest that 10b is a HDAC1-selective inhibitor and 10a is a HDAC subclass IIa-selective inhibitor.

An autoregulatory loop directs the tissue-specific expression of p63 through a long-range evolutionarily conserved enhancer

p63, a p53 family member, is essential for the development of various stratified epithelia and is one of the earliest markers of many ectodermal structures, including the epidermis, oral mucosa, apical ectodermal ridge, and mammary gland. Genetic regulatory mechanisms controlling p63 spatial expression during development have not yet been defined. Using a genomic approach, we identified an evolutionarily conserved cis-regulatory element, located 160 kb downstream of the first p63 exon, which functions as a keratinocyte-specific enhancer and is sufficient to recapitulate expression of the endogenous gene during mouse embryogenesis. Dissection of the p63 enhancer activity revealed a positive autoregulatory loop in which the p63 proteins directly bind to and are essential regulators of the enhancer. Accordingly, transactivating p63 isoforms induce endogenous p63 expression in cells that do not normally express this gene, whereas dominant negative isoforms suppress p63 expression in keratinocytes. In addition the transcription factor AP-2 also binds to the enhancer and cooperates with p63 to induce its activity. These results demonstrate that a long-range autoregulatory loop is involved in the regulation of p63 expression during embryonic development and in adult cells.

Requirement of the forkhead gene Foxe1, a target of sonic hedgehog signaling, in hair follicle morphogenesis

The forkhead transcription factor FOXE1 is mutated in patients with Bamforth-Lazarus syndrome that exhibit hair follicle defects, suggesting a possible role for Foxe1 in hair follicle morphogenesis. Here, we report that Foxe1 is specifically expressed in the lower undifferentiated compartment of the hair follicle, at a time and site that parallel activation of the Shh signaling pathway. The Foxe1 protein is also expressed in human and mouse basal cell carcinoma in which hedgehog signaling is constitutively activated, whereas it is undetectable in normal epidermis and squamous cell carcinoma. Moreover, expression of a dominant-negative form of Gli2 in skin results in complete suppression of Foxe1 expression in the hair follicle, whereas transcriptionally active Gli2 stimulates activity of the Foxe1 promoter. Foxe1-null skin displays aberrant hair formation with the production of thinner and curly pelage hairs. Although the hair follicle internal structure is conserved and several lineage markers are properly expressed, the orderly downgrowth of follicles is strikingly disrupted, causing disorientation, misalignment and aberrantly shaped of hair follicles. Our findings provide a strong indication that the defect in Bamforth-Lazarus syndrome is due to altered FOXE1 function in the hair follicle, and is independent of systemic defects present in affected individuals. In addition, we establish Foxe1 as a downstream target of the Shh/Gli pathway in hair follicle morphogenesis, and as a crucial player for correct hair follicle orientation into the dermis and subcutis.